US20040057836A1 - Hydraulic pump circuit - Google Patents
Hydraulic pump circuit Download PDFInfo
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- US20040057836A1 US20040057836A1 US10/253,973 US25397302A US2004057836A1 US 20040057836 A1 US20040057836 A1 US 20040057836A1 US 25397302 A US25397302 A US 25397302A US 2004057836 A1 US2004057836 A1 US 2004057836A1
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- Prior art keywords
- fluid
- valve
- flow
- hydraulic pump
- passageway
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
- F04B1/12—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis
- F04B1/14—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis having stationary cylinders
- F04B1/141—Details or component parts
- F04B1/146—Swash plates; Actuating elements
- F04B1/148—Bearings therefor
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
- F04B1/12—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis
- F04B1/14—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis having stationary cylinders
- F04B1/141—Details or component parts
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
- F04B53/06—Venting
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
- F04B53/18—Lubricating
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
- F15B21/04—Special measures taken in connection with the properties of the fluid
- F15B21/044—Removal or measurement of undissolved gas, e.g. de-aeration, venting or bleeding
Definitions
- the present disclosure is directed to a circuit for a hydraulic pump and, more particularly, to a circuit for bleeding air from the inlet to a hydraulic pump.
- Hydraulic pumps are commonly used for many purposes in many different applications.
- Vehicles such as, for example, highway trucks and off-highway work machines, commonly include hydraulic pumps that are driven by an engine in the vehicle to generate a flow of pressurized fluid.
- the pressurized fluid may be used for any of a number of purposes during the operation of the vehicle.
- a highway truck for example, uses pressurized fluid to operate a fuel injection system or a braking system.
- a work machine for example, uses pressurized fluid to propel the machine around a work site or to move a work implement.
- a hydraulic pump typically draws operating fluid, such as, for example, oil, from a reservoir and applies work to the fluid to increase the pressure of the fluid.
- the hydraulic pump directs the pressurized fluid into a fluid rail or another similar supply system for use during the operation of the vehicle.
- the hydraulic pump may be configured to vary the rate at which the pressurized fluid is directed into the fluid rail. This may be accomplished with a variable displacement pump or with a fixed displacement pump that has a variable flow.
- a hydraulic pump usually includes a pumping element that applies the work to the fluid to increase the pressure of the fluid.
- the pumping element includes a sliding, rotating, or spinning part, such as, for example, a gear, gearotor, piston, vane, or swash plate. These moving parts are typically lubricated to prevent excessive wear due to friction.
- the engine lubrication system in the vehicle may provide the operating fluid that is pressurized by the hydraulic pump and the lubricating fluid that is used to lubricate the moving parts of the hydraulic pump.
- the supply of fluid may, however, also include air that is drawn into the system. This is particularly a problem when the engine is starting after having been idle for a period of time.
- the oil in the lubrication system may drain from the system and return to the reservoir. The draining oil is replaced by air pockets, which are purged from the lubrication system when the engine is started.
- an air bleed valve may be disposed in the outlet path of the pump. This type of valve can remove any air that is included in the flow of pressurized fluid.
- the hydraulic pump must pressurize both the fluid and the air before the air is purged from the system through the air bleed valve. The additional work that is required to pressurized the air, which is subsequently released from the system, decreases the efficiency of the hydraulic pump.
- the present disclosure is directed to a circuit for a hydraulic pump.
- the circuit includes a supply of fluid.
- a pumping element is operable to increase the pressure of fluid received from the supply of fluid and to generate a flow of pressurized fluid.
- An inlet passageway connects the pumping element with the supply of fluid.
- a drain passageway is connected to the inlet passageway.
- a valve is disposed in the drain passageway., The valve is moveable between a first position where the valve prevents a flow of fluid relative to the drain passageway and a second position where the valve allows a flow of fluid relative to the drain passageway.
- the present disclosure is directed to a method of removing air from a hydraulic pump.
- a flow of an operating fluid is supplied to an inlet passageway of the hydraulic pump.
- a pumping element is operated to increase the pressure of the flow of fluid supplied to the pump and to generate a flow of pressurized fluid.
- a valve is moved from a first position to a second position to allow fluid to flow from the inlet passageway to a drain passageway when the pressure of the fluid in inlet passageway is above a predetermined limit.
- FIG. 1 is a schematic and diagrammatic representation of a hydraulic circuit for a hydraulic pump in accordance with an exemplary embodiment of the present invention.
- FIG. 2 is a cross-sectional view of an exemplary embodiment of a valve for a hydraulic circuit in accordance with the present invention.
- hydraulic circuit 10 includes a tank 12 that contains a supply of fluid.
- Tank 12 may be part of a lubrication system for the vehicle, such as an oil sump .
- the fluid within tank 12 may be a hydraulic fluid, such as, for example, a lubricating oil, although tank 12 may store other types of fluids.
- hydraulic circuit 10 may include a supply pump 14 .
- Supply pump 14 may be a relatively low pressure pump, such as, for example, a sump pump that may be commonly included in a lubrication system to distribute oil to various systems in an engine.
- Supply pump 14 may increase the pressure of the fluid to a relatively low pressure, such as about 70 Kpa. This relatively low pressurized fluid may then be directed into an inlet line 16 .
- Hydraulic circuit 10 may also include a high pressure pump, such as hydraulic pump 20 , to further increase the pressure of the operating fluid.
- a high pressure fluid may be required to operate certain systems.
- the high pressure fluid may be used to operate a fuel injection system and/or a braking system.
- the high pressure fluid may be used to operate other types of systems as well.
- hydraulic pump 20 is depicted as a fixed displacement variable flow pump. It is contemplated, however, that hydraulic pump 20 may another type of pump.
- hydraulic pump 20 may be a constant displacement constant flow pump or a variable displacement pump.
- Hydraulic pump 20 includes a housing 21 and an inlet 22 .
- Inlet 22 may be connected to inlet line 16 to receive fluid from supply pump 14 .
- Inlet 22 directs the low pressure operating fluid to a pumping element 26 .
- Pumping element 26 is operable to increase the pressure of the operating fluid provided through inlet 22 .
- pumping element 26 includes a series of pistons 32 that are driven by a swashplate 28 .
- pumping element 26 may include a gear, gearotor, or vane pump.
- an input shaft 52 is provided to drive pumping element 26 .
- Input shaft 52 is mounted for rotating movement on a bearing 50 .
- Input shaft 52 may be driven, for example, by an engine on the vehicle.
- Input shaft 52 may include a spline or keyed end that may be operatively engaged with the crankshaft or gear train of the engine.
- Input shaft 52 may be connected to the engine in any manner readily apparent to one skilled in the art.
- swashplate 28 has an angled driving surface that is engaged with pistons 32 .
- the angle surface of swashplate 28 causes each piston 32 to reciprocate within a bore as swashplate 28 rotates.
- the reciprocating movement of each piston 32 pressurizes fluid contained within the bore and supplied through inlet 22 .
- the angle of swashplate 28 may be varied to vary the displacement of each piston 32 within hydraulic pump 20 .
- a pivoting shoe 30 may be disposed between each piston 32 and the angled surface of swashplate 28 .
- Each shoe 30 rides along the surface of swashplate 28 as swashplate 28 rotates.
- Each shoe 30 provides a pivoting motion to accommodate for the angled surface of swashplate 28 .
- a check valve 36 may be disposed at the outlet of each bore.
- Each check valve 36 may be configured to open when the fluid within the bore reaches a predetermined level. When pumping element pressurizes the operating fluid to the predetermined pressure, check valve 36 will open to allow the pressurized fluid to flow from the bore.
- Hydraulic pump 20 may include a collector 38 . Pressurized fluid released from each bore may be directed to collector 38 .
- Collector 38 stores a supply of pressurized fluid that is released by pistons 32 .
- Pump collector 38 is connected to an outlet 24 , which may be further connected to an outlet line 18 .
- Outlet line 18 may be connected to a fluid rail 19 .
- Fluid rail 19 may be configured to distribute pressurized fluid to a system, such as, for example, a fuel injection system associated with the vehicle and/or engine.
- hydraulic pump 20 may include a control device 44 that is connected to outlet 24 through a control line 40 .
- control device 44 governs the flow rate of pressurized fluid produced by hydraulic pump 20 by controlling the position of a metering device 34 .
- control device 44 may perform any controlling function that is common in a hydraulic pump, such as, for example, displacement control, flow rate control, output pressure control, torque or horsepower control, or load control.
- the position of metering device 34 may control the flow rate of pressurized fluid produced by each piston 32 .
- Metering device 34 may be, for example, a metering sleeve that is moveable between a first position and a second position. Movement of metering device 34 from the first position to the second position may act to decrease the flow rate of pressurized fluid generated by each piston 32 .
- a drain passageway 46 may be connected to inlet 22 . Drain passageway 46 may lead to bearing 50 of input shaft 52 . It should be noted, however, that drain passageway 46 may lead to another bearing within hydraulic pump 20 , another surface within hydraulic pump 20 that requires lubrication, directly to tank 12 , or to some other desired location.
- a valve 48 may be disposed in drain passageway 46 .
- Valve 48 has a first, or closed, position, where valve 48 prevents fluid from flowing through drain passageway 46 .
- Valve 48 also has a second, or open, position, where valve 48 allows fluid to flow through drain passageway 46 .
- a fluid flow through drain passageway 46 may be selectively controlled.
- Valve 48 may be, for example, a check valve, a spool, valve, or any other type of valve operable to selectively allow a flow of fluid through a fluid passageway.
- valve 48 may be a check valve.
- valve 48 includes a body 60 .
- Body 60 defines a valve inlet 62 and a valve outlet 64 .
- a poppet 66 is slidably disposed within body 60 .
- Poppet 66 is configured to engage a seat 70 that surrounds inlet 62 .
- a spring 68 may be disposed in housing 60 to bias poppet 66 into engagement with seat 70 . The engagement of poppet 66 with seat 70 prevents fluid from flowing from valve inlet 62 to valve outlet 64 .
- Valve 48 may be disposed in drain passageway 46 so that valve inlet 62 is exposed to fluid from inlet 22 . Valve inlet 62 directs this fluid against poppet 66 . When the force exerted by the fluid on poppet 66 exceeds the countering force exerted by spring 68 , poppet 66 will disengage from seat 70 and allow fluid to flow from valve inlet 62 through valve outlet 64 .
- Spring 68 may be selected to allow poppet 66 to disengage seat 70 when poppet 66 is subject to a fluid having a predetermined pressure.
- spring 68 may be configured to allow poppet 66 to disengage seat 70 when the fluid has a pressure of about 70 Kpa.
- valve 68 may be configured to open at other pressures.
- the described hydraulic circuit 10 may be included as part of a vehicle to provide pressurized fluid to a system in the vehicle.
- the vehicle may be, for example, a highway truck or an off-highway work machine.
- valve 48 When the vehicle, or engine, that includes hydraulic circuit 10 is not in operation, both supply pump 14 and hydraulic pump 20 will be idle. Accordingly, the oil in inlet line 16 and inlet 22 will be at a low pressure, so that valve 48 remains closed. In the closed position, valve 48 prevents oil from draining from inlet line 16 and inlet 22 through drain passageway 46 . Valve 48 will thereby preventing the formation of air pockets in hydraulic circuit 10 .
- supply pump 14 and hydraulic pump 20 will also start operating.
- Supply pump 14 will provide a supply of relatively low pressure oil through inlet line 16 and inlet 22 .
- Pumping element 26 of hydraulic pump 20 further increases the pressure of the oil.
- the high pressure oil is directed through outlet 24 to fluid rail 19 for use by another system in the vehicle.
- Valve 48 may be configured to open when exposed to fluid having a pressure slightly lower than the standard output pressure of supply pump 14 .
- Valve 48 will, therefore, open when supply pump 14 is operating normally and providing a stream of fluid at a typical output pressure. The opening of valve 48 will allow oil to flow from inlet 22 through drain passageway 46 .
- Drain passageway 46 may be connected with inlet 22 at the highest elevation in inlet 22 . With this placement, the force of gravity will act on the oil to cause the oil to continue to flow through inlet 22 and to pumping element 26 . Any air that is mixed with the oil supplied to hydraulic pump 20 will tend to collect adjacent to or in drain passageway 46 . When valve 48 opens in response to an increase in the pressure of the supply oil, the collected air, along with some of the oil will flow through drain passageway 46 .
- Drain passageway 46 may lead to bearing 50 that supports input shaft 52 .
- the oil flowing through drain passageway 46 will lubricate bearing 50 .
- the lubrication will prevent excessive wear on input shaft 52 .
- the amount of maintenance necessary to keep hydraulic pump 20 operational may be reduced.
- the foregoing disclosure provides a hydraulic circuit 10 for a hydraulic pump 20 that allows for the removal of air at the inlet to the hydraulic pump 20 and may be used to lubricate the moving parts of the hydraulic pump 20 .
- the efficiency of the hydraulic pump 20 may be increased.
- the described hydraulic circuit 10 may prevent the formation of air pockets in the flow of pressurized fluid that is used to operate an auxiliary system on the vehicle, such as, for example, a fuel injection system.
Abstract
A circuit for a hydraulic pump is provided. The circuit includes a supply of fluid. A pumping element is operable to increase the pressure of fluid received from the supply of fluid and to generate a flow of pressurized fluid. An inlet passageway connects the pumping element with the supply of fluid. A drain passageway is connected to the inlet passageway. A valve is disposed in the drain passageway. The valve is moveable between a first position where the valve prevents a flow of fluid relative to the drain passageway and a second position where the valve allows a flow of fluid relative to the drain passageway.
Description
- The present disclosure is directed to a circuit for a hydraulic pump and, more particularly, to a circuit for bleeding air from the inlet to a hydraulic pump.
- Hydraulic pumps are commonly used for many purposes in many different applications. Vehicles, such as, for example, highway trucks and off-highway work machines, commonly include hydraulic pumps that are driven by an engine in the vehicle to generate a flow of pressurized fluid. The pressurized fluid may be used for any of a number of purposes during the operation of the vehicle. A highway truck, for example, uses pressurized fluid to operate a fuel injection system or a braking system. A work machine, for example, uses pressurized fluid to propel the machine around a work site or to move a work implement.
- A hydraulic pump typically draws operating fluid, such as, for example, oil, from a reservoir and applies work to the fluid to increase the pressure of the fluid. The hydraulic pump directs the pressurized fluid into a fluid rail or another similar supply system for use during the operation of the vehicle. The hydraulic pump may be configured to vary the rate at which the pressurized fluid is directed into the fluid rail. This may be accomplished with a variable displacement pump or with a fixed displacement pump that has a variable flow.
- A hydraulic pump usually includes a pumping element that applies the work to the fluid to increase the pressure of the fluid. The pumping element includes a sliding, rotating, or spinning part, such as, for example, a gear, gearotor, piston, vane, or swash plate. These moving parts are typically lubricated to prevent excessive wear due to friction.
- The engine lubrication system in the vehicle may provide the operating fluid that is pressurized by the hydraulic pump and the lubricating fluid that is used to lubricate the moving parts of the hydraulic pump. The supply of fluid may, however, also include air that is drawn into the system. This is particularly a problem when the engine is starting after having been idle for a period of time. When the engine is not operating, the oil in the lubrication system may drain from the system and return to the reservoir. The draining oil is replaced by air pockets, which are purged from the lubrication system when the engine is started.
- The inclusion of air in the flow of pressurized fluid generated by the hydraulic pump may impair or delay the operation of the system that uses the pressurized fluid. As shown in U.S. Pat. No. 5,454,359 to Howell, an air bleed valve may be disposed in the outlet path of the pump. This type of valve can remove any air that is included in the flow of pressurized fluid. However, the hydraulic pump must pressurize both the fluid and the air before the air is purged from the system through the air bleed valve. The additional work that is required to pressurized the air, which is subsequently released from the system, decreases the efficiency of the hydraulic pump.
- The hydraulic pump circuit of the present disclosure solves one or more of the problems set forth above.
- According to one aspect, the present disclosure is directed to a circuit for a hydraulic pump. The circuit includes a supply of fluid. A pumping element is operable to increase the pressure of fluid received from the supply of fluid and to generate a flow of pressurized fluid. An inlet passageway connects the pumping element with the supply of fluid. A drain passageway is connected to the inlet passageway. A valve is disposed in the drain passageway., The valve is moveable between a first position where the valve prevents a flow of fluid relative to the drain passageway and a second position where the valve allows a flow of fluid relative to the drain passageway.
- In another aspect, the present disclosure is directed to a method of removing air from a hydraulic pump. A flow of an operating fluid is supplied to an inlet passageway of the hydraulic pump. A pumping element is operated to increase the pressure of the flow of fluid supplied to the pump and to generate a flow of pressurized fluid. A valve is moved from a first position to a second position to allow fluid to flow from the inlet passageway to a drain passageway when the pressure of the fluid in inlet passageway is above a predetermined limit.
- FIG. 1 is a schematic and diagrammatic representation of a hydraulic circuit for a hydraulic pump in accordance with an exemplary embodiment of the present invention; and
- FIG. 2 is a cross-sectional view of an exemplary embodiment of a valve for a hydraulic circuit in accordance with the present invention.
- As shown in FIG. 1,
hydraulic circuit 10 includes atank 12 that contains a supply of fluid.Tank 12 may be part of a lubrication system for the vehicle, such as an oil sump . The fluid withintank 12 may be a hydraulic fluid, such as, for example, a lubricating oil, althoughtank 12 may store other types of fluids. - As also shown,
hydraulic circuit 10 may include asupply pump 14.Supply pump 14 may be a relatively low pressure pump, such as, for example, a sump pump that may be commonly included in a lubrication system to distribute oil to various systems in an engine.Supply pump 14 may increase the pressure of the fluid to a relatively low pressure, such as about 70 Kpa. This relatively low pressurized fluid may then be directed into aninlet line 16. -
Hydraulic circuit 10 may also include a high pressure pump, such ashydraulic pump 20, to further increase the pressure of the operating fluid. A high pressure fluid may be required to operate certain systems. For example, in a vehicle, the high pressure fluid may be used to operate a fuel injection system and/or a braking system. One skilled in the art will recognize that the high pressure fluid may be used to operate other types of systems as well. - In the illustrated exemplary embodiment,
hydraulic pump 20 is depicted as a fixed displacement variable flow pump. It is contemplated, however, thathydraulic pump 20 may another type of pump. For example,hydraulic pump 20 may be a constant displacement constant flow pump or a variable displacement pump. -
Hydraulic pump 20 includes ahousing 21 and aninlet 22.Inlet 22 may be connected toinlet line 16 to receive fluid fromsupply pump 14.Inlet 22 directs the low pressure operating fluid to apumping element 26. -
Pumping element 26 is operable to increase the pressure of the operating fluid provided throughinlet 22. In the illustrated embodiment,pumping element 26 includes a series ofpistons 32 that are driven by aswashplate 28. It should be understood that another type ofpumping element 26 may also be used. For example,pumping element 26 may include a gear, gearotor, or vane pump. - As schematically illustrated in FIG. 1, an
input shaft 52 is provided to drivepumping element 26.Input shaft 52 is mounted for rotating movement on abearing 50.Input shaft 52 may be driven, for example, by an engine on the vehicle.Input shaft 52 may include a spline or keyed end that may be operatively engaged with the crankshaft or gear train of the engine.Input shaft 52 may be connected to the engine in any manner readily apparent to one skilled in the art. - As schematically illustrated,
swashplate 28 has an angled driving surface that is engaged withpistons 32. The angle surface ofswashplate 28 causes eachpiston 32 to reciprocate within a bore asswashplate 28 rotates. The reciprocating movement of eachpiston 32 pressurizes fluid contained within the bore and supplied throughinlet 22. It should be noted that the angle ofswashplate 28 may be varied to vary the displacement of eachpiston 32 withinhydraulic pump 20. - A pivoting
shoe 30 may be disposed between eachpiston 32 and the angled surface ofswashplate 28. Eachshoe 30 rides along the surface ofswashplate 28 asswashplate 28 rotates. Eachshoe 30 provides a pivoting motion to accommodate for the angled surface ofswashplate 28. - As further illustrated in FIG. 1, a
check valve 36 may be disposed at the outlet of each bore. Eachcheck valve 36 may be configured to open when the fluid within the bore reaches a predetermined level. When pumping element pressurizes the operating fluid to the predetermined pressure,check valve 36 will open to allow the pressurized fluid to flow from the bore. -
Hydraulic pump 20 may include acollector 38. Pressurized fluid released from each bore may be directed tocollector 38.Collector 38 stores a supply of pressurized fluid that is released bypistons 32. -
Pump collector 38 is connected to anoutlet 24, which may be further connected to anoutlet line 18.Outlet line 18 may be connected to afluid rail 19.Fluid rail 19 may be configured to distribute pressurized fluid to a system, such as, for example, a fuel injection system associated with the vehicle and/or engine. - As also schematically shown in FIG. 1,
hydraulic pump 20 may include acontrol device 44 that is connected tooutlet 24 through acontrol line 40. In the illustrated exemplary embodiment,control device 44 governs the flow rate of pressurized fluid produced byhydraulic pump 20 by controlling the position of ametering device 34. One skilled in the art may recognize, however thatcontrol device 44 may perform any controlling function that is common in a hydraulic pump, such as, for example, displacement control, flow rate control, output pressure control, torque or horsepower control, or load control. - The position of
metering device 34 may control the flow rate of pressurized fluid produced by eachpiston 32.Metering device 34 may be, for example, a metering sleeve that is moveable between a first position and a second position. Movement ofmetering device 34 from the first position to the second position may act to decrease the flow rate of pressurized fluid generated by eachpiston 32. - As also schematically illustrated in FIG. 1, a
drain passageway 46 may be connected toinlet 22.Drain passageway 46 may lead to bearing 50 ofinput shaft 52. It should be noted, however, thatdrain passageway 46 may lead to another bearing withinhydraulic pump 20, another surface withinhydraulic pump 20 that requires lubrication, directly totank 12, or to some other desired location. - A
valve 48 may be disposed indrain passageway 46.Valve 48 has a first, or closed, position, wherevalve 48 prevents fluid from flowing throughdrain passageway 46.Valve 48 also has a second, or open, position, wherevalve 48 allows fluid to flow throughdrain passageway 46. By controlling the position ofvalve 48, a fluid flow throughdrain passageway 46 may be selectively controlled.Valve 48 may be, for example, a check valve, a spool, valve, or any other type of valve operable to selectively allow a flow of fluid through a fluid passageway. - As illustrated in FIG. 2,
valve 48 may be a check valve. In this exemplary embodiment,valve 48 includes abody 60.Body 60 defines avalve inlet 62 and avalve outlet 64. Apoppet 66 is slidably disposed withinbody 60.Poppet 66 is configured to engage aseat 70 that surroundsinlet 62. Aspring 68 may be disposed inhousing 60 to biaspoppet 66 into engagement withseat 70. The engagement ofpoppet 66 withseat 70 prevents fluid from flowing fromvalve inlet 62 tovalve outlet 64. -
Valve 48 may be disposed indrain passageway 46 so thatvalve inlet 62 is exposed to fluid frominlet 22.Valve inlet 62 directs this fluid againstpoppet 66. When the force exerted by the fluid onpoppet 66 exceeds the countering force exerted byspring 68,poppet 66 will disengage fromseat 70 and allow fluid to flow fromvalve inlet 62 throughvalve outlet 64. -
Spring 68 may be selected to allowpoppet 66 to disengageseat 70 whenpoppet 66 is subject to a fluid having a predetermined pressure. For example,spring 68 may be configured to allowpoppet 66 to disengageseat 70 when the fluid has a pressure of about 70 Kpa. One skilled in the art will recognize thatvalve 68 may be configured to open at other pressures. - Industrial Applicability
- The operation of an exemplary embodiment of the described hydraulic circuit will now be described with reference to the figures. The described
hydraulic circuit 10 may be included as part of a vehicle to provide pressurized fluid to a system in the vehicle. The vehicle may be, for example, a highway truck or an off-highway work machine. - When the vehicle, or engine, that includes
hydraulic circuit 10 is not in operation, bothsupply pump 14 andhydraulic pump 20 will be idle. Accordingly, the oil ininlet line 16 andinlet 22 will be at a low pressure, so thatvalve 48 remains closed. In the closed position,valve 48 prevents oil from draining frominlet line 16 andinlet 22 throughdrain passageway 46.Valve 48 will thereby preventing the formation of air pockets inhydraulic circuit 10. - When the engine of the vehicle is started, both
supply pump 14 andhydraulic pump 20 will also start operating.Supply pump 14 will provide a supply of relatively low pressure oil throughinlet line 16 andinlet 22. Pumpingelement 26 ofhydraulic pump 20 further increases the pressure of the oil. The high pressure oil is directed throughoutlet 24 tofluid rail 19 for use by another system in the vehicle. -
Valve 48 may be configured to open when exposed to fluid having a pressure slightly lower than the standard output pressure ofsupply pump 14. -
Valve 48 will, therefore, open whensupply pump 14 is operating normally and providing a stream of fluid at a typical output pressure. The opening ofvalve 48 will allow oil to flow frominlet 22 throughdrain passageway 46. -
Drain passageway 46 may be connected withinlet 22 at the highest elevation ininlet 22. With this placement, the force of gravity will act on the oil to cause the oil to continue to flow throughinlet 22 and to pumpingelement 26. Any air that is mixed with the oil supplied tohydraulic pump 20 will tend to collect adjacent to or indrain passageway 46. Whenvalve 48 opens in response to an increase in the pressure of the supply oil, the collected air, along with some of the oil will flow throughdrain passageway 46. -
Drain passageway 46 may lead to bearing 50 that supportsinput shaft 52. The oil flowing throughdrain passageway 46 will lubricatebearing 50. The lubrication will prevent excessive wear oninput shaft 52. Thus, the amount of maintenance necessary to keephydraulic pump 20 operational may be reduced. - As will be apparent, the foregoing disclosure provides a
hydraulic circuit 10 for ahydraulic pump 20 that allows for the removal of air at the inlet to thehydraulic pump 20 and may be used to lubricate the moving parts of thehydraulic pump 20. By removing the air before the air is pressurized by the pumpingelement 26, the efficiency of thehydraulic pump 20 may be increased. In addition, the describedhydraulic circuit 10 may prevent the formation of air pockets in the flow of pressurized fluid that is used to operate an auxiliary system on the vehicle, such as, for example, a fuel injection system. - It will be apparent to those skilled in the art that various modifications and variations can be made in the described hydraulic circuit without departing from the scope of the invention. Other embodiments may be apparent to those skilled in the art from consideration of the specification and practice of the hydraulic circuit disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the present disclosure being indicated by the following claims and their equivalents.
Claims (20)
1. A circuit for a hydraulic pump, comprising:
a supply of fluid;
a pumping element operable to increase the pressure of fluid received from the supply of fluid and to generate a flow of pressurized fluid;
an inlet passageway connecting the pumping element with the supply of fluid;
a drain passageway connected to the inlet passageway; and
a valve disposed in the drain passageway, the valve moveable between a first position where the valve prevents a flow of fluid relative to the drain passageway and a second position where the valve allows a flow of fluid relative to the drain passageway.
2. The circuit of claim 1 , further including a supply pump disposed in the inlet passageway and adapted to increase the pressure of the fluid supplied to the pumping element to a predetermined pressure.
3. The circuit of claim 2 , wherein the valve is a check valve configured to move to the second position when exposed to fluid having the predetermined pressure.
4. The circuit of claim 3 , wherein the predetermined pressure is approximately 70 Kpa.
5. The circuit of claim 1 , further including an input shaft supported by a bearing and wherein the drain passageway directs the flow of fluid from the inlet passageway to the bearing.
6. The circuit of claim 1 , further including a fluid rail and wherein the flow of pressurized fluid is directed into the fluid rail.
7. The circuit of claim 1 , wherein the pumping element includes a piston slidably disposed in a bore.
8. The circuit of claim 7 , wherein the piston is driven by a swashplate.
9. The circuit of claim 1 , wherein the fluid is a lubricating oil and the valve allows a mixture of air and lubricating oil to flow through the drain passageway.
10. A method of removing air from a hydraulic pump, comprising:
supplying a flow of an operating fluid to an inlet passageway of the hydraulic pump;
operating a pumping element to increase the pressure of the flow of fluid supplied to the hydraulic pump and to generate a flow of pressurized fluid; and
moving a valve from a first position to a second position to allow a fluid to flow from the inlet passageway to a drain passageway when the pressure of the fluid in inlet passageway is above a predetermined limit.
11. The method of claim 10 , further including lubricating a bearing in the hydraulic pump with at least a portion of the fluid flowing through the drain passageway.
12. The method of claim 10 , further including moving the valve to the first position when the pressure of the fluid in the inlet passageway is below the predetermined limit.
13. The method of claim 10 , wherein the predetermined limit is about 70 Kpa.
14. A hydraulic pump, comprising:
a housing having a fluid inlet and a fluid outlet;
a pumping element operable to increase the pressure of fluid received through the fluid inlet and to generate a flow of pressurized fluid through the fluid outlet;
an inlet passageway connecting the fluid inlet with the pumping element;
a drain passageway connected with the inlet passageway; and
a valve disposed in the drain passageway, the valve moveable between a first position where the valve prevents a flow of fluid relative to the drain passageway and a second position where the valve allows a flow of fluid relative to the drain passageway.
15. The hydraulic pump of claim 14 , wherein the valve is a check valve configured to move to the second position when exposed to fluid having a predetermined pressure.
16. The hydraulic pump of claim 15 , wherein the predetermined pressure is approximately 70 Kpa.
17. The hydraulic pump of claim 14 , further including an input shaft supported by a bearing and wherein the drain passageway directs the flow of fluid from the inlet passageway to the bearing.
18. The hydraulic pump of claim 17 , wherein the pumping element includes a piston slidably disposed in a bore.
19. The hydraulic pump of claim 18 , wherein the piston is driven by a swashplate supported by the bearing.
20. The hydraulic pump of claim 14 , wherein the fluid is a lubricating oil and the valve allows a mixture of air and lubricating oil to flow from the inlet passageway to the drain passageway.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/253,973 US20040057836A1 (en) | 2002-09-25 | 2002-09-25 | Hydraulic pump circuit |
EP20030018897 EP1403531A1 (en) | 2002-09-25 | 2003-08-20 | Hydraulic pump circuit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/253,973 US20040057836A1 (en) | 2002-09-25 | 2002-09-25 | Hydraulic pump circuit |
Publications (1)
Publication Number | Publication Date |
---|---|
US20040057836A1 true US20040057836A1 (en) | 2004-03-25 |
Family
ID=31977813
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/253,973 Abandoned US20040057836A1 (en) | 2002-09-25 | 2002-09-25 | Hydraulic pump circuit |
Country Status (2)
Country | Link |
---|---|
US (1) | US20040057836A1 (en) |
EP (1) | EP1403531A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130336815A1 (en) * | 2012-06-14 | 2013-12-19 | Hydro Leduc | Hydraulic axial piston pump able to operate in both directions |
US20150144655A1 (en) * | 2012-06-01 | 2015-05-28 | Zhengzhou Sanhua Technology & Industry Co., Ltd | Supplying device of fixed colorants volume for a colorant dispenser |
Citations (28)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US78928A (en) * | 1868-06-16 | Territory | ||
US434448A (en) * | 1890-08-19 | Water-tank | ||
US1788288A (en) * | 1927-05-21 | 1931-01-06 | Linke Hofmann Werke Ag | Oil-injection apparatus for internal-combustion engines |
US1972560A (en) * | 1931-11-26 | 1934-09-04 | Heller Ernst | Machine tool feeding means |
US2442361A (en) * | 1944-09-04 | 1948-06-01 | Hulman Julius | Fluid system automatic vent valve |
US2931314A (en) * | 1955-05-17 | 1960-04-05 | Sundstrand Corp | Air purging apparatus for pumps |
US3698838A (en) * | 1971-02-11 | 1972-10-17 | Ingersoll Rand Co | Automatic fluid supply and control means |
US3867071A (en) * | 1972-09-22 | 1975-02-18 | Ezra D Hartley | Pumping system with air vent |
US3948147A (en) * | 1972-02-12 | 1976-04-06 | Robert Bosch G.M.B.H. | Hydraulic system with air-venting arrangement |
US3973398A (en) * | 1975-09-12 | 1976-08-10 | Deere & Company | Hydraulic system and automatically shiftable direction control valve therefor |
US4734019A (en) * | 1986-12-05 | 1988-03-29 | Hale Fire Pump Company | Pumping system |
US4944154A (en) * | 1986-12-09 | 1990-07-31 | Honda Giken Kogyo Kabushiki Kaisha | Hydraulically operated continuously variable transmission |
US4967555A (en) * | 1987-10-14 | 1990-11-06 | Honda Giken Kogyo Kabushiki Kaisha | Hydraulic continuously variable speed transmission with relief valve to prevent engine stall |
US5039284A (en) * | 1990-05-08 | 1991-08-13 | Walbro Corporation | Fuel pump with a vapor vent valve |
US5253988A (en) * | 1991-02-27 | 1993-10-19 | Maag Pump Systems Ag | Gear pump |
US5313924A (en) * | 1993-03-08 | 1994-05-24 | Chrysler Corporation | Fuel injection system and method for a diesel or stratified charge engine |
US5454359A (en) * | 1994-12-01 | 1995-10-03 | Navistar International Transportation Corp. | Continuous high pressure rail deaeration system for fuel injection system |
US5471959A (en) * | 1994-08-31 | 1995-12-05 | Sturman; Oded E. | Pump control module |
US5567123A (en) * | 1995-09-12 | 1996-10-22 | Caterpillar Inc. | Pump displacement control for a variable displacement pump |
US5782161A (en) * | 1995-12-28 | 1998-07-21 | Unisia Jecs Corporation | Axial plunger pump with a partition between the lubricating chamber and the working fluid chamber |
US6098519A (en) * | 1996-09-09 | 2000-08-08 | Hitachi, Ltd. | Fuel pump |
US6135093A (en) * | 1998-03-02 | 2000-10-24 | Zexel Corporation | Plunger pump |
US6192864B1 (en) * | 1999-06-15 | 2001-02-27 | Isuzu Motors Limited | Common-rail fuel-injection system |
US20020015645A1 (en) * | 2000-07-14 | 2002-02-07 | Takeshi Yamada | Compressor |
US6390072B1 (en) * | 2000-05-30 | 2002-05-21 | Robert H. Breeden | Pump assembly |
US6428689B1 (en) * | 1999-01-27 | 2002-08-06 | Sanyo Electric Co., Ltd. | Water purifying and dispensing apparatus, and method of purifying chlorine-containing water |
US6481979B2 (en) * | 2000-12-26 | 2002-11-19 | Visteon Global Technologies, Inc. | Lubrication passage and nozzle for swash plate type compressor |
US6517325B2 (en) * | 2000-06-30 | 2003-02-11 | Hitachi, Ltd. | Air compressor and method of operating the same |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CH390686A (en) * | 1959-12-04 | 1965-04-15 | Eckerle Otto | Feed pump system |
GB2297128B (en) * | 1994-12-01 | 1998-08-05 | Sauer Sundstrand Ltd | Closed centre hydraulic systems |
JPH09236082A (en) * | 1996-02-29 | 1997-09-09 | Unisia Jecs Corp | Liquid pump |
IT1310754B1 (en) * | 1999-11-30 | 2002-02-22 | Elasis Sistema Ricerca Fiat | VALVE SYSTEM FOR INLET PRESSURE CONTROL OF A LIQUID IN A HIGH PRESSURE PUMP, AND RELATED VALVE |
JP2002195129A (en) * | 2000-12-27 | 2002-07-10 | Mitsubishi Electric Corp | Variable delivery fuel supply system |
-
2002
- 2002-09-25 US US10/253,973 patent/US20040057836A1/en not_active Abandoned
-
2003
- 2003-08-20 EP EP20030018897 patent/EP1403531A1/en not_active Withdrawn
Patent Citations (28)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US78928A (en) * | 1868-06-16 | Territory | ||
US434448A (en) * | 1890-08-19 | Water-tank | ||
US1788288A (en) * | 1927-05-21 | 1931-01-06 | Linke Hofmann Werke Ag | Oil-injection apparatus for internal-combustion engines |
US1972560A (en) * | 1931-11-26 | 1934-09-04 | Heller Ernst | Machine tool feeding means |
US2442361A (en) * | 1944-09-04 | 1948-06-01 | Hulman Julius | Fluid system automatic vent valve |
US2931314A (en) * | 1955-05-17 | 1960-04-05 | Sundstrand Corp | Air purging apparatus for pumps |
US3698838A (en) * | 1971-02-11 | 1972-10-17 | Ingersoll Rand Co | Automatic fluid supply and control means |
US3948147A (en) * | 1972-02-12 | 1976-04-06 | Robert Bosch G.M.B.H. | Hydraulic system with air-venting arrangement |
US3867071A (en) * | 1972-09-22 | 1975-02-18 | Ezra D Hartley | Pumping system with air vent |
US3973398A (en) * | 1975-09-12 | 1976-08-10 | Deere & Company | Hydraulic system and automatically shiftable direction control valve therefor |
US4734019A (en) * | 1986-12-05 | 1988-03-29 | Hale Fire Pump Company | Pumping system |
US4944154A (en) * | 1986-12-09 | 1990-07-31 | Honda Giken Kogyo Kabushiki Kaisha | Hydraulically operated continuously variable transmission |
US4967555A (en) * | 1987-10-14 | 1990-11-06 | Honda Giken Kogyo Kabushiki Kaisha | Hydraulic continuously variable speed transmission with relief valve to prevent engine stall |
US5039284A (en) * | 1990-05-08 | 1991-08-13 | Walbro Corporation | Fuel pump with a vapor vent valve |
US5253988A (en) * | 1991-02-27 | 1993-10-19 | Maag Pump Systems Ag | Gear pump |
US5313924A (en) * | 1993-03-08 | 1994-05-24 | Chrysler Corporation | Fuel injection system and method for a diesel or stratified charge engine |
US5471959A (en) * | 1994-08-31 | 1995-12-05 | Sturman; Oded E. | Pump control module |
US5454359A (en) * | 1994-12-01 | 1995-10-03 | Navistar International Transportation Corp. | Continuous high pressure rail deaeration system for fuel injection system |
US5567123A (en) * | 1995-09-12 | 1996-10-22 | Caterpillar Inc. | Pump displacement control for a variable displacement pump |
US5782161A (en) * | 1995-12-28 | 1998-07-21 | Unisia Jecs Corporation | Axial plunger pump with a partition between the lubricating chamber and the working fluid chamber |
US6098519A (en) * | 1996-09-09 | 2000-08-08 | Hitachi, Ltd. | Fuel pump |
US6135093A (en) * | 1998-03-02 | 2000-10-24 | Zexel Corporation | Plunger pump |
US6428689B1 (en) * | 1999-01-27 | 2002-08-06 | Sanyo Electric Co., Ltd. | Water purifying and dispensing apparatus, and method of purifying chlorine-containing water |
US6192864B1 (en) * | 1999-06-15 | 2001-02-27 | Isuzu Motors Limited | Common-rail fuel-injection system |
US6390072B1 (en) * | 2000-05-30 | 2002-05-21 | Robert H. Breeden | Pump assembly |
US6517325B2 (en) * | 2000-06-30 | 2003-02-11 | Hitachi, Ltd. | Air compressor and method of operating the same |
US20020015645A1 (en) * | 2000-07-14 | 2002-02-07 | Takeshi Yamada | Compressor |
US6481979B2 (en) * | 2000-12-26 | 2002-11-19 | Visteon Global Technologies, Inc. | Lubrication passage and nozzle for swash plate type compressor |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20150144655A1 (en) * | 2012-06-01 | 2015-05-28 | Zhengzhou Sanhua Technology & Industry Co., Ltd | Supplying device of fixed colorants volume for a colorant dispenser |
US10378523B2 (en) * | 2012-06-01 | 2019-08-13 | Zhengzhou Sanhua Technology & Industry Co., Ltd | Supplying device of fixed colorants volume for a colorant dispenser |
US20130336815A1 (en) * | 2012-06-14 | 2013-12-19 | Hydro Leduc | Hydraulic axial piston pump able to operate in both directions |
Also Published As
Publication number | Publication date |
---|---|
EP1403531A1 (en) | 2004-03-31 |
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Owner name: CATERPILLAR INC., ILLINOIS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:ABDELRAHMAN, ASHRAF B;GIBSON, DENNIS;BURKITT, JOSEPH;REEL/FRAME:013336/0735;SIGNING DATES FROM 20020920 TO 20020924 |
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STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |