WO2013152889A1

WO2013152889A1 - Pump element

Info

Publication number: WO2013152889A1
Application number: PCT/EP2013/053313
Authority: WO
Inventors: Thomas Kremer; Hendrik THOMANN
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2012-04-10
Filing date: 2013-02-20
Publication date: 2013-10-17
Also published as: DE102012205747A1

Abstract

The invention relates to a pump element with a piston guiding unit (2) which receives a piston (3) that can be moved by means of an actuating part (4) and a spring (9). The piston guiding unit (2) can be fixed on or in a housing (1), and the spring (9) applies a spring force onto the piston (3) relative to the piston guiding unit (1) via a spring plate (6). The aim of the invention is to carry out a lubrication for sliding bearings of a push rod drive starting from the housing (1). This is achieved in that the spring plate (6) is provided with at least one opening for the feed-through of lubricant. Thus, a lubrication by the push rod drive is not necessary, and the lubrication can be provided by the hydraulic system in a simple manner.

Description

title

Pump element description

Field of the invention

The invention relates to a pump element with a piston movable by means of an actuating part and a spring receiving piston guide unit, wherein the piston guide unit is fastened to or in a housing and the spring acts on the piston via a spring plate against the piston guide unit with spring force. Furthermore, the invention relates to a hydraulic system for controlling gas exchange valves on reciprocating internal combustion engines with such a pump element.

Background of the invention

Such a pump element can be used to build up pressure in hydraulic systems, such. B. in a hydraulic valve train for reciprocating internal combustion engines. Such a pump element is fastened with or in a housing which can also accommodate parts of the hydraulic system, in particular the hydraulic medium, via which the pressure is transmitted within the system.

To build up pressure in the housing, the piston of the pump element is moved in a piston guide unit, wherein the piston guide unit is attached to the housing. The piston is moved indirectly via an actuating part or directly from the outside in motion. As a rule, this movement is not a pure axial movement, so that an at least partially radial movement takes place on the cylinder or actuating part, which requires a slide bearing.

This is problematic that this slide bearing is arranged on the one hand outside the hydraulic medium leading housing and thus the hydraulic medium is not used as a lubricant. Thus, the plain bearing, the For example, between the piston and a drag lever is arranged, are not lubricated by means of existing hydraulic medium in the housing.

In particular, the spring plate proves to be particularly cumbersome, because this must be attached directly or indirectly to the piston, but also brought into contact with a biasing spring. With a corresponding leakage can thus reach the lubricating hydraulic means to the spring plate, but not beyond this. From DE 10 2010 021394 A1 a pump element is known, which has a spring plate, which is biased relative to the piston guide unit and at the same time prevents lubricant from reaching the side opposite the spring. Especially in large engine applications of the so-called. UniAir system, in which the pump components are arranged vertically hanging down, although gravity causes the lubricant arrives at the spring plate, but the same drips down the circumference and thus lubrication of a plain bearing, the immediate is arranged under the spring plate makes impossible. However, this Gleitla- delay is indispensable in large engine applications, because the housing should be designed with its hydraulic lines for reasons of cost no larger than necessary, whereby a transmission of the actuating force via mechanical (non-hydraulic) means such. As rods or levers, is also required. To make matters worse, that the sliding bearing can accept various Ausbil- fertilize, including ball-head bearings, hinge-like bearings or the like.

OBJECT OF THE INVENTION The object of the invention is to develop a pump element of the type mentioned at the beginning in such a way that gravity-based lubrication in the vertical direction is supported without affecting the other functions of the pump element. This object is achieved in a pump element of the type mentioned above in that the spring plate has at least one opening for the passage of lubricant. According to the invention, the piston of the pump element can be moved by means of an actuating part and a spring. The spring force of the spring is used to load the piston, wherein in an unactuated state, the piston is held in an initial position. In this case, the actuating member only acts as a coupling element to another actuating force transmitting part, which is in operative connection with the actuating part. For example, the actuating member may be designed as a plunger head and the interacting with this part as a pan element.

The piston guide unit has at least two functions, namely on the one hand to ensure the attachment to the housing, and on the other hand to keep the piston in its direction of leadership feasible. The spring plate is used to the spring force of the spring, which acts against the piston guide unit initially the spring plate, but with this also the piston with spring force, especially since the piston is directly or indirectly connected to the spring plate.

According to the invention, the spring plate has at least one opening for the passage of lubricant. The lubricant may in this case consist of the hydraulic medium which is contained in the housing. The opening is designed in such a way that the lubricant can easily reach the other (lower) side of the spring plate, following the gravitational force. For example, the size of the opening or other properties of the opening can be placed on possible entrained micro particles in order to prevent clogging. Furthermore, it is possible to provide not just one, but a plurality of openings, so that a sufficient lubricant supply is ensured. There are round holes for simplicity, d. H. Holes, on, which can be introduced on the spring plate.

Advantageously, the spring plate on a recess in which the piston or a connectable with this component is arranged. This recess can be arranged centrally in the spring plate. It is important that the recess, in contrast to the opening, is provided for the piston or the construction element which can be connected to it. to arrange part on or in the spring plate and connect to this. Thus, the spring force can be transmitted from the spring via the spring plate on the piston. The connectable component may in particular be a plunger head, a ball head or the pin of a hinge.

In an advantageous embodiment, the spring plate on a support area, which includes the recess radially. In this way, the spring force is transmitted evenly to the spring plate, so that tilting or jamming of the spring plate can be effectively counteracted. A tilting of the spring plate would have the consequence that the leadership of the piston within the piston guide unit can not be guaranteed and thus it could lead to increased friction or increased fuel consumption.

Advantageously, the at least one opening between the support area and the recess is arranged. In this way, it is ensured that the lubricant flow, which is supported by the spring, as well as the piston, can flow through the at least one opening as possible without further obstacles. Due to the proximity to the spring or the piston, the lubricant flow also remains sufficiently large to be able to lubricate a sliding surface on the other side of the spring plate.

Advantageously, the recess is bounded by at least one fastening region of the spring plate. However, it is also possible to provide a plurality of fastening regions on the spring plate which, for example, are arranged in the shape of a coronet or are arranged next to one another at least in the circumferential direction, wherein the fastening regions are spaced apart in the circumferential direction.

Advantageously, the at least one attachment region, or the attachment regions, is / are arched out of a plane of the support region. This facilitates the attachment of the spring plate insofar that this by means of a mounting ring on a cylindrical body, such as. As the piston, fastened by first the spring plate is mounted on, for example, the piston and then the mounting ring is attached to the piston to produce a mold flow relative to the spring plate. Advantageously, the at least one opening opens into the recess. Thus, a spring plate can be produced in a particularly efficient manner, because in spite of the mouth mounting areas arise, which are separated from each other in the circumferential direction. Furthermore, it is no longer necessary that the lubricant must penetrate into the support region of the spring plate, but can continue to flow through the opening or through the spring plate on the piston or on the actuating part, without coming into unnecessary contact with the spring plate. This option also proves to be very advantageous because in the attachment area openings can be arranged without adversely affecting the function of the attachment.

In an advantageous embodiment, a plurality of two, three, four or more openings is provided, which are arranged symmetrically, in particular star-shaped. A symmetrical arrangement makes the installation of the spring plate very easy, since its orientation does not have to be respected. Furthermore, the number of openings may be chosen such that a structural integrity of the spring plate is not affected, but a sufficiently large flow area for the lubricant is provided.

The fastening ring already mentioned by way of example can in particular be embodied as an open fastening ring which, for example, snaps into a circumferential groove on the piston. The spring plate is fixed for example by means of such a fastening ring on the pump element. The fastening ring produces a positive fit for transmitting the spring force to the piston. This can be done in a variety of different ways. For example, the fastening ring could alternatively engage in a groove of the spring plate.

Advantageously, the pump element according to the invention is used as part of a hydraulic system for controlling gas exchange valves on reciprocating internal combustion engines. It is intended to forward mechanical actuating force, which is passed on, for example, by a lever or the like and comes from the reciprocating internal combustion engine, in the housing with the piping system for hydraulic power transmission.

Further advantageous embodiments and preferred developments of the invention can be taken from the description of the figures and / or the dependent claims. The invention will be described and explained in more detail below with reference to the embodiments illustrated in the figures and the description of the figures. Brief description of the drawings

Show it:

1 is a cut along the operating direction pump unit,

2 shows the pump unit of Fig. 1 in a perspective view,

Fig. 3 of the spring plate of Fig. 1 in different views, and Fig. 4 shows the spring plate of Fig. 3 in the installed state.

DETAILED DESCRIPTION OF THE DRAWINGS FIG. 1 shows a pump unit in longitudinal section along the direction of actuation B. The pump unit consists of a piston guide unit 2, the spring 9, the piston 3, the spring plate 6, the fastening ring 15 and the actuating part 4 designed as a plunger head Actuating part 4 materially executed with the piston 3, so be integrated into this, in order to reduce the variety of components.

The sleeve 12 transmits motive force to the socket element 5, in which the actuating part 4 is mounted. In this way, B force is transmitted in the direction of movement, wherein the sleeve 12 and the socket element 5 need not necessarily be arranged concentric to the direction of movement, but perform a partial radial movement when actuated in the sliding bearing between socket element 5 and actuator 4.

When actuated, the actuating part 4 is moved in the direction of actuation B, that is to say in the direction of the housing 1, the spring 9 being further tensioned and the piston 3 is also moved in the piston guide unit 2 along the direction of movement B. In the process, the hydraulic medium is compressed in the compression space 8 and the actuating force is converted into a hydraulic force. The housing 1 may have a complex shape, wherein the different hydraulic units are connected to hydraulic lines, which are used for power transmission. For example, a hydraulic valve train can be accomplished in which both switching valves, pump units or valve brakes are accommodated within the housing.

The pump unit is screwed to the housing 1 via the piston guide unit 2. Alternative forms of attachment, such as press-fitting, are also possible. The hydraulic medium can flow out of the hydraulic pressure system through the leakage gap 7, which is formed by the piston 3 and the piston guide unit 2, wherein it continues to flow on the piston 3 down to the spring plate 6, following the gravitational force. The hydraulic, liquid medium can flow through the openings 1 1, without being retained by the spring plate 6. Furthermore, it flows over the fastening ring 15, which ensures a positive connection for the spring plate 6, in order subsequently to reach the actuating part 4. From there, it easily gets into the sliding bearing between the actuating part 4 and the socket element 5. Especially in large engine applications, a possible push rod drive is arranged below the pump unit with a camshaft lying below, so that the removal is initially bridged with push rods, or even the sleeve 12 , but in any case a sliding bearing is required. Due to the dimensions, it is very disadvantageous to introduce lubricants, such as oil, from the camshaft or other source via the ram rod drive. By means of the pump element and its spring plate, however, an oil supply from the housing 1 out is possible. Figure 2 shows the built-in pump element in the arbitrarily cut housing 1, which, as already stated, may have a plurality of receptacles of hydraulic units. Figures 3a, 3b and 3c show the spring plate 6 of the pump unit of Figures 1 and 2 from different perspectives. The spring plate 6 has in a radially outer disc-shaped region of the support area 14 for the spring 9, which comprises the recess 13 for the arrangement of the actuating part 4. The spring plate 6 comprises the piston 3 and is fixed by the mounting ring in a groove in the piston 3. This prevents that an additional force is applied by the spring to the press fit of the operating part 4.

There are a total of four openings 1 1 are provided, which are opposite to each other in pairs, or arranged in a star shape. As a result, a uniform lubricant passage is achieved.

The openings 1 1 further open into the recess 13, whereby the recess 13 is radially expanded. Between the openings 1 1 each attachment areas 10 are arranged, which are arched out of the disc plane of the support area 14 and form a throat in the direction of movement B. This ensures that the attachment of the spring plate 6 is a problem-free lubricant passage through the openings 1 1 is not in the way.

Due to the turned-up fastening regions 10 results in a very easy method of attachment by means of the fastening ring 15, which rests in formed as a ram head actuator 4. During installation, the spring plate 6 is first pulled over the actuating part 4 and then over the piston 3, after which the optionally open fastening ring 15 is moved via the actuating part 4 to snap into a groove of the piston 3 and henceforth a form fit for the spring plate 6 to form.

The course of the biasing force of the spring 9 thus extends from the spring 9 via the support portion 14 of the spring plate 6 in the mounting portions 10 and of these in turn on the mounting ring 15, which transmits the force on the actuating part 4 on the piston 3. Figure 4 shows the spring plate 6 in the direction of movement B, which is partially covered by the sleeve 12 and the cup member 5. Parts of the openings 1 1 can still be seen from this line of sight, whereby an unhindered flow of lubricant can be demonstrated. Advantageously, additional contact points of the pump or the push rod drive can be supplied with lubricant on the way to the camshaft or other power source.

The exemplary embodiment shown in the figures, including the possible variations of the exemplary embodiment listed in the text, can be further developed at several points. For example, it is not mandatory that the leakage gap 7 between the piston guide unit 2 and the piston 3 is arranged, but there are also other leaks that are to be realized, for example, only on the piston or on the piston guide unit alone or in conjunction with other components possible.

Furthermore, the attachment methods of the spring plate can vary significantly and include other components, such. As screws, washers or the like.

In addition, the sliding bearings, which must be supplied with lubricant, also executable in any conceivable form, such as Kugelkopfpfannen arrangements, hinges or the like. Furthermore, in addition to a hydraulic valve train, other types of hydraulic systems are conceivable, the component of which may be a pump element according to the invention. The required boundary conditions for the pump unit are a regularly recurring actuating force and a hydraulic system arranged in the housing, which is to forward the force. In summary, the invention relates to a pump element with a movable piston by means of an actuating member and a spring piston guide unit, wherein the piston guide unit can be fastened to or in a housing and the spring acts on the piston via a spring plate against the piston guide unit with spring force. The aim is to achieve a lubrication for sliding bearings of a push rod drive from the housing. This will be proposed to provide the spring plate with at least one opening for the passage of lubricant. Thus, a lubrication on the part of the push rod drive is not required and can be easily taken over by the hydraulic system.

LIST OF REFERENCE NUMBERS

B direction of movement

1 housing

2 piston guide unit

3 pistons

4 actuating part

5 pan element

6 spring plates

7 leakage gap

8 compression space

9 spring

10 mounting area

1 1 opening

12 sleeve

13 recess

14 circulation area

15 fixing ring

Claims

claims

Pump element with a by means of an actuating part (4) and a spring (9) movable piston (3) receiving piston guide unit (2), wherein the piston guide unit (2) on or in a housing (1) can be fastened and the spring (9) the piston (3) via a spring plate (6) against the piston guide unit (2) acted upon by spring force, characterized in that the spring plate (6) has at least one opening (1 1) for the passage of lubricant.

Pump element according to claim 1, wherein the spring plate (6) has a recess (13) in which the piston (3) or a component which can be connected thereto, in particular a plunger head (4), is arranged.

Pump element according to claim 1 or 2, wherein the spring plate (6) has a bearing region (14) which radially surrounds the recess (13).

Pump element according to claim 3, wherein the at least one opening (1 1) between support area (14) and the recess (13) is arranged.

Pump element according to claim 4, wherein the recess (13) of at least one mounting portion (10) of the spring plate (6) is limited.

The pumping element of claim 5, wherein the at least one mounting portion (10) is arched out of a plane of the support portion (14).

Pump element according to one of claims 4 to 6, wherein the at least one opening (1 1) opens into the recess (13).

Pump element according to one of the preceding claims, wherein a plurality of 2, 3, 4 or more openings (1 1) is provided, which are arranged symmetrically, in particular star-shaped.

9. Pump element according to one of the preceding claims, wherein the spring plate (6) by means of a fastening ring (15), in particular an open fastening ring (15) is fixed to the pump element.

10. A hydraulic system for controlling gas exchange valves on reciprocating internal combustion engines with a pump element according to one of the preceding claims as a component.