DE102004004687B4 - Electric motor and series - Google Patents

Abstract

Electric motor, comprising a rotor shaft (4) which is mounted in an output-side bearing plate (9) via an output-side bearing and in an input-side bearing plate (10) via an input-side bearing, the stator housing (11) between the bearing plates (9, 10) A sensor (5) is arranged on the rotor shaft (4) on the axially output side than the output side bearing and is electrically connected to an antenna part (6) provided on the rotor shaft (4), which transmits electromagnetic radiation to a stationary antenna part ( 7) transmits and / or receives from it, which is arranged on a mounting flange (8), the sensor (5) being provided axially between the mounting flange (8) and the output-side bearing, the mounting flange (8) forming the housing for the electric motor is and is connected to the output-side bearing plate (9), wherein the sensor (5) is housed protected by the mounting flange (8), the provided for a shaft sealing ring Before installation space is used to install the sensor (5) instead of a shaft seal.

Description

The invention relates to an electric motor and a method for producing an electric motor of a series of electric motors.

From the publications W. Baldauf, VDI progress reports, series 8, No. 380, 1994 and J. Michel, dissertation TU Munich 1996 systems for measuring a physical quantity such as torque in a rotatable shaft are known. The physical quantities include by way of example also the axial and / or transverse force and the torque, which are transmitted to the rotatable shaft. Under transverse force is understood in this document to the axis of the rotatable shaft radially acting force component, ie the radial force. Under axial force is understood in this document to the axis of the rotatable shaft axially acting force component.

For measuring such physical quantities, various methods and methods are known. Common to all is that they are elaborate and expensive. Those systems which have one or more sensors on a rotatable shaft require power supply to the co-rotating part of the electronics. Some of these batteries are used, which must be replaced after a certain period of operation and need a lot of space. In addition, in particular batteries imbalance-generating masses, which must be compensated by correspondingly expensive countermeasures. In addition, the rotatable part of the electronics also requires a lot of space. High electrical and / or magnetic fields can additionally complicate the use. In addition, there are contacts, for example for batteries, which can lead to sparks in exceptional cases. Therefore, explosion-proof versions are expensive to produce.

From the DE 100 23 961 A1 For example, a system for measuring physical flows in an axle or rotatable shaft is known. In this case, an SAW sensor is used and it is known to attach a sensor on the axial output side as the output side bearing of a shaft and electrically connect an inner antenna to the sensor. The rotating antenna part transmits or receives electromagnetic radiation of a stationary antenna part, wherein both antennas are arranged in the immediate vicinity of each other. The stationary outdoor antenna is connected to a housing, which is the housing of an engine. Next, an electric motor is mentioned.

From the DE 195 46 595 A1 For example, a speed and / or direction sensor device is known on the A side of an electric motor.

From the US 5 577 152 A a motor arrangement with rotor shaft is known, which has a pulse width modulated operated power electronics, wherein a sensor is arranged on the A side.

From the DE 198 59 930 A is also known an electric motor assembly with rotor shaft and control unit, wherein a sensor is arranged on the A-side.

From the DE 34 43 024 A1 is an electric motor with fan known, with associated electronic components are integrated with the engine, so form a common unit with the same degree of protection.

The invention is therefore the object of developing an electric motor and a method for producing an electric motor of a series of electric motors, the system should be inexpensive to produce and should be integrated into existing series without much effort. The process also aims to reduce storage costs and storage space requirements.

According to the invention the object is achieved in the system according to the features specified in claim 1 and in the method according to the features indicated in claim 15.

Essential features of the invention in the electric motor are that it comprises at least one rotor shaft which is mounted on at least one output-side bearing in at least one output-side end shield,
a sensor being arranged on the rotor shaft on the axial output side as the output-side bearing, which is electrically connected to an antenna part provided on the rotor shaft, which transmits and / or receives electromagnetic radiation to a stationary antenna part, which is arranged on a mounting flange,
wherein the mounting flange is housing forming for the electric motor and is connected to the output side bearing plate.

The advantage here is that the torque exiting the motor fully and completely through the range of the sensor and therefore is very accurately measurable. In addition, the sensor can be accommodated in a protected manner by a mounting flange, wherein the space region otherwise present on the output side can be used for a shaft sealing ring for the sensor.

In another embodiment of the invention, the sensor is comprised of a system for measuring physical quantities in an axle or rotatable shaft,
wherein a first stationary electronic circuit by means of electromagnetic waves and / or electromagnetic wave trains with at least the one Sensor exchanges energy and information at least unidirectionally at least temporarily,
and that the sensor is connected or coupled to the rotatable shaft such that electromagnetic waves and / or electromagnetic wave trains transmitted from the sensor to the first electronic circuit comprise information about the values of the physical quantities,
and that the first stationary electronic circuit is connected to at least one stationary antenna part. The advantage here is that no energy supply is to be accommodated on the rotating shaft.

In a further embodiment of the invention, the first stationary electronic circuit exchanges radar wave trains with the sensor, wherein at least one sensor is designed as a SAW sensor and connected to the rotatable shaft such that information about the values of the torque and / or the axial and / or or lateral force is contained in the radar wave trains or radar returns radiated by the SAW sensor. The advantage here is that a very robust system can be used, namely SAW sensors or synonymous SAW sensors. These can also be used in the industrial sector, ie with high vibration vibrations, temperatures and accelerations, since the technology can be implemented on silicon wafers or the like.

In a further embodiment according to the invention, the sensor operates passively, in particular it does not comprise a battery. The advantage here is that the mass of the shaft is not to increase for attaching a battery.

In another embodiment of the invention, the sensor includes means for converting electromagnetic waves, such as radar waves or the like, into acoustic waves and back, and responds to irradiated electromagnetic wave trains with time-delayed electromagnetic waves, the time delay being affected by the physical quantities or their change. The advantage here is that a transit time measurement of pulses or a phase shift with continuous transmission can be detected and from this the value of the torque can be determined.

In a further embodiment of the invention, the sensor comprises means for converting electromagnetic waves, such as radar waves or the like, into electrical current for supplying an electrical circuit to the sensor, and the electrical circuit comprises means for determining or changing the physical quantities, the sensor providing information about the certain values of the physical quantities or their change by means of electromagnetic waves. In particular, the sensor comprises a transponder. The advantage here is that known devices and sensors are easy and inexpensive to use.

In a further embodiment of the invention, the shaft is an output shaft, in particular a drive component, such as transmission, engine or the like. The advantage here is that the output torque can be detected and the control of the engine comprehensive drive is thus possible with this.

In another embodiment of the invention, the physical quantities are the torque transmitted by the shaft, the torque transmitted to the rotatable shaft, and / or the axial and / or shear force occurring in or on the shaft. The advantage here is that even such variables are detectable.

In a further embodiment of the invention, the sensor or at least parts of the sensor is installed in a bore or axial bore of the rotatable shaft. The advantage here is that the sensor is particularly protected providable.

In a further embodiment of the invention, the sensor or at least parts of the sensor is installed in the bore or axial bore of the rotatable shaft by means of a cartridge. The advantage here is that the sensor is easy to integrate during manufacture.

In a further embodiment of the invention, the sensor is installed on the inside and / or outside of the rotatable shaft. The advantage here is that the sensor is protected attachable and / or can detect the torque very accurately on the surface.

In a further embodiment of the invention, the rotatable shaft has a, in particular plan, receiving area for the sensor. The advantage here is that the interface is very suitable for silicon covered by the sensor.

Essential features of the electric motor series are that it comprises at least two sizes,
wherein the series in at least one size comprises first electric motors with sensor and second electric motors without sensor,
wherein the second electric motors have a driven-side shaft sealing ring axially on the output side from the driven-side bearing,
wherein the first electric motors have no output side shaft seal but a mounting flange, with the output side bearing plate is connected and comprises a stationary antenna part.

The advantage here is that an existing series of electric motors without sensor without great effort to electric motors with sensor can be extended by the sensor is provided in the spatial area of the shaft seal and a mounting flange is added. The number of additional necessary parts is therefore low.

Further advantageous embodiments will be apparent from the dependent claims.

LIST OF REFERENCE NUMBERS

1

output shaft

2

sensor cartridge

3

stator

4

rotor

5

SAW sensor

6

rotatable antenna part

7

stationary antenna part

8th

mounting flange

9

end shield

10

end shield

11

stator

The invention will now be explained in more detail with reference to an illustration:

1 shows an electric motor according to the invention, which is a stator 3 and a rotor 4 includes. The rotor is over bearings 2 in the campsite signs 9 and 10 stored. The output side bearing plate is B-side with the stator housing 11 and A-side, ie output side, with the mounting flange 8th connected, which is a stationary antenna part 7 includes, are radiated with the electromagnetic waves, of the relative thereto, with the rotor 4 rotatable antenna part 6 are receivable. Likewise, the antenna part 6 emit electromagnetic waves from the stationary antenna part 7 be sent.

The sensor 5 is with the rotatable antenna part 6 electrically connected. It is mechanical with the rotor shaft 1 connected. The sensor is axially between the output side bearing 2 and the mounting flange 8th positioned.

The mounting flange 8th is with the output side end shield 9 connected.

In a first embodiment of the invention, a transponder is used as the sensor. In such a system, the first stationary electronic circuit transmits a high frequency electromagnetic wave train which is radiated over the outside antenna and received by the inside antenna. Under wave train is understood in this document not only a single pulse but also a pulse train.

The transponder has a further electronic circuit which derives its supply energy from said wave train. In addition, this further electronic circuit comprises at least one highly integrated chip, such as microprocessor or the like, to the smallest sensor, such as piezoelectric elements or strain gauges or the like, are connected to measure physical quantities. The further electronic circuit, after the beginning of the arrival of the wave train described, sends back a wave train which is modulated and / or coded in such a way that information about the values of the physical quantities picked up by the sensors can be received and processed by the first electronic circuit.

In particular, the axial and / or transverse force occurring on the rotatable shaft and / or the torque transmitted to the shaft are detected as physical variables.

It is advantageous in the use of said transponder, that the high frequency is almost arbitrary selectable, in particular transponder can be used in the system according to the invention with frequencies of 100 kHz or even up to 10 GHz.

In further exemplary embodiments according to the invention, transponders can also be used in which the different frequencies are used for energy and information transmission. Thus, the associated waves do not interfere and it is even an essentially simultaneous energy and information exchange to the transponder out and from the transponder forth executable.

In a second embodiment of the invention, no transponder is used as the sensor, but a surface acoustic wave sensor (SAW sensor). It is the first electronic circuit via the antenna part 7 radiated high frequency in the range of about 3 GHz. But it can also be used frequencies from 100 MHz to 10 GHZ. The over the antenna part 6 received wave train is applied as an electrical voltage to piezo elements, which then oscillate in time with the wave train. The piezoelectric elements are applied to a small plate and thus produce surface waves which run up to also on the plate applied reflectors and are then reflected there. The reflected parts meet at least partially back to the piezo elements, which thus again convert these surface acoustic waves into electrical voltages. Thus, as it were, a respective wave train assigned to a reflector is reflected back. Via the stationary antenna part, the first electronic circuit receives the signal and processes the information transmitted to it by means of the echoes.

Since the propagation time of the surface acoustic waves depends on physical quantities, such as temperature and stress conditions of the plate, information on compression and expansion in different directions of the plate can be obtained and measured by suitable arrangement of the reflectors. Said torque and said axial and / or lateral force can be determined from such information from the first electronic circuit.

An advantage is the robust, insensitive to interference, simple and therefore cost-effective design of the system. In addition, the parts or components required specifically for the invention can be used within existing gearboxes and engine series and can be used without dimensional changes or significant redesigns.

In particular, a stationary, ie uniform blasting of the waves is possible. The described transit time effects then cause a phase shift of the reflected and received by the stationary antenna part waves, which are then thus mixed with the radiated. The connected electronic circuit evaluates this and it is thus possible to determine from the change of the signals, the change of the physical quantities, in particular the value of the torque.

The physical quantities are thus measured continuously. In further development, the measured values are evaluated together with measured values of a speed sensor.

The antennas described in this specification also include in each case all embodiments of a capacitive, inductive, substantially capacitive and / or substantially inductive coupling.

Claims (11)

Electric motor, comprising a rotor shaft ( 4 ), which have an output-side bearing in a driven-side end shield ( 9 ) is mounted and via a drive-side bearing in a drive-side end shield ( 10 ), wherein the stator housing ( 11 ) between the bearing plates ( 9 . 10 ), wherein a sensor ( 5 ) axially output side than the output side bearing on the rotor shaft ( 4 ) arranged with one on the rotor shaft ( 4 ) provided antenna part ( 6 ) is electrically connected, the electromagnetic radiation to a stationary antenna part ( 7 ) and / or receives from this, which on a mounting flange ( 8th ) is arranged, wherein the sensor ( 5 ) axially between the mounting flange ( 8th ) and the output-side bearing is provided, wherein the mounting flange ( 8th ) is housing-forming for the electric motor and with the output-side end shield ( 9 ), the sensor ( 5 ) from the mounting flange ( 8th ), wherein the space provided for a shaft seal space is used to instead of a shaft seal the sensor ( 5 ). Electric motor according to claim 1, characterized in that the sensor ( 5 ) of a system for measuring physical quantities in an axle or rotatable shaft, wherein a first stationary electronic circuit by means of electromagnetic waves and / or electromagnetic wave trains with at least one sensor ( 5 ) Exchanges energy and information at least unidirectionally at least temporarily, and that the sensor ( 5 ) is connected or coupled to the rotatable shaft in such a way that the sensor ( 5 ) electromagnetic waves transmitted to the first electronic circuit and / or electromagnetic wave trains comprise information about the values of the physical quantities, and that the first stationary electronic circuit with at least one stationary antenna part ( 7 ) connected is. Electric motor according to at least one of the preceding claims, characterized in that the first stationary electronic circuit emits and receives radar wave trains, wherein at least one sensor ( 5 ) is implemented as a SAW sensor and connected to the rotatable shaft in such a way that information about the values of the torque and / or the axial and / or lateral force is contained in the radar wave trains or radar returns radiated by the SAW sensor. Electric motor according to at least one of the preceding claims, characterized in that the sensor operates passively, that includes no battery. Electric motor according to at least one of claims 1 to 3, characterized in that the sensor ( 5 ) Means for converting electromagnetic waves, such as radar waves or the like, into acoustic waves and back, and responds to irradiated electromagnetic wave trains with time-delayed electromagnetic wave trains, the time delay being influenced by the physical quantities or their change. Electric motor according to at least one of the preceding claims, characterized in that the sensor ( 5 ) is an SAW sensor. Electric motor according to at least one of the preceding claims, characterized in that the sensor ( 5 ) Means for converting electromagnetic waves, such as radar waves or the like, into electrical current for supplying an electrical circuit of the sensor ( 5 ) and the electrical circuit comprises means for determining the physical quantities or their change, and in that the sensor ( 5 ) Returns information about the determined values of the physical quantities or their change by means of electromagnetic waves. Electric motor according to at least one of the preceding claims, characterized in that the sensor ( 5 ) comprises a transponder. Electric motor according to at least one of the preceding claims, characterized in that the physical quantities are the torque transmitted by the shaft, the torque transmitted to the rotatable shaft and / or the axial and / or lateral force occurring in or on the shaft. Electric motor according to at least one of the preceding claims, characterized in that the sensor ( 5 ) is installed on the outside of the rotatable shaft. Method for producing an electric motor of a series of electric motors from a modular system, comprising - at least one rotor shaft ( 4 ) - at least one output-side bearing - a driven-side shaft seal - at least one output-side end shield ( 9 ) - a sensor ( 5 ) - an antenna part ( 6 ) - a stationary antenna part ( 7 ) - a mounting flange ( 8th ) wherein the rotor shaft ( 4 ) of the electric motor via at least one output-side bearing in at least one output-side end shield ( 9 ), wherein the electric motor is optionally produced as a first or second electric motor, wherein in at least one size of the first electric motor with sensor ( 5 ) and the second electric motor without sensor ( 5 Is executed, (i) wherein the second electric motors have a driven-side shaft seal axially on the output side of the output side bearing, (ii) wherein the first electric motors have no output side shaft seal but a mounting flange ( 8th ) connected to the output side shield ( 9 ) and a stationary antenna part ( 7 ), wherein a sensor ( 5 ) axially output side than the output side bearing on the rotor shaft ( 4 ) is arranged and wherein the space provided for the shaft seal space is used to instead of the shaft seal the sensor ( 5 ), whereby the sensor ( 5 ) with one on the rotor shaft ( 4 ) provided antenna part ( 6 ) is electrically connected, the electromagnetic radiation to a stationary antenna part ( 7 ) and / or receives from this, which is arranged on a mounting flange, wherein the mounting flange is housing-forming for the first electric motor and with the output-side end shield ( 9 ) connected is.

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