EP1960733A1

EP1960733A1 - Rotation angle sensor and rotation angle sensor system

Info

Publication number: EP1960733A1
Application number: EP06792331A
Authority: EP
Inventors: Christian Ruetz
Original assignee: Valeo Schalter und Sensoren GmbH
Current assignee: Valeo Schalter und Sensoren GmbH
Priority date: 2005-12-11
Filing date: 2006-09-30
Publication date: 2008-08-27
Also published as: US7932716B2; US20090309583A1; WO2007065496A1

Abstract

Rotation angle sensor and rotation angle sensor system for determining the angle of rotation of a shaft which can rotate at its shaft end, having a housing, having a shaft mount which is mounted on the housing such that it can rotate, having at least one signal transducer arranged on the shaft mount and having at least one signal receiver which is arranged on the housing and interacts with the signal transducer, wherein the shaft mount is designed in a manner such that the housing is attached only by means of the shaft mount at the shaft end.

Description

Title: Rotation angle sensor and rotation angle sensor system

description

The invention relates to a rotation angle sensor for determining the rotation angle of a rotatable shaft at its shaft end.

Angle of rotation sensors are on from the prior art

Shaft ends are known in which signal transmitters are arranged on the shaft side, the signals of which are received by non-rotatably arranged signal receivers.

Such sensors have various disadvantages.

For example, the assembly is complex since the shaft end is to be arranged in such a way that the signal transmitters are positioned precisely in the detection range of the signal receivers

Final assembly position. If the signal generators are not exactly aligned with the signal receivers, problems with sensor accuracy occur. In addition, it is disadvantageous that sealing such angle of rotation sensors is very complex, since on the one hand the space at the shaft end and on the other hand the space in the area of the signal receivers must be sealed.

The present invention is therefore based on the object of developing a rotation angle sensor of the type mentioned at the outset in such a way that the disadvantages mentioned are remedied. In particular, a simple assembly of the angle of rotation sensor should be possible, and its

Functional reliability should be increased.

This task is solved by a rotation angle sensor with a housing, with one rotatably mounted on the housing

Shaft recording, with at least one on the shaft recording arranged signal transmitter and with at least one rotatably arranged on the housing, interacting with the signal transmitter signal receiver, the shaft receptacle being designed such that the housing is fastened in space only via the shaft receptacle at the shaft end.

By providing a housing on which the

Wave recording with the signal generators and secondly the signal receivers are arranged to be exact

Positioning of the signal generator and the signal receiver within the housing enables. Axial and radial

Tolerances between the signal generator and the signal receiver are kept as small as possible. The positionally accurate arrangement of the shaft with respect to the angle of rotation sensor is also made possible by the fact that the housing only has the

Shaft holder is attached to the shaft end. In this respect, no separate components for fastening the

Angle of rotation sensor required. This has the advantage that there are no undesired tolerances or tolerance chains that lead to a non-optimal arrangement of the

Guide housing opposite the shaft end. Because the housing is only mounted on the shaft end, the shaft receptacle is aligned very precisely with respect to the shaft end, and thus the signal transmitter to it

Signal receiver. This increases the accuracy of the rotation angle sensor.

Another advantage of the invention is that all sensor-relevant components are arranged within one housing. Such a rotation angle sensor can

Sensor manufacturers are preassembled and their functionality is checked after the preassembly. The sensor can then be easily attached to the intended one

Shaft end can be mounted. In order to prevent the housing from rotating when the shaft rotates, the housing advantageously includes an anti-rotation device. The anti-rotation device can advantageously be braced against a component which is arranged in a stationary manner in the room. Such a component can be, for example, a housing of a larger unit, for example an electric motor, within which the rotation angle sensor according to the invention can be installed. The anti-rotation device can be designed, for example, as a pin protruding from the housing of the angle-of-rotation sensor, which pin engages in a stationary recess. To compensate for axial tolerances, the cutout can be designed as a pin receptacle extending in the axial direction, so that an anti-rotation lock is also ensured if the pin does not fully engage the pin receptacle in the axial direction, but at least in sections. A

Anti-rotation can also be ensured by an asymmetrical

Weight distribution of the housing are formed. This also ensures that due to the particular weight of the housing, the housing is not rotated when the shaft rotates.

According to a further advantageous embodiment of the

According to the invention, it can be provided that the anti-rotation device comprises an intermediate element which is arranged between the housing and the fixedly arranged component in such a way that, on the one hand, it is at least conditionally displaceable relative to the housing in a movement which is essentially perpendicular to the central longitudinal axis of the shaft or the housing is and that it is the other

a second direction of movement is preferably mounted transversely to this first direction of displacement relative to the stationary component m. Due to the provision of such an intermediate element

are guaranteed that tolerances or radial eccentricities occurring in the radial direction Rotation of the shaft are compensated for, namely without the housing being rotated and without undesirable tensile or compressive stresses occurring on the stationary component and / or on the housing. Overall, the measuring accuracy of the sensor is increased.

In this regard, it is advantageous if the intermediate part is arranged so as to be displaceably mounted on the housing and / or on the fixedly arranged component via a tongue and groove connection and / or a pin-elongated hole connection. Radial eccentricities can be compensated in a suitable manner by tongue-and-groove connections, which enable the intermediate part to be moved at least to a certain extent in the corresponding displacement direction. The same applies to

Pin-slot connections, in which pins are provided which engage in corresponding slots extending perpendicular to the shaft axis.

In order to secure the intermediate element in the axial direction on the housing and / or on the stationary component, it can be provided that a corresponding tongue and groove connection is provided, which has T-slots and T-springs which are designed to be complementary thereto. This can be achieved, for example, that the intermediate element by providing such

Connection in the axial direction can be pre-assembled captively on the housing. The intermediate element can in particular provide pins on the side facing the stationary component, the pins provided in the stationary component, transverse to the grooves

engage the elongated slots. The direction of displacement of the intermediate element relative to the housing via the tongue and groove connection advantageously extends perpendicularly to a direction of displacement which can be provided via the pin-elongated hole connection between the intermediate element and the stationary component. For permanently secure attachment of the shaft holder to the shaft end, it can be provided in particular that

Shaft receptacle can be attached to the shaft end by means of a press, adhesive, latching and / or screw connection.

For the rotatable mounting of the shaft holder on the housing is advantageously between the shaft holder and the

Housing a pivot bearing arranged. Such a pivot bearing can be, for example, a roller bearing, such as a ball or groove bearing, or a plain bearing.

The shaft receptacle as such can advantageously be designed in such a way that it has a sleeve section for the shaft end and a signal transmitter receptacle section facing away from the sleeve section and designed concentrically therewith. The signal transmitter receiving section can in particular delimit a circular space within which the signal transmitter can be arranged. The signal transmitter can be designed, for example, as an annular or circular disk, which is then in an appropriately designed one

Signal generator receiving section is arranged.

The signal transmitter can advantageously as

Magnetic element can be formed, in particular as a ring or circular disk magnet. With such a design, the signal receiver is advantageously designed as a magnetic field sensor, in particular as a Hall element. In particular, two are used to generate opposing signals

Magnetic field sensors are provided which have phase-shifted, analog output signals. These phase-shifted, analog output signals can then be used to determine the angle of rotation of the shaft within one revolution in a known manner.

According to a further development, it is conceivable that at

Magnetic element trained signal transmitter of the signal receiver and in particular an electrical with the signal receiver connected number memory is supplied with electrical energy by an induction coil, which is arranged around a pulse wire, with a sudden magnetic reversal in the pulse wire due to the magnetic element when the shaft holder is rotated, as a result of which sufficient electrical energy at the induction coil to supply the sensor

or the cell memory is provided. Such an embodiment generates an increment signal, by means of which it is possible to deduce the number of revolutions of the shaft. Due to the training described, the number memory works autonomously and independently of an exhaustible energy source. In this context, the disclosure content of patent application DE 10 2004 062 448 is used in its entirety. The m disclosed in the aforementioned German patent application is therefore also considered to be disclosed in the present application. The

Pulse wire preferably has a soft magnetic core and a hard magnetic sheath.

The induction coil can also be used to supply additional electrical and electronic components required for evaluating the angle of rotation.

A further development of the invention provides that m

Extension of the axis of rotation of the shaft two crosswise

arranged pulse wires with induction coils are provided. This results in an arrangement with a

particularly high efficiency; in this way it can have enough energy to supply the signal receiver

or a number memory or other electrical components required for signal evaluation are made available.

It is advantageous if the signal receiver on an im

Housing arranged circuit board is arranged. On this circuit board, for example, the one mentioned Number memory and an evaluation unit for determining the angle of rotation of the shaft can be arranged.

The housing of the angle of rotation sensor is advantageously designed to be essentially rotationally symmetrical. In this way, an optimal arrangement of the individual components of the sensor can be achieved in a comparatively small installation space. It is also conceivable for the housing to include a cover for at least largely sealing the housing.

This can increase the sensitivity of the sensor to environmental influences.

According to the invention, it is conceivable that the signal receiver is separated from the signal transmitter by a wall in one

is arranged in the housing closed space from the environment. In this way, the signal receiver, which can be arranged in particular on a circuit board, and other components are reliably protected from environmental influences.

In principle, the rotation angle sensor according to the invention can be used wherever a rotation angle of a shaft is to be determined. The rotation angle sensor can in particular be arranged on the free end of a steering shaft of a vehicle or on the motor shaft of an electric motor for driving a steering shaft of a vehicle. The angle of rotation sensor can within the motor housing of an electric motor, in particular an electric motor for driving a

Steering shaft.

The object mentioned at the outset is also achieved by a rotation angle sensor system comprising a rotation angle sensor according to the invention and a shaft end, the fastening of the housing of the rotation angle sensor in space only taking place via the shaft mounting of the rotation angle sensor at the shaft end. As already mentioned, the shaft end can be used with the Shaft receptacles can be arranged via, for example, press, adhesive, latching and / or screw connections.

Further details and advantageous embodiments of the invention can be found in the following description, on the basis of which the one shown in the drawing

Embodiment of the invention is described and explained in more detail.

FIG. 1 shows a longitudinal section through an electric motor which has a rotation angle sensor according to the invention,

FIG. 2 shows a longitudinal section through the rotation angle sensor according to FIG. 1;

Figure 3 is an exploded view of the

Angle of rotation sensor according to Figures 1 and 2;

Figure 4 shows the sensor cover and an intermediate part

Arrangement on the sensor cover in

perspective view from one side; and

Figure 5 shows the sensor cover including the intermediate part

Figure 4 is a perspective view from the other side.

The longitudinal section through an electric motor 10 is shown in FIG. The electric motor 10 comprises a motor housing 12 on which two end shields 14 are arranged. The two bearing plates 14 carry the shaft 18 of the bearing 16

Electric motor 10. The rotor 20 of the electric motor is arranged on the shaft 18 between the two bearings 16. On the housing side, opposite the rotor 20, the stator 22 is provided on the housing 12.

A rotation angle sensor 26 is attached to the shaft end 24 of the shaft 18 located in the housing 12. The angle of rotation sensor 26 is supported by a pm-like anti-rotation device 28 to prevent rotation on the housing 12. For this purpose, the housing 12 has a pin receptacle 30 running in the axial direction.

In the installed state in FIG. 1, the angle of rotation sensor 26 is electrically connected to a motor board 34 via electrical contacts 32. The motor board 34 points in the

Figures, not shown, electrical and electronic components for driving the electric motor 10. The

Motor board 34 is covered by a removable housing cover 36.

The electric motor 10 can in particular in one

electromechanical steering of a motor vehicle are used. A steering shaft can be driven via the shaft 18, for example, directly or with the interposition of a transmission.

The precise angle of rotation of the shaft 18 can be determined with the angle of rotation sensor 26. As is clear from the section according to FIG. 2 and the illustration according to FIG. 3, the angle of rotation sensor 26 has its own housing 38, on which a shaft holder 42 which is rotatable via a bearing 40 is arranged. The shaft receptacle 42 has a sleeve section 44 on the side facing the shaft, on which the shaft end 24 is arranged in a rotationally fixed and rigid manner. To attach the

Shaft end 24 on shaft receptacle 44 can in particular be provided with a press, adhesive, latching and / or screw connection. The arrangement of the angle of rotation sensor 26 at the shaft end 24 is such that the angle of rotation sensor 26 is only attached to the shaft end. The rotation angle sensor 26 is consequently not arranged on the housing 12 of the electric motor or on another stationary component. The contacts 32 and the anti-rotation device 28 are not provided for fastening the angle of rotation sensor 26 in the electric motor 10.

As is also clear from FIG. 2, the

Shaft receptacle 42 on its sleeve section 44

facing away from a signal generator section 46. The circular signal transmitter section 46 receives a signal transmitter 48 which is designed as a circular disk magnet. Due to the rigid connection between the shaft end 24 and the shaft holder 42, the signal generator 48

rotationally coupled to the shaft 18.

In the housing 38 is on a sensor board 50

Double magnetic field sensor 52 arranged. When the shaft 18 or the signal generator 48 is rotated on

Double magnetic field sensor 52 generates phase-shifted output signals which are evaluated by means of evaluation electronics also provided on the sensor board 50. The angle of rotation of the shaft 18 can then be determined from these signals within one revolution or a section of rotation

determine. On the side of the sensor board 50 facing away from the magnetic field sensor 52 and also facing away from the signal transmitter 48, two pulse wires 54 arranged in a cross arrangement and embedded in the coil body 54 are provided. Induction coils 56 are arranged on the coil bodies 54 in such a way that when the magnetic field changes due to the rotation of the signal transmitter 48, there is an abrupt magnetic reversal of the pulse wires, as a result of which energy is made available on the induction coil. This energy is used to operate a counter memory provided on the switch board 50. The number of revolutions of the shaft 18 or the number of rotation angle sections of the shaft 18 can be determined with the counter memory. The magnetic signal generator 48 can be used as increment coding; at a The respective polarity reversal of a signal receiver sends a signal to the number memory. Overall, the magnetic signal generator as well as the pulse wires together

Coil body 54 and coils 56 be designed so that enough energy is provided to supply all the electrical components on the sensor board 50 with enough energy. This results in an independently working rotation angle sensor.

As is clear from the figures, the two coil formers 54, or the pulse wires arranged therein, cross on the central longitudinal axis of the shaft 18

or the circular disk magnet 48.

As is particularly clear from FIGS. 2 and 3, the sensor board 50 is arranged in a space 58 which is sealed off from the shaft holder 42. The space 58 can be closed tightly via a sensor cover 60. It is thereby achieved that the sensor board 50 together with electronics is protected from environmental influences in the housing 38 of the

Angle of rotation sensor is arranged. The magnetic one

Signals coming in the form of signals due to

Magnetic fields changing shaft rotation penetrate the closed wall 62 provided between the signal generator 48 and the signal receiver 52.

The rotation angle sensor 26 can be installed in this way: First, the sensor is mounted on the shaft end 24. Then the anti-rotation device 28 in the

associated pin receptacle 30 introduced on the housing 12.

Finally, the electrical contacting of the

Angle of rotation sensor with the motor board 34 via the contacts 32. Of course, it is also conceivable that the electrical contacts also parallel to the central longitudinal axis of the

Shaft holder 42 can be arranged. This can advantageously ensure that contacting the Sensor with a corresponding circuit board takes place simultaneously with the insertion of the anti-rotation device 28 into the pin receptacle 30. This eliminates one step.

FIGS. 4 and 5 show a sensor cover 62 which can be used instead of the sensor cover as shown in FIGS. 1 to 3. As is clear from FIG. 4, the sensor cover 60 has on it

On the outside in cross section T-shaped springs 64 which are arranged along a direction 66 running perpendicular to the shaft 18.

When assembled, the springs are 64 m

provided T-grooves 68 which are arranged on an intermediate part 70. With springs 64 inserted into the T-grooves 68, the cover 62, and thus the entire sensor 26, can at least be moved relative to the intermediate part 70 along the direction 66.

The intermediate part 70 has the cover 62 on it

facing away from two pins 72, which are arranged along a direction 77 extending transversely to the direction 66.

In the assembled state, the two pins 72 engage in the slot 30 according to FIG. 1 in corresponding elongated holes provided on the housing 12. The elongated holes to be provided for receiving the pins 72 advantageously have a width which corresponds to the diameter of the pins 72 or is only slightly larger. The elongated holes extend at least to a limited extent in the direction 77, so that the intermediate element 70 relative to the housing 12

is at least partially movable in the direction 77.

Due to the design described in FIGS. 4 and 5, it is consequently achieved that movement compensation of the sensor cover 62 in the radial direction is possible, however without allowing the sensor cover 62 to rotate when the shaft 18 is rotated. This increases the measuring accuracy of the sensor 26.

The intermediate element 70 can be arranged in a preassembly position on the sensor cover 62 due to the provision of the T-slot connection. Because of the pins 72 which extend far enough in the axial direction and which engage in correspondingly deep elongated holes, a certain amount of play occurring in the axial direction can be compensated for.

Particular advantage of that shown in the figures

Embodiment of the invention is that the signal transmitter and the signal receiver within the sensor 26 are firmly positioned relative to one another and form a closed system. The tolerance chains are due to the arrangement of the

corresponding components in the same housing very low.

This results in a very high level of functional reliability and measuring accuracy of the sensor. Due to the attachment of the angle of rotation sensor 26 to the shaft end 24, the arrangement of the angle of rotation sensor 26 is also not dependent on other components in space, such as the housing 12 of the

Electric motor 10. This also results in a very high functional accuracy of the sensor 26.

Claims

1. Rotation angle sensor (26) for determining the rotation angle (24) of a rotatable shaft (18) at its shaft end, with a housing (38), with a shaft mount (42) rotatably mounted on the housing (38), with at least one on the shaft mount arranged signal transmitter (48) and having at least one signal receiver (52) arranged on the housing (38) and interacting with the signal transmitter (48), the shaft holder (42) being designed such that the housing (38) is fastened only via the shaft holder (42) at the shaft end (24).

2. Sensor (26) according to claim 1, characterized in that the housing (38) comprises an anti-rotation device (28) of the housing.

3. Sensor (26) according to claim 2, characterized in that the anti-rotation device (28) is supported on a component (12) arranged in a stationary manner in the room.

4. Sensor (26) according to claim 2 or 3, characterized

characterized in that the anti-rotation device is formed by an asymmetrical weight distribution of the housing.

5. Sensor (26) according to claim 2 or 3, characterized

marked that the anti-rotation lock

Intermediate element (70), which is arranged between the housing (38) and the fixedly arranged component (12) such that it is on the one hand essentially perpendicular to the housing (38) m

Movement direction (66) running in the central longitudinal axis is displaceably mounted and that, on the other hand, it is preferably transverse to this first displacement direction (66) relative to the stationary component (12) is displaceable in a second direction of movement (77).

6. Sensor (26) according to claim 5, characterized in that the intermediate part (70) via a tongue and groove connection (64, 68) and / or a pin-slot connection (72) on the housing (38) and / or is arranged displaceably mounted on the stationary component (12).

7. Sensor (26) according to claim 6, characterized in that a tongue and groove connection is provided, the T-slots (68) and complementary T-springs (64).

8. Sensor (26) according to any one of the preceding claims, characterized in that the shaft receptacle (42) by means of a press, adhesive, locking and / or

Screw connection can be fastened to the shaft end (24).

9. Sensor (26) according to any one of the preceding claims, characterized in that a rotary bearing (40) is arranged between the shaft holder (42) and the housing (38).

10. Sensor (26) according to any one of the preceding claims, characterized in that the shaft receptacle (42) has a sleeve section (44) for the shaft end and one facing away from the sleeve section (44)

Signal generator receiving section (46).

11. Sensor (26) according to any one of the preceding claims, characterized in that the signal transmitter (48) is designed as a magnetic element and / or that the

Signal receiver (52) is designed as a magnetic field sensor.

12. Sensor (26) according to any one of the preceding claims, characterized in that the signal transmitter (48) is designed as a magnetic element and that the

Signal receiver and / or a number memory electrically connected to the signal receiver from one

Induction coil (56) is supplied with electrical energy, which is arranged around a pulse wire, the rotation of the shaft holder (42) and the

Magnetic element (48) due to the changing magnetic field (48), an abrupt magnetic reversal takes place on the pulse wire, whereby sufficient electrical energy is provided on the induction coil (56) to operate the number memory.

13. Sensor (26) according to claim 12, characterized in that m extension of the axis of rotation of the shaft (18) two cross-arranged pulse wires with induction coils (56) are provided.

14. Sensor (26) according to any one of the preceding claims, characterized in that the signal receiver (52) are arranged on a circuit board (50) arranged in the housing.

15. Sensor (26) according to claim 14, characterized in that an evaluation unit for determining the angle of rotation of the shaft (18) is arranged on the circuit board.

16. Sensor (26) according to any one of the preceding claims, characterized in that the housing (28) in

Is essentially rotationally symmetrical and / or comprises a cover for at least largely tight closing.

17. Sensor (26) according to any one of the preceding claims, characterized in that the signal receiver (52) by a wall (62) from the signal transmitter (48) separated in a space (58) which is closed off from the surroundings is arranged in the housing (38).

18. Sensor (26) according to any one of the preceding claims, characterized in that the angle of rotation sensor (26) is installed within a motor housing (12) of an electric motor (10).

19. rotation angle sensor system comprising a rotation angle sensor (26) according to one of the preceding claims and a

Shaft end (24), the attachment of the housing in space only via the shaft holder (42) of the

Angle of rotation sensor (26) at the shaft end (24).