Rotor position sensor and motor assembly

Abstract

The present invention relates to a rotor position sensor (16) for a motor vehicle, which is used to detect the rotational position of a rotor (18) of an electric motor (12). The rotor position sensor includes a sensor housing (22), in which components of the rotor position sensor (16) are installed. It is characterized in that at least a part of the sensor housing (22) is configured to close a cover of a motor housing (14) of the electric motor (12). In addition, a motor assembly (10) having an electric motor (12) and a rotor position sensor (16) is provided.

Description

Field of the Invention

[0001] The present invention relates to a rotor position sensor for a motor vehicle and a motor assembly having an electric motor and a rotor position sensor. Background Art

[0002] In an electric motor, especially in a synchronous motor excited by permanent magnets or a synchronous motor excited by current, it is necessary to determine the rotational position of the rotor in order to drive the motor. This position is usually determined via a so-called rotor position sensor, which in turn includes a rotor position sensor-rotor and a rotor position sensor-stator.

[0003] In accordance with the position of the rotor, the individual coils in the stator of the electric motor must be supplied with high voltage in sequence to generate a surrounding magnetic field.

[0004] Generally, the rotor position sensor is installed within the motor and is demarcated outwardly by additional housing components.

[0005] The disadvantage here is that a relatively large (axial) space and a large number of components are required. Summary of the Invention

[0006] Accordingly, it is an object of the present invention to provide a rotor position sensor and a motor assembly having a rotor position sensor, which can achieve a particularly cost-effective and compact structural form.

[0007] According to the present invention, the object is solved by a rotor position sensor for a motor vehicle, which is used to detect the rotational position of the rotor of an electric motor, wherein the rotor position sensor includes a sensor housing in which components of the rotor position sensor are installed, and at least a part of the sensor housing is configured to close a cover of the motor housing of the electric motor.

[0008] In this way, the following advantages are achieved, that is, a separate cover is not required to close the motor housing of the electric motor, and the rotor position sensor is arranged in the motor housing. Therefore, the rotor position sensor or the entire motor assembly is optimized in terms of the required installation space and cost. By integrating the cover into the rotor position sensor, a separate cover can thus be dispensed with. The reduced number of components has a particularly favorable effect on the production cost.

[0009] The rotor position sensor is preferably a self-enclosed unit. This means that the rotor position sensor can be obtained as a pre-assembled unit and can be installed in a single assembly step during final assembly.

[0010] Components arranged in the sensor housing are, for example, coils, lines leading to the coils, and a control and / or evaluation unit, which is connected to the lines in a signal-transmitting manner.

[0011] The sensor housing is preferably a one-piece molded part. Thus, complex geometries on the sensor housing can be manufactured in a cost-effective manner. However, if required, the sensor housing can also be a milled part.

[0012] The material of the sensor housing can be a metallic material or plastic.

[0013] According to one embodiment, the sensor housing has a flange for fixing the rotor position sensor at the motor housing of an electric motor. In this way, the rotor position sensor can be fixed particularly easily, for example by means of threaded elements or other fixing devices. The flange is preferably provided with fixing lugs or tightening lugs.

[0014] The cover is formed, in particular, together with one side of the sensor housing by a protruding region of the sensor housing, such as the flange.

[0015] On the outer side of the rotor position sensor, in particular on the outer side of the sensor housing, a seal for sealing the motor housing of the electric motor can be provided. The seal can be embodied as an O-ring or a liquid seal. Thus, the rotor position sensor can also enclose the motor housing in a fluid-tight manner in the assembled state. If required, by a suitable design of the seal, a seal conforming to all IPXX classes can be achieved, i.e., the seal can be dust-tight, fluid-tight, and / or gas-tight. Since the seal is arranged on the sensor housing, the assembly of the electric motor in which the rotor position sensor is arranged is further simplified. The seal then does not have to be manipulated separately.

[0016] The seal is preferably arranged in a circumferential groove on the sensor housing or on a sealing surface. By providing the groove, the seal is on the one hand supported in a loss-free manner before assembly and on the other hand prevents the seal from slipping during the assembly of the rotor position sensor. Since the groove also provides a corresponding positioning position for the seal, incorrect assembly can be reliably avoided by acting. In the case of a liquid seal, the seal can be applied to the sealing surface.

[0017] According to one embodiment, the sensor housing has a abutment surface for the abutment of a spring element. In particular, the abutment surface serves to restrain the spring element and thus pre-tension the rolling bearing when the rotor position sensor is assembled. In this way, the number of required components can be further reduced. In particular, no separate bearing ring is required to position the spring element. The assembly is also simplified because the spring element is automatically positioned when the rotor position sensor is inserted.

[0018] The abutment surface is formed, for example, on a circumferential radially outwardly extending flange constructed on the sensor housing. Such a flange can be formed particularly easily on the sensor housing, for example during injection molding of the sensor housing.

[0019] According to one embodiment, a pressure compensation element is integrated in the sensor housing. Thereby, the assembly of a separate pressure compensation element can be dispensed with and the number of required components can be reduced, which has a favorable effect on the assembly time and the total cost.

[0020] Furthermore, a cable through-guide for the sensor cable can be provided in the sensor housing and / or the sensor cable can be at least partially integrated in the sensor housing. The sensor cable is integrated, for example, by overmolding, i.e., it is integrated into the sensor housing during the manufacture of the sensor housing. This significantly simplifies the assembly, since the sensor cable does not have to be manually passed through the corresponding clearance. Alternatively or additionally, a corresponding cable through-guide can be provided, which enables subsequent installation of the sensor cable and simple replacement of the sensor cable, for example in the event of a fault. Furthermore, by providing the cable through-guide, a plug does not have to be installed in the sensor housing.

[0021] It can be clearly seen from the foregoing description that different functions can be integrated in the rotor position sensor according to the invention. Thus, the rotor position sensor according to the invention is a highly integrated rotor position sensor. Thereby, on the one hand, the required installation space (axially) is significantly reduced, and on the other hand, the number of components to be installed during final assembly is reduced.

[0022] According to the invention, the object is also solved by a motor assembly having an electric motor mounted in a motor housing and having a rotor position sensor constructed as described above. The rotor position sensor is at least partially received in the motor housing and fixed at the motor housing. The rotor position sensor at least closes the motor housing outwardly on the side where the rotor position sensor is received in the motor housing.

[0023] As already described in connection with the rotor position sensor, an additional cover for closing the motor housing can be dispensed with in this way. Description of the Drawings

[0024] Other advantages and features of the invention result from the following description and the attached drawings. In the drawings:

[0025] Figure 1 A motor assembly according to the invention is shown in a sectional view,

[0026] Figure 2 A rotor position sensor according to the invention is shown in a perspective view, and

[0027] Figure 3 Shown in another perspective view Figure 2 the rotor position sensor in Detailed Description

[0028] Figure 1 Shown in a sectional view is a motor assembly 10 having an electric motor 12 and a rotor position sensor 16, the electric motor being mounted in a motor housing 14. For the sake of simplicity, the electric motor 12 including a rotor 18 and a stator 20 is only schematically drawn.

[0029] The motor assembly 10 further includes a drive shaft 19 supported by means of two rolling bearings 21. To allow for a certain clearance, one of the rolling bearings 21 abuts against a spring element 23, in particular against a disc spring.

[0030] For the sake of easier manufacturability, the motor housing 14 is preferably constructed in multiple parts.

[0031] Most of the rotor position sensor 16 is received in the motor housing 14 and fixed, in particular screwed, to the motor housing 14. Here, the rotor position sensor 16 extends into the motor housing 14 such that the rotor position sensor can detect the rotational position of the rotor 18, which is also referred to as the angular position.

[0032] Figure 2 and 3 The rotor position sensor 16 is shown in perspective views respectively.

[0033] The rotor position sensor 16 has a sensor housing 22. The sensor housing 22 is preferably an injection-molded component, i.e., an integrally manufactured component.

[0034] Mounted in the sensor housing 22 are a rotor position sensor rotor 24 and a rotor position sensor stator 26, as Figure 1 shown in

[0035] In addition, there are provided a line 25 leading to the stator coil of the rotor position sensor stator 26 and a control and / or evaluation unit 27, which is connected to the line 25 in a signal-transmitting manner. These are schematically shown in Figure 1

[0036] In addition, different geometries are constructed on the sensor housing 22. Through these structures, in particular, reinforcement of the sensor housing 22 can be achieved, so that the sensor housing is constructed to be mechanically stable accordingly.

[0037] In addition, a circumferential flange 28 is constructed on the sensor housing 22 of the rotor position sensor 16, and the flange has a plurality of fixing lugs or tightening lugs 30.

[0038] ​Furthermore, the sensor housing 22 has a groove 32, which is preferably configured circumferentially on the sensor housing 22.

[0039] A seal 34 is arranged in the groove 32. The seal 34 can be, for example, an O-ring embedded in the groove 32. The seal 34 can also be integrally formed on the sensor housing 22. The integrally formed seal 34 has the advantage that the seal does not slip during assembly.

[0040] For example, the seal 34 and the sensor housing 22 are manufactured by a two-component injection molding method (2K injection molding method), so that the seal material is lockingly arranged on the sensor housing 22.

[0041] In any case, the seal 34 is arranged outside the rotor position sensor 16, more precisely outside the sensor housing 22.

[0042] Regarding the assembled state of the sensor housing 22, the groove 32 is configured on the side of the sensor housing 22 that faces the motor assembly 10 when viewed from the flange 28.

[0043] Instead of the groove 32, the sensor housing 22 can only have a sealing surface. A liquid sealant can be applied to this sealing surface, or as already described in connection with the groove 32, a seal can be integrally injection molded on this sealing surface, especially when manufacturing the seal by a two-component injection molding method.

[0044] The sensor housing 22 also has a abutment surface 36, which is arranged on a circumferential radially outwardly extending flange 38 on the sensor housing 22. The abutment surface 36 is used for the abutment of the spring element 23.

[0045] Furthermore, a cable through-guide 40 for the sensor cable 42 is provided in the sensor housing 22 of the illustrated embodiment.

[0046] During the manufacture of the sensor housing 22, the sensor cable 42 can already be integrated in the sensor housing 22, for example, injection molded over by the material of the sensor housing 22. This means that during the manufacture of the sensor housing 22, the sensor cable 42 has already been placed in the mold, and then the material for the sensor housing 22 is introduced into the mold in order to manufacture the sensor housing 22.

[0047] In this regard, the sensor cable 42 can be integrated in the sensor housing 22. Thereby, the cable through-guide 40 is sealed well enough outwardly.

[0048] Furthermore, a functional surface 44 is provided, on which a pressure compensation element 46 is applied.

[0049] To make the functional surface 44 visible, the pressure compensation element 46 is not shown inFigure 2 is shown. The functional surface 44 is here the outer side of the sensor housing 22, which, in the assembled state of the rotor position sensor 16, is arranged outside the motor housing 14 or forms the outer surface of the motor assembly 10.

[0050] The sensor housing 22 is constructed in one piece, i.e., the flange 28, the groove 32, the flange 38, the cable passage guide 40 and / or the functional surface 44 are integrally formed together in the sensor housing 22.

[0051] Due to the geometry of the sensor housing 22 described above, the rotor position sensor 16 is configured such that it can perform different functions during assembly and during operation of the motor assembly 10. Here, the rotor position sensor 16 forms a self - enclosed unit. This means that the rotor position sensor 16 can be assembled in a single assembly step.

[0052] As Figure 1 shown, when the rotor position sensor 16 is fixed to the motor housing 14, the sensor housing 22 forms a cover for enclosing the motor housing 14. In particular, the flange 28 forms part of the cover. This means that the rotor position sensor 16 encloses the motor housing 14 outwardly at least on the side where the rotor position sensor 16 is received in the motor housing 14.

[0053] When the rotor position sensor 16 is inserted during the assembly of the motor assembly 10, the seal 34 seals the motor housing 14 outwardly.

[0054] Furthermore, when the rotor position sensor 16 is inserted into the motor housing 14, the abutment surface 36 comes into contact with the spring element 23 and pre - loads the spring element.

[0055] Furthermore, the rotor position sensor 16 serves as a pressure compensation element.

Claims

1. A rotor position sensor (16) for a motor vehicle, for detecting the rotational position of a rotor (18) of an electric motor (12), wherein, The rotor position sensor (16) includes a sensor housing (22) in which components of the rotor position sensor (16) are mounted. It is characterized in that at least a part of the sensor housing (22) is configured to enclose a cover of the motor housing (14) of the electric motor (12), and the rotor position sensor (16) is received in the motor housing (14). The sensor housing (22) has a flange (28) for fixing the rotor position sensor (16) to the motor housing (14) of the electric motor (12). The cover is formed together with one side of the sensor housing by the flange. The sensor housing (22) has a abutment surface (36) for the abutment of a spring element (23), and the abutment surface (36) is for restraining the spring element (23) and thus preloading a rolling bearing (21) abutting on the spring element (23) when the rotor position sensor is assembled.

2. The rotor position sensor (16) according to claim 1, characterized in that, A seal (34) for sealing the motor housing (14) of the electric motor (12) is provided on the outer side of the rotor position sensor (16).

3. The rotor position sensor (16) according to claim 1, characterized in that, A seal (34) for sealing the motor housing (14) of the electric motor (12) is provided on the outer side of the sensor housing (22).

4. The rotor position sensor (16) according to claim 2 or 3, characterized in that, The seal (34) is arranged in a circumferential groove (32) or on a sealing surface on the sensor housing (22).

5. The rotor position sensor (16) according to any one of claims 1 to 3, characterized in that, The abutment surface (36) is formed on a circumferential radially outwardly extending flange (38) on the sensor housing (22).

6. The rotor position sensor (16) according to any one of claims 1 to 3, characterized in that, A pressure compensation element (46) is integrated in the sensor housing (22).

7. The rotor position sensor (16) according to any one of claims 1 to 3, characterized in that, A cable through - guiding portion (40) for a sensor cable (42) is provided in the sensor housing (22) and / or the sensor cable (42) is at least partially integrated in the sensor housing (22).

8. A motor assembly (10), the motor assembly having an electric motor (12) mounted in a motor housing (14) and having a rotor position sensor (16) according to any one of claims 1 to 7, wherein, The rotor position sensor (16) is at least partially received in and fixed to the motor housing (14), and the rotor position sensor (16) outwardly seals the motor housing (14) at least on the side where the rotor position sensor (16) is received in the motor housing (14).

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