Bearing cover

Abstract

A bearing cover (10) has a bearing receiving space (18) for a bearing (9) and has a fastening region (17) for fastening the bearing cover (10) to a housing body (7). The bearing receiving space (18) of the bearing cover (10) is decoupled electrically from the fastening region (17) of the bearing cover (10) to prevent an undesired flow of electric current across the bearing (9).

Claims

1. A bearing cover comprising: a sleeve formed from metal and having a bearing receiving space formed radially on an inside of the sleeve for receiving a bearing; fastening arms extending out on from the sleeve and being formed from metal, each of the fastening arms having a fastening region configured for fastening the bearing cover to a housing body; a cover body disposed on a radially outer side of the sleeve and being formed from an electrically insulating plastic so that the electrically insulating plastic of the cover body surrounds the fastening arms, wherein: the electrically insulating plastic of the cover body separates the bearing receiving space of the sleeve electrically from the fastening region of the bearing cover to prevent flow of electric current across the bearing.

2. The bearing cover of claim 1, wherein the bearing cover has fastening eyelets in the fastening region.

3. The bearing cover of claim 1, wherein the bearing cover further comprises a seal receiving space.

4. An electrical machine that comprises: a stator; a rotor that can rotate relative to the stator; the bearing cover of claim 1 and a bearing arranged in the bearing receiving space of the bearing cover.

5. The electrical machine of claim 4, further comprising a rotation speed sensor mounted to the bearing cover and configured for sensing rotation speed of the rotor.

6. The bearing cover of claim 1, wherein the sleeve and the fastening arms define an insert about which the electrically insulating plastic is molded so that the fastening arms are encapsulated and surrounded completely by the electrically insulating plastic.

7. The bearing cover of claim 1, wherein the fastening arms extend integrally from the sleeve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective of a bearing cover for a rotation speed sensor according to a first embodiment.

(2) FIG. 2 is a similar illustration to FIG. 1 of a rotation speed sensor according to a second embodiment with an insert part composed of metal material.

(3) FIG. 3 is a perspective illustration of the insert part from FIG. 2 on its own.

(4) FIG. 4 is a similar illustration to FIG. 1 of a rotation speed sensor according to a third embodiment comprising a sleeve composed of a plastic material.

(5) FIG. 5 is a perspective sectional illustration of the bearing cover of FIG. 4.

(6) FIG. 6 is a partially highly schematic sectional illustration of an electrical machine that comprises a stator and a rotor that can rotate relative to the stator and has a rotor shaft rotatably mounted by a roller bearing arranged in a bearing receiving space of the bearing cover of FIG. 1.

DETAILED DESCRIPTION

(7) FIG. 6 illustrates a highly simplified section through an electrical machine 1 of a motor vehicle. The electrical machine 1 comprises a stator 2 and a rotor 3. The rotor 3 can be rotated, by way of a rotor shaft 4, about a rotation axis 5 relative to the stator 2 in a housing 6. A rotation speed sensor 40 is provided to detect the rotation speed. The rotation speed sensor 40 may be of known design.

(8) The housing 6 comprises a housing body 7 with an opening is surrounded by a bearing cover 10 of the rotation speed sensor 40. The bearing cover 10 comprises a fastening region 17 radially on the outside. In the fastening region 17, the bearing cover 10 is fastened to the housing body 7 with the aid of fastening means (not illustrated). The bearing cover 10 comprises a bearing receiving space 18 for receiving a bearing 9, in particular a roller bearing 9, radially on the inside.

(9) The roller bearing 9 serves to rotatably mount the rotor shaft 4. The bearing cover 10 comprises, in addition to the bearing receiving space 18, a seal receiving space 41 for receiving a radial shaft sealing ring 8 radially on the inside. The radial shaft sealing ring 8, through which the rotor shaft 4 extends, functions to seal off a housing interior of the electrical machine 1 from the surrounding area.

(10) A total of six fastening eyelets 11 to 16 are fitted to the bearing cover 10 for the purpose of forming the fastening region 17. The fastening eyelets 11 to 16 each comprise a passage hole for the passage of a fastening means, such as a screw. The design and the function of the bearing cover 10 in FIGS. 1 to 5 are substantially the same. However, the three different variants of the bearing cover 10 which are illustrated in FIGS. 1 to 5 comprise different cover bodies 19; 29; 39.

(11) FIG. 1 is a perspective view of the bearing cover 10 with the cover body 19 from FIG. 6 on its own. The cover body 19 of the bearing cover 10 in FIG. 1 is formed entirely from an electrically insulating plastic. The fastening eyelets 11 to 16 are integrally connected to the cover body 19 and formed from the same material as the bearing receiving region 18 and the seal receiving region 41 of the bearing cover 10.

(12) The cover body 29 of the second variant, illustrated in FIGS. 2 and 3, of the bearing cover 10 comprises a sleeve 20, which is shown in a perspective view on its own in FIG. 3. The sleeve 20 is formed from a metal material. A total of six fastening arms 21 to 26 extend radially outward from the sleeve 20. The fastening arms 21 to 26 are integrally connected to the sleeve 20.

(13) The fastening eyelets 11 to 16 are cut out from the free ends of the fastening arms 21 to 26. The fastening arms 21 to 26 with the fastening eyelets 11 to 16 are surrounded entirely by an insulating plastic material 28, as shown in FIG. 2.

(14) The bearing cover 10 illustrated in FIG. 2 is produced, for example, using a plastic injection-molding process. The sleeve 20 with the fastening arms 21 to 26 is an insert part that is encapsulated by injection molding with the insulating plastic material 28 in an appropriate injection mold.

(15) In the third variant, illustrated in FIGS. 4 and 5, of the bearing cover 10, the cover body 39 with the fastening eyelets 11 to 16 is formed from a metal material. A sleeve 30 composed of a plastic material is pressed into the metal cover body 39. The sleeve 30 is formed from an electrically insulating plastic material for the purpose of electrically decoupling the fastening region 17 from the bearing receiving space 18.