US-12618460-B2 - Axle support assembly for an electrical device

Abstract

An axle support assembly is provided for an electrical device, and which comprises an axle support defining an axle receiver having a cylindrical or substantially cylindrical side wall and an internal base portion. There is also an axle having an end which is dimensioned to be press-fit into the axle receiver. At least one venting channel extends between the internal base portion of the axle receiver and an exterior of the axle support when the axle is press fit into the axle receiver.

Inventors

• Michael Watzek
• Simon Weisflog

Assignees

• Johnson Electric International AG

Dates

Publication Date

20260505

Application Date

20230724

Priority Date

20210125

Claims (13)

1. 1 . An axle support assembly for an electrical device, the axle support assembly comprising: an axle support defining an axle receiver having a cylindrical or substantially cylindrical side wall and a closed internal base portion configured to receive an end of an axle by press-fit insertion; the axle having the end which is dimensioned to be press-fit into the axle receiver; and at least one venting channel is formed as an open groove in the cylindrical or substantially cylindrical side wall of the axle support or in the axle, wherein the venting channel is formed contiguously with the cylindrical or substantially cylindrical side wall of the axle support and the venting channel forms a bounded conduit from the closed internal base portion of the axle support through to an exterior of the axle support for pressure relief during assembly, wherein the press-fit engagement is configured to maintain water-tight integrity of the axle support assembly after assembly.
2. 2 . The axle support assembly as claimed in claim 1 , wherein the axle is formed from metal.
3. 3 . The axle support assembly as claimed in claim 1 , wherein the axle support is formed from a plastics material or metal.
4. 4 . The axle support assembly as claimed in claim 1 , wherein the axle is formed from a harder and/or stiffer material than the axle support.
5. 5 . The axle support assembly as claimed in claim 1 , wherein the venting channel is formed in the axle.
6. 6 . The axle support assembly as claimed in claim 1 , wherein the venting channel has a rectilinear cross-section.
7. 7 . The axle support assembly as claimed in claim 1 , wherein the venting channel has an at least in part circular cross-section.
8. 8 . The axle support assembly as claimed in claim 1 , wherein the axle is a gear-support axle.
9. 9 . An electrical device comprising an axle support assembly as claimed in claim 1 .
10. 10 . The electrical device as claimed in claim 9 , wherein the axle support is formed as part of a device housing of the electrical device.
11. 11 . The electrical device as claimed in claim 10 , wherein the venting channel extends between the internal base portion of the axle receiver and an interior of the device housing.
12. 12 . The electrical device as claimed in claim 9 , wherein the axle support is formed as part of an intermediate support structure within a device housing of the electrical device.
13. 13 . The electrical device as claimed in claim 9 , wherein the electrical device is an actuator.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This non-provisional patent application is a continuation application of PCT Application No. PCT/EP2022/050682, filed on Jan. 13, 2022, which claims priority to GB Patent Application No. 2100939.4, filed on Jan. 25, 2021, all of which are incorporated herein by reference in their entirety. FIELD OF THE INVENTION The present invention relates to an axle support assembly for an electrical device, particularly but not necessarily for an actuator. The invention further relates to an electrical device having such an axle support assembly. BACKGROUND When assembling actuators, it is common for the gear-support axles which support the gears of the gear train following the motor to be connected directly with the actuator housing, or with one or more intermediate plates or structures within the housing. One option is to integrally form the gear axles with the actuator housing, but this can prove complex to manufacture. In most instances, separate axles will be installed into dedicated supports in the actuator housing, which are installed separately when the gear train is ready to be assembled. The axles can either be loose fit, in which case there is large noise generated by vibrations between the axle and the actuator housing in use, as well as creating a less stable axle. This is therefore the less preferred option. Alternatively, the axles can be press fit, tightly fitting into the corresponding support axle. Where there is a tight press fit, the axles will be lubricated, typically with grease, prior to installation. This can lead to low noise and high axle stability. The problem with this approach is that a high degree of manufacturing precision is required. When the axle is press fit into the actuator housing the grease becomes locked into the bottom of the axle support, along with air pockets which become compressed as the axle is urged into place during assembly. This can lead to cracking of the actuator housing. This issue can be overcome by drilling a hole from the inside of axle support to the outside of the actuator, but this leads to additional issues with grease contamination from the actuator. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an improve means of fixing an axle in place in an electrical device which avoids the above-referenced issues. According to a first aspect of the invention, there is provided an axle support assembly for an electrical device, the axle support assembly comprising: an axle support defining an axle receiver having a cylindrical or substantially cylindrical side wall and an internal base portion; an axle having an end which is dimensioned to be press-fit into the axle receiver; and at least one venting channel which extends between the internal base portion of the axle receiver and an exterior of the axle support when the axle is press fit into the axle receiver. By providing an outlet from the axle support for compressed air and excess grease to escape, the build-up of force inside the axle support as the axle is installed is eliminated. This reduces the risk of cracking of the axle support. Similarly, by providing a press-fit arrangement, the problems associated with more loose-fit axle fixing mechanisms, such as increased vibrational damage and noise are avoided. The axle may preferably be formed from metal. Optionally, the axle support may be formed from a plastics material or metal. In one arrangement, the axle may be formed from a harder and/or stiffer material than the axle support. The axles have the advantage of, particularly in actuator arrangements, providing a stiffening effect to counteract compressive forces on the device housing. In particular, this is the case for metal axles used in plastic housings; however, this is also the case for which cracking of the housing is most commonly experienced in the art. The present invention overcomes this issue. Optionally the venting channel may be formed contiguously with the cylindrical or substantially cylindrical side wall of the axle support. The simplest option from a manufacturing perspective is to cut a channel into the side of the axle support, since the device housing will typically be formed from an easier material to work with than the axle. This is especially true if the housing is formed by an injection or compression moulding process, since extraction of the housing from tooling is a factor which must be considered. In one alternative embodiment, the venting channel may form a bounded conduit from the internal base portion of the axle support through to the exterior of the axle support. The venting channel is configured to relieve air or fluid pressure generated during press-fit insertion of the axle into the axle receiver while maintaining the water-tight housing after assembly. In this embodiment, the bounded conduit provides a means of evacuating air or grease to a user-desired location, which may allow, for example, extra