Low axial play drive system

• US 7,966,904 B2
• Filed: 05/05/2006
• Issued: 06/28/2011
• Est. Priority Date: 05/05/2006
• Status: Active Grant

• Current Assignee: Questek Manufacturing Corporation
• Original Assignee: Questek Manufacturing Corporation
• Inventors: Krueger, Dale R.
• Primary Examiner(s): Ridley; Richard W
• Assistant Examiner(s): DIAZ, THOMAS C
• Application Number:
  US11/381,756
• Publication Number:
  US 20070295134A1
• Time in Patent Office: 1,880 Days
• Field of Search: 744/25, 744/09, 744/40, 359/873, 359/877, 384/613
• US Class Current: 74/425
• CPC Class Codes: B60R 1/074 for retracting the mirror arrangements to a non-use position alongside the vehicle
• CPC Class Codes: F16H 1/203 with non-parallel axes F16H1/22 takes precedence
• CPC Class Codes: Y10T 74/19623 Backlash take-up
• CPC Class Codes: Y10T 74/19828 Worm
• CPC Class Codes: Y10T 74/19898 Backlash take-up

Abstract

A drive system for rotating an assembly, such as an external vehicle mirror housing, about an axis is provided with a drive housing containing a worm drive assembly coupled to an axis gear mounted about the axis. The worm drive assembly is rotated by an electric motor. The axis gear is stationary with respect to the axis, such that rotation of the worm drive assembly will cause it to travel about the axis gear. Such movement of the worm drive assembly will cause the drive housing and the associated external vehicle mirror housing to rotate about the axis. Thrust transmitted to the worm drive assembly is transmitted to a central portion of the drive housing by a shaft retainer associated with the worm drive assembly. Play between the axis gear and the worm drive assembly is prevented by eliminating separation between adjacent components of the worm drive assembly.

Claims

1. A drive system for rotating an assembly about an axis, comprising:

a drive housing;

an electric motor associated with the drive housing;

a first journal bearing mounted within the drive housing;

a second journal bearing mounted within the drive housing and aligned with the first journal bearing;

a shaft retainer mounted within the drive housing intermediate the first journal bearing and the second journal bearing, wherein the shaft retainer is substantially stationary with respect to the drive housing, and wherein the shaft retainer includes an aperture aligned with the first journal bearing and the second journal bearing;

a shaft extending from the first journal bearing to the second journal bearing and through the aperture, wherein the shaft is operatively coupled to the electric motor and mounted for rotation within the drive housing;

at least one thrust bearing axially fixed to the shaft at a location where it is engaged with the shaft retainer such that thrust loads on the shaft are transmitted to the shaft retainer;

a drive gear mounted on the shaft for rotation therewith, the drive gear, said at least one thrust bearing and shaft being axially fixed with respect to the shaft retainer such that there is no separation between the drive gear, said at least one thrust bearing and shaft retainer; and

an axis gear engaging the drive gear and mounted coaxially with the axis.

2. The drive system of claim 1 wherein the assembly is an external vehicle mirror housing.

3. The drive system of claim 1 wherein the shaft is substantially axially stationary with respect to the shaft retainer.

4. The drive system of claim 1 wherein the shaft retainer is a plate.

5. The drive system of claim 4 wherein the drive housing comprises an upper enclosure and a bottom floor, and wherein the plate is retained by the upper enclosure and the bottom floor.

6. A drive system for rotating an assembly about an axis, comprising:

a drive housing;

an electric motor associated with the drive housing;

a motor shaft extending into the drive housing and rotatably driven by the electric motor;

a motor pinion mounted on the motor shaft for rotation therewith;

a first shaft mounted for rotation in the drive housing;

a spur gear mounted on the first shaft for rotation therewith, wherein the spur gear engages the motor pinion;

a worm mounted on the first shaft for rotation therewith;

a second shaft mounted for rotation in the drive housing;

a worm gear mounted on the second shaft for rotation therewith, wherein the worm gear engages the worm;

a drive gear mounted on the second shaft for rotation therewith;

a shaft retainer associated with the second shaft between the worm gear and the drive gear, wherein the shaft retainer is substantially stationary with respect to the drive housing;

at least one thrust bearing axially fixed to the shaft at a location where it is engaged with the shaft retainer such that thrust loads on the second shaft are transmitted to the shaft retainer, the drive gear, thrust bearing, worm gear and second shaft being axially fixed with respect to the shaft retainer such that there is no separation between the drive gear, thrust bearing, shaft retainer and worm gear; and

an axis gear engaging the drive gear and mounted coaxially with the axis.

7. The drive system of claim 6 wherein the assembly is an external vehicle mirror housing.

8. The drive system of claim 6 wherein the shaft retainer is a plate.

9. The drive system of claim 8 wherein the drive housing comprises an upper enclosure and a bottom floor, and wherein the plate is retained by the upper enclosure and the bottom floor.

10. A drive system for rotating an assembly about an axis, comprising:

a drive housing including a shaft retainer;

an electric motor associated with the drive housing;

a shaft having a first end and a second end, the first and second ends being within the drive housing and supported by first and second bearings, wherein the shaft is operatively coupled to the electric motor and mounted for rotation within the drive housing;

at least one thrust transfer member axially fixed to the shaft between the first and second bearings and at a location where the thrust transfer member is engaged with the shaft retainer such that thrust loads on the shaft are transmitted to the shaft retainer and the first and second ends of the shaft remain spaced from the drive housing and wherein the thrust transfer member comprises a first thrust bearing and further comprising a second thrust bearing mounted on the shaft with the shaft retainer intermediate the first and second thrust bearings;

a drive gear mounted on the shaft for rotation therewith, the drive gear, thrust transfer member and shaft being axially fixed with respect to the shaft retainer such that there is no separation between the drive gear, thrust transfer member and shaft retainer; and

an axis gear engaging the drive gear and mounted coaxially with the axis.

11. The drive system of claim 10 wherein the drive housing comprises an upper enclosure and a lower floor, each having a recess formed therein, and the shaft retainer comprises a plate received in the recesses of the upper enclosure and lower floor.