NYLON RESIN DRIVEN PULLEY

• US 20140090921A1
• Filed: 09/27/2013
• Published: 04/03/2014
• Est. Priority Date: 09/28/2012
• Status: Active Grant

• Current Assignee: Steering Solutions IP Holding Corporation (Nexteer Automotive Group Ltd.)
• Original Assignee: Steering Solutions IP Holding Corporation (Nexteer Automotive Group Ltd.)
• Inventors: Shavrnoch, James J., Strieter, Troy P., Dodak, Tony M., Otto, Jeffrey M., Vorwerck, Conrad G.
• Granted Patent: US 9,637,164 B2
• Time in Patent Office: Days
• US Class Current: 180/444
• CPC Class Codes: B62D 5/0424 the axes of motor and final driven element of steering gear, e.g. rack, being parallel
• CPC Class Codes: B62D 5/0448 Ball nuts
• CPC Class Codes: F16H 2025/2081 Parallel arrangement of drive motor to screw axis
• CPC Class Codes: F16H 2025/2096 using endless flexible members
• CPC Class Codes: F16H 25/2204 with balls
• CPC Class Codes: F16H 25/2214 with elements for guiding the circulating balls
• CPC Class Codes: F16H 55/06 Use of materials; Use of treatments of toothed members or worms to affect their intrinsic material properties coatings for lubrication F16H57/041; producing gear wheels from plastics or substances in a plastic state B29D15/00; heat treatment C21D9/32; electrolytic surface treatment C25D; heating by electromagnetic field H05B6/00
• CPC Class Codes: F16H 55/171 Toothed belt pulleys
• CPC Class Codes: F16H 55/48 manufactured exclusively or in part of non-metallic material, e.g. plastics F16H55/38, F16H55/42, F16H55/46 take precedence ; manufacture of wooden wheels B27H7/00

Abstract

A torque transmitting assembly is provided. The assembly includes a ball nut having an outer diameter and keyway slot therein, and a pulley positioned on the ball nut. The pulley includes a cylindrical outer surface, a bore extending through the pulley such that the pulley includes an inner surface, and at least one torque member formed on the inner surface and projecting radially inward to be received by the keyway slot.

Claims

1. A torque transmitting assembly comprising:

a ball nut having an outer diameter and keyway slot therein; and

a pulley positioned on the ball nut, the pulley having a cylindrical outer surface, a bore extending through the pulley such that the pulley includes an inner surface, and at least one torque member formed on the inner surface and projecting radially inward to be received by the keyway slot.

2. The torque transmitting assembly of claim 1, wherein the pulley is made from glass filled nylon.

3. The torque transmitting assembly of claim 1, wherein the bore comprises a first section having a first radius and a second section having a second radius, the first radius being greater than the second radius.

4. The torque transmitting assembly of claim 3, wherein the pulley is pressed onto the ball nut.

5. The torque transmitting assembly of claim 4, wherein the pulley inner surface is configured to deform in the region of the second section when pressed onto the ball nut to present a substantially flat portion along the outer surface.

6. The torque transmitting assembly of claim 1, further comprising a plurality of teeth circumferentially spaced along the pulley outer surface.

7. A steering system comprising:

a motor;

a shaft rotatably coupled to the motor;

a first pulley coupled to the shaft;

a ball screw; and

a ball nut assembly operatively associated with the ball screw and the first pulley to transmit torque therebetween, the ball nut assembly comprising a ball nut and a second pulley coupled to the ball nut, wherein the second pulley comprises an inner surface defining a bore, a cut-out formed in the inner surface, and at least one torque member extending from the inner surface into the bore.

8. The system of claim 7, wherein the second pulley is fabricated from a polymer.

9. The system of claim 8, wherein the second pulley is fabricated from nylon resin.

10. The system of claim 7, wherein the ball nut includes a keyway slot, the keyway slot receiving the at least one torque member.

11. The system of claim 7, wherein the ball nut includes a ball guide and a groove at least partially receiving the ball guide, and wherein the cut-out provides clearance to the ball guide when the second pulley is coupled to the ball nut.

12. The system of claim 7, further comprising a retainer, wherein the ball nut further includes a groove on an end thereof and the retainer is inserted into the groove, the retainer configured to bias the pulley in the axial direction of the ball screw.

13. The system of claim 7, further comprising a bearing rotatably receiving the ball nut, and a retaining nut abutted against the bearing.

14. The system of claim 7, further comprising a flange coupled to the second pulley.

15. A method of fabricating a ball nut assembly, the method comprising:

providing a ball nut having a keyway slot; and

forming a pulley having an inner surface defining a bore, a cut-out formed in the inner surface, and a torque member extending radially inward from the inner surface, wherein the keyway slot is configured to receive the torque member therein.

16. The method of claim 15, wherein forming the pulley further comprises fabricating the pulley from nylon resin.

17. The method of claim 15, further comprising forming a groove on an end of the ball nut and inserting a retainer into the groove.

18. The method of claim 15, further comprising inserting the pulley onto the ball nut such that torque member is at least partially within the keyway slot.

19. The method of claim 18, further comprising deforming a portion of the pulley proximate the cut-out to define a generally flat portion of the pulley.

20. The method of claim 15, further comprising forming a flange and coupling the flange to the pulley.