Self-tolerance compensating S-cam brake system and vehicle having the same

Patent metadata

Field	Value
Publication number	US-10487895-B2
Application number	US-201715836770-A
Country	US
Kind code	B2
Filing date	Dec 8, 2017
Priority date	Sep 26, 2017
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

An S-cam brake system having is disclosed. The system includes a roller assembly, an S-cam, a shoe, and an S-cam brake. The roller assembly is configured to allow relative movement between a roller and a roller pin. The roller assembly is interposed between the S-cam and the shoe. Relative movement between a roller and a roller pin can compensates a defect in machining the outer contact surface of the S-cam roller or a defect in concentricity of roller seating depressions of the shoe.

First claim

What is claimed is:

1. An S-cam brake system comprising
a roller pin, and a roller having a pin hole into which the roller pin is inserted,
wherein the pin hole has an inner circumferential surface with a predetermined curvature as a pin contact surface, and due to the curvature, a contact section and a non-contact section are formed between the inner circumferential surface of the pin hole and an outer circumferential surface of the roller pin so that relative movement of the roller and relative movement of the roller pin are generated between the roller and the roller pin.

2. The S-cam brake system of claim 1 , wherein the curvature is formed with a convex protrusion of the pin contact surface as a peak.

3. The S-cam brake system of claim 1 , wherein the protrusion is disposed at a position corresponding to ½ of an overall length of the roller.

4. The S-cam brake system of claim 1 , wherein the relative movement of the roller makes rotation of the roller relative to the roller pin.

5. The S-cam brake system of claim 4 , wherein the rotation of the roller converts a defective partial contact state of the roller due to a machining tolerance error into a contact state of the roller.

6. The S-cam brake system of claim 1 , wherein the relative movement of the roller pin makes rotation of the roller pin relative to the roller.

7. The S-cam brake system of claim 6 , wherein the rotation of the roller pin converts a defective concentric close contact state of the roller pin due to a machining tolerance error into a close contact state of the roller pin.

8. The S-cam brake system of claim 1 , wherein the roller and the roller pin that are coupled to each other are assembled with a retainer, and the retainer that is fixed to the roller pin locks a side surface of the roller in place.

9. The S-cam brake system of claim 8 , wherein the roller pin comprises:
a pin body inserted into the pin hole; left and right pin ends extending from respective left and right sides of the pin body to protrude out of the roller; and an annular groove formed around a circumferential surface of each of the left and right pin ends, wherein the retainer comprises left and right retainers respectively fitted into the annular groove of the left pin end and the annular groove of the right pin end.

10. The S-cam brake system of claim 8 , wherein the roller, the roller pin and the retainer form a roller assembly, and an S-cam brake includes the roller assembly.

11. A vehicle comprising:
the S-cam brake system of claim 1 , wherein the S-cam brake system further comprises:
a brake chamber into which compressed air is supplied,
a slack adjuster configured to be pushed by the brake chamber, and
an S-cam configured to be rotated by the slack adjuster and push the roller.

12. The vehicle of claim 11 ,
wherein the S-cam brake system comprises a pair of first and second roller assemblies, each of which comprises the roller and the roller pin, and
wherein the S-cam brake system comprises a pair of left and right shoes, and
wherein the first roller assembly is disposed on the left shoe on a left side of the S-cam and configured to push the left shoe, and the second roller assembly is disposed on the right shoe on a right side of the S-cam and configured to push the right shoe.

13. The vehicle of claim 12 , wherein the roller is configured such that rotation of the roller relative to the roller pin and rotation of the roller pin are generated.

14. The vehicle of claim 13 , wherein, while the roller of each of the first and second roller assemblies makes contact with a corresponding one of left and right cam head outer surfaces of the S-cam, the rotation of the roller converts a defective partial contact state of the roller relative to the corresponding one of the left and right cam head outer surfaces into a contact state of the roller, and, while the roller pin of each of the first and second roller assemblies makes contact with a corresponding of the left and right shoes, the movement of the roller pin converts a defective concentric close contact state of the roller pin relative to the corresponding one of the left and right shoes into a close contact state of the roller pin.

15. The vehicle of claim 11 , wherein the compressed air is generated by a pneumatic apparatus when a brake pedal is operated.

16. The vehicle of claim 11 , wherein the operation of pushing the slack adjuster is embodied by coupling of a chamber push rod of the brake chamber to the slack adjuster, and the rotation of the S-cam is performed when a cam shaft extending from a central portion of an “S”-shaped cam head of the S-cam is rotated by the slack adjuster.

17. The vehicle of claim 11 , wherein the S-cam brake system is installed on a left wheel, and another S-cam brake system is installed on a right wheel.

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Park Hyung-Bin

Classifications

• F16D2125/30

  acting on two or more cam followers, e.g. S-cams · CPC title

• F16D65/22

  adapted for pressing members apart {, e.g. for drum brakes} · CPC title

• F16D51/14

  fluid actuated · CPC title

• F16D65/38 Primary

  Slack adjusters · CPC title

• F16D65/68

  with eccentric or helical body · CPC title