Tensioner for belts and chains

• US 5,967,923 A
• Filed: 02/14/1997
• Issued: 10/19/1999
• Est. Priority Date: 03/11/1996
• Status: Expired due to Term

• Current Assignee: Schaeffler Technologies AG & Co.KG (INA-Holding Schaeffler GmbH & Co. KG)
• Original Assignee: INA Walzlager Schaeffler KG
• Inventors: Petri, Werner
• Primary Examiner(s): Walsh, Donald P.
• Assistant Examiner(s): MARCELO, EMMANUEL MONSAYAC
• Application Number:
  US08/801,900
• Time in Patent Office: 977 Days
• Field of Search: 474/138, 474/101, 474/110, 474/117, 474/135, 474/136
• US Class Current: 474/138
• CPC Class Codes: F16F 1/128 with motion-limiting means, e.g. with a full-length guide element or ball joint connections; with protective outer cover F16F1/121 takes precedence
• CPC Class Codes: F16F 9/3242 of cylinder ends, e.g. caps
• CPC Class Codes: F16F 9/363 the guide being mounted between the piston and the sealing, enabling lubrication of the guide
• CPC Class Codes: F16F 9/49 Stops limiting fluid passage, e.g. hydraulic stops or elastomeric elements inside the cylinder which contribute to changes in fluid damping fluid-actuated displacement devices with means for accelerating or decelerating the stroke F15B15/22
• CPC Class Codes: F16H 2007/0812 Fluid pressure
• CPC Class Codes: F16H 2007/0859 Check valves
• CPC Class Codes: F16H 2007/0891 Linear path
• CPC Class Codes: F16H 7/0848 with means for impeding reverse motion

Abstract

A tensioner for belts and chains having a housing (1) in which a cylinder (3) containing a slidably guided piston (4) is arranged which piston (4) is supported radially by a guide bush (5), one end of a compression spring (13) engaging the piston (4), while the other end thereof engaging a cylinder base (6) of the cylinder (3), which cylinder base (6) is axially supported on a housing bottom (9) by a self-adjusting bearing (10) whereby, to improve the correction of alignment errors between the cylinder (3) and the piston (4), a plurality of peripherally adjacent raised portions (10) made of a ductile material are arranged between the housing bottom (9) and the cylinder base (6) and are plastically deformable under loading by the spring-loaded cylinder base (6).

Claims

1. A tensioner for traction means comprising a housing (1) on which a hydraulically damped piston (4) which is slidably guided in a cylinder (3) is radially supported by a guide bush (5), the traction means being tensioned by a compression spring (13) whose one end engages the piston (4) and whose other end engages a cylinder base (6) of the cylinder (3), which cylinder base (6) is supported on a housing bottom (9) by a self-adjusting bearing (10) characterized in that a plurality of peripherally adjacent raised portions (10) made of a ductile material are,provided between the housing bottom (9) and the cylinder base (6), and said raised portions (10) are plastically deformable under loading by the spring-loaded cylinder base (6).

2. A tensioner of claim 1 wherein the cylinder base (6) is supported radially in the housing (1) by a radial support (7).

3. A tensioner of claim 2 wherein the radial support is formed by a plurality of circumferentially spaced radial projections (7) on the housing (1).

4. A tensioner of claim 1 wherein the housing (1) and the raised portions (10) formed integrally thereon are made of an aluminum alloy, and the cylinder base (6) is made of steel.

5. A tensioner of claim 1 wherein the raised portions (10) are formed out of strips whose long ends facing the cylinder base (6) comprise two intersecting surfaces (25) which form a contact edge (24) for the cylinder base (6).

6. A tensioner of claim 5 wherein imaginary extensions of the contact edges (24) intersect at an axis of the cylinder (3).

7. A tensioner of claim 1 wherein the cylinder base (6), the cylinder (3) and the piston (4) define a pressure chamber (12), the cylinder base (6) comprises a non-return valve (11) opening towards the pressure chamber (12), and the cylinder base (6) further comprises a reception bore (8) for the cylinder (3) which bears closely against a wall of the reception bore (8).

8. A tensioner of claim 1 wherein a spring retainer (14) arranged on the piston (4) is fixed in an axial direction by a corrugated ring (19) which engages into a circumferential groove (20) made on the piston (4), the circumferential groove (20) tapers in radially inward direction while being defined by at least one bevel (21) and a cylindrical base surface (22) of the piston (4).