TENSIONER

• US 20190323580A1
• Filed: 02/27/2019
• Published: 10/24/2019
• Est. Priority Date: 04/18/2018
• Status: Active Grant

• Current Assignee: Tsubakimoto Chain Company
• Original Assignee: Tsubakimoto Chain Company
• Inventors: Watanabe, Masanori, Takagi, Yudai, Kurematsu, Yuji
• Granted Patent: US 11,125,304 B2
• Time in Patent Office: Days
• CPC Class Codes: F16H 2007/0802 Actuators for final output members
• CPC Class Codes: F16H 2007/0806 Compression coil springs
• CPC Class Codes: F16H 2007/0812 Fluid pressure
• CPC Class Codes: F16H 2007/0814 with valves opening on surplus pressure
• CPC Class Codes: F16H 2007/0859 Check valves
• CPC Class Codes: F16H 2007/0872 Sliding members
• CPC Class Codes: F16H 2007/0893 Circular path
• CPC Class Codes: F16H 2007/0895 Internal to external direction
• CPC Class Codes: F16H 2007/0897 External to internal direction
• CPC Class Codes: F16H 7/08 Means for varying tension of belts, ropes, or chains pulleys of adjustable construction F16H55/52 ; gearings with endless belts F16H7/02; tensioning for chains or belts specially adapted for cycles B62M9/16; belt or chain tensioning arrangements for endless conveyors B65G23/44
• CPC Class Codes: F16H 7/0836 of the fluid and restriction type, e.g. dashpot
• CPC Class Codes: F16H 7/0848 with means for impeding reverse motion

Abstract

An orifice member is disposed in a plunger including a plunger hole that forms a hydraulic chamber in conjunction with a plunger housing hole in a housing. The orifice member includes a deformed fitting section deformed to fit on the inner circumferential surface of the plunger hole, a communication section that causes a surface in contact with the top surface on the front side of the plunger hole and a surface on the hydraulic chamber side to communicate, and an orifice groove that communicates with the communication section and an external relief hole provided in the plunger on the surface in contact with the top surface on the front side of the plunger hole to constitute an orifice.

Claims

1. A tensioner comprising:

a plunger including a plunger hole opening on a rear side;

a housing including a plunger housing hole opening on a front side that slidably houses the plunger;

main urging means for urging the plunger toward the front side; and

an orifice member that causes an inside of a hydraulic chamber formed between the plunger housing hole and the plunger hole and an external space to communicate, wherein

the plunger includes an external relief hole opening on a top surface on the front side of the plunger hole and communicating with the external space,

the orifice member includes a deformed fitting section deformed to fit on an inner circumferential surface of the plunger hole, an orifice groove provided on a surface in contact with the top surface, and a communication section that causes the surface in contact with the top surface and a surface on the hydraulic chamber side to communicate, and

the orifice groove is formed to communicate with the communication section and the external relief hole and thus to constitute an orifice.

2. The tensioner according to claim 1, wherein the orifice member is formed of a resin material.

3. The tensioner according to claim 1, wherein the communication section is a cutout groove section provided on an outer circumferential surface of the orifice member.

4. The tensioner according to claim 1, wherein

the main urging means is a coil spring, and

the orifice member also functions as a spring receiving section for the coil spring.

5. The tensioner according to claim 4, wherein the orifice member includes an extending section extending to an inner circumferential side of the coil spring.