Tensioner

Patent metadata

Field	Value
Publication number	US-10634223-B2
Application number	US-201715683971-A
Country	US
Kind code	B2
Filing date	Aug 23, 2017
Priority date	Sep 7, 2016
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

An object of the present invention is to provide a simple-structured tensioner capable of consistently exhibiting the check valve function irrespective of the form of oil supply passages. The tensioner includes a plunger, a housing, a biasing unit, an oil supply passage, and a check valve. The check valve includes a plurality of valve members and a ball seat member. The ball seat member includes a plurality of oil passages and a plurality of seat parts. The check valve further includes a passage forming member having an oil inlet disposed between the plurality of oil passages and the oil supply passage.

First claim

What is claimed is:

1. A tensioner comprising:
a plunger having a plunger hole that is open on a rear side;
a housing having a plunger bore that is open on a front side and accommodates the plunger;
a biasing unit that is accommodated inside an oil pressure chamber formed between the plunger bore and a rear end of the plunger such as to be able to freely expand and contract and that biases the plunger toward the front side;
an oil supply passage for supplying oil from outside the housing into the oil pressure chamber; and
a check valve that allows oil to flow from the oil supply passage into the oil pressure chamber and prevents the oil from flowing out from the oil pressure chamber to the oil supply passage,
the check valve including a plurality of valve members and a ball seat member,
the ball seat member including a plurality of oil passages each having an inlet open toward the oil supply passage and an outlet open toward the oil pressure chamber, and a plurality of seat parts allowing the respective valve members to sit thereon at the respective outlets of the oil passages,
the oil passages and the seat parts being provided in the same number as the number of the valve members, and
the check valve further including a passage forming member having an oil inlet disposed between the plurality of oil passages and the oil supply passage,
wherein the passage forming member is detachable from the ball seat member,
wherein the passage forming member has a distribution space for distributing oil flowing in from the oil inlet to the plurality of oil passages, the distribution space being formed adjacent to the oil inlet on the oil pressure chamber side, and
wherein the oil inlet has an inner diameter smaller than an inner diameter of the distribution space.

2. The tensioner according to claim 1 , wherein a connecting part for connecting the plurality of valve members is provided between the plurality of valve members.

3. The tensioner according to claim 1 , wherein the ball seat member is fixed to the housing or to the plunger, and
an installation recess in which the passage forming member is installed is formed in a side face of the ball seat member that faces the oil supply passage.

4. The tensioner according to claim 1 , wherein the passage forming member is formed to accommodate the ball seat member such as to be movable in a front to back direction,
the check valve includes a seat biasing unit that biases the ball seat member toward the oil pressure chamber, and a relief passage,
the relief passage is formed such as to connect the oil pressure chamber and the oil supply passage when the ball seat member moves toward the oil supply passage, and to be closed when the ball seat member moves toward the oil pressure chamber.

5. The tensioner according to claim 1 , wherein the check valve further includes a retainer that restricts movement of the valve members,
the ball seat member is fixed to the housing or to the plunger, and
a retainer installation recess in which the retainer is installed is formed in a side face of the ball seat member that faces the oil pressure chamber.

6. The tensioner according to claim 1 , wherein a housing hole for connecting outside of the housing with the plunger bore is formed in a bottom part on a rear side of the housing, and
the oil supply passage is comprises the housing hole.

7. The tensioner according to claim 1 , wherein the check valve is installed inside the plunger hole and divides an internal space formed between the housing and the plunger into the oil pressure chamber and an oil reservoir chamber,
a connection/adjustment groove is formed at least in one of an outer circumferential surface of the plunger and an inner circumferential surface of the plunger bore,
a housing oil supply hole for supplying oil to the connection/adjustment groove is formed in the housing,
a plunger oil supply hole for supplying oil from the connection/adjustment groove into the oil reservoir chamber is formed in the plunger, and
the oil supply passage is configured by the oil reservoir chamber, the connection/adjustment groove, the housing oil supply hole, and the plunger oil supply hole.

Assignees

• Tsubakimoto Chain Co

Inventors

• Watanabe Masanori

Classifications

• F16H7/08 Primary

  Means for varying tension of belts, ropes or chains  (pulleys of adjustable construction F16H55/52) · CPC title

• F16H2007/0812

  Fluid pressure · CPC title

• F16K15/044

  spring-loaded · CPC title

• F16H9/26

  with members having orbital motion · CPC title

• F16H2007/0859

  Check valves · CPC title