Tensioner with first and second damping members and increased damping

Patent metadata

Field	Value
Publication number	US-10859141-B2
Application number	US-201615770911-A
Country	US
Kind code	B2
Filing date	Oct 27, 2016
Priority date	Oct 28, 2015
Publication date	Dec 8, 2020
Grant date	Dec 8, 2020

Abstract

In an aspect, a tensioner includes a shaft and base unit that is mountable to an engine, an arm pivotable about the shaft and base unit, a pulley on the arm engageable with a belt, a spring urging the arm in a free arm direction, a first damping member fixed on the shaft and base unit, which receives a first radial force from a first segment of the spring causing a first amount of frictional force between the first damping member and a surface that moves with the tensioner arm, and a second damping member on the arm, which receives a second radial force from a second segment of the tensioner spring that is spaced axially from the first segment of the spring, causing a second amount of frictional force between the second damping member and a surface that is stationary with the shaft and base unit.

First claim

The invention claimed is:

1. A tensioner for an endless drive member on an engine, comprising:
a shaft and base unit that is mountable to be stationary relative to the engine;
a tensioner arm that is pivotable relative to the shaft and base unit about a tensioner arm axis;
an endless drive member engagement member on the tensioner arm and engageable with the endless drive member;
a tensioner spring that urges the tensioner arm in a free arm direction;
a first damping member that is fixed relative to the shaft and base unit, and which receives a first radial force from a first segment of the tensioner spring that causes a first amount of frictional force between the first damping member and a surface that moves with the tensioner arm; and
a second damping member that is fixed relative to the tensioner arm, and which receives a second radial force from a second segment of the tensioner spring that is spaced axially from the first segment of the tensioner spring, that causes a second amount of frictional force between the second damping member and a surface that is stationary with the shaft and base unit,
wherein the surface that moves with the tensioner arm is on the tensioner arm, and
wherein the surface that is stationary with the shaft and base unit is on the first damping member,
wherein the first damping member receives a third radial force from the second segment of the tensioner spring that causes a third amount of frictional force between the first damping member and the surface that moves with the tensioner arm, such that a total frictional force between the first damping member and the surface that moves with the tensioner arm is contributed to by the first and third radial forces.

2. A tensioner as claimed in claim 1 , wherein the first damping member directly radially engages a radially outer face of the tensioner arm, the second damping member directly radially engages a radially outer face of the first damping member, and the tensioner spring directly radially engages both the first and second damping members.

3. A tensioner as claimed in claim 1 , wherein the tensioner spring is a helical torsion spring.

4. A tensioner as claimed in claim 1 , wherein the first segment of the tensioner spring has a first spring end that is fixed relative to the shaft and base unit and the second segment of the tensioner spring has a second spring end that is fixed relative to the tensioner arm.

5. A tensioner as claimed in claim 1 , wherein the endless drive member engagement member is a pulley that is rotatable about a pulley axis that is offset from the tensioner arm axis.

6. A tensioner for an endless drive member on an engine, comprising:
a shaft and base unit that is mountable to be stationary relative to the engine;
a tensioner arm that is pivotable relative to the shaft and base unit about a tensioner arm axis;
an endless drive member engagement member on the tensioner arm and engageable with the endless drive member;
a tensioner spring that urges the tensioner arm in a free arm direction;
a first damping member that is fixed relative to the shaft and base unit, and which receives a first radial force from a first segment of the tensioner spring that causes a first amount of frictional force between the first damping member and a surface that moves with the tensioner arm; and
a second damping member that is fixed relative to the tensioner arm, and which receives a second radial force from a second segment of the tensioner spring that is spaced axially from the first segment of the tensioner spring, that causes a second amount of frictional force between the second damping member and a surface that is stationary with the shaft and base unit,
the surface that moves with the tensioner arm is on the second damping member, and
wherein the surface that is stationary with the shaft and base unit is on the shaft and base unit,
wherein the second damping member receives a third radial force from the first segment of the tensioner spring that causes a third amount of frictional force between the second damping member and the surface that is stationary with the shaft and base unit, such that a total frictional force between the second damping member and the surface that is stationary with the shaft and base unit is contributed to by the second and third radial forces.

7. A tensioner as claimed in claim 6 , wherein the second damping member directly radially engages a radially outer face of the shaft and base unit, the first damping member directly radially engages a radially outer face of the second damping member, and the tensioner spring directly radially engages both the first and second damping members.

8. A device that is engageable with an endless drive member on an engine, comprising:
a first main device member that is mountable to a first point relative to the engine;
a second main device member that is pivotable relative to the first main device member about an axis;
an endless drive member engagement member on the second main device member and engageable with the endless drive member;
a spring that is positioned to apply a spring force between the first and second main device members;
a first damping member that is fixed relative to the first main device member, and which receives a first radial force from a first segment of the spring that causes a first amount of frictional force between the first damping member and a surface that moves with the second main device member; and
a second damping member that is fixed relative to the second main device member, and which receives a second radial force from a second segment of the spring that is spaced axially from the first segment of the spring, that causes a second amount of frictional force between the second damping member and a surface that moves with the first main device member,
wherein the surface that moves with the second main device member is on the second main device member, and
wherein the surface that moves with the first main device member is on the first damping member,
wherein the first damping member receives a third radial force from the second segment of the spring that causes a third amount of frictional force between the first damping member and the second main device member, such that a total frictional force between the first damping member and the second main device member is contributed to by the first and third radial forces.

9. A device as claimed in claim 8 , wherein the first main device member is a shaft and base unit that is mountable to be stationary relative to the engine, and wherein the second main device member includes a tensioner arm that is pivotable relative to the shaft and base unit about the axis, and wherein the endless drive member engagement member is a pulley that is rotatable about a pulley axis that is offset from the axis.

10. A device as claimed in claim 8 , wherein the first damping member directly radially engages a radially outer face of the second main device member, the second damping member directly radially engages a radially outer face of the first damping member, and the spring directly radially engages both the first and second damping members.

11. A device as claimed in claim 8 , wherein the spring is a helical torsion spring.

12. A device as claimed in claim 8 , wherein the first segment of the spring has a first spring end that is fixed relative to the first main device member and the second segment of the spring has a second spring end that is fixed relative to the second main device member.

13. A device that is engageable with an endless drive member on an engine, comprising:
a first main device member that is mountable

Assignees

• Litens Automotive Inc

Inventors

• Frankowski Marek

Classifications

• F16H7/1218 Primary

  of the dry friction type · CPC title

• F16H2007/0865

  Pulleys · CPC title

• F16H2007/081

  Torsion springs · CPC title

• F16H2007/0893

  Circular path · CPC title

• F16H2007/084

  having vibration damping characteristics dependent on the moving direction of the tensioner · CPC title