Variable force tensioner arm with cap disk spring

Patent metadata

Field	Value
Publication number	US-11486473-B2
Application number	US-201816959291-A
Country	US
Kind code	B2
Filing date	Jan 31, 2018
Priority date	Jan 31, 2018
Publication date	Nov 1, 2022
Grant date	Nov 1, 2022

Abstract

A stack of disk springs are placed between a second piston of a dual hydraulic variable force tensioner system and a hydraulic tensioner arm to allow much higher spring rates if desired. The springs may be stacked in multiple configurations to provide different spring rates. Package space can be reduced depending on the number of springs and orientations of said springs within the tensioner arm.

First claim

What is claimed is:

1. A tensioner arm comprising:
a body having a first surface for contacting a chain or belt and a second surface opposite the first surface, the second surface defining a cavity;
a cap received within the body, the cap having a first end and a second end, the first end being opposite the second end, wherein the first end of the cap is present within the cavity of the body of the tensioner arm; and
at least two spring sets, each spring set being oriented within the cavity between the first end of the cap and the body of the tensioner arm, wherein a first spring set of the at least two spring sets is oriented in a first direction between the first end of the cap and the cavity and a second spring set of the at least two spring sets is oriented in a second direction, opposite the first direction and the at least two spring sets bias the cap away from the body of the tensioner arm.

2. The tensioner arm of claim 1 , further comprising a flange extending from the body within the cavity and received by the at least two spring sets.

3. The tensioner arm of claim 1 , wherein each spring set of the at least two spring sets comprises two springs and the springs of each spring set are coned disc springs having an outer circumference with an edge surrounding a center.

4. The tensioner arm of claim 3 , wherein the springs of each spring set are oriented in the same direction within the corresponding spring set.

5. The tensioner arm of claim 3 , wherein the first spring set is oriented within the cavity in a first orientation such that the edge of the outer circumference of the springs of the first spring set lay adjacent to the cap and the second spring set is oriented within the cavity such that the center of the springs of the second spring set contacts the center of the springs of the first spring set in the first orientation.

6. The tensioner arm of claim 1 , wherein the at least two spring sets combine to have a spring constant of between 150 N/mm to 400 N/mm.

7. The tensioner arm of claim 1 , wherein the cap has a cap body in which the cap body and a first surface of the cap body of the cap is received within the cavity of the tensioner arm.

8. A tensioner arm comprising:
a body having a first surface for contacting a chain or belt and a second surface opposite the first surface, the second surface defining a cavity;
a cap received within the body, the cap having a first end and a second end, the first end being opposite the second end, wherein the first end of the cap is present within the cavity of the body of tensioner arm; and
a plurality of spring sets stacked within the cavity between the first end of the cap and the body of the tensioner arm for biasing the cap away from the body of the tensioner arm, each spring set comprising a first spring and a second spring, wherein the first spring of each spring set is oriented in a first orientation and a second spring of each spring set is oriented in a second orientation, opposite the first orientation.

9. The tensioner arm of claim 8 , further comprising a flange extending from the body within the cavity and received by the plurality of spring sets.

10. The tensioner arm of claim 8 , wherein each spring of each spring set of the plurality of spring sets is a coned disc spring having an outer circumference with an edge surrounding a center.

11. The tensioner arm of claim 10 , wherein in the cavity, the edge of the outer circumference of the first spring of a spring set contacts the cap and the edge of the outer circumference of the second spring of another spring set contacts the body of the tensioner arm.

12. The tensioner arm of claim 8 , wherein in the cavity and between the cap and the body of the tensioner arm are three spring sets.

13. The tensioner arm of claim 8 wherein in the cavity and between the cap and the body of the tensioner arm are four spring sets.

14. The tensioner arm of claim 8 , wherein the plurality of spring sets combine to have a spring constant of between 150 N/mm to 400 N/mm.

15. The tensioner arm of claim 8 , wherein the cap has a cap body in which the cap body and a first surface of the cap body of the cap is received within the cavity of the tensioner arm.

16. A tensioning system for tensioning a belt or a chain comprising:
a tensioner arm comprising:
a body having a first surface for contacting the chain or the belt and a second surface opposite the first surface, the second surface defining a cavity;
a cap received within the cavity of the body, the cap having a first end and a second end, the first end being opposite the second end, wherein the first end of the cap is present within the cavity of the body of the tensioner arm; and
at least two spring sets, each spring set being oriented within the cavity between the first end of the cap and the body of the tensioner arm, wherein at least one of the at least two spring sets is oriented in a first direction between the first end of the cap and the cavity and a second spring set of the at least two spring sets is oriented in a second direction, opposite the first direction and the at least two spring sets bias the cap away from the body of the tensioner arm,

a tensioner comprising:
a housing having a first axially extending bore with a first fluid input and a second axially extending bore with a second fluid input;
a first piston slidably received by the first axially extending bore, forming a first pressure chamber, which is in fluid communication with the first fluid input, between the first piston and the first axially extending bore, the first piston comprising a first piston body having a first end and a second end;
a first piston spring received within the first pressure chamber between the first piston and the first axially extending bore for biasing the first piston away from the housing;
a second piston slidably received within the second axially extending bore, the second piston comprising a second piston body having:
an open end;
a closed end;
a bottom surface at the open end;
a top surface at the closed end;
an outer circumference; and
a hollow interior having an inner diameter;

the second axially extending bore forming a second pressure chamber, that is defined between the inner diameter of the second piston body and the second axially extending bore, in fluid communication with the second fluid input through a check valve;
a second piston spring in the second pressure chamber, the second piston spring having a first end in contact with the second piston and a second end in contact with a bottom of the second axially extending bore, biasing the second piston away from the housing;
wherein the closed end of the second piston contacts the cap in the tensioner arm.

17. The tensioning system of claim 16 , wherein the first piston body has an outer circumference comprising a series of grooves.

18. The tensioning system of claim 17 , further comprising an expandable clip engaging the series of grooves on the outer circumference of the first piston body.

19. The tensioner system of claim 16 , wherein the cap has a cap body in which the cap body and a first surface of the cap body of the cap is received within the cavity of the tensioner arm.

Assignees

• Borgwarner Inc

Inventors

• Cobb Keith B
• Simmons Sean
• Todd Kevin

Classifications

• F16H7/08 Primary

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

• F16H2007/0806

  Compression coil springs · CPC title

• F16H2007/0872

  Sliding members · CPC title

• F16H2007/0893

  Circular path · CPC title

• F16H2007/185

  the guiding surface in contact with the belt, rope or chain having particular shapes, structures or materials · CPC title