Isolator that includes first and second isolation spring arrangement in series

Patent metadata

Field	Value
Publication number	US-10794448-B2
Application number	US-201615560098-A
Country	US
Kind code	B2
Filing date	Mar 21, 2016
Priority date	Mar 20, 2015
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

In an aspect, an isolator is provided for isolating a device driven by an engine via an endless drive member. The isolator includes a shaft adapter that is connectable with a shaft of the device and that defines an isolator axis, a rotary drive member that is engageable with the endless drive member, a first isolation spring arrangement that includes a first torsion spring, and that is positioned to transfer torque between the shaft adapter and an intermediate drive member, and a second isolation spring arrangement that is positioned to transfer torque between the intermediate member and the rotary drive member.

First claim

The invention claimed is:

1. An isolator for isolating a device driven by an engine via an endless drive member, comprising:
a shaft adapter that is connectable with a shaft of the device, the shaft adapter defining an isolator axis;
a rotary drive member that is engageable with the endless drive member;
a first isolation spring that is positioned to transfer torque between the shaft adapter and an intermediate drive member; and
a second isolation spring arrangement that is positioned to transfer torque between the intermediate member and the rotary drive member,
wherein the intermediate member and the shaft adapter each have a spring bypass surface, wherein the spring bypass surfaces are positioned to engage one another to provide a solid drive connection between the intermediate member and the shaft adapter during relative rotation during torque transfer from the shaft adapter to the intermediate member thereby bypassing the first isolation spring arrangement, such that, torque transfer from the rotary drive member to the shaft adapter is carried out through the first isolation spring arrangement, and torque transfer from the shaft adapter to the rotary drive member is carried out through the second isolation spring arrangement and the solid drive connection.

2. An isolator as claimed in claim 1 , wherein the first and second spring arrangements are positioned such that torque transfer from the rotary drive member to the shaft adapter is transmitted through the first and second isolation spring arrangements.

3. An isolator as claimed in claim 1 , wherein the first isolation spring arrangement includes a torsion spring.

4. An isolator as claimed in claim 1 , wherein the second isolation spring arrangement includes a second torsion spring having an outer diameter that is larger than an outer diameter of the first torsion spring.

5. An isolator as claimed in claim 4 , wherein the second torsion spring radially surrounds at least a portion of the first torsion spring.

6. An isolator as claimed in claim 4 , wherein the rotary drive member has an endless drive member engagement surface and wherein the second torsion spring is axially spaced from the endless drive member engagement surface.

7. An isolator as claimed in claim 4 , wherein the first torsion spring has a first spring rate and the second torsion spring has a second spring rate that is different than the first spring rate.

8. An isolator as claimed in claim 1 , wherein the first and second spring arrangements are positioned such that torque transfer from the rotary drive member to the shaft adapter is transmitted through the first and second isolation spring arrangements.

9. An isolator as claimed in claim 1 , wherein the second isolation spring arrangement includes at least one helical compression spring.

10. An isolator as claimed in claim 9 , wherein the at least one helical compression spring is arcuate about the isolator axis and has an outer diameter that is larger than an outer diameter of the first torsion spring.

11. An isolator as claimed in claim 9 , wherein the rotary drive member has an endless drive member engagement surface, and wherein the at least one helical compression spring is arcuate about the isolator axis and extends radially beyond the endless drive member engagement surface.

12. An isolator as claimed in claim 9 , wherein the at least one helical compression spring includes two first helical compression springs.

13. An isolator as claimed in claim 12 , wherein the at least one helical compression spring further includes two second helical compression springs nested within the two first helical compression springs.

14. An isolator as claimed in claim 12 , wherein the two second helical compression springs are shorter than the two first helical compression springs.

15. An isolator as claimed in claim 14 , wherein the two first helical compression springs together have a first helical compression spring rate and wherein the two second helical compression springs together have a second helical compression spring rate that is different than the first helical compression spring rate.

16. An isolator for isolating a device driven by an engine via an endless drive member, comprising:
a shaft adapter that is connectable with a shaft of the device, the shaft adapter defining an isolator axis;
a rotary drive member that is engageable with the endless drive member;
a first isolation spring that is positioned to transfer torque between the shaft adapter and an intermediate drive member; and
a second isolation spring arrangement that is positioned to transfer torque between the intermediate member and the rotary drive member,
wherein over a first range of relative angular movement between the rotary drive member and the shaft adapter the first and second isolation spring arrangements provide a first finite overall spring rate for the isolator, over a second range of relative angular movement between the rotary drive member and the shaft adapter the first and second isolation spring arrangements provide a second finite overall spring rate for the isolator that is higher than the first overall spring rate, and wherein over a third range of relative angular movement between the rotary drive member and the shaft adapter the first and second isolation spring arrangements provide a third finite overall spring rate for the isolator that is higher than the second overall spring rate.

17. An isolator as claimed in claim 16 , wherein the first, second and third ranges of relative angular movement between the rotary drive member and the shaft adapter are made up respectively of first, second and third ranges of movement of the rotary drive member in a first rotational direction relative to the shaft adapter.

18. An isolator as claimed in claim 17 , wherein over a first range of movement of the shaft adapter in the first rotational direction relative to the rotary drive member the first and second isolation spring arrangements provide a fourth overall spring rate for the isolator, and wherein over a second range of movement of the shaft adapter in the first rotational direction relative to the rotary drive member the first and second isolation spring arrangements provide a finite fifth overall spring rate for the isolator that is higher than the fourth overall spring rate.

Assignees

• Litens Automotive Inc

Inventors

• Replete Boris

Classifications

• B60K25/02 Primary

  directly from an engine shaft · CPC title

• F16F15/12366

  acting on multiple sets of springs · CPC title

• F16F15/121

  using springs as elastic members, e.g. metallic springs {(F16F15/133 takes precedence)} · CPC title

• F16H2055/366

  with means providing resilience or vibration damping · CPC title

• F16H55/36

  Pulleys (with features essential for adjustment F16H55/52) · CPC title