Isolator with double acting spring system with reduced noise

Patent metadata

Field	Value
Publication number	US-10690228-B2
Application number	US-201715792388-A
Country	US
Kind code	B2
Filing date	Oct 24, 2017
Priority date	May 23, 2013
Publication date	Jun 23, 2020
Grant date	Jun 23, 2020

Abstract

An isolator is provided for use with an engine and in particular an engine that is assisted or started by MGU (Motor-Generator Unit) or a motor through an endless drive member. It comprises a double acting spring system for isolating crankshaft pulley from torsion vibration at the crankshaft, and in extreme conditions, such as during engine startup and accelerations or decelerations of the engine crankshaft relative to the pulley and when isolator operates in an “engine-driven” mode with the engine crankshaft is driven by the belt.

First claim

The invention claimed is:

1. An isolator, comprising:
a spring having a first spring end and a second spring end;
a shaft adapter that is mountable to a crankshaft for rotation about an axis, wherein the shaft adapter has a first adapter drive surface that is engageable with the first spring end and a second adapter drive surface that is angularly spaced from the first adapter drive surface by an adapter drive surface spacing and that is engageable with the second spring end; and
a pulley that is engageable with an endless drive member and that is rotatable relative to the shaft adapter, wherein the pulley has a first pulley drive surface that is engageable with the first spring end and a second pulley drive surface that is angularly spaced from the first pulley drive surface by a pulley drive surface spacing and that is engageable with the second spring end, a friction member that is fixedly connected to one of the pulley and the shaft adapter and is frictionally engageable with the other of the pulley and the shaft adapter,
wherein torque is transferrable from the shaft adapter to the spring through the first spring end, and from the spring to the pulley through the second spring end,
wherein torque is transferrable from the pulley to the spring through the first spring end, and from the spring to the shaft adapter through the second spring end,
wherein one of the adapter and pulley drive surface spacings is larger than the other of the adapter and pulley drive surface spacings,
wherein, when transitioning from torque transfer from the shaft adapter to the pulley to torque transfer from the pulley to the shaft adapter, the second adapter drive surface engages the second spring end at a different time than the first adapter drive surface disengages from the first spring end, and the second pulley drive surface disengages from the second spring end at a different time than the first pulley drive surface engages the first spring end,
and wherein when transitioning from torque transfer from the pulley to the shaft adapter to torque transfer from the shaft adapter to the pulley the first adapter drive surface engages the first spring end at a different time than the second adapter drive surface disengages from the second spring end, and the first pulley drive surface disengages from the first spring end at a different time than the second pulley drive surface engages the second spring end.

2. An isolator as claimed in claim 1 , further comprising a first end member that is engaged with the first spring end and a second end member that is engaged with the second end of the spring, wherein the first pulley drive surface and first adapter drive surface are both engageable with the first spring end through the first end member and wherein the second pulley drive surface and second adapter drive surface are both engageable with the second spring end through the second end member.

3. An isolator as claimed in claim 2 , further comprising a bushing, wherein the first and second end members each have a radially inner surface that is slideable on the bushing to permit movement one of the first and second end members relative to the bushing during relative movement between the shaft adapter and the pulley.

4. An isolator as claimed in claim 3 , wherein each of the first and second end members has one of a projection and a recess, and the bushing has the other of a projection and a recess, wherein the projection extends into the recess and wherein the projection and recess extend circumferentially and radially, so as to lock the end members axially in position while permitting circumferential movement of the end members.

5. An isolator as claimed in claim 4 , wherein the pulley includes an inner portion that is rotatably mounted to the shaft adapter, an outer portion that engages the endless drive member, a web that connects the inner and outer portions, and a cover member that partially encloses a spring chamber defined in part by the web and the outer portion, wherein the end members are constrained axially by the cover member and the web, and radially by the bushing and by the outer portion of the pulley, so as to permit travel along a circumferential path.

6. An isolator as claimed in claim 5 , wherein the pulley includes a structural member and a lining member that lines the outer portion and the web of the pulley and that is positioned to directly face the spring.

7. An isolator as claimed in claim 2 , further comprising a first bumper on the first end member that is engaged with the first adapter drive surface during torque transfer therewith and that is engaged with the first pulley drive surface during torque transfer therewith; and
a second bumper on the second end member that is engaged with the second adapter drive surface during torque transfer therewith and that is engaged with the second pulley drive surface during torque transfer therewith.

8. An isolator as claimed in claim 2 , wherein one of the adapter and pulley drive surface spacings is larger than the other than the other of the adapter and pulley drive surface spacings by a spacing difference that is less than 5 degrees and greater than 0.5 degrees.

9. An isolator as claimed in claim 1 , wherein the pulley is rotatably mounted to the hub via at least one bearing.

10. An isolator as claimed in claim 1 , wherein the shaft adapter includes a hub that is mountable to a crankshaft of an engine, and a driver that is mountable to the hub.

11. An isolator as claimed in claim 1 , wherein the pulley drive surface spacing is larger than the adapter drive surface spacing.

12. An isolator as claimed in claim 1 , wherein the spring is a first spring and wherein the isolator further comprises a second spring having a first spring end and a second spring end,
wherein the first adapter drive surface is one of two first adapter drive surfaces that are engageable with the first spring ends of the two springs respectively and wherein the second adapter drive surface is one of two second adapter drive surfaces that are angularly spaced from the first adapter drive surfaces and that are engageable with the second spring ends of the two springs, and
wherein the first pulley drive surface is one of two first pulley drive surfaces that are engageable with the first spring ends of the two springs respectively and wherein the second pulley drive surface is one of two second pulley drive surfaces that is angularly spaced from the first pulley drive surfaces and that are engageable with the second spring ends of the two springs respectively.

13. An isolator as claimed in claim 12 , wherein the two springs exhibit polar symmetry, the adapter drive surfaces exhibit polar symmetry, and the pulley drive surfaces exhibit polar symmetry.

14. An isolator as claimed in claim 1 , wherein one of the adapter and pulley drive surface spacings is larger than the other than the other of the adapter and pulley drive surface spacings by a spacing difference that is selected based on a moment of inertia of the pulley and a moment of inertia of the shaft adapter.

15. An isolator as claimed in claim 14 , wherein one of the adapter and pulley drive surface spacings is larger than the other than the other of the adapter and pulley drive surface spacings by a spacing difference that is selected based on a maximum torque to be transferred.

16. An isolator as claimed in claim 1 , wherein the spring is an arcuate helical coil compression spring.

Assignees

• Litens Automotive Inc

Inventors

• Starodoubov Vladimir I
• Antchak John
• Boyes Andrew M
• Replete Boris

Classifications

• F16F15/121

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

• B60Y2300/58

  Engine torque vibration dampers, e.g. flywheels, dual-mass-springs · CPC title

• F16H55/36 Primary

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

• F16D3/66

  the elements being metallic, e.g. in the form of coils · CPC title

• F16H7/18

  Means for guiding or supporting belts, ropes, or chains (construction of pulleys F16H55/36) · CPC title