TOLERANCE RING WITH EDGE BUMP DIFFERENCE

• US 20120087044A1
• Filed: 10/07/2010
• Published: 04/12/2012
• Est. Priority Date: 10/07/2010
• Status: Active Grant

• Current Assignee: Intri-Plex Technologies Incorporated (MMI International Limited)
• Original Assignee: Intri-Plex Technologies Incorporated (MMI International Limited)
• Inventors: Schmidt, Ryan John, Hanrahan, Kevin Patrick, Brink, Damon Douglas, Dexter, David Django, Parsy, Philippe Jacques
• Granted Patent: US 8,385,024 B2
• Time in Patent Office: Days
• US Class Current: 360/265.6
• CPC Class Codes: F16C 2370/12 Hard disk drives or the like
• CPC Class Codes: F16C 27/00 Elastic or yielding bearings or bearing supports, for exclusively rotary movement shock-damping bearings for watches or clocks G04B31/02
• CPC Class Codes: F16D 1/0835 due to the elasticity of the ring or sleeve
• CPC Class Codes: G11B 5/4813 Mounting or aligning of arm assemblies, e.g. actuator arm supported by bearings, multiple arm assemblies, arm stacks or multiple heads on single arm G11B5/484 takes precedence
• CPC Class Codes: G11B 5/5569 details of specially adapted mobile parts, e.g. electromechanical control devices motors in general H02K
• CPC Class Codes: Y10T 403/7058 Split or slotted bushing

Abstract

A novel tolerance ring includes a hollow cylindrical body defining a longitudinal axis that passes axially through its center. A circumferential gap divides the hollow cylindrical body so that the hollow cylindrical body includes first and second longitudinal edges that define the circumferential gap. A plurality of bumps protrude radially from the hollow cylindrical body, and consists of a plurality of gap-adjacent bumps and a plurality of non-gap-adjacent bumps. At least one of the plurality of bumps is circumferentially between the gap and each of the non-gap-adjacent bumps. None of the plurality of bumps is circumferentially between the gap and each of the gap-adjacent bumps. The tolerance ring includes a means for increasing an otherwise lower average radial compressive stiffness of the gap-adjacent bumps to become substantially equal to an average radial stiffness of the non-gap-adjacent bumps.

Claims

1. A tolerance ring comprising:

a hollow cylindrical body defining a longitudinal axis that passes axially through its center;

a circumferential gap that divides the hollow cylindrical body so that the hollow cylindrical body includes first and second longitudinal edges that define the circumferential gap;

a plurality of bumps that protrude radially from the hollow cylindrical body, there being no bump that protrudes radially from the hollow cylindrical body that is not included in the plurality of bumps, the plurality of bumps consisting of a plurality of gap-adjacent bumps and a plurality of non-gap-adjacent bumps, there being at least one of the plurality of bumps circumferentially between the gap and each of the non-gap-adjacent bumps, there being none of the plurality of bumps circumferentially between the gap and each of the gap-adjacent bumps;

wherein each of the plurality of bumps defines a bump cross-sectional profile along a radial cross-section, the bump cross-sectional profile including a central plateau of approximately constant radial protrusion from the hollow cylindrical body, and wherein an average span of the central plateaus of the gap-adjacent bumps is more than an average span of the central plateaus of the non-gap-adjacent bumps.

2. The tolerance ring of claim 1 wherein the bump cross-sectional profile defines a total bump span measured from where protrusion from the hollow cylindrical body begins to where such protrusion ends, and wherein a ratio of the average span of the central plateaus of the gap-adjacent bumps to an average total bump span of the gap-adjacent bumps is more than a ratio of the average span of the central plateaus of the non-gap-adjacent bumps to an average total bump span of the non-gap-adjacent bumps.

3. The tolerance ring of claim 1 wherein the bump cross-sectional profile is oriented parallel to the longitudinal axis so that the average span of the central plateaus of the gap-adjacent bumps is an average length of the central plateaus of the gap-adjacent bumps that is measured parallel to the longitudinal axis, and the average span of the central plateaus of the non-gap-adjacent bumps is an average length of the central plateaus of the non-gap-adjacent bumps that is also measured parallel to the longitudinal axis.

4. The tolerance ring of claim 2 wherein the total bump span is a total bump length measured parallel to the longitudinal axis from where protrusion from the hollow cylindrical body begins to where such protrusion ends.

5. The tolerance ring of claim 1 wherein the bump cross-sectional profile is oriented circumferentially so that the average span of the central plateaus of the gap-adjacent bumps is an average width of the central plateaus of the gap-adjacent bumps that is measured circumferentially, and the average span of the central plateaus of the non-gap-adjacent bumps is an average width of the central plateaus of the non-gap-adjacent bumps that is also measured circumferentially.

6. The tolerance ring of claim 2 wherein the total bump span is a total bump width measured circumferentially from where protrusion from the hollow cylindrical body begins to where such protrusion ends.

7. The tolerance ring of claim 2 wherein the average total bump span of the gap-adjacent bumps is approximately equal to the average total bump span of the non-gap-adjacent bumps.

8. The tolerance ring of claim 1 wherein the average span of the central plateaus of the gap-adjacent bumps is more than the average span of the central plateaus of the non-gap-adjacent bumps by at least 50 microns.

9. The tolerance ring of claim 1 wherein each of the plurality of bumps has a radial compressive stiffness that opposes compressive deformation of that bump normal to the longitudinal axis, and wherein an average value of the radial stiffnesses of all of the gap adjacent bumps is greater than an average value of the radial stiffnesses of all of the non-gap-adjacent bumps.

10. The tolerance ring of claim 9 wherein an average value of the radial stiffnesses of the gap adjacent bumps is at least 5% more than an average value of the radial stiffnesses of the non-gap-adjacent bumps.

11. The tolerance ring of claim 9 wherein an average value of the radial stiffnesses of the gap-adjacent bumps is at least 0.4 N/μ

m more than an average value of the radial stiffnesses of the non-gap-adjacent bumps.

12. A tolerance ring comprising:

a hollow cylindrical body defining a longitudinal axis that passes axially through its center;

a circumferential gap that divides the hollow cylindrical body so that the hollow cylindrical body includes first and second longitudinal edges that define the circumferential gap;

a plurality of bumps that protrude radially from the hollow cylindrical body, there being no bump that protrudes radially from the hollow cylindrical body that is not included in the plurality of bumps, the plurality of bumps consisting of a plurality of gap-adjacent bumps and a plurality of non-gap-adjacent bumps, there being at least one of the plurality of bumps circumferentially between the gap and each of the non-gap-adjacent bumps, there being none of the plurality of bumps circumferentially between the gap and each of the gap-adjacent bumps;

wherein each of the plurality of bumps defines a maximum bump height measured away from the hollow cylindrical body and radially with respect to the longitudinal axis with the bump in an undeformed state, and wherein an average bump height of the non-gap-adjacent bumps is less than an average bump height of the gap-adjacent bumps by at least 20 microns.

13. The tolerance ring of claim 12 wherein each of the first and second longitudinal edges defines a longitudinal edge length that is measured approximately parallel to the longitudinal axis, the first and second longitudinal edges being separated circumferentially from each other by a circumferential gap extent that is substantially less than the longitudinal edge length.

14. The tolerance ring of claim 12 wherein each of the plurality of bumps has a radial compressive stiffness that opposes compressive deformation of that bump normal to the longitudinal axis, and wherein an average value of the radial stiffnesses of all of the gap adjacent bumps is greater than an average value of the radial stiffnesses of all of the non-gap-adjacent bumps.

15. A tolerance ring comprising:

a hollow cylindrical body defining a longitudinal axis that passes axially through its center;

a circumferential gap that divides the hollow cylindrical body so that the hollow cylindrical body includes first and second longitudinal edges that define the circumferential gap;

a plurality of bumps that protrude radially from the hollow cylindrical body; and

a plurality of openings extending through the tolerance ring.

16. The tolerance ring of claim 15 wherein each of the plurality of openings is disposed circumferentially between two of the plurality of bumps.

17. The tolerance ring of claim 16 wherein each of the plurality of openings is an elongated slot having a maximum length that is oriented parallel to the longitudinal axis.

18. The tolerance ring of claim 15 wherein

there is no bump that protrudes radially from the hollow cylindrical body that is not included in the plurality of bumps, and the plurality of bumps consists of a plurality of gap-adjacent bumps and a plurality of non-gap-adjacent bumps, there being at least one of the plurality of bumps circumferentially between the gap and each of the non-gap-adjacent bumps, there being none of the plurality of bumps circumferentially between the gap and each of the gap-adjacent bumps;

and

wherein each of the plurality of openings extends through a corresponding one of the non-gap-adjacent bumps.

19. The tolerance ring of claim 18 wherein at least two of the gap-adjacent bumps do not include any hole therethrough.

20. The tolerance ring of claim 18 wherein at least one gap-adjacent bump includes a hole therethrough, but said hole is smaller than any of the plurality of openings.

21. The tolerance ring of claim 18 wherein each of the plurality of bumps has a radial compressive stiffness that opposes compressive deformation of that bump normal to the longitudinal axis, and wherein an average value of the radial stiffnesses of all of the gap adjacent bumps is greater than an average value of the radial stiffnesses of all of the non-gap-adjacent bumps.

22. A tolerance ring comprising:

a hollow cylindrical body defining a longitudinal axis that passes axially through its center;

a circumferential gap that divides the hollow cylindrical body so that the hollow cylindrical body includes first and second longitudinal edges that define the circumferential gap;

a plurality of bumps that protrude radially from the hollow cylindrical body, there being no bump that protrudes radially from the hollow cylindrical body that is not included in the plurality of bumps, the plurality of bumps consisting of a plurality of gap-adjacent bumps and a plurality of non-gap-adjacent bumps, there being at least one of the plurality of bumps circumferentially between the gap and each of the non-gap-adjacent bumps, there being none of the plurality of bumps circumferentially between the gap and each of the gap-adjacent bumps; and

a means for increasing an otherwise lower average radial compressive stiffness of the gap-adjacent bumps to become substantially equal to an average radial stiffness of the non-gap-adjacent bumps.