ENGINE BRAKING PRIMARY CLUTCH FOR CVT SYSTEMS

• US 20110092325A1
• Filed: 06/05/2010
• Published: 04/21/2011
• Est. Priority Date: 10/15/2009
• Status: Active Grant

• Current Assignee: Team Industries Incorporated
• Original Assignee: Team Industries Incorporated
• Inventors: Vuksa, Zoran, Okeson, Shane C., Nelson, Bruce A.
• Granted Patent: US 8,668,623 B2
• Time in Patent Office: Days
• US Class Current: 474/14
• CPC Class Codes: F16H 2059/186 Coasting
• CPC Class Codes: F16H 55/56 of which the bearing parts are relatively axially adjustable
• CPC Class Codes: F16H 55/563 actuated by centrifugal masses
• CPC Class Codes: F16H 61/21 Providing engine brake control
• CPC Class Codes: F16H 61/66272 characterised by means for controlling the torque transmitting capability of the gearing
• CPC Class Codes: F16H 63/067 mechanical actuating means
• CPC Class Codes: F16H 9/18 only one flange of each pulley being adjustable

Abstract

A continuously variable transmission (CVT) system including a primary clutch assembly with an engine braking assembly is provided. The primary clutch assembly includes first and second sheave assemblies, a cylindrical sleeve coupler and an engine braking assembly. The first sheave portion has a centrally extending post. The cylindrical sleeve coupler is rotationally mounted on a portion of the post. The sleeve coupler has an engaging surface that is configured to engage an inner face of a drive belt. The second sheave portion has a central passage that is rotationally mounted on the sleeve coupler. The engine braking assembly is operatively coupled to the second sheave portion and the sleeve coupler to axially move the second sheave portion toward the first sheave portion to engage first and second side faces of the drive belt when the sleeve coupler attempts to overrun the post of the first sheave portion in a rotational direction provided by a rotational output of an engine operatively coupled to the primary clutch.

Claims

1. A primary clutch assembly comprising:

a first sheave portion having a first conical-faced surface, the first conical-faced surface configured to engage a first side face of a drive belt, the first sheave portion further having a post centrally extending from the first conical-faced surface;

a cylindrical sleeve coupler rotationally mounted on a portion of the post proximate the first conical-faced surface, the sleeve coupler having an engaging surface configured to engage an inner face of the drive belt;

a second sheave portion having a central passage rotationally mounted on the sleeve coupler, the second sheave portion having a second conical-faced surface positioned to face the first conical-faced surface of the first sheave portion, the second conical-faced surface configured to engage a second side face of the drive belt; and

an engine braking assembly operatively coupled to the second sheave portion and the sleeve coupler to axially move the second sheave portion toward the first sheave portion to engage the first conical-faced surface of the first sheave portion with the first side face of the drive belt and the second conical-faced surface of the second sheave portion with the second side face of the drive belt when the sleeve coupler attempts to overrun the post of the first sheave portion in a rotational direction provided by a rotational output of an engine operatively coupled to the primary clutch.

2. The primary clutch assembly of claim 1, wherein the engine braking assembly further comprises:

a ramp coupler having a first end and a second end, the ramp coupler rotationally mounted on the post of the first sheave portion, the first end of the ramp coupler rotationally coupled to the sleeve coupler, the second end of the ramp coupler having at least one coupler ramp;

a one way clutch (OWC) rotationally mounted on the post of the first sheave portion, the OWC having at least one clutch ramp positioned to engage the at least one coupler ramp of the ramp coupler, wherein rotational movement of the ramp coupler in relation to the post rotates the at least one coupler ramp of the ramp coupler in relation to the at least one clutch ramp of the OWC thereby axially moving the second sheave portion in relation to the first sheave portion.

3. The primary clutch assembly of claim 1, wherein the at least one clutch ramp extends radially from a surface defining an outer perimeter of the OWC.

4. The primary clutch of claim 2, further comprising:

the first end of the ramp coupler having a plurality of ramp coupler dogs; and

the sleeve coupler having a plurality of sleeve coupler dogs configured to be mated with the ramp coupler dogs of the ramp coupler to provide the rotational coupling between the ramp coupler and the sleeve coupler.

5. The primary clutch of claim 2, wherein the OWC is further generally ring shaped having first side, a second side, a central passage and a plurality of cavities, each cavity having a pin roller opening to the central passage, a biasing member passage and a ramped surface, the OWC further comprising:

a pin roller received in each cavity; and

a biasing member received in each biasing member passage, each biasing member applying a biasing force on an associated pin roller, wherein the biasing force on an associated roller pin forces the roller pin on the ramped surface of the cavity so that a portion of the roller pin extends out of an associated pin roller opening thereby engaging the post to prevent rotation of the OWC in relation to the post in a first direction and further wherein the associated roller pin is retained within the cavity to allow rotation of the OWC in relation to the post in a second direction.

6. The primary clutch of claim 5, wherein the OWC further comprises:

a first plain bearing defining a first opening of the central passage proximate the first side of the OWC;

a second plain bearing defining a second opening of the central passage proximate the second side of the OWC, the pin roller openings in the passage being positioned between the first plain bearing and the second plain bearing.

7. The primary clutch of claim 1, further comprising:

a first bearing positioned between the post and the sleeve coupler to allow rotation between the post and the sleeve coupler.

8. The primary clutch of claim 7, further comprising:

a second bearing positioned between the sleeve coupler and the second sheave portion.

9. The primary clutch of claim 1, further comprising:

the second sheave portion having a first side and a second side, the first side including the second conical-faced surface;

a cover coupled to the second side of the second sheave portion;

a spider having a first side, a second side and a central spider passage mounted to the post, the spider positioned between the second sheave portion and the cover;

a biasing member positioned between the cover and the spider to assert a biasing force; and

a sheave moving member configured to counter the biasing force of the biasing member based on a rotation of the primary clutch beyond a select rotational speed to move the second sheave portion axially in relation to the first sheave portion.

10. The primary clutch of claim 1, wherein the sheave moving member further comprises:

a plurality of flyweights rotationally coupled the second side of the second sheave portion, the plurality of flyweights configured to exert a push force on the spider to counter the biasing force in response to a rotational speed of the primary clutch beyond the select rotational speed.

11. The primary clutch assembly of claim 1, wherein the engine braking assembly further comprises:

the second sheave portion having a first side and a second side, the second conical-faced surface position on the first side of the second sheave portion;

a braking ramp rim extending around an opening to the central passage on the second side of the second sheave portion, the braking ramp rim varying in height from the second side of the second sheave portion;

a OWC rotationally mounted on the sleeve coupler, the OWC configured to rotate independent of the rotation of the sleeve coupler in one direction and lock on to the rotation of the sleeve coupler in another direction, the OWC having a plurality of bores; and

a plurality of torque buttons, a portion of each torque button received in a respective bore of the OWC, each torque button having an end configured to engage at least a portion of the braking ramp to selectively move the second sheave portion towards the first sheave portion when the OWC locks on the sleeve coupler.

12. The primary clutch of claim 11, further comprising:

at least one return biasing member configured to return the OWC to a non-engine braking position when the OWC is no longer locked on the sleeve coupler.

13. The primary clutch of claim 11, wherein the sleeve coupler further includes at least one bearing positioned to engage the post.

14. A continuously variable transmission (CVT) comprising:

a primary clutch configured to receive a rotational output of an engine, the primary clutch including,

a first sheave portion having a first conical-faced surface, the first conical-faced surface configured to engage a first side face of a drive belt,

a post centrally extending from the first conical-faced surface, and

a second sheave portion having a central passage rotationally mounted on the post, the second sheave portion having a second conical-faced surface positioned to face the first conical-faced surface, the second conical-faced surface configured to engage a second side face of the drive belt;

an engine braking assembly including,

a cylindrical sleeve coupler rotationally mounted on a portion of the post of the first sheave portion proximate the first conical-faced surface, the sleeve coupler having a engaging surface configured to engage an inner face of the drive belt, the sleeve coupler further having a portion positioned between the post and the second sheave portion, and

a one way clutch (OWC) in rotational communication with the post of the first sheave portion and the sleeve coupler, the OWC configured to cause the second sheave portion to move towards the first sheave portion when the sleeve coupler attempts to overrun the rotation of the post of the first sheave portion; and

a second clutch, the secondary clutch including,

a secondary sheave system configured to engage the drive belt, the secondary sheave assembly configured to provide a rotational output to a drive train.

15. The CVT of claim 14, further comprising:

a cylindrical ramp coupler having a first end and a second end, the ramp coupler rotationally mounted on the post of the first sheave portion, the first end of the ramp coupler rotationally coupled to the sleeve coupler, the second end of the ramp coupler having at least one coupler ramp; and

the OWC rotationally mounted on the post of the first sheave portion, the OWC having at least one clutch ramp, the at least one clutch ramp positioned to engage the at least one coupler ramp of the ramp coupler, wherein rotational movement of the sleeve coupler in relation to the post rotates the at least one coupler ramp of the ramp coupler in relation to the at least one clutch ramp of the OWC causing the second sheave portion to move axially in relation to the first sheave portion.

16. The CVT of claim 14 further comprising:

the second sheave portion having a first side and a second side, the second conical-faced surface position on the first side of the second sheave portion;

a braking ramp rim extending around an opening to the central passage on the second side of the second sheave portion, the braking ramp rim varying in height from the second side of the second sheave portion;

the OWC rotationally mounted on the sleeve coupler, the OWC configured to rotate independent of the rotation of the sleeve coupler in one direction and lock on to the rotation of the sleeve coupler in another direction, the OWC having at least one bore; and

at least one torque button, a portion of the at least one torque button received in the at least one bore of the OWC, the at least one torque button having an end configured to engage at least a portion of the braking ramp to selectively move the second sheave portion towards the first sheave portion when the OWC locks on the sleeve coupler.

17. The CVT of claim 14, wherein the primary clutch further comprises:

the second sheave portion having a first side and a second side, the first side including the second conical-faced surface;

a cover coupled to the second side of the second sheave portion;

a spider having a first side, a second side and a central spider passage mounted to the post, the spider positioned between the second sheave portion and the cover;

a biasing member positioned between the cover and the spider to assert a biasing force; and

a sheave moving member configured to counter the biasing force of the biasing member pivot based on a rotation of the primary clutch beyond a select rotational speed to move the second sheave portion axially in relation to the first sheave portion.

18. A one way clutch (OWC) comprising:

generally a ring shaped housing having a central passage, the housing further including a plurality of cavities, each cavity including a central passage opening to the central passage, the central passage configured to receive a rotating sleeve,

a one way assembly including a plurality of roller pins, each roller pin received in an associated cavity in the housing, the one way assembly configured to allow the housing to rotate freely about the sleeve when the sleeve rotates in a first direction and lock onto the rotation of the sleeve when the sleeve rotates in a second direction; and

at least one moving member extending from a surface of the housing configured and arranged to selectively move an adjacent part away from the housing when the OWC is locked onto the rotation of the sleeve.

19. The OWC of claim 18, the one way assembly further comprising:

the housing having a first side and a second side, each cavity further including a ramped surface and a biasing member passage;

and

a biasing member received in each biasing member passage, each biasing member exerting a biasing force on an associated roller pin, wherein the biasing force on an associated roller pin forces the associated roller pin on the ramped surface of the cavity such that a portion of the roller pins extends out of an associated central passage opening of the cavity to engage the sleeve positioned in the central passage of the housing thereby locking the rotation of the housing with the rotation of the sleeve when the sleeve rotates in the second direction, further wherein each roller pin is received within an associated cavity to allow rotation of the housing independent of the rotation of the sleeve when the sleeve rotates in the first direction.

20. The OWC of claim 18, wherein the at least one moving member further comprises:

at least one clutch ramp extending from the surface of the housing.

21. The OWC of claim 20, wherein the ring shaped body further includes an outer parameter, the at least one clutch ramp extending radially from a surface defining the outer parameter.

22. The OWC of claim 18, wherein the at least one moving member is at least one torque button extending from the surface of the housing.

23. The OWC of claim 22, wherein the housing has at least one bore, a portion of the at least one torque button received in the at least one bore.

24. The OWC of claim 18, further comprising:

the housing having at least one slot; and

at least one return biasing member configured to be received in the at least one slot.

25. The OWC of claim 18, further comprising:

a first plain bearing defining a first opening of the central passage proximate a first side of the housing; and

a second plain bearing defining a second opening of the central passage proximate a second side of the housing.