Drive pulley for a continuously variable transmission

Patent metadata

Field	Value
Publication number	US-11396930-B2
Application number	US-201916555737-A
Country	US
Kind code	B2
Filing date	Aug 29, 2019
Priority date	Aug 31, 2018
Publication date	Jul 26, 2022
Grant date	Jul 26, 2022

Abstract

A drive pulley for a continuously variable transmission (CVT) has a pulley shaft with a fixed sheave, a movable sheave and a back plate thereon. The movable sheave has a movable sheave surface with first and second surface portions that faces the back plate. A biasing member biases the sheaves away from each other. A slider is disposed between the back plate and the movable sheave. The slider has a flat engagement zone surface, and a curved driving zone surface extending outward from the engagement zone surface. From rest, as the pulley shaft accelerates, the engagement zone surface of the slider slides radially outward against the first portion of the movable sheave surface and then the driving zone surface of the slider slides radially outward against the second portion of the movable sheave thereby pushing the movable sheave toward the fixed sheave. A vehicle having the CVT is also disclosed.

First claim

What is claimed is:

1. A drive pulley for a continuously variable transmission (CVT), the drive pulley comprising:
a pulley shaft;
a fixed sheave fixedly connected on the pulley shaft;
a back plate fixedly connected on the pulley shaft, the back plate including a back plate surface facing the fixed sheave;
a movable sheave disposed on the pulley shaft axially between the back plate and the fixed sheave, the movable sheave having a movable sheave surface facing the back plate surface, the movable sheave surface having a first surface portion and a second surface portion axially outward from the first surface portion, the movable sheave being slidable along the pulley shaft,
the fixed sheave, the movable sheave and the back plate being rotatable together with the pulley shaft;
a biasing member biasing the movable sheave away from the fixed sheave; and
a slider disposed between the back plate surface and the movable sheave surface, the slider having a back plate contacting surface contacting the back plate surface, a flat engagement zone surface, and a curved driving zone surface extending radially outward from the engagement zone surface,
the slider being movable radially in response to rotation of the pulley shaft between a first position, a second position and a third position, the second position being radially outward from the first position, the third position being radially outward from the second position,
movement of the slider from the first position to the second position moving the movable sheave toward the fixed sheave,
movement of the slider from the second position to the third position moving the movable sheave toward the fixed sheave,
when the slider moves between the first and second positions:
the back plate contacting surface of the slider slides along the back plate surface of the back plate, and
the engagement zone surface of the slider slides along the first surface portion of the movable sheave surface of the movable sheave; and

when the slider moves between the second and third positions:
the back plate contacting surface of the slider slides along the back plate surface of the back plate, and
the driving zone surface of the slider slides along the second surface portion of the movable sheave surface of the movable sheave.

2. The drive pulley of claim 1 , wherein the driving zone surface of the slider is out of contact with the movable sheave surface when the slider is between the first position and the second position.

3. The drive pulley of claim 1 , wherein the engagement zone surface of the slider is out of contact with the movable sheave surface when the slider is between the second position and the third position.

4. The drive pulley of claim 1 , wherein:
the first surface portion of the movable sheave surface is a flat portion;
the second surface portion of the movable sheave surface is a curved portion; and
the curved portion extends toward the back plate as the curved portion extends radially away from the pulley shaft.

5. The drive pulley of claim 4 , wherein the engagement zone surface of the slider is parallel to the flat portion of the movable sheave surface.

6. The drive pulley of claim 4 , wherein:
the back plate surface extends toward the fixed sheave as the back plate surface extends radially away from the pulley shaft;
the back plate contacting surface of the slider extends toward the fixed sheave as the back plate contacting surface extends radially away from the pulley shaft;
the engagement zone surface of the slider extends toward the back plate as the engagement zone surface extends radially away from the pulley shaft; and
the flat portion of the movable sheave surface extends toward the back plate as the flat portion extends radially away from the pulley shaft.

7. The drive pulley of claim 1 , wherein:
the movable sheave and the fixed sheave are adapted to receive a belt therebetween and for applying a pinching force on the belt;
the pinching force increasing as the slider moves from the first position to the second position; and
the pinching force decreasing as the slider moves from the second position to the third position.

8. The drive pulley of claim 1 , wherein the slider defines a cavity therein and has a weight removably received in the cavity.

9. The drive pulley of claim 8 , wherein the slider defines an aperture therein, the aperture communicating with the cavity and being sized to receive a tool therein for pushing the weight out of the cavity.

10. The drive pulley of claim 1 , wherein:
the back plate defines a radially extending rib extending along the back plate surface;
the slider defines a recess in the back plate contacting surface of the slider; and
the rib is received in the recess, the rib guiding the slider along the back plate surface as the slider slides along the back plate surface.

11. The drive pulley of claim 1 , further comprising a damper disposed between the back plate and the movable sheave for transferring rotational forces from the back plate to the movable sheave.

12. The drive pulley of claim 11 , wherein:
the damper is a plurality of dampers, each damper of the plurality of dampers defining a recess;
the back plate defines a plurality of recesses, each recess of the plurality of recesses of the back plate receiving a corresponding damper of the plurality dampers therein; and
the movable sheave defining a plurality of ribs, each rib of the plurality of ribs of the movable sheave being received in the recess of a corresponding one of the plurality of dampers, the plurality of dampers sliding relative to the plurality of ribs of the movable sheave as the movable sheave moves along the pulley shaft.

13. The drive pulley of claim 1 , wherein the driving zone surface of the slider is convex and the second surface portion of the movable sheave surface is concave.

14. The drive pulley of claim 1 , wherein the biasing member is a spring disposed around the pulley shaft and disposed at least partially radially between the pulley shaft and the movable sheave.

15. The drive pulley of claim 1 , wherein:
the slider is a plurality of sliders, the plurality of sliders being distributed circumferentially about the pulley shaft;
the movable sheave surface is a plurality of movable sheave surfaces, the plurality of movable sheave surfaces being distributed circumferentially about the pulley shaft;
the back plate surface is a plurality of back plate surfaces, the plurality of back plate surfaces being distributed circumferentially about the pulley shaft;
each slider of the plurality of sliders is disposed between a corresponding back plate surface of the plurality of back plate surfaces and a corresponding movable sheave surface of the plurality of movable sheave surfaces.

16. A continuously variable transmission (CVT) comprising:
the drive pulley of claim 1 ;
a driven pulley; and
a CVT belt looped around the drive pulley and the driven pulley to transfer torque therebetween.

17. A vehicle, comprising:
a motor;
at least one ground engaging member; and
the CVT of claim 16 , the CVT being operatively connected between the motor and the at least one ground engaging member.

18. A slider for a drive pulley of a continuously variable transmission (CVT), comprising:
a body having a:
an inward side;
an outward side;
a back plate contacting surface for contacting a back plate surface of a back plate of the drive pulley, the back plate contacting surface extending from the inward side toward the outward side, the back plate contacting su

Assignees

• Bombardier Recreational Products Inc

Inventors

• Aitcin Xavier-Pierre
• Geoffroy Catherine

Classifications

• F16H55/563 Primary

  actuated by centrifugal masses · CPC title

• F16H55/36

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

• B62M9/06

  using a single chain, belt, or the like · CPC title

• F16H55/56

  of which the bearing parts are relatively axially adjustable · CPC title

• B62D63/02

  Motor vehicles · CPC title