CONTINUOUSLY VARIABLE TRANSMISSION ENGINE BRAKING SYSTEM

• US 20190323593A1
• Filed: 04/22/2019
• Published: 10/24/2019
• Est. Priority Date: 04/23/2018
• Status: Active Grant

• Current Assignee: Team Industries Incorporated
• Original Assignee: Team Industries Incorporated
• Inventors: Eck, Brian George, Reddick, Jeffrey Paul, Olson, Allen Lloyd, Okeson, Shane Clair
• Granted Patent: US 11,339,866 B2
• Time in Patent Office: Days
• CPC Class Codes: F16G 1/28 with a contact surface of special shape, e.g. toothed
• CPC Class Codes: F16H 29/12 between rotary driving and driven members F16H29/20, F16H29/22 take precedence
• CPC Class Codes: F16H 55/171 Toothed belt pulleys
• 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 9/14 using only one pulley built-up out of adjustable conical parts
• CPC Class Codes: F16H 9/18 only one flange of each pulley being adjustable
• CPC Class Codes: F16H 9/24 using chains or toothed belts, belts in the form of links; Chains or belts specially adapted to such gearing

Abstract

A drive clutch having an engine braking feature for a continuously variable transmission is provided. The drive clutch includes a post that is coupled to an output of an engine. A fixed sheave, coupled to the post, has a fixed sheave belt engagement face. A movable sheave assembly that includes a movable sheave belt engaging face, is configured to move axially on the post to move the movable sheave belt engaging face in relation to the fixed sheave belt engaging face depending on a rotational speed of the drive clutch. An idler bearing is mounted on the post at least in part between the movable sheave belt engaging face and the fixed sheave belt engaging face. The idler bearing includes a one-way rotational assembly and has an outer belt engaging surface with outward extending cogs configured to engage teeth of a belt to prevent slippage during engine braking.

Claims

1. A drive clutch having an engine braking feature for a continuously variable transmission, the drive clutch comprising:

a post configured to be coupled to an output of an engine;

a fixed sheave coupled to the post, the fixed sheave having a fixed sheave belt engagement face;

a movable sheave assembly mounted on the post, the movable sheave assembly having a movable sheave belt engaging face that is configured to move axially on the post to move the movable sheave belt engaging face in relation to the fixed sheave belt engaging face depending on a rotational speed of the drive clutch; and

an idler bearing mounted on the post at least in part between the movable sheave belt engaging face of the movable sheave assembly and the fixed sheave belt engaging face of the fixed sheave, the idler bearing including a one-way rotational assembly that allows rotation of the idler bearing in relation to the post in a first direction and prevents rotation of the idler bearing in a second direction to provide engine braking assistance, the idler bearing further having an outer belt engaging surface with outward extending cogs.

2. The drive clutch of claim 1, wherein the outward extending cogs of the idler bearing extend across the outer belt engaging surface at least a distance of a width of an inner surface of a belt used to convey torque between the drive clutch and a drive train of a vehicle.

3. The drive clutch of claim 1, wherein the outward extending-cogs of the idler bearing extend across the outer belt engaging surface less than the width of an inner surface of a belt used to convey torque between the drive clutch and a drive train of a vehicle.

4. The drive clutch of claim 1, wherein the shape of the outward extending cogs are selected to create a desired friction between the idler bearing and a belt used to convey torque between the drive clutch and a drive train of a vehicle.

5. The drive clutch of claim 1, wherein each cog includes at least one ramp surface.

6. The drive clutch of claim 1, wherein the outer belt engaging surface of the idle bearing includes a first portion that has a first diameter and a second portion that has a second smaller diameter, the outward extending cogs extending from the second portion of the outer belt engaging surface.

7. The drive clutch of claim 1, wherein the one-way rotational assembly is received within a central recess of the fixed sheave.

8. A vehicle with a continuously variable transmission with an engine braking function, the vehicle comprising:

an engine to produce torque;

a continuously variable transmission including,

a drive clutch, the drive clutch including,

a post coupled to an output of the engine,

a fixed sheave coupled to the post, the fixed sheave having a fixed sheave belt engagement face,

a movable sheave assembly mounted on the post, the movable sheave assembly having a movable sheave belt engaging face that is configured to move axially on the post to move the movable sheave belt engaging face in relation to the fixed sheave belt engaging face depending on the rotational speed of the drive clutch,

an idler bearing mounted on the post at least in part between the movable sheave belt engaging face of the movable sheave assembly and the fixed sheave belt engaging face of the fixed sheave, the idler bearing including a one-way rotational assembly that allows rotation of the idler bearing in relation to the post in a first direction and prevents rotation of the idler bearing in a second direction to provide engine braking assistance, the idler bearing having an outer belt engaging surface with outward extending cogs; and

a drivetrain; and

a belt to convey torque between the drive clutch and the drivetrain, the belt including an inner surface having teeth that are configured to engage the cogs of the idler bearing when the movable sheave belt engaging face of the movable sheave assembly is positioned at least a distance of a width of the belt away from the fixed sheave belt engaging face of the fixed sheave.

9. The continuously variable transmission engine braking system of claim 8, wherein the outward extending cogs of the idler bearing extend across the outer belt engaging surface of the idler bearing a distance of a width of the inner surface of the belt.

10. The continuously variable transmission engine braking system of claim 8, wherein the outward extending cogs of the idler bearing extend across the outer belt engaging surface of the idler bearing a distance of less than a width of the inner surface of the belt.

11. The continuously variable transmission engine braking system of claim 8, wherein the teeth of the belt extend across the entire width of the inner surface of the belt.

12. The continuously variable transmission engine braking system of claim 8, wherein the teeth of the belt extend across less than the width of the inner surface of the belt.

13. A belt for a continuously variable transmission, the belt comprising:

an inner surface having inner protruding teeth that are configured to engage cogs of an idler bearing of a drive clutch when a movable sheave belt engaging face of a movable sheave assembly of the drive clutch is positioned at least a distance of a width of the belt away from a fixed sheave belt engaging face of a fixed sheave of the drive clutch.

14. The belt of claim 13, wherein the inner protruding teeth of the belt extend across a width of the inner surface of the belt.

15. The belt of claim 13, wherein the inner protruding teeth of the belt extend partially across a width of the inner surface of the belt.

16. The belt of claim 13, wherein the belt include an outer surface, the outer surface including outer protruding teeth.

17. The belt of claim 13, wherein each inner protruding tooth is defined by a ramp surface and generally a straight edge surface.

18. A drive clutch of a continuously variable transmission having an engine braking function, the drive clutch comprising:

a post configured to be coupled to an output of an engine;

a fixed sheave coupled to the post, the fixed sheave having a fixed sheave belt engagement face and a central recess;

a movable sheave assembly mounted on the post, the movable sheave assembly having a movable sheave belt engaging face that is configured to move axially on the post to move the movable sheave belt engaging face in relation to the fixed sheave belt engaging face depending on the rotational speed of the drive clutch;

an idler bearing mounted on the post, the idler bearing having a first portion positioned at least in part between the movable sheave belt engaging face of the movable sheave assembly and the fixed sheave belt engaging face of the fixed sheave and a second portion received within the central recess of the fixed sheave; and

a one-way rotational assembly received within the central recess of the fixed sheave, the one-way rotation assembly engaging the idler bearing to allow the idler bearing to rotate in relation to the post in a first direction and prevent rotation of the idler bearing in relation to the post in a second direction.

19. The drive clutch of claim 18, wherein the one-way rotational assembly further comprises:

a sprag received within the central recess of the fixed sheave, the sprag having an inner surface that is engaged with the second portion of the idler bearing, the sprag having a one-way rotation feature; and

a sprag housing, at least a portion of the sprag housing receive within the central recess of the fixed sheave, an inner surface of the sprag housing received within the central recess engaging an outer surface of the sprag, an outer surface of the sprag housing received within the central recess engaging an inner surface of the central recess of the fixed sheave.

20. The drive clutch of claim 18, wherein the idler bearing has an outer belt engaging surface with outward extending cogs.