High-low shifting active torque management continuously variable transmission system

Patent metadata

Field	Value
Publication number	US-12467533-B2
Application number	US-202418919758-A
Country	US
Kind code	B2
Filing date	Oct 18, 2024
Priority date	Oct 18, 2023
Publication date	Nov 11, 2025
Grant date	Nov 11, 2025

Abstract

A high-low shifting active torque management continuously variable transmission (CVT) system is provided. A primary pulley of a CVT is in operational communication with an engine. A high variable torque limiting clutch and a low variable torque limiting clutch selectively couple torque between a secondary pulley of the CVT and at least one drive axle of a vehicle when the vehicle when respectfully activated. The high variable torque limiting clutch and the low variable torque limiting clutch are configured to dynamically adjust a respective slippage threshold to above a then current output torque of the CVT and below a then current clamping force generated by the primary pulley and the secondary pulley on a torque connecting endless looped member of the CVT when respectfully activated.

First claim

The invention claimed is:

1 . A high-low shifting active torque management continuously variable transmission system, the system comprising:
a continuously variable transmission (CVT) including a primary pulley and a secondary pulley, the primary pulley in operational communication with an engine to receive engine torque; a high variable torque limiting clutch selectively coupling torque between the secondary pulley of the CVT and at least one drive axle of a vehicle when the vehicle is traveling in a high range, the high variable torque limiting clutch configured to dynamically adjust a slippage threshold of the high variable torque limiting clutch to be above a then current output torque of the CVT and below a then current clamping force generated by the primary pulley and the secondary pulley on a torque connecting endless looped member of the CVT when the high variable torque limiting clutch is activated; and a low variable torque limiting clutch selectively coupling torque between the secondary pulley of the CVT and the at least one drive axle of the vehicle when the vehicle is traveling in a low range, the low variable range torque limiting clutch configured to dynamically adjust a slippage threshold of the low variable range torque limiting clutch to be above the then current output torque of the CVT and below the then current clamping force generated by the primary pulley and the secondary pulley on the torque connecting endless looped member of the CVT when the low variable range torque limiting clutch is activated.

2 . The system of claim 1 , wherein the slippage threshold of the high variable torque limiting clutch and the slippage threshold of the low variable torque limiting clutch are a threshold where adjacent plates in an associated clutch pack of the high variable torque limiting clutch and the low variable torque limiting clutch slip therein limiting the torque passing through the associated high variable torque limiting clutch and the low variable torque limiting clutch.

3 . The system of claim 1 , further comprising:
a high-low gear set that includes the high variable torque limiting clutch and the low variable torque limiting clutch.

4 . The system of claim 3 , wherein the high-low gear set further comprises:
a carrier coupled to an input shaft to a gearbox; and a sun gear operationally engaged with the carrier, the sun gear further operationally engaged with the secondary pulley of the CVT.

5 . The system of claim 1 , further comprising:
a hydraulic system configured to activate the high variable torque limiting clutch and the low variable torque limiting clutch.

6 . The system of claim 5 , wherein the hydraulic system further comprises:
a hydraulic pump; and a valve for each of the high variable torque limiting clutch and the low variable torque limiting clutch, each valve located in a fluid path between the hydraulic pump and an associated one of the high variable torque limiting clutch and the low variable torque limiting clutch, each valve configured to regulate hydraulic pressure delivered to the associated one of the high variable torque limiting clutch and the low variable torque limiting clutch.

7 . The system of claim 6 , further comprising;
at least one operator input; a memory to store at least operating instructions; and a controller configured to implement the operating instructions stored in the memory, the controller configured to control each valve based on the stored operating instructions and an operator input signal from the at least one operator input.

8 . The system of claim 1 , further comprising:
a forward clutch operationally positioned between an output of the engine and the primary pulley of the CVT, the forward clutch configured to be selectively activated; and a reverse clutch operationally positioned between the output of the engine and the primary pulley of the CVT, the reverse clutch configured to be selectively activated.

9 . The system of claim 8 , further comprising:
a forward-reverse planetary gear set including the forward clutch and the reverse clutch.

10 . A vehicle including an active torque management continuously variable transmission system, the vehicle comprising:
an engine to generate torque; a continuously variable transmission (CVT) including,
a primary pulley in operational communication with the engine to receive the torque generated by the engine,
a secondary pulley, and
an endless looped member engaged with the primary pulley and the secondary pulley to pass the torque between the primary pulley and the secondary pulley;
a high variable torque limiting clutch selectively coupling the torque between the secondary pulley of the CVT and at least one drive axle of the vehicle when the vehicle is traveling in a high range, the high variable torque limiting clutch configured to dynamically adjust a slippage threshold of the high variable torque limiting clutch to be above a then current output torque of the CVT and below a then current clamping force generated by the primary pulley and the secondary pulley on the endless looped member when the high variable torque limiting clutch is activated; and a low variable torque limiting clutch selectively coupling the torque between the secondary pulley of the CVT and the at least one drive axle of the vehicle when the vehicle is traveling in a low range, the low variable torque limiting clutch configured to dynamically adjust a slippage threshold of the low variable torque limiting clutch to be above the then current output torque of the CVT and below the then current clamping force generated by the primary pulley and the secondary pulley on the endless looped member when the low variable torque limiting clutch is activated.

11 . The vehicle of claim 10 , further comprising:
a hydraulic system configured to activate the high variable torque limiting clutch and the low variable torque limiting clutch, the hydraulic system including,
a hydraulic pump,
a high valve located in a high fluid path between the hydraulic pump and the high variable torque limiting clutch, the high valve configured to regulate hydraulic pressure delivered to the high variable torque limiting clutch to selectively adjust a torque transfer provided by the high variable torque limiting clutch, and
a low valve located in a low fluid path between the hydraulic pump and the low variable torque limiting clutch, the low valve configured to regulate hydraulic pressure delivered to the low variable torque limiting clutch to selectively adjust a torque transfer provided by the low variable torque limiting clutch;
at least one operator input; a memory to store at least operating instructions; and a controller configured to implement the operating instructions stored in the memory, the controller configured to control each of the high valve and the low valve at least based on the stored operating instructions and an operator input signal from the at least one operator input.

12 . The vehicle of claim 11 , further comprising:
a forward clutch operationally positioned between an output of the engine and the primary pulley of the CVT; a forward valve located in a forward fluid path between the hydraulic pump and the forward clutch, the forward valve configured to selectively activate the forward clutch; a reverse clutch operationally positioned between the output of the engine and the primary pulley of the CVT, the reverse clutch configured to be selectively activated; a reverse valve located in a reverse fluid path between the hydraulic pump and the reverse clutch, the reverse valve configured to selectively activate the reverse clutch; and th

Assignees

• Team Ind Inc

Inventors

• Younggren Bruce H
• Fisk Jordan E
• Mueller Michael Allen
• Lenk Brandon P
• Fullum Daniel James

Classifications

• F16H59/14

  Inputs being a function of torque or torque demand · CPC title

• F16H2037/026

  Layouts with particular features of reversing gear, e.g. to achieve compact arrangement · CPC title

• F16H2061/6618

  Protecting CVTs against overload by limiting clutch capacity, e.g. torque fuse · CPC title

• F16H2059/0221

  for selecting modes, e.g. sport, normal, economy · CPC title

• F16H2059/148

  Transmission output torque, e.g. measured or estimated torque at output drive shaft · CPC title