CVT Stepless Speed Changer With Steel-Ring Friction Pair
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Solution Overview
Problem
Existing CVT gearboxes suffer from low driving torque, short service life, and limited gear ratio due to wear in the speed changing mechanism, particularly surface contact fatigue and adhesive wear, which is exacerbated by high contact stress.
Innovation Solution
A stepless speed changer for CVT gearboxes utilizing a steel-ring friction pair instead of a chain-steel belt drive, with a speed changing mechanism mounted on a shaft body and connected via a clamping mechanism using a hydraulic system, and a speed regulating mechanism for independent acceleration and deceleration control, reducing contact stress and improving torque transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a chain-steel belt drive friction pair is used in the speed changing mechanism, then the structure can transmit torque, but the contact stress is high causing wear, surface contact fatigue, and short service life
Solution Approach 1:
The patent extracts and removes the chain-steel belt drive friction pair from the system, replacing it with a steel-ring friction pair. This extraction eliminates the high contact stress and wear problems associated with the chain-steel belt drive while retaining the torque transmission function.
Solution Approach 2:
The patent employs a steel-ring friction pair that is designed to be more durable and resistant to wear compared to the chain-steel belt drive. The steel-ring structure is inherently more robust, providing extended service life and reduced maintenance requirements.
2Reliability
If the contact stress is reduced to improve service life, then wear and fatigue are reduced, but the driving torque becomes low and difficult to raise
Solution Approach 1:
The patent utilizes a composite friction pair structure consisting of steel-ring components that combine high strength and wear resistance. The steel-ring friction pair is constructed from materials and structural configurations that simultaneously provide low contact stress and high torque transmission capability.
3Ease of manufacture
If a steel-ring friction pair replaces chain-steel belt drive, then cost and manufacture difficulty are lowered, but the structural complexity of the speed changing mechanism changes
Solution Approach 1:
The steel-ring friction pair is designed with simpler manufacturing processes compared to chain-steel belt drives. The steel-ring structure can be produced using conventional machining methods, reducing manufacturing complexity and cost while eliminating the need for complex chain and belt assembly procedures.
4Power
If the speed changing mechanism is pressurized to ensure normal torque transmission, then torque transmission is improved, but the contact stress increases causing wear and failure
Solution Approach 1:
The patent removes the problematic chain-steel belt drive friction pair that requires high pressurization to transmit torque. The replaced steel-ring friction pair inherently provides better torque transmission with lower contact stress, eliminating the need for excessive pressurization.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enhances torque output by 1.5 times, increases service life, and simplifies manufacturing, making the CVT gearbox more versatile and cost-effective, with improved reliability and reduced interference between clamping and speed regulation.
Implementation Method 1
the clamping mechanism guarantees that the speed changing mechanism transmits a torque normally by use of pressurization of a first hydraulic system
Implementation Method 2
the speed regulating mechanism achieves speed change of the speed changing mechanism by use of acceleration and deceleration control of a second hydraulic system
Implementation Method 3
a radial end face of the input frictional ring is clamped between a radial end face of the intermediate rolling body and an annular groove disposed on the input flange, a radial end face of the output frictional ring is clamped between the radial end face of the intermediate rolling body and an annual groove disposed on the output flange
Data Source
AI summary
A stepless speed changer applied to a CVT gearbox is provided which comprises a speed changing mechanism, a clamping mechanism, and a speed regulating mechanism, and the speed changing mechanism is mounted on a shaft body and connected with a power input mechanism and a power output mechanism respectively along both sides of the shaft body; the clamping mechanism is distributed along an axial direction of the shaft body and located at both sides of the speed changing mechanism, and the clamping mechanism guarantees the speed changing mechanism transmits a torque normally by use of pressurization of a first hydraulic system; the speed regulating mechanism is located at a radial end of the shaft body and combined with the speed changing mechanism, and the speed regulating mechanism achieves speed change of the speed changing mechanism by use of acceleration and deceleration control of a second hydraulic system, which solves the structural problems of the existing CVT gearbox, for instance, low input torque, limited speed-change range, high cost and the like. With a steel-ring friction pair replacing a chain-steel belt drive friction pair, both cost and manufacture difficulty are greatly lowered.