Cycloid Speed Reducer With Wedge Cam Anti-Backlash Seat Swivel
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Solution Overview
Problem
Speed reduction devices for vehicle seat swivel mechanisms experience backlash and play due to meshing issues between planetary gears, leading to uncomfortable seat movement and potential gear damage from reverse rotational forces.
Innovation Solution
A speed reduction device incorporating a cycloid inner gear with wedges pressed by a spring, a cam, and rotational force transmission pins to prevent play and backlash, and a ring gear for eccentric rotation, which engages with the cycloid inner gear to block external forces and prevent transmission to the worm gear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If planetary gears are used in the speed reduction device, then rotational torque of the motor is increased, but backlash occurs due to play in the meshing portion between gears
Solution Approach 1:
A cam is introduced as an intermediary component between the transmission gear and the final output gear. The cam profile is designed to maintain continuous contact and eliminate backlash while transmitting rotational force, thereby resolving the meshing play issue without compromising torque transmission capability
Solution Approach 2:
The speed reduction device transitions from static gear meshing to dynamic cam-based force transmission. The cam mechanism dynamically adjusts the contact points and maintains optimal engagement throughout the rotation cycle, eliminating the static backlash problems inherent in traditional planetary gear systems
2Force
If multiple speed reduction gears are combined to increase torque, then rotational torque is amplified, but impact between gear teeth reduces gear strength and may damage the motor
Solution Approach 1:
The cam acts as a mediator that distributes and smooths the transmission of rotational force, preventing direct impact between gear teeth. This intermediary mechanism reduces shock loads and protects the gear system from damage while maintaining torque amplification
Solution Approach 2:
The cam profile is designed to cushion and absorb impact forces before they reach the gear teeth. By pre-configuring the cam surface geometry, the system prepares for and mitigates potential impact damage, protecting the gear strength throughout operation
3Ease of operation
If external force is reversely input to the speed reduction gears, then seat swivel operation can be adjusted, but backlash causes unexpected seat movement and discomfort
Solution Approach 1:
The cam mechanism serves as an intermediary that allows smooth reverse input for adjustment while preventing backlash-induced movement during stable positioning. The cam profile enables controlled movement during adjustment but maintains rigid engagement during steady-state operation
Solution Approach 2:
The system dynamically responds to external forces by transitioning between adjustment mode and stable positioning mode. During adjustment, the cam allows controlled movement; during stable operation, the same mechanism prevents backlash and maintains position stability
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 effectively prevents seat movement and gear damage by eliminating play and backlash, ensuring stable seat positioning and protecting the motor components from reverse rotational forces.
Implementation Method 1
a pair of wedges pressed against the inner peripheral surface of a through hole of the cycloid inner gear by elastic restoring force of a spring
Implementation Method 2
a cam formed to be integrated with the transmission gear, a cycloid inner gear, a pair of wedges pressed against the inner peripheral surface of a through hole of the cycloid inner gear
Implementation Method 3
a cycloid inner gear having a through hole formed in a center portion thereof and a plurality of rotational force transmission pins formed on an outer surface thereof, the cycloid inner gear being partially engaged with the ring gear while being eccentric with respect to the transmission gear
Data Source
AI summary
Disclosed is a speed reduction device for a vehicle motor. The speed reduction device includes an output gear connected to an output shaft of the motor, a transmission gear engaged with the output gear, a cam formed to be integrated with the transmission gear, a cycloid inner gear, a pair of wedges compressed against the inner peripheral surface of a through hole of the cycloid inner gear by elastic restoring force of a spring and configured to closely contact the cam, a ring gear partially engaged with the cycloid inner gear when the cycloid inner gear is eccentrically rotated, an end plate, and a final output gear configured to finally output rotational force of the cycloid inner gear, thereby preventing backlash between gears during rotational driving of the motor and reliably preventing movement of a seat after swivel adjustment is completed.