Axial-Actuated Pawl Freewheel for Compact Low-Wear Locking
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Solution Overview
Problem
Existing pawl freewheels have complex and space-intensive designs, leading to difficult handling and high manufacturing costs, as well as significant wear on the actuating device and pawls, which reduces their service life and functionality.
Innovation Solution
A pawl freewheel design featuring an actuating device with an inclined impinging surface on the actuating pin, allowing for easy pivoting of the pawls in the axial direction, combined with a compact and simple construction, including a radial surface and a curved impinging surface for reduced wear, and multiple actuating pins for synchronized movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a rotatable actuating device with an adjusting ring is used to pivot pawls between locked and open positions, then the pawl freewheel achieves functional reliability, but the device becomes complex and space-intensive, leading to difficult handling and high manufacturing costs
Solution Approach 1:
The patent extracts the essential actuating function from the complex rotatable adjusting ring mechanism and implements it through a simplified axial displacement mechanism. The actuating pin with its inclined face provides the necessary pawl pivoting action through simple axial movement, eliminating the need for rotational components and reducing overall device complexity while maintaining reliability
Solution Approach 2:
Instead of using rotational movement (circumferential adjustment) to pivot the pawls, the invention inverts the approach by using axial displacement of an actuating pin with an inclined face. This inversion transforms the actuating motion from rotational to linear, significantly simplifying the device structure and improving ease of operation
2Reliability
If a rotatable actuating device with an adjusting ring is used to pivot pawls, then the pawl freewheel achieves reliable operation, but handling becomes difficult and manufacturing costs increase
Solution Approach 1:
The patent removes the complex rotational adjusting ring mechanism and retains only the essential axial actuating function. The actuating pin with its inclined face provides direct, intuitive control through axial displacement, making the device easier to operate while ensuring reliable pawl engagement and disengagement
Solution Approach 2:
The invention inverts the traditional rotational actuation approach into an axial displacement approach. This inversion makes the actuating action more intuitive and easier to perform, as linear motion is generally simpler to control and apply than rotational motion, while maintaining full operational reliability
3Force
If traditional actuating devices are used with significant contact surfaces, then reliable force transmission is achieved, but wear on the actuating device and pawls increases, reducing service life
Solution Approach 1:
The actuating pin features a curved or inclined contact surface instead of a flat traditional contact face. This curved geometry concentrates the force transmission onto a smaller, optimized contact area, reducing relative wear while maintaining sufficient force transmission capability for reliable pawl actuation throughout the service life
Data Source
AI summary
A pawl freewheel with a first race, a second race and pawls between the first and second race, which comprise at least one first pawl, which can be pivoted between a locked position in which the first race is rotationally drivingly coupled in a first direction of rotation relative to the second race via the first pawl to the second race and an open position, in which the first race is rotatable in the first direction of rotation relative to the second race wherein an actuating device is provided with an actuating pin which interacts with the first pawl which can be displaced from a first actuating position in which the first pawl is pivoted into the locked position, in the axial direction relative to the first pawl into a second actuating position, in which the first pawl is pivoted into the open position.