Cam-Based Torque Limiter With Cylindrical Rings for Overload Reset
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing overload protecting devices face challenges such as increased machining costs, complex ring shapes, limited torque transmission capacity, and inability to continuously use the device after an overload state returns to normal.
Innovation Solution
The proposed overload protecting device features an inner and outer ring with cylindrical surfaces, a torque transmission mechanism with cams and urging means, allowing for high torque transmission and accurate allowable torque setting, and enabling continuous use after the overload state normalizes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If engagement portions are provided on the inner peripheral surface of the outer ring to transmit torque, then torque transmission is enabled, but the shapes of both the inner ring and the outer ring become complicated and machining costs are raised
Solution Approach 1:
The torque transmission function is segmented into multiple discrete cams arranged circumferentially between the inner and outer rings. Each cam independently transmits torque through simple cylindrical contact surfaces, avoiding the need for complex engagement portions on the ring surfaces themselves. This segmentation allows torque transmission while maintaining simple ring geometries.
Solution Approach 2:
Multiple cams are introduced as intermediary elements between the inner and outer rings to perform torque transmission. These cams have simple cylindrical outer peripheral surfaces that contact the inner ring, and simple inner peripheral surfaces that contact the outer ring, eliminating the need for complex shaped engagement portions on the rings while still enabling effective torque transmission.
2Power
If the number of torque transmission spots is limited to one circumference, then the structure remains simple, but it is difficult to increase the transmission torque
Solution Approach 1:
The single-circumference limitation is overcome by segmenting the torque transmission function into multiple cams arranged circumferentially. Each cam provides an independent torque transmission spot, and multiple cams work simultaneously to transmit torque. This segmentation increases the total transmission torque capacity while keeping each individual cam structurally simple.
Solution Approach 2:
Instead of increasing transmission spots in the radial direction (which would complicate the ring shapes), the solution adds transmission spots in the circumferential dimension by arranging multiple cams around the circumference. This dimensional approach increases torque capacity without complicating the basic ring structures.
3Reliability
If a one-way clutch with cam is used to exceed the limit of allowable torque, then emergency overload protection is available, but it cannot be continuously used after the overload state returns to normal
Solution Approach 1:
The cam mechanism is designed to be dynamically reversible. When overload occurs, the cam rotates relative to the inner ring, allowing the inner ring to rotate in the overload protection direction. When the load returns to normal, the cam automatically returns to its original position through elastic deformation of the inner ring, enabling continuous operation without manual intervention or permanent damage.
Solution Approach 2:
The elastic deformation capability of the inner ring is utilized as a cushioning mechanism. The inner ring can elastically deform to allow cam rotation during overload, and then automatically recover its original shape when the load normalizes, providing built-in reset functionality that enables continuous use after overload events.
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
This solution simplifies the structure, reduces machining costs, enhances torque transmission capacity, and improves the accuracy of allowable torque settings, while allowing continuous operation even after an overload event.
Implementation Method 1
a cam (130) which has a rotationally symmetric shape with respect to a rotation center, and in which a minimum diameter connecting the minimum radius parts at two spots and a maximum diameter connecting the maximum radius parts at two spots are disposed so as to form an angle other than 90°
Data Source
AI summary
To provide an overload protecting device with a simple structure and a low machining cost, capable of increasing a transmission torque, improving accuracy of an allowable torque to be set, and capable of continuous use even after an overload state, once it returns to a normal torque. A torque transmission mechanism for torque transmission, cam sliding surfaces 111, 121 of an inner ring 120 and an outer ring 110have cylindrical shapes, the torque transmission mechanism has a plurality of cams 130 provided in a circumferential direction between the cam sliding surfaces 111, 121 and urging means 140 for urging the plurality of cams 130 in a rotating direction thereof, and the cam 130 has a plurality of minimum radius parts and a plurality of maximum radius parts disposed alternately and formed having a rotationally symmetric shape to a rotation center thereof.