Eccentric Oscillation Speed Reducer Clearance Optimization
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Solution Overview
Problem
Eccentric oscillation type speed reducers face challenges in achieving low lost motion while minimizing mechanical loss, as reducing component clearance leads to increased mechanical loss due to interference between components.
Innovation Solution
The speed reducer design incorporates specific relationships between component clearances, where the pin hole clearance and inter-tooth clearance are set to be negative, with the absolute value of the eccentric bearing clearance being greater than the absolute values of these clearances, to allow for reduced lost motion without increasing mechanical loss, as expressed by conditions (1) and (2).
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If component clearance is reduced to achieve low lost motion, then positioning accuracy is improved, but mechanical loss increases due to interference between components
Solution Approach 1:
The patent applies parameter changes by establishing specific mathematical relationships between different clearance parameters. The pin hole clearance is set to a negative value within a specific range, and the inter-tooth clearance is set to satisfy expression (2), creating an optimized clearance configuration that reduces lost motion while preventing component interference and mechanical loss
Solution Approach 2:
The patent implements dynamics by allowing the external gear to oscillate relative to the eccentric body while maintaining controlled clearances. The pin body is synchronized with the axial rotation component of the external gear, enabling dynamic movement that accommodates negative clearances without causing interference, thus achieving low lost motion without increasing mechanical loss
Data Source
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AI summary
There is provided an eccentric oscillation type speed reducer (10) in which an increase in mechanical loss can be suppressed while a lost motion is reduced. An eccentric oscillation type speed reducer (10) includes an eccentric body (12), an external gear (16) that is made to oscillate by the eccentric body (12), an internal gear (18) that meshes with the external gear (16), an eccentric bearing (20) that is disposed between the eccentric body (12) and the external gear (16), and a pin body (22) that is synchronized with an axial rotation component of the external gear (16) . In a case where an internal clearance of the eccentric bearing (20) in a radial direction is referred to as an eccentric bearing clearance (X1) and a clearance between the pin body (22) and the pin hole (32) in an anti-maximum eccentric direction (Db) from an axial center (C22) of the pin body (22) in a case where the axial center (C22) of the pin body (22) is in a maximum eccentric direction (Da) is referred to as a pin hole clearance (X2), the pin hole clearance (X2) is negative and the following expression (1) is satisfied. EccentricbearingclearanceX1+pinholeclearanceX2>0