Rotary Encoder Clamping Mechanism for High Force
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Solution Overview
Problem
Existing rotary encoders face challenges in achieving high clamping forces between the shaft to be measured and the encoder shaft due to geometric limitations, which affect the accuracy and reliability of angular position measurements.
Innovation Solution
The rotary encoder design includes a ring body supported by an actuating means, with a snap ring and conical surfaces, allowing for increased clamping forces through lever ratios and bending moments, enabling secure clamping of the shaft while maintaining the ability to determine relative angular positions using an inductive measuring principle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a clamping coupling with direct contact between actuating screw and ring is used, then the structure is simple, but the clamping forces are comparatively small due to geometric conditions
Solution Approach 1:
A component with a flat cross-section is introduced as an intermediary between the actuating means and the ring body. This component acts as a lever that amplifies the clamping force by creating different moment arms: the first force application point on the ring body is at a smaller radial distance from the axis than the second force application point, while the corresponding points on the shaft follow the same pattern. This intermediary component transforms the simple screw-ring contact into a lever-based force amplification system.
Solution Approach 2:
The solution moves from a single-point contact geometry to a distributed contact geometry involving multiple points at different radial distances from the axis. By defining first and second points on both the ring body and shaft at different radial positions, the invention creates a two-dimensional force distribution pattern that enables moment-based force amplification, transitioning from simple linear contact to a more complex spatial arrangement that exploits rotational geometry.
2Force
If the web is made thin-walled at the base to increase flexural softness, then the clamping force is increased, but the structural strength is reduced
Solution Approach 1:
The web is designed with non-uniform thickness, being very thin-walled at the base (where high flexural softness is needed) and presumably thicker at other locations (where structural strength is needed). This local variation in geometry allows the web to exhibit different mechanical properties at different locations: high flexibility at the base for force amplification and adequate strength elsewhere for structural integrity.
Solution Approach 2:
The web is designed with conical surfaces on both the inner surface of the ring body and the outer surface of the shaft. These conical geometries create curved, tapered structures that naturally distribute stresses more effectively than flat surfaces. The conical shape provides geometric reinforcement that compensates for the reduced material thickness, allowing the thin-walled base to achieve high flexural softness while maintaining adequate structural strength through the curvature and taper of the conical surfaces.
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 design achieves high clamping forces and secure fixation of the shaft, enhancing the accuracy and reliability of angular position measurements while allowing for precise adjustment and operation.
Implementation Method 1
The rotary encoder comprises a first group of components and a second group of components, the groups of components being arranged such that they can rotate relative to one another about an axis. The first component group has a detector arrangement. The second group of components includes a code disk... which can be scanned by the detector arrangement in order to determine the relative angular position of the two component groups with respect to one another.
Data Source
Figure 1~2
Figure 3~4
Figure 5a~5b
AI summary
The encoder has a stator (10) with a detector system and a rotor (20) with a code disk. A shaft (21) has a bar, and a retainer (22) is arranged between an outer surface and an inner surface of a ring body. The detector system scans the code disk to determine a relative angular position between the stator and the rotor with respect to each other. Points on the inner surface of the ring body and points on an outer surface of the shaft have different distances, such that a force acts on the bar via the retainer, so that a machine part inserted into a bore hole of the shaft is clampable.