Rotating Servo Control for Segmented Sprocket Transmissions
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Solution Overview
Problem
Existing control devices for changeable transmissions with wheel rim segments suffer from constant mechanical contact and friction between stationary and rotating units, leading to stress, wear, noise, and high assembly costs, as well as the need for precise manufacturing tolerances.
Innovation Solution
The control device eliminates the mechanical interface between stationary and rotating units by using electrically actuated control elements that rotate with the wheel blades, allowing independent adjustment of each wheel rim segment without mechanical contact, utilizing sensors and energy accumulators to ensure precise shifting without rod assemblies or cables.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If mechanical control elements are used to enforce movements of wheel rim segments by constant contact with stationary units, then the adjustment of wheel rim segments can be achieved, but friction, wear, noise, and stress occur due to constant mechanical contact
Solution Approach 1:
The patent replaces the mechanical control system with constant contact with an electromagnetic control system. Electromagnetic actuators mounted on the rotating hub generate magnetic fields that directly actuate the wheel rim segments without mechanical contact, thereby eliminating friction, wear, noise, and stress associated with mechanical interfaces.
Solution Approach 2:
The patent removes the stationary mechanical actuator from the system entirely. By mounting all control elements on the rotating hub itself, the system extracts the harmful stationary-mechanical-contact component and replaces it with a self-contained electromagnetic actuation system that rotates with the wheel.
2Ease of operation
If mechanical control elements with constant contact are used, then wheel rim segment adjustment is enforced, but exact manufacturing tolerances and high adjustment expenditures are required during assembling
Solution Approach 1:
The electromagnetic actuation system eliminates the need for precise mechanical tolerances between stationary and rotating components. Electromagnetic fields can be precisely controlled electronically without requiring tight mechanical fits, thereby reducing manufacturing complexity and assembly adjustment requirements.
Solution Approach 2:
The system changes from mechanical parameter control (physical contact, friction, wear) to electromagnetic parameter control (magnetic field strength, electrical signals). This allows for easier adjustment and control without being constrained by mechanical tolerance stacks.
3Ease of operation
If a stationary actuator with mechanical power transmission to corotating parts is used, then control of wheel rim segments is achieved, but the interface between rotating and stationary units causes friction and wear
Solution Approach 1:
The patent replaces the mechanical power transmission interface between stationary and rotating units with an electromagnetic system. All actuators are mounted on the rotating hub and use electromagnetic fields to control the wheel rim segments, eliminating the need for mechanical power transmission across the rotating-stationary interface and thereby improving reliability.
4Ease of operation
If mechanical control elements are used, then adjustment of wheel rim segments can be enforced, but the system generates noise and requires high adjustment expenditures
Solution Approach 1:
The electromagnetic actuation system replaces noisy mechanical components (gears, cams, contact actuators) with quiet electromagnetic motors and actuators. This eliminates mechanical noise from gear meshing, contact friction, and impact, while also reducing assembly costs through simplified tolerances and fewer precision-machined parts.
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 reduces wear, noise, and assembly costs by eliminating mechanical contact and tolerancing issues, enabling efficient and precise shifting operations with reduced maintenance needs, and allows for automatic gear changes based on rotation speed and load.
Implementation Method 1
the control device comprises at least one electrically actuatable control element, in particular a actuator
Data Source
AI summary
A control device for controlling a transmission ratio between a traction means and a sprocket set rotatable about an axle may include at least two sprockets alternatively wrapped around by the traction means. At least one of the sprockets may include several independently adjustable rim segments. Adjustment of the rim segments in relation to a fixed plane may be effected by a control device in a direction substantially transverse to the plane. The control device includes at least one electrically actuatable control element, e.g., a servomotor. The at least one control element is configured to rotate with the sprockets.