Segmented Sprocket Transmission Control Without Mechanical Contact
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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 exact manufacturing tolerances and complex assembly processes.
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
1Reliability
If mechanical control elements are used to actuate wheel rim segments by moving onto stationary switches or ramps, then the wheel segments can be adjusted, but constant mechanical contact causes friction, wear, stress, and noise
Solution Approach 1:
The patent replaces the mechanical control system with an electrically actuatable control element. Instead of mechanical elements moving onto stationary switches or ramps, an actuator (electric motor) directly moves the wheel rim segment electrically, eliminating constant mechanical contact and the associated friction and wear.
Solution Approach 2:
The patent extracts and removes the stationary mechanical interface (switches or ramps) from the system. By eliminating the stationary mechanical components that caused friction and wear, the system transitions to a fully rotating electrical control system mounted on the hub flange.
2Ease of operation
If mechanical control elements with stationary interfaces are used, then adjustment can be enforced, but exact manufacturing tolerances and high adjustment expenditures are required
Solution Approach 1:
The patent replaces the complex mechanical interface requiring exact tolerances with a simplified electrical actuation system. The actuator mounted on the hub flange directly controls the wheel rim segment without requiring mechanical interfaces between stationary and rotating parts, significantly reducing manufacturing and assembly complexity.
3Productivity
If a central control device rotationally decoupled from the stationary actuator is used, then all wheel segments can be simultaneously triggered, but mechanical power transmission between corotating and non-corotating parts causes constant friction
Solution Approach 1:
The patent replaces the mechanical power transmission system with an electrically actuatable control element mounted on the hub flange. This allows simultaneous triggering of all wheel segments through electrical control without requiring mechanical power transmission between corotating and non-corotating parts, eliminating constant friction.
4Adaptability or versatility
If mechanically actuated control devices are used, then transmission ratio changes can be enforced, but stress and wear on mechanical components increase
Solution Approach 1:
The patent replaces the mechanically actuated control system with an electrically actuatable control element. This substitution maintains the ability to adjust transmission ratios while eliminating the stress and wear associated with mechanical actuation, as the actuator directly moves the wheel rim segment without intermediate mechanical contacts.
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 mounting expenditures and the ability to perform actuations without interfaces, resulting in a more reliable and cost-effective transmission system.
Implementation Method 1
the movement of the wheel rim segments is effected by an electrically actuatable control element, in particular an 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.