Tube Expander Indexing Assembly for Stable Motor Load
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Solution Overview
Problem
Existing tube expanders with electric motor-driven jaws face instability due to instantaneous load increase when the jaws get stuck, compromising operational stability.
Innovation Solution
A tube expander design where the action force for jaw rotation is not directly from the electric motor, utilizing an ejector pin, rotary member, and energy storage member to drive intermittent jaw rotation, ensuring stable motor operation by accumulating and releasing energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the electric motor directly drives the jaws to rotate intermittently, then the work efficiency is improved, but the operational stability of the electric motor deteriorates due to instantaneous load increase when jaws get stuck
Solution Approach 1:
The patent introduces an indexing mechanism as an intermediary between the electric motor and the jaws. This mechanism includes a drive wheel, indexing plate with positioning holes, and positioning pins that transfer and control the rotational motion. The intermediary decouples the direct drive relationship, allowing the motor to operate continuously at stable speed while the jaws rotate intermittently only when properly positioned, thus preventing instantaneous load spikes when jaws encounter resistance
Solution Approach 2:
The indexing mechanism performs preliminary positioning before the jaws engage in expansion work. The drive wheel rotates continuously and预先 positions the jaws at correct intervals using the indexing plate and positioning pins. This preliminary action ensures that jaws are properly aligned and ready to rotate only when needed, preventing forced rotation and load spikes during actual expansion operations
2Ease of operation
If the jaws are forced to rotate when stuck, then the rotation function is maintained, but the electric motor load increases instantaneously compromising operational stability
Solution Approach 1:
The indexing mechanism serves as a mediator that controls jaw rotation timing and positioning. Rather than forcing rotation, the mechanism allows jaws to rotate only when properly positioned through the indexing plate's positioning holes and drive wheel's continuous rotation. This controlled intermediary action maintains rotation functionality while preventing forced rotation that would cause motor load spikes
Solution Approach 2:
The system transitions from static forced rotation to dynamic controlled intermittent rotation. The drive wheel rotates continuously at constant speed, while the jaws rotate intermittently based on their positioning relative to the indexing plate's holes. This dynamic approach allows the system to adapt to loading conditions, maintaining rotation function when possible while avoiding forced rotation that would compromise motor stability
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
Enhances work efficiency by eliminating the need for manual rotation and stabilizes the electric motor's load, preventing instantaneous increases when the jaws stall.
Implementation Method 1
the rotary member rotating forward drives the energy storage member to be elastically deformed to accumulate energy, and the rotary member rotating forward is drivingly disengaged from the indexing member; and while the ejector pin is moving rearward, the energy storage member recovers from elastic deformation driving the rotary member to rotate reversely
Data Source
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AI summary
Disposed is a tube expander, which relates to a power tool, including an expansion die, an ejector pin, a drive element, and an indexing assembly, the expansion die including jaws, the indexing assembly including a rotary member rotatably disposed, an energy storage member connected to the rotary member, and an indexing member driving the jaws to rotate, the indexing member being disposed between the rotary member and the jaws and operable to transmit an intermittent rotational action, the rotary member and the indexing member being operable to drivingly engage or drivingly disengage with respect to each other; the ejector pin moving forward drives the rotary member to rotate forward, the rotary member rotating forward drives the energy storage member to be elastically deformed for the latter to accumulate energy, the rotary member rotating forward being drivingly disengaged from the indexing member; the energy storage member recovers from the elastic deformation during rearward movement of the ejector pin driving the rotary member to rotate reversely, the rotary member rotating reversely being drivingly engaged with the indexing member to push the jaws to rotate. The load of the electric motor does not increase instantaneously when the jaws stall, i.e., the driving load the electric motor is stable, which helps ensure operational stability of the electric motor.