Solenoid Spool Hub Projection for Reverse Coil Winding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional solenoid arrangements for starter motors face challenges in designing solenoid coil windings that require increased resistance without increasing amp-turn excitation, particularly in terms of physical dimensions and spatial constraints, and lack flexibility in providing optimal resistance and amp-turn excitation, especially when reversing turns are not feasible on the innermost layer.
Innovation Solution
A solenoid arrangement featuring a spool with a reverse turn hub projection allows for a change in winding direction, enabling a single layer of coil windings to add resistance without increasing amp-turn excitation, and includes a turn member on the coil retaining surface to facilitate this design, providing additional flexibility in balancing amp-turn excitation and resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If reverse turns are used in conventional coil arrangements to increase resistance without increasing amp-turn excitation, then coil resistance is improved, but spatial flexibility and design adaptability are worsened due to constraints on where reverse turns can be implemented
Solution Approach 1:
The patent introduces a hub projection that extends in the radial dimension from the spool hub, creating a new spatial location for implementing reverse turns. This allows the coil winding to reverse direction at the projection rather than being constrained to flange locations, adding a radial dimension to the winding path and enabling greater design flexibility in achieving desired resistance and amp-turn characteristics.
Solution Approach 2:
The hub projection serves as an intermediary structural element that facilitates the coil winding reversal. By providing a dedicated projection on the hub, the patent creates an intermediate structure that enables the reverse turn function without requiring modifications to the flange structure or other existing components, thus improving adaptability while maintaining resistance control.
2Loss of energy
If two full layers of reversing turns are implemented in conventional designs, then resistance without increased amp-turn excitation is achieved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent extracts the reverse turn function from the conventional multi-layer flange-based arrangement and relocates it to a single hub projection structure. This simplification reduces the number of layers required from two full layers to a more manageable configuration centered on the projection, thereby reducing device complexity while maintaining the resistance control function.
Solution Approach 2:
The hub projection creates a localized region for implementing the reverse turn, concentrating the complexity in a specific area rather than distributing it across multiple layers and flange structures. This localizes the design complexity to a single manageable feature, making the overall coil winding process simpler and more manufacturable.
3Loss of energy
If conventional flange-based reverse turn arrangements are used, then some resistance control is achieved, but adaptability for innermost layer reversing turns is lost
Solution Approach 1:
By moving the reverse turn implementation from the flange plane to the radial dimension via the hub projection, the patent enables reverse turns to be implemented in the innermost layer of the coil winding. The projection extends radially outward, allowing the winding to reverse at a location accessible from the inner layers, thus gaining adaptability that was previously unavailable in conventional flange-based designs.
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 enhances the flexibility in optimizing solenoid coil resistance and amp-turn excitation, allowing for improved plunger movement and reduced unwanted heat generation, while maintaining spatial constraints and cost-effectiveness.
Implementation Method 1
Energization of the solenoid moves a solenoid shaft (also referred to herein as the 'plunger') in an axial direction. The movement of the solenoid plunger closes electrical contacts, thereby delivering full power to the electrical motor.
Implementation Method 2
For the energization of the solenoid assembly to move the solenoid plunger and hold the plunger for pinion-flywheel engagement, solenoid assemblies typically utilize two coils, i.e., a pull-in coil and a hold-in coil.
Implementation Method 3
Once the vehicle engine is started, the operator of the vehicle then will open the ignition switch, which deenergizes the solenoid assembly. As a result of this deenergization, the magnetic field that caused the plunger to move decreases and at some point is overcome by a return spring.
Data Source
Figure 1~3
Figure 4
Figure 5A~5C
AI summary
A solenoid arrangement for a starter motor includes a plunger configured to move in an axial direction and a coil positioned radially outward from the plunger. The coil is wound on a spool that includes a first end and a second end with a hub extending between the first end and the second end. A projection is positioned on the hub of the spool. The coil engages the projection in such a manner that a winding direction of the coil is reversed at the projection.