Grooved Resolver Rotor Hub Assembly for Damage-Free Torque Locking
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Solution Overview
Problem
Existing methods for connecting a resolver rotor to a torque converter pump hub, such as press-fit, heat and cool shrink fit, and welding, require tightly controlled tolerances and risk damage or warping, necessitating a cost-effective and quality-improving solution without increasing costs or assembly time.
Innovation Solution
A method involving forming axially extending grooves on the hub and corresponding projections on the resolver rotor, with a shallow assembly angle to facilitate assembly and prevent untwisting, providing an interference fit and sliding fit for precise centering and secure attachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If press-fit, heat and cool shrink fit, welding or staking is used to connect the resolver rotor to the hub, then the connection strength is improved, but the risk of warping or damaging the resolver rotor and/or hub increases
Solution Approach 1:
The connection interface is segmented into multiple axial grooves on the hub and corresponding radial projections on the rotor, distributing the connection function across multiple discrete features rather than relying on a single aggressive joining method
Solution Approach 2:
Instead of using external joining forces (press-fit, welding, staking) to force parts together, the invention inverts the approach by using the operational torque itself to lock the connection in place through the angled groove geometry
2Strength
If press-fit, heat and cool shrink fit, welding or staking is used to connect the resolver rotor to the hub, then the connection strength is improved, but tightly controlled tolerances are required
Solution Approach 1:
The invention changes the geometric parameter of the groove interface by introducing a deliberate assembly angle (5-45 degrees) relative to the axial direction, transforming the connection from a precision-fit problem to a self-aligning mechanical engagement
3Ease of operation
If a shallow assembly angle groove is used, then the rotational movement required for assembly is reduced, but the restraint against untwisting must be sufficient
Solution Approach 1:
The angled groove creates a wedge-like geometric relationship between the rotor projection and hub groove, where the inclined surfaces convert axial assembly force into both rotational alignment and locking restraint
Solution Approach 2:
The operational torque from the hub automatically locks the rotor in place through the angled groove geometry, with the system using its own operating forces to maintain the connection without additional fastening elements
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 method ensures secure and precise assembly of the resolver rotor on the hub, eliminating damage risks and achieving a reliable connection without the need for tight tolerances, while maintaining cost-effectiveness and reducing assembly complexity.
Implementation Method 1
the at least one projection being configured to have an interference fit with the at least one groove upon assembling of the resolver rotor onto the hub
Implementation Method 2
the angle is sufficient to act as restraint to untwisting of the resolver rotor off the hub
Implementation Method 3
the clockwise or anti-clockwise direction of the groove assembly angle works so that operational torque of the hub will act to 'lock' the resolver rotor against a stop shoulder of the hub
Implementation Method 4
an outer surface of the hub and an inner surface of the resolver rotor have a sliding fit in an area or areas other than an area of the at least one groove and the at least one projection. This provides for centering of the resolver rotor on the hub
Data Source
AI summary
A method of assembling a resolver rotor to a hub of a transmission assembly is provided. The method includes: forming a generally axially extending groove in an outer surface of the hub, the groove extending at an assembly angle greater than 0 degrees relative to an axial direction from a hub end toward a hub base, the assembly angle being positive in a direction that is opposite to a rotation direction of the hub in use; forming a projection on an inner surface of the resolver rotor, the projection being configured to have an interference fit with the groove upon assembly; and assembling the resolver rotor onto the hub with the at least one projection traveling along and interfering with a portion of the at least one groove as the resolver rotor moves to a seated position toward the hub base. A transmission assembly is also provided.