Vehicle Driving Device Sensor Mounting and Sealing
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Solution Overview
Problem
Conventional vehicle driving devices face issues with reduced rotation position detecting precision and increased size due to magnetism interference and complex assembly processes, particularly with the placement and sealing of rotation detecting sensors.
Innovation Solution
A vehicle driving device configuration where the rotation detecting sensor's sensor stator is fixed to the drive case's end wall using a stator fastener that penetrates through the end wall, with a seal member surrounding the pump chamber to prevent oil leakage and simplify assembly, allowing for a compact design by overlapping sensor and motor components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the rotation detecting sensor is disposed between the oil pump and motor rotor with the sensor stator extended to overlap with the motor rotor and motor stator axially, then the sensor can be mounted to the rotation shaft, but magnetism from the motor rotor and motor stator is transmitted to the sensor, lowering rotation position detecting precision
Solution Approach 1:
The sensor stator is extracted from the rotation shaft mounting location and relocated to the drive case housing. This separates the sensor from the magnetic field source (motor rotor and stator), eliminating magnetic interference while maintaining detection functionality. The sensor stator is now mounted on the drive case housing rather than the rotation shaft, physically removing it from the harmful magnetic environment.
2Ease of manufacture
If the sensor stator is mounted to the drive case housing with the fastener penetrating through the housing, then assembly is simplified, but multiple seal members are needed to prevent oil leakage, increasing assembly work
Solution Approach 1:
The sealing functions are merged into a single integrated seal member. This seal member simultaneously seals the oil pump chamber and the through hole where the sensor stator fastener penetrates the drive case housing. By combining multiple sealing functions into one component, the number of seal members is reduced from multiple to one, simplifying assembly while maintaining comprehensive sealing.
3Measurement precision
If the rotation detecting sensor is extended to overlap with the motor rotor and motor stator axially, then the sensor can be positioned for detection, but the size of the driving device in the axial direction increases
Solution Approach 1:
The sensor stator mounting is transitioned from axial extension to radial/planar mounting on the drive case housing. Instead of extending the sensor axially to overlap with the motor components, the sensor stator is mounted on the housing surface in a different dimensional orientation. This allows the sensor to detect rotation without increasing the axial length of the driving device, as the detection function is achieved through the housing-mounted configuration rather than axial overlap.
4Measurement precision
If dedicated position adjusting holes and plugs are provided to adjust the rotation position of the rotation detecting sensor, then sensor positioning is enabled, but worker workability is lowered
Solution Approach 1:
The sensor stator positioning is designed to be self-aligning or automatically positionable during assembly, eliminating the need for dedicated position adjusting holes and plugs. The mounting structure on the drive case housing provides inherent positioning features that guide the sensor stator into the correct rotational position during installation. This self-service approach allows workers to install the sensor without performing complex positioning adjustments, significantly improving workability while maintaining detection precision.
Data Source
AI summary
A vehicle driving device includes a rotation shaft, a motor, a drive case having an end wall, a rotation detecting sensor, and an oil pump. The rotation detecting sensor has a sensor rotor and a sensor stator which is fixed to an inner surface of the end wall by a stator fastener. The oil pump includes a pump rotor, an oil pump cover and a seal member. The oil pump cover is joined to a joining surface formed on the outer surface of the end wall by fastening a cover fastener to a cover screw hole. The cover screw hole is formed into a shape opened only to the outside of the drive case and disposed outside of the seal member and a through hole through which the stator fastener is inserted is disposed on the joining surface inside of the seal member.