Temperature Sensor Bushing Assembly for Railway Axles
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Solution Overview
Problem
The assembly of temperature sensors on railway vehicle axle housings is complicated by the need for precise machining tolerances and the challenge of preventing the electrical cable from rotating during assembly, which complicates the process and requires additional connectors for cable connection post-assembly.
Innovation Solution
A method and device using a bushing with internally and externally threaded components, where the threads have the same pitch, allowing the temperature sensor with an attached electrical cable to be screwed into the housing without rotating, thus eliminating the need for precise machining and additional connectors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the sensor is attached using a protrusion and hole with very precise dimensions, then stable contact and reliable temperature reading are achieved, but manufacturing complexity and machining cost increase significantly
Solution Approach 1:
A threaded bushing is introduced as an intermediary component between the sensor and the housing. The bushing has external threads that engage with the housing and internal threads that engage with the sensor body, serving as a mediator that transfers the attachment function without requiring precise machining of the housing hole. This intermediary component absorbs the tolerance requirements, allowing the housing to be manufactured with standard tolerances while maintaining reliable sensor contact.
2Ease of manufacture
If the sensor is screwed into the housing to avoid precise machining, then ease of manufacture improves, but the electrical cable rotates during assembly requiring additional connectors
Solution Approach 1:
The electrical cable is pre-attached to the sensor body before the assembly operation. The bushing is designed with internal threads that engage with the sensor body in a way that prevents rotation during the screwing operation. By performing the cable attachment in advance and designing the threading geometry to prevent rotation, the need for additional connectors and post-assembly cable connections is eliminated.
3Reliability
If the cable is connected after assembly to prevent rotation, then stable electrical connection is achieved, but assembly time and process complexity increase
Solution Approach 1:
The cable is attached to the sensor body before the assembly operation, reversing the conventional sequence. The bushing's internal threading is designed to engage with the sensor body in a manner that prevents rotation during screwing, thereby maintaining electrical connection stability without requiring post-assembly connector installation. This preliminary action eliminates additional assembly steps and reduces overall assembly time.
Data Source
AI summary
A method for assembling sensor on a housing. The sensor provided with a body, a protrusion and an electrical connection cable. The housing being provided with a blind hole shaped to engage with the protrusion of the sensor. The assembly method provides the following phases: a) inserting the protrusion in the blind hole of the housing bringing an end wall of the protrusion into contact with a bottom wall of the blind hole, b) tightening a bushing to a first tightening torque value, the bushing having an external thread that engages with an internal thread of the blind hole and an internal thread that engages with an external thread of the protrusion, in which all of the threads have the same pitch, c) tightening a hexagonal nut to a second tightening torque value.