Tangential Rail Grinding Machine with Segmented Cylindrical Wheels
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Solution Overview
Problem
Tangential grinding machines face limitations in restoring rail profiles due to abrasive wheel oscillation following rail undulations, requiring multiple cup wheels for complete profile restoration, leading to faceting and metallurgical stress, and are hindered by obstacles and mass balancing issues.
Innovation Solution
A grinding machine with two cylindrical wheels mounted on a base structure, adjustable via pneumatic and gearmotor systems, allowing for controlled longitudinal grinding, inclination, and convergence to maintain contact with the rail, enabling precise restoration of rail profiles without faceting and accommodating obstacles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If cup grinding wheels are used to operate on narrow longitudinal bands, then the grinding width is increased, but the overall device size becomes excessive and faceting occurs
Solution Approach 1:
The grinding wheel is segmented into two independent cylindrical grinding units that can operate simultaneously on opposite sides of the rail. Each unit has its own frame and mounting structure, allowing them to work independently while covering the entire rail profile without requiring multiple wheels mounted on trucks.
Solution Approach 2:
The invention transitions from using multiple wheels arranged horizontally (on trucks) to using two cylindrical wheels positioned vertically on opposite sides of the rail. This dimensional change allows complete profile restoration without increasing device complexity or causing faceting.
2Reliability
If abrasive wheels oscillate to follow the rail profile, then the wheel-rail contact is maintained, but longitudinal undulation defects are reproduced
Solution Approach 1:
The grinding units are mounted on frames that can oscillate vertically to maintain wheel-rail contact, but the frames themselves are rigidly connected to the base structure, preventing longitudinal oscillation. This dynamic vertical adjustment maintains contact while the rigid connection eliminates reproduction of longitudinal undulations.
Solution Approach 2:
The two grinding units are positioned asymmetrically on opposite sides of the rail with different vertical positions. This asymmetric configuration allows each wheel to independently follow the rail profile while the rigid frame connection prevents synchronous oscillation that would reproduce longitudinal defects.
3Manufacturing precision
If two grinding units are rigidly connected to the base structure, then longitudinal profile grinding is enabled, but the grinding units cannot adapt to rail undulations
Solution Approach 1:
The frames mounting the grinding units are rigidly connected to the base structure to prevent longitudinal oscillation, but each grinding unit can still oscillate vertically on its frame. This dynamic capability allows adaptation to rail undulations while maintaining precise longitudinal profile control.
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
The machine achieves perfect and efficient grinding of railway, tramway, and subway rails by eliminating longitudinal defects and facilitating grinding of complex rail sections like switches and crossovers, with controlled micrometric movements and adjustable wheel positions ensuring accurate profile restoration.
Implementation Method 1
a pneumatic regulator is used to apply a controlled working pressure via pneumatic cylinders
Implementation Method 2
a grinding device consisting essentially of a grinding wheel of abrasive material which when rotated removes by abrasion a part of the material with which it comes into contact
Data Source
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AI summary
A tangential grinding machine slidable on rails to be ground includes a base structure mounted on wheels slidable on the rails to be ground; a grinding unit freely slidable along the cross-members of the base structure, the grinding unit having a frame rigidly movable vertically relative to the base structure towards and away from the rail, the frame being rigidly coupled to at least two longitudinally aligned plates supporting a grinding wheel with a rotatable axis transverse to the rail longitudinal axis; and a bar hinged at its ends to the base structure and to the grinding unit respectively, there being connected to the frame supporting the plates a gear motor provided with a vertical axis worm gear, the end of which rests on the grinding unit, a control unit being associated with the gear motor to control frame descent following wear of the grinding wheel.