Control system for hydrokinetic brakes
AssigneeBritish Railways Board
InventorsAnthony G. L. Shore, Kevin S. Preston, David A. Churchill
Life of this patent
Estimating the term…
Abstract
A control system for a hydrokinetic brake has a pressurized working fluid reservoir connected to the hydrokinetic brake by fluid feed and return lines. A regulating valve sets the pressure in the reservoir at a value related to a required braking torque. The inlet pressure of the hydrokinetic brake is maintained at a fixed value lower than the reservoir pressure, for example by an atmosphere vent, during normal braking operation so that the outlet pressure of the brake and hence the braking torque has a direct relationship with the reservoir pressure, irrespective of the rotational speed of the brake.
Claims10
A method for controlling a brake system embodying a hydrokinetic brake of the type having a rotor and a stator together defining a toroid and also having inlet and outlet ports for liquid flowing continually through the brake during brake application from said inlet port to said outlet port, comprising the steps of:
- maintaining for each desired braking torque an essentially constant flow of said liquid into said inlet port from a liquid reservoir, said essentially constant flow being independent of the speed of rotation of said rotor;
- conveying said liquid from said outlet port to said liquid reservoir;
- controlling the braking torque of said brake essentially independently of the speed of rotation of said rotor by setting the pressure acting on said liquid reservoir in accordance with the desired braking torque;
- maintaining the pressure at said inlet port at a fixed pressure which is lower than the pressure in said reservoir, said fixed pressure being independent of the desired braking torque and the speed of rotation of said rotor.
A control system for a hydrokinetic brake, said brake having a rotor and a stator together defining a toroid and also having an inlet port and an outlet port for liquid flowing continually through the brake from said inlet port to said outlet port during brake application, comprising:
- a liquid reservoir;
- first means for selectively setting the pressure in said reservoir in accordance with the desired braking torque;
- second means for conveying liquid at an essentially constant flow rate, in accordance with the pressure selected by said first means, from said reservoir to said inlet port during brake application, said second means conveying liquid at different, substantially constant flow rates for each desired braking torque irrespective of the speed of rotation of said rotor;
- third means for constantly maintaining the pressure at said inlet port at a fixed pressure which is lower than the pressure in said reservoir during brake application;
- and
- fourth means for continually conveying liquid from said outlet port to said reservoir during brake application.
Dependencies are inferred from the claim text.