The brake chamber with a spring-loaded energy accumulator (Fig. a) is designed to actuate the brake mechanisms of the wheels of the rear bogie of the car when the service, spare and parking brakes are turned on
It consists of two main parts; brake chamber and a cylinder with a spring-loaded energy accumulator built on top of the brake chamber.
The brake chamber is an integral part of the pneumatic drive circuit for the brakes (working) wheels of the rear bogie and is activated when compressed air is supplied to it.
The spring-loaded energy accumulator is an integral part of the pneumatic drive circuit for the brakes (parking and spare) of the rear bogie wheels and is actuated by a spring when compressed air is released from its cavity.
In the initial position, when the car is disengaged (Fig. 1. b), compressed air is only in the cavity of the energy accumulator cylinder.
When the car is braked by a service brake (Fig. 1, c), compressed air from the brake valve is supplied to the cavity of the brake chamber housing above the membrane 9.
The membrane, bending, moves the rod 11, turns the expanding fist through the adjusting lever and presses the pads against the brake drum with a force proportional to the pressure of the compressed air supplied to the membrane.
When the car is released, compressed air is removed from this cavity into the atmosphere through the brake valve and the parts of the brake chamber take their original position, and the brake shoes move away from the brake drum under the action of the coupling springs.
The parking brake is activated (Fig. d) by the complete release of compressed air into the atmosphere from the cavity of the energy accumulator cylinder through the accelerating valve controlled by a manual brake valve.
When the air pressure in the cavity of the energy accumulator cylinder decreases, the piston moves under the action of a pre-compressed spring 5 and acts on the diaphragm (diaphragm 9) and rod 11 through the pusher.
The latter, moving, turns the adjusting lever with an expanding fist, pressing the brake pads against the drum.
The parking brake is turned off by supplying compressed air to the cavity of the energy accumulator cylinder under piston 3, which, moving together with the pusher 2, compresses the spring 5 and allows the rod 11 of the brake chamber to return to its original position under the action of the return spring 12.
When the vehicle is braked and released by the emergency brake, compressed air is released from the cylinders or is partially admitted into the cylinders of the energy accumulators.
The air pressure in the cylinders of the energy accumulators depends on the position of the brake valve handle.
If there is a leak in the circuit of the pneumatic drive of the parking (or spare) brake or if the pressure in the receivers of this circuit is reduced, the wheels of the rear bogie of the car may be automatically braked by the springs of the energy accumulators.
The movement of the car in this case is provided by releasing the wheels with a pneumatic or mechanical release device.
The device for mechanical release is made in the form of a screw 6 with a thrust bearing 8, mounted in the pusher tube 2 of the spring energy accumulator.
When the screw 6 is rotated (Fig. e), the piston 3 moves along with the pusher 2, compressing the spring. This releases the rod 11, which, under the action of the return spring 12, returns the adjusting lever with the expanding fist to the disengaged position.
To quickly remove the screw, the tool kit includes a 24X 27 socket wrench and a special handle that is inserted into the free end of the wrench to rotate it.
The pneumatic release system has an emergency release circuit, which consists of a part of a triple safety valve (see compressed air supply II in the figure), a pneumatic valve 8, a part of a two-way bypass valve 7, pipelines and hoses connecting the devices.
The drive of the emergency brake release system is powered from the service brake circuits I and II when the pressure in them is more than 500 kPa.
When the automatic tap button 10 is pressed, compressed air flows to the auxiliary bypass valve 23 and then to the energy storage cylinders. The wheels of the rear bogie are released.
The emergency brake release system provides (approximately) three times the full Not releasing the parking brake after emergency self-braking in order to drive away from the stop.