Systems and methods for retarding the speed of a railcar

A system for retarding a railcar having wheels, the system comprising:

• a brake and an actuator configured to move the brake between a closed position in which the brake contacts the wheels of the railcar and an open position in which the brake does not contact the wheels of the railcar;
• a hydraulic circuit through which a hydraulic fluid flows between the actuator and a reservoir;
• a first pump operably connected within the hydraulic circuit and configured to provide the hydraulic fluid to the actuator for operating the brake;
• a heat exchanger operably connected within the hydraulic circuit and configured to cool the hydraulic fluid flowing therethrough, wherein the heat exchanger prevents the hydraulic fluid within the hydraulic circuit from exceeding a target operating temperature;
• a second pump operably connected within the hydraulic circuit and configured to provide the hydraulic fluid to the heat exchanger;
• a motor that operates at least one of the first pump and the second pump;
• and
• an enclosure in which the first pump, the second pump, and the motor are situated for protection, wherein the enclosure comprises a housing and a cover separated from the housing, wherein the cover at least partially shades the housing, and wherein the cover is positioned above the housing such that a gap remains therebetween to provide a thermal buffer between the housing and the cover.

A method for cooling a system for slowing a railcar, the system including a brake that slows the railcar when in a closed position and does not slow the railcar when in an open position, and the system further including an actuator that moves the brake into and between the closed position and the open position, wherein the actuator is fluidly coupled to a reservoir and a pump to form a hydraulic circuit and the pump is operated by a variable speed motor, the method comprising:

• measuring a temperature of hydraulic fluid within the hydraulic circuit and comparing the temperature to a threshold;
• controlling a valve to cause the hydraulic fluid to flow to a heat exchanger when the temperature of the hydraulic fluid exceeds the threshold, and controlling the valve to cause the hydraulic fluid to bypass the heat exchanger when the temperature of the hydraulic fluid is less than the threshold, wherein the heat exchanger is configured to exchange heat with the hydraulic fluid to prevent the temperature of the hydraulic fluid from exceeding a target operating temperature;
• measuring a pressure of the hydraulic fluid within the hydraulic circuit;
• and
• controlling a speed of the variable speed motor and controlling a displacement of the pump during operation thereof based on the pressure of the hydraulic fluid.

A method for cooling a system for slowing a railcar, the system including a brake that slows the railcar when in a closed position and does not slow the railcar when in an open position, and the system further including an actuator that moves the brake into and between the closed position and the open position, the method comprising:

• fluidly coupling the actuator, a reservoir, and a pump operated by a variable speed motor to form a hydraulic circuit through which a hydraulic fluid flows;
• fluidly coupling the variable speed motor to a coolant circuit through which a coolant flows, wherein the coolant remains fluidly isolated from the hydraulic fluid;
• changing a displacement of the pump and a speed of the variable speed motor during operation thereof;
• and
• circulating the coolant through the coolant circuit to prevent the variable speed motor from overheating during operation of the system for slowing the railcar.