Abstract: A noise-suppressor for fluid-borne noises in a hydraulic system comprises a cylindrical shaped housing consisting of a pair of cup-shaped end caps and a tubular center section connected therebetween such that the joint between the section and end caps is spaced from the end of the housing. The housing includes fins on the outer surface for radiating heat therefrom. An inertance tube is disposed within the housing coaxially thereof and communicating directly with the outlet thereof which in turn is coaxial with an inlet thereto.

Abstract: A railroad passenger car suspension system in which a car body is supported on trucks in the running mode through rotary hydraulic actuators. All of the necessary conditions for passenger comfort, increased train speed and safety are met. The level of centrifugal force at curves is sensed and the car tilted so that the direction of force is felt by the passengers in a comfortable manner. Flush floor level of the car with station platforms, regardless of passenger load, wheel wear or platform level is attained. Lowered spring rate in the suspension system provides improved ride characteristics. Means are provided for steering the car trucks.

Abstract: An apparatus and method for operating an auxiliary hydraulic load at low noise levels. A pump having a capacity which is sufficiently large to supply the load with the necessary volume of hydraulic fluid at relatively low pump speeds is driven by an engine operating at a speed near its idling speed. Throttle control means control the fuel supply to the engine at a level sufficient to drive the pump while maintaining the engine speed near its idling speed. When the engine speed is increased to a predetermined level in excess of its idling speed, means are provided to maintain the output from the pump at or below a predetermined flow rate to not overload the pump means or the auxiliary load. The pump may include a variable displacement pump or a plurality of fixed displacement pumps with means to vary the pump output in response to the pressure demand from the auxiliary load to maintain the torque input requirements for the pump below a predetermined level.

Abstract: An apparatus and method for operating an auxiliary hydraulic load at low noise levels. A pump having a capacity which is sufficiently large to supply the load with the necessary volume of hydraulic fluid at relatively low pump speeds is driven by an engine operating at a speed near its idling speed. Throttle control means control the fuel supply to the engine at a level sufficient to drive the pump while maintaining the engine speed near its idling speed. When the engine speed is increased to a predetermined level in excess of its idling speed, means are provided to maintain the output from the pump at or below a predetermined flow rate to not overload the pump means or the auxiliary load. The pump may include a variable displacement pump or a plurality of fixed displacement pumps with means to vary the pump output in response to the pressure demand from the auxiliary load to maintain the torque input requirements for the pump below a predetermined level.