Cylinder block positive hold-down for cold start-up
AssigneeSundstrand Corporation
InventorsVictor N. Benson, Wayne A. Flygare, William J. Puskac
Life of this patent
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Abstract
An integrated drive generator for an aircraft and a method of making and operating the same result in improved operation of the integrated drive generator, especially during cold start-up. This is accomplished through the use of at least one stop to prevent each of the cylinder blocks in the hydraulic pump and motor assembly of the integrated drive generator from moving away from the port plate more than a predetermined amount which will ensure establishment of hydraulic continuity between the pump and motor without substantial delay during cold start-up of the integrated drive generator.
Claims24
In a method of making an integrated drive generator comprising providing a hydraulic pump and motor assembly including a variable displacement hydraulic pump and a fixed displacement hydraulic motor which have respective cylinder blocks arranged for rotation within housing means on opposite sides of a stationary port plate of the hydraulic pump and motor through which hydraulic continuity between the pump and motor is established during normal operation of the integrated drive generator, and wherein means are provided for resiliently biasing at least one of the cylinder blocks in the direction of the port plate such that a hydrostatic balance of the at least one cylinder block and the port plate can be established during normal operation of the integrated drive generator, the improvement comprising providing at least one stop to prevent the at least one cylinder block from moving away from the port plate more than a predetermined amount which will ensure establishment of hydraulic continuity between the pump and motor without substantial delay during cold start-up of the integrated drive generator, wherein the at least one stop prevents the at least one cylinder block from moving more than 0.010 inch away from the port plate.
In a method of making an integrated drive generator comprising providing a hydraulic pump and motor assembly including a variable displacement hydraulic pump and a fixed displacement hydraulic motor which have respective cylinder blocks arranged for rotation within housing means on opposite sides of a stationary port plate of the hydraulic pump and motor through which hydraulic continuity between the pump and motor is established during normal operation of the integrated drive generator, and wherein means are provided for resiliently biasing at least one of the cylinder blocks in the direction of the port plate such that a hydrostatic balance of the at least one cylinder block and the port plate can be established during normal operation of the integrated drive generator, the improvement comprising providing at least one stop to prevent the at least one cylinder block from moving away from the port plate more than a predetermined amount which will ensure establishment of hydraulic continuity between the pump and motor without substantial delay during cold start-up of the integrated drive generator, wherein the at least one stop prevents the at least one cylinder block from moving more than 0.010 inch away from the port plate, and further comprising providing at least one shim between the port plate and the housing means during assembly of the hydraulic pump and motor assembly to closely control the predetermined amount.
In a method of operating an integrated drive generator, the integrated drive generator having a hydraulic pump and motor comprising a variable displacement pump and a fixed displacement hydraulic motor which have respective cylinder blocks arranged for rotation within housing means on opposite sides of a stationary port plate of the hydraulic pump and motor through which hydraulic continuity between the pump and motor is established during normal operation of the integrated drive generator, said method comprising resiliently biasing at least one cylinder block in the direction of the port plate and establishing a hydrostatic balance of the at least one cylinder block and the port plate during normal operation of the integrated drive generator, the improvement comprising preventing the at least one cylinder block from moving away from the port plate more than a predetermined amount which will ensure establishment of hydraulic continuity between the pump and motor without substantial delay during cold start-up of the integrated drive generator, wherein the at least one cylinder block is prevented from moving more than 0.010 inch away from the port plate.
The method according to claim 16, wherein the at least one stop is provided on a shaft on which said at least one cylinder block is mounted.
An integrated drive generator comprising a hydraulic pump and motor which includes a variable displacement hydraulic pump and a fixed displacement hydraulic motor, the pump and motor having respective cylinder blocks arranged for rotation within housing means on opposite sides of a stationary port plate of the hydraulic pump and motor through which hydraulic continuity between the pump and motor is established during normal operation of the integrated drive generator, means for resiliently biasing at least one of the cylinder blocks in the direction of the port plate such that a hydrostatic balance of the at least one cylinder block and port plate can be established during normal operation of the integrated drive generator, and at least one stop for preventing the at least one cylinder block from moving away from the port plate more than a predetermined amount which will ensure establishment of hydraulic continuity between the pump and motor without substantial delay during cold start-up of the integrated drive generator, wherein the at least one stop prevents the cylinder blocks from moving more than 0.010 inch away from the port plate.
An integrated drive generator comprising a hydraulic pump and motor assembly which includes a variable displacement hydraulic pump and a fixed displacement hydraulic motor, the pump and motor having respective cylinder blocks arranged for rotation within housing means on opposite sides of a stationary port plate of the hydraulic pump and motor assembly through which hydraulic continuity between the pump and motor is established during normal operation of the integrated drive generator, means for resiliently biasing the cylinder blocks in the direction of the port plate such that a hydrostatic balance of the cylinder blocks and port plate can be established during normal operation of the integrated drive generator, and at least one stop for preventing each cylinder block from moving away from the port plate more than a predetermined amount which will ensure establishment of hydraulic continuity between the pump and motor without substantial delay during cold start-up of the integrated drive generator, wherein the at least one stop prevents the at least one cylinder block from moving more than 0.010 inch away from the port plate, and further comprising at least one shim located between the port plate and the housing means to closely control the predetermined amount.
An integrated drive generator comprising a hydraulic pump and motor which includes a variable displacement hydraulic pump and a fixed displacement hydraulic motor, the pump and motor having respective cylinder blocks arranged for rotation within housing means on opposite sides of a stationary port plate of the hydraulic pump and motor through which hydraulic continuity between the pump and motor is established during normal operation of the integrated drive generator, means for resiliently biasing at least one of the cylinder blocks in the direction of the port plate such that a hydrostatic balance of the at least one cylinder block and port plate can be established during normal operation of the integrated drive generator, and at least one stop for preventing the at least one cylinder block from moving away from the port plate more than a predetermined amount which will ensure establishment of hydraulic continuity between the pump and motor without substantial delay during cold start-up of the integrated drive generator, wherein said means for resiliently biasing the at least one cylinder block in the direction of the port plate comprises a square spring which when compressed to a solid height serves as said at least one stop.
An integrated drive generator comprising a hydraulic pump and motor which includes a variable displacement hydraulic pump and a fixed displacement hydraulic motor, the pump and motor having respective cylinder blocks arranged for rotation within housing means on opposite sides of a stationary port plate of the hydraulic pump and motor through which hydraulic continuity between the pump and motor is established during normal operation of the integrated drive generator, means for resiliently biasing at least one of the cylinder blocks in the direction of the port plate such that a hydrostatic balance of the at least one cylinder block and port plate can be established during normal operation of the integrated drive generator, and at least one stop for preventing the at least one cylinder block from moving away from the port plate more than a predetermined amount which will ensure establishment of hydraulic continuity between the pump and motor without substantial delay during cold start-up of the integrated drive generator, wherein said means for resiliently biasing includes a spring which is collapsed to solid height for interaction with a stop for preventing a cylinder block from moving away from the port plate more than said predetermined amount.
Dependencies are inferred from the claim text.