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US 5,176,066 AGranted
Axial piston pump apparatus with an improved drive mechanism
AssigneeHitachi, Ltd.
InventorsHisanobu Kanamaru, Kouji Harada
Life of this patent
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AssigneeHitachi, Ltd.
InventorsHisanobu Kanamaru, Kouji Harada
Estimating the term…
An axial piston pump apparatus includes a rotary cylinder barrel with plural cylinder bores in each of which a slidable piston is arranged. Each piston is rotatably held at one end with a piston support synchronously rotatable with the cylinder barrel. The piston support rotates in a plane inclined to the cylinder barrel, while each piston reciprocally moves in the corresponding cylinder bore to perform suction/discharging of a fluid. Two of the pistons come into surface contact with the corresponding cylinder bores; and the end of these pistons are held respectively in the piston support for radial movement to serve as drive pins for transmitting torque between the cylinder barrel and the piston support. During operation of the pump apparatus, the one end of each drive piston radially moves in accordance with rotation of the piston support, thereby preventing the drive pistons from inclining to the corresponding cylinder bores and appropriately maintaining surface contact between them. Thus, the two of the pistons serve as drive pins. This obviates the necessity of any separate drive mechanism and hence enables the reduction in size of the pump. Moreover, the drive pistons are kept is surface contact with the cylinder bores without impinging thereon thereby reducing noise and vibration of the pump apparatus.
An axial piston pump apparatus comprising a drive shaft, a cylinder barrel rotatably arranged and having a plurality of cylinder bores formed therein and arranged in one circular row around and in parallel with an axis of rotation thereof, means for connecting said drive shaft with said cylinder barrel to rotate said cylinder barrel synchronously with said drive shaft, pistons slidable arranged within the respective cylinder bores, and piston support means mounted on said drive shaft for pivotally supporting one end of each of said pistons so that said one end of each of said pistons rotates synchronously with said cylinder barrel in a plane inclined with respect to said cylinder barrel, wherein two of said pistons in said one circular row are provided to be in surface contact with corresponding cylinder bores to serve as drive pins for transmitting torque between said cylinder barrel and said piston support means and wherein said piston support means includes two slide grooves such that said two pistons are radially slidable and axially restrained to smoothly transmit a driving force from said drive shaft to said cylinder barrel.
Dependencies are inferred from the claim text.