Balanced pump-axial piston pump
AssigneeMilwaukee Electric Tool Corporation
InventorsDeep Atkare, James O. Myrhum, Jr.
Life of this patent
Estimating the term…
Abstract
A balanced pump-axial piston pump for a hydraulic tool. The balanced pump-axial piston pump includes a camshaft, cam followers, a lift block, a spring, a pump piston, a piston chamber, and a manifold. Rotation of the camshaft drives radial movement of the cam followers at the same time. The radial movement of the cam followers make the lift block move linearly along the axis of the hydraulic tool. The spring pushes the piston against the lift block so that the piston is kept in contact with the lift block. The linear movement of the lift block moves the piston linearly in the piston chamber, thereby pumping oil and providing hydraulic power.
Claims20
A pump assembly for a hydraulic tool, the pump assembly comprising:
- a manifold;
- a camshaft including a shaft portion, the camshaft extending axially into the manifold and receiving a rotational input at the shaft portion;
- a lift block that at least partially surrounds the camshaft in a radial direction, the lift block movable in an axial direction relative to the manifold;
- and
- cam followers arranged to move radially with respect to the camshaft and engage the lift block at an internal surface of the lift block.
A reciprocating assembly for a balanced pump-axial piston pump, the reciprocating assembly comprising:
- a lift block that includes an internal chamber that varies in diameter along an axial direction to define an internal cam surface, the lift block arranged to move between an extended position and a retracted position in the axial direction;
- a camshaft that extends into the internal chamber of the lift block and includes an external cam surface, the camshaft arranged to receive a rotational input;
- and
- one or more cam followers disposed, in a radial direction, between the internal cam surface of the lift block and the external cam surface of the camshaft, the one or more cam followers arranged to move radially with respect to the camshaft.
A method of providing axial pump action with a pump assembly housed within a manifold, the method comprising:
- providing a rotational input to a camshaft having an external cam surface;
- radially translating one or more cam followers relative to the camshaft by moving the one or more cam followers along the external cam surface;
- and
- axially translating a lift block to provide axial pump action by moving the one or more cam followers along an internal cam surface of the lift block, the internal cam surface formed by an internal chamber of the lift block that varies in internal diameter in an axial direction.
Dependencies are inferred from the claim text.