Hydraulic pump with two-stage operation
AssigneeEnerpac Tool Group Corp.
InventorsNathan Adam Hughes, Curtis L. Van Weelden
Life of this patent
Estimating the term…
Abstract
A pump may generally include a frame including a reservoir. The reservoir stores a hydraulic fluid. The pump may also include a motor assembly supported by the frame and a pump assembly operably driven by the motor assembly. The pump assembly is in fluid communication with the reservoir and configured to dispense the hydraulic fluid out of the frame. The pump assembly includes a first piston and a second piston, wherein the first piston dispenses hydraulic fluid out of the frame between a first pressure and a second pressure greater than the first pressure, and the second piston dispenses hydraulic fluid out of the frame between the first pressure and a third pressure, the third pressure being greater than the second pressure.
Claims16
A pump comprising:
- a frame including a reservoir configured to store hydraulic fluid;
- a motor assembly supported by the frame;
- a pump assembly operably driven by the motor assembly, the pump assembly being in fluid communication with the reservoir and configured to dispense hydraulic fluid out of the frame, the pump assembly including a first piston and a second piston;
- a hub having an outer surface defining a first passageway communicating with the first piston and a second passageway spaced from the first passageway and communicating with the second piston, the first passageway and the second passageway being in communication with a pump outlet;
- and
- a first valve having a first position in which the first passageway and the second passageway each communicate with the pump outlet, and a second position in which the first passageway is prevented from communicating with the pump outlet while the second passageway is communicating with the pump outlet.
A pump comprising:
- a frame including a reservoir configured to store hydraulic fluid;
- a motor assembly supported by the frame;
- a pump assembly operably driven by the motor assembly, the pump assembly being in fluid communication with the reservoir, the pump assembly including a first piston, a second piston, and a valve, the first piston being configured to dispense hydraulic fluid out of the frame, the second piston being configured to dispense hydraulic fluid out of the frame, the valve being configured to selectively inhibit hydraulic fluid dispensed via compression by the first piston from flowing out of an outlet of the pump assembly to thereby reduce a flow of the hydraulic fluid out of the outlet as compared to when uninhibited by the valve;
- and
- a heat exchanger including a tube and a plurality of fins each disposed around the tube, the tube receiving hydraulic fluid dispensed by the first piston when the valve inhibits hydraulic fluid dispensed by the first piston from flowing out of the frame, the hydraulic fluid traveling through the tube to the reservoir.
Dependencies are inferred from the claim text.