Valveless, mechanical, pressure regulating pump
Systems and methods are disclosed for a valveless, mechanical, pressure regulating pump for use in transmissions and other mechanical systems. The pressure regulating pump may include a casing; a pump body having an outer cylindrical portion and an inner cylindrical portion, wherein the outer cylindrical portion includes one or more inlet ports and the inner cylindrical portion includes one or more outlet ports; a piston interposed between the outer cylindrical portion and the inner cylindrical portion and configured to move axially, the piston and the inner cylindrical portion defining a chamber; a first spring at least partially interposed between the piston and the inner cylindrical portion; and a second spring interposed between the casing and the pump body, wherein the pump body is configured to move axially relative to the casing and compress the second spring when a pressure in the chamber exceeds a pre-load of the second spring.
1 . A pump, comprising:
a casing;
a pump body accommodated within the casing, the pump body comprising an outer cylindrical portion and an inner cylindrical portion, wherein the outer cylindrical portion includes one or more inlet ports and the inner cylindrical portion includes one or more outlet ports;
a piston interposed between the outer cylindrical portion and the inner cylindrical portion and configured to move axially relative to the one or more inlet ports, the piston and a top of the inner cylindrical portion defining a chamber;
a first spring at least partially interposed between the piston and the inner cylindrical portion; and
a second spring interposed between the casing and a bottom of the pump body, wherein the outer cylindrical portion and the inner cylindrical portion are configured to move axially relative to the casing and compress the second spring when a pressure in the chamber exceeds a pre-load of the second spring.
2 . The pump of claim 1 , wherein the inner cylindrical portion is housed within the outer cylindrical portion and spaced apart from the outer cylindrical portion by a cylindrical cavity, and wherein the cylindrical cavity is in fluid communication with the chamber, and wherein the first spring and the piston are positioned between the outer cylindrical portion and the inner cylindrical portion in the cylindrical cavity with the outer cylindrical portion circumferentially surrounding at least part of the piston, the piston circumferentially surrounding at least part of the first spring, and the first spring circumferentially surrounding the inner cylindrical portion.
3 . The pump of claim 2 , wherein the inner cylindrical portion has a hollow interior defining a discharge compartment, and wherein the discharge compartment is fluidly coupled to the chamber via the one or more outlet ports.
4 . The pump of claim 2 , wherein the one or more inlet ports are configured to be in fluid communication with the cylindrical cavity.
5 . The pump of claim 4 , wherein the piston is movable between a top dead center (TDC) position and a bottom dead center (BDC) position, wherein at the TDC position, the one or more inlet ports are at least partially uncovered to provide fluid communication between the one or more inlet ports and the cylindrical cavity, and wherein at the BDC position, the one or more inlet ports are covered by the piston and fluid communication between the one or more inlet ports and the cylindrical cavity is blocked.
6 . The pump of claim 1 , wherein the second spring comprises a plurality of cup springs arranged in series.
7 . The pump of claim 1 , further comprising one or more end stop devices coupled to the casing and configured to stop upward movement of the pump body.
8 . The pump of claim 1 , wherein the pump is housed in a transmission, wherein the one or more inlet ports are fluidly coupled to a sump of the transmission, and wherein the outlet port is fluidly coupled to a reservoir of the transmission.
9 . The pump of claim 1 , wherein the piston is configured to move axially via rotation of a cam coupled to a shaft.
10 . The pump of claim 1 , wherein the pump does not include an additional pressure relief valve.
11 . A method for a pressure regulating pump, comprising:
maintaining a pressure of a pump chamber of the pressure regulating pump at or below a threshold pressure by translating the pressure of the pump chamber to axial movement of a pump body of the pressure regulating pump, the pump body including a cylindrical cavity housing a spring-loaded piston and configured to fluidly couple one or more inlet ports of the pump body to an outlet port, the axial movement of the pump body moving the one or more inlet ports relative to the piston;
wherein the outlet port is positioned vertically higher than the one or more inlet ports, the outlet port at and extending through a top center of an inner cylindrical portion of the pump body positioned inside a spring of the spring-loaded piston, the inner cylindrical portion having a hollow center forming a discharge compartment fluidly coupled to the cylindrical cavity via the outlet port.
12 . The method of claim 11 , further comprising pumping a fluid with the pressure regulating pump, the pumping including intaking the fluid to the pump chamber via the one or more inlet ports during an intake stroke of the piston and exhausting the fluid from the pump chamber into the discharge compartment via the outlet port during an exhaust stroke of the piston.
13 . The method of claim 12 , wherein the pump body is housed in a casing with a body spring coupled between the pump body and the casing, and wherein maintaining the pressure of the pump chamber at or below the threshold pressure by translating the pressure of the pump chamber to axial movement of the pump body comprises, when the pressure of the pump chamber exceeds a pre-load of the body spring, axially moving the pump body via the pressure in the pump chamber.
14 . The method of claim 13 , further comprising moving the piston during the exhaust stroke via rotation of a cam on a camshaft.
15 . The method of claim 11 , wherein the one or more inlet ports have a curved, chamfered edge that allows fluid to flow into the pump body without passing a sharp corner.
16 . A pressure regulating pump, comprising:
a pump body comprising an outer cylindrical portion and an inner cylindrical portion accommodated within the outer cylindrical portion, wherein the outer cylindrical portion includes one or more inlet ports and the inner cylindrical portion includes an outlet port;
a spring-loaded piston at least partially accommodated within the pump body and between the outer cylindrical portion and the inner cylindrical portion and configured to pump fluid into and out of a pump chamber formed between the piston and the inner cylindrical portion; and
a casing housing the piston and the pump body, wherein the outer cylindrical portion and the inner cylindrical portion are configured to move axially relative to the casing.
17 . The pump of claim 16 , wherein the pump body, including the outer cylindrical portion and the inner cylindrical portion, is configured to move vertically downward when a pressure of the pump chamber exceeds a pre-load of a spring coupled between the pump body and the casing.
18 . The pump of claim 16 , wherein the pump chamber is fluidly coupled to a discharge compartment via the outlet port and is fluidly coupled to a fluid supply via the one or more inlet ports.
19 . The pump of claim 18 , wherein the piston is movable between a top dead center (TDC) position and a bottom dead center (BDC) position, wherein at the BDC position, the one or more inlet ports are covered by the piston and fluid communication between the fluid supply and the pump chamber is blocked, and wherein at the TDC position, the one or more inlet ports are at least partially uncovered to provide fluid communication between the fluid supply and the pump chamber.
20 . The pump of claim 16 , wherein the casing is cylindrical, and wherein the one or more inlet ports are positioned in an annular recess of the outer cylindrical portion, the annular recess and the casing collectively defining a suction annulus.