Electric diaphragm pump with offset slider crank
A diaphragm pump having a crankshaft that is rotatable about a rotational axis and coupled to a piston. The piston is reciprocally displaceable within a piston cylinder along an axis of motion between suction and discharge strokes. A diaphragm housing coupled to the piston cylinder at least partially defines a pumping chamber through which fluid is pumped as the piston reciprocates. The axis of motion, which intersects a connection between the piston and the connecting rod, may not intersect the rotational axis of the crankshaft such that, relative to an arrangement in which the axis of motion does intersect the rotational axis, a peak magnitude of piston side load forces during the discharge stroke is reduced and a peak magnitude of piston side load forces during the suction stroke is increased so as to attain an improved balance between the peak magnitudes of piston side load forces of the discharge and suction strokes.
1 . A diaphragm pump, comprising:
a crankcase;
a crankshaft at least partially disposed within the crankcase, the crankshaft having a crankshaft axis, and the crankshaft being configured to rotate during operation of the diaphragm pump;
three or more diaphragms that each at least partially define a pumping chamber, wherein each diaphragm of the three or more diaphragms is structured to reciprocate, along a respective cylinder axis oriented orthogonal to the crankshaft axis, between a first position and a second position to pump a fluid, wherein the three or more diaphragms are distributed evenly around the crankshaft axis such that angles formed between adjacent cylinder axes are substantially equal, each diaphragm having a first surface and a second surface opposite to the first surface, each diaphragm having a respective first washer configured to abut the first surface of the diaphragm upon reciprocation of the diaphragm toward the crankshaft, each diaphragm having a respective second washer configured to abut the second surface of the diaphragm upon reciprocation of the diaphragm away from the crankshaft;
a seal assembly configured to block flow of lubricant from the crankshaft to the first surface;
a cylinder for each of the three or more diaphragms, each cylinder arranged along its respective cylinder axis and housing a piston, the piston connected to the crankshaft by a connecting rod; and
a respective cavity positioned between each diaphragm of the three or more diaphragms and a surface of its respective cylinder, wherein each diaphragm of the three or more diaphragms fluidly separates the respective cavity from a corresponding pumping chamber, each respective cavity contains low pressure air, and at least two of the respective cavities are configured to pass the low pressure air among one another to avoid pressure buildup within the respective cavities during reciprocating motion of the three or more diaphragms.
2 . The diaphragm pump of claim 1 , comprising three diaphragms distributed evenly around the crankshaft axis such that the angles formed between adjacent cylinder axes are each 120 degrees.
3 . The diaphragm pump of claim 1 , comprising a motor connected to the crankshaft, wherein the motor is configured to provide power to rotate the crankshaft during the operation of the diaphragm pump.
4 . The diaphragm pump of claim 1 , wherein each respective piston is coupled to each diaphragm of the three or more diaphragms such that rotation of the crankshaft drives reciprocation of the respective piston and each diaphragm along the respective cylinder axis.
5 . The diaphragm pump of claim 4 , wherein the rotation of the crankshaft drives the reciprocation of the respective piston through the respective cylinder.
6 . The diaphragm pump of claim 5 , wherein each respective cylinder comprises a diaphragm-facing surface, and the reciprocation of the respective piston through the respective cylinder maintains positioning of each diaphragm coupled to the respective piston within the pumping chamber and beyond the diaphragm-facing surface of the respective cylinder.
7 . The diaphragm pump of claim 1 , wherein each first surface and corresponding diaphragm cooperatively define a respective containment cavity in which the respective first washer is disposed.
8 . A diaphragm pump comprising:
a crankshaft extending along a crankshaft axis and configured to rotate during operation of the diaphragm pump;
three or more cylinders distributed circumferentially evenly around the crankshaft axis, each cylinder arranged along its respective cylinder axis;
three or more pistons, wherein each piston of the three or more pistons is disposed within a respective cylinder of the three or more cylinders, each piston is connected to the crankshaft by a connecting rod, and rotation of the crankshaft drives movement of each piston of the three or more pistons within the respective cylinder to pump fluid;
three or more diaphragms, each diaphragm being coupled to a respective piston, each diaphragm having a first surface and a second surface opposite to the first surface, wherein a respective first washer is coupled to each diaphragm and is configured to abut the first surface of the respective cylinder upon reciprocation of its diaphragm toward the crankshaft, and a respective second washer is coupled to each diaphragm and is configured to abut the second surface of the respective cylinder upon reciprocation of its diaphragm away from the crankshaft;
a seal assembly configured to block flow of lubricant from the crankshaft to the first surface; and
a respective cavity positioned between each diaphragm of the three or more diaphragms and a surface of its respective cylinder, wherein each diaphragm of the three or more diaphragms fluidly separates the respective cavity from a corresponding pumping chamber, each respective cavity contains low pressure air, and at least two of the respective cavities are configured to pass the low pressure air among one another to avoid pressure buildup within the respective cavities during reciprocating motion of the three or more diaphragms.
9 . The diaphragm pump of claim 8 , wherein the crankshaft comprises a cam having a central axis extending parallel to and offset from the crankshaft axis, and a piston of the three or more pistons is connected to the cam.
10 . The diaphragm pump of claim 8 , comprising three or more diaphragm housings, wherein each diaphragm housing of the three or more diaphragm housings defines a chamber, and the rotation of the crankshaft drives the movement of each piston of the three or more pistons relative to a corresponding diaphragm housing to pump fluid through the chamber defined by the corresponding diaphragm housing.
11 . The diaphragm pump of claim 10 , wherein the movement of each piston of the three or more pistons relative to the corresponding diaphragm housing moves a respective diaphragm to adjust a size of the chamber to pump fluid through the chamber.
12 . The diaphragm pump of claim 11 , wherein the rotation of the crankshaft drives the movement of each piston of the three or more pistons relative to the corresponding diaphragm housing to move the respective diaphragm into and out of engagement with a corresponding cylinder of the three or more cylinders.
13 . The diaphragm pump of claim 12 , comprising a motor configured to electrically drive the rotation of the crankshaft to drive the movement of each piston of the three or more pistons relative to the corresponding diaphragm housing.
14 . The diaphragm pump of claim 13 , wherein each respective diaphragm comprises a flexible portion coupled to the corresponding diaphragm housing, the movement of each piston of the three or more pistons relative to the corresponding diaphragm housing adjusts extension of the flexible portion along its corresponding diaphragm housing, and the flexible portion does not contact the first surface of the corresponding cylinder of the three or more cylinders during the movement of each piston of the three or more pistons.
15 . The diaphragm pump of claim 8 , wherein the respective first washer and the respective second washer associated with each respective diaphragm are positioned on opposite sides of the respective diaphragm to stabilize the respective diaphragm.
16 . The diaphragm pump of claim 15 , comprising a fastener extending through a piston of the three or more pistons, the respective first washer coupled to the piston, the respective diaphragm on which the respective first washer is positioned, and the respective second washer positioned on the respective diaphragm to couple the piston, the respective first washer, the respective diaphragm, and the respective second washer to one another.
17 . A diaphragm pump, comprising:
a crankshaft extending along a crankshaft axis and configured to rotate during operation of the diaphragm pump;
three pistons connected to the crankshaft, each of the three pistons being connected to the crankshaft by a connecting rod, wherein rotation of the crankshaft drives movement of the three pistons along respective axes, and the three pistons are distributed around the crankshaft axis such that each angle formed between adjacent axes is 120 degrees;
three diaphragms, wherein each diaphragm is coupled to a respective piston of the three pistons, each diaphragm having a first surface and a second surface opposite to the first surface, a respective first washer is coupled to each diaphragm and is configured to abut the first surface upon movement of a corresponding piston toward the crankshaft, and a respective second washer is coupled to each diaphragm and is configured to abut the second surface upon movement of the corresponding piston away from the crankshaft;
a seal assembly configured to block flow of lubricant from the crankshaft to the first surface;
a cylinder for each of the three diaphragms, each cylinder arranged along its respective cylinder axis and housing one of the three pistons; and
a respective cavity positioned between each diaphragm of the three diaphragms and a surface of its respective cylinder, wherein each diaphragm of the three diaphragms fluidly separates the respective cavity from a corresponding pumping chamber, each respective cavity contains low pressure air, and at least two of the respective cavities are configured to pass the low pressure air among one another to avoid pressure buildup within the respective cavities during reciprocating motion of the three diaphragms.
18 . The diaphragm pump of claim 17 , wherein the rotation of the crankshaft drives the movement of the three pistons along the respective axes to reciprocate relative to a corresponding cylinder.
19 . The diaphragm pump of claim 17 , comprising a motor configured to electrically rotate the crankshaft to drive the movement of the three pistons along the respective axes to move the three diaphragms along the respective axes.
20 . The diaphragm pump of claim 17 , wherein each first surface and corresponding diaphragm cooperatively define a respective containment cavity in which the respective first washer is disposed.