Abstract: A self priming gear pump 14 for pumping liquids containing gases is provided with a vent pipe 26 for releasing entrapped gases that would otherwise collect at the outlet side of the pump 14. The vent pipe 26 terminates within the pump housing 21 at a zone which is out of the path of the oil centrifuged by the gears 25 and in the region lying near the point of intersection of the gears 25. An additional inlet pipe 27 which directs liquid across the main inlet into the gap between the periphery of one of the gears 25 and the housing 21 may be provided to improve liquid sealing.

Abstract: The endless camming peripheral surface of the pump housing, which performs one cycle of suction, compression and discharge of fluid in cooperation with the vanes and the rotor, comprises an increasing radius portion along which the amount of protrusion of each vane gradually increases with movement of the vane, and first and second decreasing radius portions along which the amount of protrusion gradually decreases with movement of the vane, the three portions being successively arranged in the order mentioned in the advancing direction of the vanes. Each of the three portions has such a cam profile that the velocity of radial movement of each vane varies at a rate gradually decreasing as the vane approaches the terminating end of the portion. Preferably, the above one-cycle performing portion further includes one or two constant radius portions located between the above three portions, along which the amount of protrusion of each vane is kept substantially constant with movement of the vane.

Abstract: A motor-pump unit for submerging down a well, e.g. an oil well, comprises a motor portion driving a pump portion. The motor portion is filled with fluid to prevent ingress of the surrounding medium which the pump portion pumps. The fluid is maintained at a higher pressure than the surrounding medium by including a flexible tank filled with fluid and in communication with the fluid in the motor portion. The flexible tank is compressed both by the surrounding medium and by resilient compression means so that the pressure inside the motor is higher than the surrounding pressure, thereby ensuring any leakage is outwardly from the motor. Down the well the temperature rises causing the fluid to expand, so the flexible tank is left substantially empty when the unit is prepared at the surface prior to lowering.

Abstract: An electric compressor including a cylinder having a cylinder chamber and inlet and outlet ports opening into the chamber, a piston capable of reciprocating in the chamber and having a first operative face with a first peripheral edge portion inclined at a given angle, a rotating member capable of rotating in the chamber and having an outer peripheral surface capable of opening and closing the inlet and outlet ports, and a second operative face with a second peripheral edge portion inclined at the given angle and capable of being in sliding contact with the first edge portion, the first and second operative face and the peripheral surface of the chamber defining a compression chamber, pushing device for pushing the piston toward the rotating member, and a motor for rotating the rotating member. The inlet and outlet ports are opened and closed and the piston is reciprocated so that gas is sucked into the compression chamber through the inlet port, compressed, and discharged through the outlet port.

Abstract: A low level indicator and warning device is provided wherein a diaphragm is provided directly in a line for drawing liquid from one container to another. Liquid flowing in the line washes directly across the diaphragm so that it remains clean and thus operative even in the presence of materials which might form a crust on the diaphragm.

Abstract: A hydraulic gear machine which is particularly suited for use as a reversible hydraulic gear motor includes a pair of gear elements having externally meshing outer peripheral gear portions and stub shafts which are supported in an internal chamber of a housing on respective sleeve-shaped bearings. Two such bearings are arranged at each axial side of the gear elements, one for the stub shaft of each of the gear elements which extends to this axial side. The housing includes a circumferential wall and two end walls. Sealing elements having the configuration of the numeral three are arranged at the interfaces between the bearings and the end walls. The sealing elements are oppositely oriented with respect to a common plane including the axes of rotation of the gear elements at the respective axial sides.

Abstract: A variable displacement vane pump includes a rotor (10) rotatably mounted in a casing (32). The casing (32) has a pair of relatively rotatable complementary cams (18,20). Each cam (18,20) has a surface shaped to provide an annular curvilinear track. The pump also has a first (14) and second (16) plurality of vanes slidably mounted upon the rotor (10). Each of the vanes (14,16) is sized and positioned to engage a corresponding cam (18,20). These vanes (14,16) are constrained in a radial direction by the cams (18,20) as the rotor (10) rotates. The vanes of the first (14) plurality engage one (18) of the cams, the other one (20) of the cams being engaged by the vanes of the second plurality (16).

Abstract: The present invention comprises a combined speed sensor and control valve for a rotary fluid motor such as a rotary vane air motor. Weights are pivotally attached to the opposite sides of the rotating output shaft of the air motor and are spring biased into engagement with an annular valve disc member positioned over the air inlet. Upon excessive speed of the shaft, the weights swing from engagement with the valve disc member and release the member. Air flow and air pressure within the air inlet passage cause the disc member to translate axially along the rotary shaft and close the air inlet. The air motor must be disassembled and the overspeed control reset prior to continued operation of the air motor.