Abstract: A circumferential sealing arrangement is disclosed herein. The circumferential sealing arrangement includes a structure operable to rotate about an axis and having a first surface facing radially outward. The circumferential sealing arrangement also includes a static housing circumscribing the rotatable structure. The circumferential sealing arrangement also includes at least one seal element connected to the static housing and having a second surface facing radially inward. The circumferential sealing arrangement also includes a seal runner rotatable with the structure and having a third surface facing radially outward. The third surface cooperates with the second surface to form a circumferential seal between the static housing and the rotatable structure. A radial gap is defined between the first surface of the rotatable structure and a fourth surface of the seal runner facing radially inward and opposing the first surface.

Abstract: A portable self-priming transfer pump comprising a one piece unitary housing, comprised of a first portion that houses a motor, a second casing portion within which is formed a pump cavity, and a handle; and a one piece cover fitted to the outboard end of the second portion of the housing.

Abstract: A lubrication system for a bearing assembly includes a fan shaft with a plurality of conduits, a first bearing rotatably supporting the fan shaft, and a second bearing rotatably supporting the fan shaft where the second bearing is axially spaced from the first bearing. The plurality of conduits includes at least a first conduit aligned with the first bearing and a second conduit aligned with the second bearing. A spray bar includes a plurality of supply orifices that direct lubricating fluid to the first and second bearings via at least the first and second conduits.

Abstract: The invention provides a high-speed rotor assembly for an overhung centrifugal compressor comprising a housing, a rotor component, an oil film damper and an impeller, which is adapted for connecting to a power output mechanism, wherein the rotor component is arranged inside the housing, and the oil film damper is disposed between the impeller and the rotor component, and the impeller is coupled to the rotor component. The rotor component further comprises a sleeve, a first bearing, a second bearing, a transmission shaft, a plurality of resilient elements and a spacer, wherein an end of the sleeve is connected to one of the circular rib by a screw while another end thereof is handing freely, and a oil film damper is disposed between the sleeve and another circular rib.

Abstract: Used in a thermal circulation system in which a fluid cooling agent is circulating in proper order through a compressor, a condenser, a capillary tube/expansion valve and a evaporator, an economizer is disclosed to include an enclosed vane wheel set in between the condenser and the evaporator and rotatable by the fluid cooling agent, two sealing structures mounted in the housing of the enclosed vane wheel to seal the gap between the housing and shaft of the enclosed vane wheel, and a cooling fan fixedly mounted on the shaft of the enclosed vane wheel outside the housing and rotatable with the shaft and the vanes at the shaft to cause currents of air toward the condenser for carrying heat away from the condenser.

Abstract: The quality of the lubrication of an inter-shaft bearing, particularly one with counter-rotational bushes, is improved by the presence of an obstacle on the outer bush which allows an adjustment in the quantity of oil present on the outer roll track. In particular, the drying of the roll track under the effect of the repeated running of the runners is compensated for by organizing a mandatory axial circulation.

Abstract: An improvement for a turbine generator or pump having main bearings separated by a span of shaft and a thrust equalizing mechanism adjacent one of said main bearings, the improvement comprising a stationary length compensator interposed between the thrust equalizing mechanism and its adjacent main bearing to reduce the span between said main bearings. Preferably the length compensator is composed of material that shrinks less than the shaft of the generator, and the height of the length compensator, i.e., the compensating dimension, is selected according to desired thrust equalizing mechanism operating parameters over a temperature range.

Abstract: An anti-ice formation device for a gas turbine engine is configured to be mounted within an inlet duct of the engine, and adjacent the gas turbine engine compressor inlet. The device is configured to selectively receive a flow of compressed air that is discharged from the compressor. Because the compressed air is relatively hot, the anti-ice formation device temperature increases to a temperature sufficient to prevent ice accumulation and formation in the engine inlet duct. The anti-ice formation device is also configured such that heat is not transferred to the compressor inlet housing. As a result, the anti-ice formation device does not cause impeller clearance variations, which would adversely affect engine performance.

Abstract: A subject for the invention is to provide a method of transferring a polymerizable liquid by which the polymerizable liquid can be stably transferred without arousing any mechanical-seal trouble over long. The method of transferring a polymerizable liquid utilizes a pump which has a mechanical seal having seal faces and has a flushing liquid line for supplying a flushing liquid to a flushing liquid introduction opening of the mechanical seal, wherein the flushing liquid line is equipped with a strainer, a device for adding a polymerization inhibitor, or a flushing liquid cooler.

Abstract: In a motor vehicle drive arrangement oil is supplied to a drive gear mechanism and other drive elements by an oil pump which is driven only by an electric motor and is arranged in a space in which one or more torque transmission devices such as a hydrodynamic torque converter, an operable drive clutch and at least one electric motor for forming a hybrid drive are disposed and which is formed between the oil pump and electric motor, on the one hand, and the vehicle travel drive motor on the other, the oil pump is disposed around a shaft transmitting the drive torque to the transmission and is surrounded by the electric motor driving the pump.

Abstract: In a rotodynamic pump, a seal chamber conditioning valve mechanism is positioned at least partially within the seal chamber of the pump to selectively and intermittently deliver fluid to or discharge contents from the seal chamber to modify the condition or content of the seal chamber and effectively protect the mechanical seal from failure due to, for example, built up solids or the presence of air. The conditioning valve mechanism may be actuated by a control device in communication with monitoring apparatus that determines the condition of the seal chamber, and particularly the mechanical seal face.

Abstract: A centrifugal environmentally safe pump including a motor driven pump shaft having a fluid pumping impeller affixed thereto. A plurality of annular shaft supporting bearing assemblies are disposed along the shaft adjacent a lubrication chamber, the lubrication chamber housing lubrication fluid (e.g. oil) maintained at a level below rotating portions of the bearing assemblies so as to maintain a low operating temperature within the chamber and adjacent the bearings. A lubricating fluid dispenser having a thin-profile, disc-shaped portion is affixed to the pump shaft within the lubrication chamber for rotation along with the shaft. A plurality of wire-like fluid contacting members are loosely connected along the outer periphery of the disc-shaped portion through respective bearing sleeves, the wire members for dipping into the lubricating fluid when the pump shaft is rotating thereby dispersing or misting the fluid throughout the chamber.

Abstract: Component parts for a mixing assembly adapted to be used with clean in place techniques. The component parts may include an impeller assembly, an adjustable hub assembly, and a steady bearing assembly. The bearing assembly may include a supporting structure having a fitting and a plurality of legs extending from the fitting and securely engaging the vessel, and a guide bearing bore adapted to receive a shaft, wherein the guide bearing is adapted to be removably engaged from the supporting structure and wherein the guide bearing is removable from the supporting structure shaft without necessitating removal or lifting of the shaft.

Abstract: A water pump comprises a pump body, a cylindrical supporting portion, a pulley, a shaft portion, an impeller, a seal member, a pulley cylinder portion, a wall portion, a through-hole formed, a cover covering the wall portion and the pulley cylinder portion of the pulley from one side of the pulley, and the cover formed in a cylindrical shape with a bottom portion and including a reservoir for receiving fluid that has leaked through the seal member.

Abstract: A rotor mechanism of a centrifugal compressor connectable to a power output device and configured to block leakage of lubricants and to recycle lubricants to an oil sump is provided, which includes a rotary shaft with a rolling bearing and a screw nut, a bearing housing for receiving the rolling bearing, and a bearing plate connected to the bearing housing. The screw nut has a surface provided with an oil throw seal, and the bearing housing. As the bearing plate is provided with an oil channel in contact with the oil-returning hole and either one of the bearing housing and the bearing plate is provided with a first labyrinth seal in contact with the screw nut, lubricants leaking out of the rolling bearing is allowed to go to the oil sump via the oil channel and oil-returning hole. The oil slinger thus blocks the lubricants from leaking out of the first labyrinth seal.

Abstract: A cooling fan includes a frame (30), a stator (20) and a rotor (10). The frame includes a base (32) having a central tube (34). A bearing (22) is received in the central tube. The rotor includes a hub (11) having a shaft (15) extending from the hub into the bearing. An oil retaining ring (40) is mounted on the hub around the shaft and near a top of the central hub.

Abstract: A method of assembling a gas turbine engine includes providing a gas turbine engine including a compressor, a combustor downstream from the compressor, and a turbine coupled to the compressor, and coupling a seal assembly aft of the compressor such that air discharged through the seal assembly facilitates reducing the cavity pressure, and therefore reducing the axial forces induced to an aft side of the compressor.

Abstract: A sewage pump includes a motor, a main shaft, an upper impeller, a lower impeller, a grinding wheel, a top cap, an upper bearing base with an upper mounting plate, an upper bearing base, a tube body with a wire inlet connector, a lower bearing base, a lower bearing with a lower mounting plate, a lower base and a vertical bypass. The main shaft has a quad-bearing structure to minimize deflection at high speed and high pressure and has rotary seals at each end to improve stability and sealing efficiency. Moreover, the wire inlet connector is filled with epoxy filling material to protect the wire, and the sewage pump further has moisture-sensors to timely stop the motor when sealing efficiency is failing.

Abstract: An apparatus for scavenging lubricating oil comprises an integrated slinger/runner rotatable with the turbine engine rotor discourages oil seepage out of an oil sump of a forward bearing for a gas turbine engine during all operating conditions of the gas turbine engine from idle to take-off speeds and during static non-operation. The apparatus includes a runner comprising an axially forward section and a frusto-conical aft section, and a slinger joined coaxially integrally to the aft frusto-conical aft section. The apparatus includes a means for blocking flow of oil from the frusto-conical aft section toward the axially forward section.

Abstract: A vertical centrifugal pump having a support bearing arranged above the pump and including an axial bearing (22) and a radial bearing (23). A housing (24) encasing the support bearing (22, 23) is directly connected to the flow-carrying housing (25) of the centrifugal pump. Lubrication, and optionally cooling, of the support bearing (22, 23) are performed by the pumped medium, which is conveyed to the support bearing (22, 23) through a connection leading from the pressure zone (28) of the flow-carrying housing and is discharged into the suction zone (29) of the pump, and a pump shaft seal (31) is disposed on the opposite side of the support bearing (22, 23) from the flow-carrying housing of the centrifugal pump.

Abstract: The bearing system includes a first component having a first substrate and a first coating. The first coating includes a DLC layer and a DLN layer between the DLC layer and the substrate. A second component is in sliding engagement with the first component.

Abstract: A method and device for improved pressure balancing in a bearing chamber pressurization system for gas turbine engines employ a partition member to substantially separate first and second air-oil seals of the bearing housing.

Abstract: Systems and method for controlling the flow of air through a mechanical draft system are disclosed herein. A pressure controller for controlling air pressure comprises an appliance controller configured to control the operation of a plurality of appliances, an intake fan controller configured to control the speed of an intake fan, and an exhaust fan controller configured to control the speed of an exhaust fan. The pressure controller also includes a processor configured to receive a differential pressure signal and to control the operation of the appliances, the speed of the intake fan, and the speed of the exhaust fan in response to the differential pressure signal.

Abstract: A device applied to regulating the flow rate of air flowing in a rotary shaft of a turbomachine, the shaft including at least one through orifice for passing air. The device at least one shutter member for shutting the orifice and secured to a deformable blade presenting bi-linear behavior, the blade being secured to the shaft and being suitable for deforming under the effect of the centrifugal force that results from the shaft rotating such that the shutter member is suitable for taking up two different positions depending on the speed of rotation of the shaft: one position in which it shuts the orifice; and another position in which it releases the orifice to allow air to pass through.

Abstract: A device for lubricating a component in a turbomachine, in particular a shaft bearing in a turbojet, the device comprising an annular support part defining a lubrication chamber around the component, an annular cover mounted in sealed manner on the part and including a lubricating oil inlet, and an annular channel for passing a flow of pressurizing and cooling air, which channel is formed between the part and the cover, and communicates with ducts in the support part and an annular enclosure formed in the cover for passing the pressurizing and cooling air.

Abstract: The present invention relates to a process fluid handling device in an electrochemical cell system having a fluid barrier between a process fluid compartment and a drive compartment of the fluid handling device. The fluid barrier comprises an interconnection compartment, filled with barrier gas. The pressure of the interconnection compartment is maintained above the process fluid and drive compartments, by fluid communication with barrier gas stored in a storage device. The barrier gas is preferably a non-reactive and dehumidified gas. The present invention also contemplates methods of isolating the hydrogen-containing process fluid in the process fluid compartment from the drive compartment, which is preferably in fluid communication with the ambient.

Abstract: A fluid flow engine comprises a shaft supported in a bearing housing by means of a bearing shell. There are at least two lubricating bores in the bearing shell each having a predetermined geometry as to diameter, length and angular arrangement with respect to the bearing shell. At least one turbine rotor is on one end of the shaft. A turbine housing provides a turbine space for accommodating the turbine rotor, the turbine housing being connected to the bearing housing. There are sound suppressing means arranged within the bearing housing.

Abstract: A vacuum pump of the invention comprises, in a common pump body (100): molecular drag pump stages (5) in series with regenerative pump stages (9). The molecular drag pump stages (5) comprise a molecular drag rotor (5a) including a blind axial cavity (5c) open towards the downstream end, and the motor (7) is housed at least in part in said blind axial cavity (5c). The drive shaft (8) is coupled via its upstream end (8a) to the molecular drag rotor (5a), and it is coupled via its downstream portion (8b) to the regenerative rotor (9a). The motor (7) is secured to the central segment of the drive shaft (8). This provides a universal pump of small size, enabling pumping to be performed from 1000 mbar down to 10?8 mbar, and suitable for being placed in the vicinity of a vacuum chamber.

Abstract: A drainage pump has a pump part in which blades mounted on a rotary shaft are arranged in a pump casing and an underwater bearing unit which uses pumped water mixed with hard particles as a lubricant and has a sliding bearing for journaling the rotary shaft. A portion of the rotary shaft journaled by the sliding bearing is formed of a cemented carbide material and a shaft journaling surface of the sliding bearing is formed of a thermoplastic resin material to be embedded with hard particles.

Abstract: A CO2 compressor for an air conditioner of a motor vehicle is suggested having a sealing device, assigned to the driveshaft of the CO2 compressor, which is implemented as a sliding ring. The CO2 compressor features a lubrication device, in which the sealing device is supplied a lubricant flow effected by centrifugal forces.

Abstract: A turbocharger having a turbine wheel mounted to a seal boss at one end of a shaft and a compressor wheel mounted to the other end of the shaft. The seal boss includes an annular face angled relative to a radial plane extending through the shaft so that as the shaft rotates oil present on the annular face is projected into an oil collecting groove in a direction radially away from the shaft and axially away from an annular passage in a housing wall.

Abstract: An exemplary bore for a shaft of a turbomachine includes a longitudinal axis extending generally from an inner end to an outer end of the bore, an outer seat disposed proximate to the outer end of the bore at an outer seat radius for an outer seal ring wherein the outer seat comprises an inner end, an outer end, a step at the inner end extending radially inward to a step radius, and a chamfer at the outer end extending radially inward over an outward axial distance to a chamfer plateau radius and an inner seat disposed inward the outer seat at an inner seat radius for an inner seal ring wherein the outer seat radius exceeds the inner seat radius. Various other exemplary devices, systems, methods, etc., are also disclosed.

Abstract: Liquid seal pump of the helical screw type including a pump housing (3) with an inlet (2), an outlet (6), and within the housing provided a helical screw rotor (7) driven by means of a motor (8). The outlet (6) of the pump (3) is provided with a sealing liquid tank (4) for supplying of liquid to the pump and thereby maintaining the liquid seal under idle running of the pump.

Abstract: A fluid pump including provisions for cooling and/or flushing in the vicinity of a static seal. In one embodiment, the invention includes an open channel fluid passageway defined on a generally flat surface of a pump housing. A centrifugal rotor with a generally flat backplate rotates proximate a surface of the housing. The fluid passageways are adapted and configured to have a pathway that includes a directional component parallel to the direction of rotation, such that fluid drag from the rotating backplate induces flow within the passageway. The passages of the exit can be positioned such that flow exiting the passageway is at least partly tangential to the seal and/or the seal housing.

Abstract: A device for centering a component positioned inside and rotationally secured at its end to a turbine hollow shaft positioned in a gas turbine engine. The device includes a sheath enclosing and solidly joined to the component, and an elastic ring interposed between the sheath and the shaft. The ring includes a plurality of pairs of opposed shoes extending radially outwardly therefrom and configured to radially expand so as to extend against an inner portion of the shaft. The shoes include thin, elastic cylindrical walls having an external diameter configured slightly less than the internal diameter of the shaft prior to assembly onto the shaft, and arranged to expand to the inner wall of the shaft when assembled thereon.

Abstract: An axial thrust balancing system for a centrifugal compressor, having improved safety characteristics, the centrifugal compressor comprising a rotor having impellers adjacent to each other and connected by a shaft, the rotor rotating in a stator, the centrifugal compressor additionally including a balancing piston, a balancing line being provided between an intake of a first compression stage and an area downstream of the balancing piston; this system comprises an intake mechanical gas seal around the shaft upstream of the first compression stage and an outlet mechanical gas seal downstream of the balancing piston, the balancing line being closable by blocking elements.

Abstract: A centrifugal pump has a pump case and a rotatable impeller disposed within the pump case. A central aperture is defined within the rearward wall of the pump case to facilitate the connection of an impeller drive shaft to the impeller. A drive shaft seal is disposed within the central aperture to seal the impeller drive shaft to the pump case. At least one or more grooves are defined in the rearward wall of the pump case to carry liquids to and from the drive shaft seal. One or more radial ridges are disposed on the rearward side of the impeller to encourage liquids to flow within the grooves to and from the drive shaft seal to continuously wash away precipitates around the seal and to cool the seal.

Abstract: The present invention provides a method and apparatus for balancing the pressure across a front bearing in a compressor housing. The present invention may protect the bearing from lubricant migration by eliminating pressure differentials across the bearing. When a blower or fan is running, the bearing experiences the same pressure differential that is across the blower. Unless this pressure is balanced, lubricant may migrate from the bearing very quickly. The present invention may provide a pressure balance and sealing across the front bearing of a blower or fan. A plurality of grooves on the face of a compressor impeller and a plurality of grooves on a compressor shaft surface restrict the gas flow to balance pressure across a bearing. Alternatively, a labyrinth seal may cooperate with a plurality of grooves on the face of a compressor impeller to balance pressure across the bearing.

Abstract: A pump of the rotor/stator type for wet cementitious material includes a suction housing for receiving and directing the material into a rotor/stator combination for delivery to the location of use. The suction housing is in the form of a rectangular closed structure having a material receiving flange and enclosing coupling between a drive shaft and an end of a rotor. The housing includes top, bottom and side panels, one of which includes the aforementioned material receiving flange. Each of the panels is easily removed from the suction housing to facilitate cleaning and removal of material residue after use, as well as maintenance and repair of the pump. Cementitious material may be introduced through either the top, bottom or either of the side panels by appropriate positioning of the material receiving flange. The pump further includes a lubricant reservoir for lubricating the drive shaft to extend pump operating lifetime.

Abstract: An improved diesel engine water pump includes three main features that aid in extending the maintenance-free life of the pump. The impeller shaft is carried by tapered roller shaft support bearings of which the impeller bearing has a floating outer race that is urged axially by a preload spring to provide a prescribed axial preload that maintains concentricity of the shaft with the axis and prolongs bearing life. An improved oil seal combines an oil slinger, a stationary deflector and a lip oil seal with a return passage to the engine to more effectively limit oil leakage from the pump. An improved water seal includes pressurized water jets fed from the pump volute that flush wear particles from the water seal surface and increase water seal life. Further details of these features are also disclosed.

Abstract: A method of minimizing oil consumption in a gas turbine engine, by avoiding reliance on air intake into the engine oil circuit for bearing chamber oil sealing purposes. The engine oil circuit has bearing chambers with hydropad seals between the shaft and bearing chamber. During engine operation the ring rotates to cast oil radially outwardly from the shaft axis toward the outer periphery of the bearing chamber under centrifugal force, independent of any gas pressure differential across the sealing surfaces of the hydropad seal.

Abstract: A turbocharger including means for preventing or reducing coking, particularly following engine shutdown, without noticeably increasing weight or volume of the turbocharger. The turbocharger bearing housing (14) has defined therein a lubrication flow path for bearing lubricant and a lubricant drain gallery (40) below a shaft (20), and in accordance with the invention at least a portion of a wall (42) of the lubricant drain gallery (40) is coated with an oil repellant and/or heat insulating coating (44).

Abstract: Enclosure for liquid lubricated rotating elements (12, 16, 17). A first rotating element (16) with at least one bearing (13, 14, 15) lubrication fluid drainage point that cooperates with a second rotating element (17). A partition wall (21) is mounted between the drainage point and the second element (16, 17), in such a manner that lubrication fluid is substantially prevented from migrating from the drainage point to the second element.

Abstract: In a vacuum pump of the regenerative type or including a regenerative section in which a rotatable vertical shaft is supported by upper and lower bearings, a lubricating system for lubricating the upper bearing comprising an axial bore extending along the shaft and communicating at its upper end with at least one oil hole in alignment with the upper bearing, the lower open end of the axial bore extending in to a shaft reservoir located in a sump for containing lubricating fluid, the arrangement being such that centrifugal force generated by the rotation of the shaft will cause the lubricating fluid in the shaft reservoir to pass along the axial bore as a thin film towards the oil hole and hence to the upper bearing, in which at least one port is formed in a wall of the shaft reservoir to permit the passage of lubricating fluid therethrough from the sump in a controlled manner dependent upon the head of lubricating fluid in the sump above the port.

Abstract: A seal of a vertical pump with a front casing disposed on a main casing which has a motor disposed therein. A volute chamber is disposed inside the front casing to receive a centrifugal impeller. A suction inlet is disposed axially on the front casing opposite the motor. A water outlet is disposed thereon opposite the lateral side of the impeller to engage with a discharge pipe. The suction inlet and outlet are in communication with a volute chamber. The pump has a non-contact seal disposed on the impeller. The seal can jam when a liquid crystallizes. Therefore, if no heat is generated due to the friction of the seal, the pump operates better. Furthermore, it prevents a back impeller vane from stirring the air and ejecting the liquid with a lot of air bubbles when the pump operates. Therefore, it eliminates the air bubbles from causing problems during the manufacturing process of a printed circuit board.

Abstract: The invention relates to an exhaust gas turbocharger (1) having a housing and having a shaft (2) which is arranged so as to be capable of rotating about its longitudinal axis in the housing and on which a turbine wheel (4) and a compressor wheel (3) are seated and which is guided in radial bearings (5, 6) and in at least one axial bearing (9), the radial bearings (5, 6) being embodied as passive, permanent-magnetic bearings which each have a bearing plate (12, 16) which is seated on the shaft (2) as a rotor, and at least one stator (19, 20, 21, 22) which is disposed axially opposite to said rotor. In order to achieve a radial oscillation damping of the shaft (2) in a simple manner, it is proposed according to the invention that a resilient element (60, 61) is disposed between the stator (19, 20, 21, 22) and a part (37, 38) which is fixed to the housing.

Abstract: A draining and cooling system for gas turbine cushions where the above-mentioned gas turbine has its own drain unit (11), which consists of two essentially concentric rings connected to each other by means of a number of spokes (12, 13). In the draining system described, the lubricating and cooling oil is fed into the gas turbine's drain unit (11) by means of at least a first pipe (14), located inside one of the spokes (12) and is drained by means of at least a second pipe (20), located inside one of the spokes (13).

Abstract: The invention recites a power turbine assembly including a turbine rotor and a plurality of turbine blades mounted to said rotor and adapted to rotate said rotor in response to a flow of hot gas over said blades. A support structure having a journal bearing and at least one other bearing supports said rotor for rotation, said journal bearing having a proximal end and a distal end with respect to said turbine blades. A supply of lubricant communicates with said journal bearing to provide lubricant between said rotor and an inner surface of said journal bearing, said lubricant damping rotational frequencies of said rotor and creating a temperature gradient from greater than about 1000° F. at said blades to less than about 350° F. at said distal end.

Abstract: A lubrication system for equipment (e.g. centrifugal pump) employing a rotating shaft and corresponding support bearings is disclosed. The lubrication system includes a lubricant dispenser having a plurality of blades or dispensing members pivotally attached thereto, the dispenser affixed to the shaft for rotation therewith. Centrifugal force created by rotation of the shaft to which the dispensing blades are attached causes the blades to extend radially outward from the shaft center during operation so as to dispense the lubricant throughout a lubricating or misting chamber in order to lubricate the adjacent bearings. The system is also advantageous in that the blades are permitted to pivot or flap downward toward the shaft in either direction so that the dispenser may be more easily inserted into the misting chamber during manufacturing of the device or replacement of the lubricating system.

Abstract: A cooling water pump for internal combustion engine includes a base and an outer cover forming a water input chamber, an impeller supported on a shaft within said chamber, fed shaft includes a bearing/seal unit mounted within the base and the shaft extended outwardly for connection to the engine. A one-piece, fully enclosed and double shrouded impeller is secured to the shaft. Impeller has a central hub with an outer peripheral concave surface, a bottom convex end wall, vanes are secured to the central portion of the concave wall in the bottom wall and project outwardly therefrom with an outer top shroud. The base has a recess within which the bearing/seal unit is mounted. The recess extends outwardly beyond the outer edge convex wall of the hub from a cooling chamber. The vanes direct a portion of the water flowing through the passageway into the recess for cooling purposes and then back into the radially outer portion of the passageway for discharge with the flowing water into the outlet passageway.