Abstract: A fluid system for plural motor driven pumps is disclosed. The fluid system includes a hydraulic motor, a fluid reservoir, and a plurality of fixed displacement pumps. A control valve selectively directs flow of fluid to either a reservoir or the hydraulic motor. A control system responsive to an external condition and an internal condition generates a signal for each condition. The control valve is operated by the signals. The internal signal may be generated by an internal pressure monitoring device.

Abstract: A cooling fan including a fan module, a microcontroller, and a bus interface. The microcontroller is coupled to the fan module and is capable of adjusting a speed of the cooling fan based on a status of a second cooling fan and adjusting the speed of the cooling fan based on a temperature detected. The bus interface is in communication with the microcontroller, the second cooling fan, and the system to receive and output data.

Abstract: A radiator blower, in particular for motor vehicles, is indicated that comprises a plurality of individual fans (11, 12), each having an electrical drive motor (13, 14), and a plurality of switches (S1, S2, S3), each capable of being switched over into two positions, by means of which the drive motors (13, 14) are capable of being turned on and back off individually or in a series or parallel connection. To prevent disturbing noises from developing when the individual fan (11, 12) comes to rest after being turned off, when the operating drive motor or motors (13, 14) is/are turned off, an electronic control unit (20) forces the switches (S1, S2, S3)—at least temporarily—over into switch positions that bring about a short-circuiting of the turned-off drive motor or motors (FIG. 1).

Abstract: The invention relates to a method for controlling the supply of a pressure medium on rail vehicles which are coupled together in a tractive link both mechanically and in order to enable the flow of said pressure medium, whereby said pressure medium is supplied by a main air container pipe which extends through all rail vehicles and which is fed with a pressure medium via a plurality of compressors individually mounted in each rail vehicle. The aim of the invention is to allow a balanced use of the compressors included in the tracture link. In order to achieve this, a changeable or fixed order of priority is defined for the compressors according to the total number of compressors in the tracture link, whereby the number of compressors activated depends on the order of priority necessary to meet the actual required amount of pressure medium.

Abstract: A system for variable speed control of a plurality of motors under variable load demand is provided. The system includes a constant power source and a plurality of motors having electrical circuits with switches to connect with the constant power source. The system further includes a variable speed drive for driving each of the plurality of motors at variable speed, wherein each of the plurality of motors includes a switch to connect with the variable speed drive. Each of the plurality of motors is selectively electrically connected with the variable speed drive and the constant power source via the switches, for driving the each of the plurality of motors at one of variable and constant speed in response to load demands. To prevent short cycling of the motors under situations of increasing system demand, the control algorithm for the electrical switches provides hysteresis by overspeeding one of the motors before switching from variable speed mode to constant speed mode.

Abstract: A hybrid vehicle includes: a metal V-belt type infinitely variable gear-change mechanism 20 whereby the rotation of an engine E is subjected to change in gear ratio, a forwards clutch 14 and a reverse brake 15 that perform engagement/disengagement control of the engine and the infinitely variable gear-change mechanism, and a second motor generator 50 capable of driving the drive wheels arranged parallel with the engine. The control device is provided with a first hydraulic pump 3 for engine drive, a second hydraulic pump 56 that is driven by an electric motor 55 for pump drive, and a forwards/reverse clutch control valve 73 that performs changeover control of supply of working hydraulic pressure to the forwards clutch 14 etc.

Abstract: A liquid pump includes a container body, a vacuuming device, and a liquid-discharging device. The container body has an upper portion, a lower portion, a vent hole formed in the upper portion, a cap mounted removably on the upper portion for closing the vent hole, a liquid inlet formed in the upper portion, a guide tube connected to the liquid inlet, a liquid outlet formed in the lower portion, and a plug mounted removably on the lower portion for closing the liquid outlet. The vacuuming device is mounted on the container body and is operable so as to reduce air pressure within the container body. The liquid-discharging device includes a connecting rod connected to the plug and movable between a closing position and an opening position. The liquid-discharging device further includes a biasing unit connected to the connecting rod for biasing the connecting rod to the closing position.

Abstract: A method and apparatus for detecting the dry-run operation of a submersible fuel pump operating in a network of fuel pumps is disclosed in which the pump controller is able to switch itself off upon detection of a dry-run condition. After shutting itself off, the pump controller can request assistance from another pump in the pump network. When fuel is added to the tank, the fuel pump controller will detect the presence of the fuel and reactivate the pump.

Abstract: A plurality of turbo engines (1, 2, 3) cooperate in a station, and each turbo engine with the drive machine (4, 5, 6) driving it forms a machine unit, with which a machine controller (28, 29, 30) is associated. To control these turbo engines (1, 2, 3) in parallel or tandem operation to observe at least one process variable, which is preset by the station and is common to all turbo engines (1, 2, 3), the preset, common process variable is set directly to each of the machine controllers (28, 29, 30), and this preset, common process variable is controlled exclusively via the machine controllers (28, 29, 30) associated with the particular machine unit.

Abstract: Generally, a vacuum pumping system having efficient power usage is provided. In one embodiment, the vacuum pumping system includes a first pump, a check valve and a second pump. The check valve and second pump are coupled in parallel to an exhaust line of the first pump. The first pump and second pump have a ratio of internal volume that is about 20 to about 130. In another embodiment, the vacuum pumping system includes a first pump, a check valve and a second pump. The check valve and second pump are coupled in parallel to an exhaust line of the first pump. The first pump and second pump have a ratio of power consumption that is about 5 to about 20. In yet another embodiment, the first pump and second pump have a ratio of pumping capacity that is about 50 to about 200.

Abstract: A system for variable speed control of a plurality of motors under variable load demand is provided. The system includes a constant power source and a plurality of motors having electrical circuits with switches to connect with the constant power source. The system further includes a variable speed drive for driving each of the plurality of motors at variable speed, wherein each of the plurality of motors includes a switch to connect with the variable speed drive. Each of the plurality of motors is selectively electrically connected with the variable speed drive and the constant power source via the switches, for driving the each of the plurality of motors at one of variable and constant speed in response to load demands. To prevent short cycling of the motors under situations of increasing system demand, the control algorithm for the electrical switches provides hysteresis by overspeeding one of the motors before switching from variable speed mode to constant speed mode.

Abstract: A system for variable speed control of a plurality of compressors under variable load demand. The system includes a constant power source and a plurality of compressor motors having switches to connect with the constant power source. The system further includes a variable speed drive for driving any one of the plurality of compressor motors at variable speed, wherein each of the plurality of compressor motors includes a switch to connect with the variable speed drive. Each of the plurality of compressor motors is selectively electrically connected with the variable speed drive or the constant power source via the switches, for driving the each of the plurality of motors at one of variable or constant speed in response to compressor load demands.

Abstract: A pump control system incorporates a programmed processor and respond to input from multiple floats. The programmed processor can respond to detected float failures in real time by reassigning control, lag, or lead functions from a failing float to one of the remaining functioning floats. Pump alternating functionality can be provided if any two of a plurality of four or more floats continue to function as expected.

Abstract: The infusion device comprises a central controller (10) and a plurality of infusion apparatus (12) each connected via a data channel (15) with the controller (10). Each infusion apparatus (12) is provided with a unique identification number. When an infusion apparatus (12) is connected to the controller (10) the identification number is requested and the controller (10) checks whether this identification number has already been allocated. If this is not the case, the controller (10) sends the inverted identification number back to the infusion apparatus (12). The infusion apparatus (12) accepts commands from the controller (10) only if the returned signal corresponds to the identification number.

Abstract: A fan assembly includes a first fan and a second fan. The first fan has a first housing and a first blade assembly. The first blade assembly includes a plurality of blades attached to a hub, and is configured to rotate about a first axis of rotation in a first direction. The second fan includes a second housing and a second blade assembly. The second blade assembly also includes a plurality of blades attached to a hub. The second blade assembly, however, is configured to rotate about a second axis of rotation in a second direction that is opposite the first direction of rotation. The first axis of rotation and the second axis of rotation can be coincidental or they can be slightly offset.

Abstract: An apparatus for and a method of evacuating a vacuum chamber (process chamber) or the like of a semiconductor fabrication facility, for example. The evacuating apparatus has a vacuum chamber to be evacuated, a discharge pipe connecting the vacuum chamber to an atmospheric port, a vacuum pump connected to the discharge pipe and operable at a variable rotational speed, and a controller for controlling the rotational speed of the vacuum pump.

Abstract: Fluid pump control modes in a medical perfusion system include a Back Off Response Mode, a Flow Servo Mode, a Pressure Servo Mode, and a Master-Slave Servo Mode. In the Back Off Response Mode, pump's speed is decremented to a new speed when an excessive flow rate or pressure condition is detected. The new speed is maintained until an additional decrement is required or until the Back Off Response Mode is exited. In the Flow Servo Mode, a pump's speed is controlled to maintain a fluid flow rate indicated by a user as a setpoint. In the Pressure Servo Mode, a pump's speed is controlled to maintain a pressure indicated by the user as a setpoint. In the Master-Slave Servo Mode, a slave pump receives an indication of a master pump's speed, and the slave pump speed is controlled to maintain a specified percentage of the master pump's speed.

Abstract: Disclosed herewith is a micro-fan. The micro-fan includes a hub attached to a rotating shaft and a plurality of blades extended from the side surface of the hub. In the micro-fan, if a leading edge is defined as the foremost edge of each of the blades consisting of a straight line portion and one or more arc portions, a trailing edge is defined as the rearmost edge of each of the blades, a chord line is defined as a line connecting two opposite points respectively situated in the leading and trailing edges and a blade angle is defined as an angle formed by the chord line and the horizontal line passing through the same point of the leading edge as that through which the chord line passes and lying in the same vertical plane as that in which the leading edge lies, the straight line portions of the leading and trailing edges are perpendicular to the hub and form a predetermined inside angle.

Abstract: It is an object of the present invention to make it possible to control a discharge pressure in a multi-stage variable speed compressor always to be a desired target pressure, whereby the multi-stage variable speed compressor can be operated with a discharge pressure of a good precision and to make it possible to perform the control without needing operation data as used in the prior art, at all.

Abstract: A system, such as a computer system, has cooling fans, each having a fan motor and fan blades. The fan motor operates to rotate the fan blades at a variable rotational speed. A frequency generator generates a reference speed signal having a reference frequency and a reference phase. Tachometers measure the variable rotational speeds of the fan blades of corresponding fans and provide corresponding fan speed signals representative of the variable rotational speeds of the corresponding fans. Each fan speed signal has a fan frequency and a fan phase. Motor controllers control the variable rotational speed of corresponding fan blades of corresponding fans based on the reference speed signal and the corresponding fan speed signals.

Abstract: A pump control system incorporates a programmed processor and respond to input from multiple floats. The programmed processor can respond to detected float failures in real time by reassigning control, lag, or lead functions from a failing float to one of the remaining functioning floats. Pump alternating functionality can be provided if any two of a plurality of four or more floats continue to function as expected.

Abstract: A resonator pump system includes a resonating structure configured for resonating, and a fluid pump coupled to and driven by the resonating structure. An energy source is operatively coupled to the resonating structure for maintaining resonance.

Abstract: The invention relates to a system for regulating the pressure in an enclosure (1) that is to contain processed gas for manufacturing semiconductor components or micro- or nano-technology devices, the enclosure being connected by pipework (2) to a pump unit (3) comprising a dry mechanical primary pump (4) and at least one secondary pump (5). According to the invention, the system further comprises a speed controller (6) controlling simultaneously the speeds of rotation of the dry mechanical primary pump (4) and of said at least one secondary pump (5).

Abstract: A cooling apparatus includes a plurality of fan units having a fan respectively, a plurality of temperature sensors detecting temperature of an object of cooling, included in the fan units respectively, and a control portion deciding the speed of the fan according to the temperature detected by the temperature sensors in a self-control mode and increasing the speed of at least one of the other fans when the speed of any one of the fans is lower than a prescribed threshold in a coordinative control mode.

Abstract: An apparatus and method for providing redundant power and redundant fan speed control to a plurality of fans is provided. A first power supply input is electrically connected to a second power supply input to provide a combined power supply input. First and second fan speed controllers each having an input and an output are provided, along with first and second power converters each having an input and an output. The combined power supply input is electrically connected to the input of the first fan speed controller and the input of the first power converter. The combined power supply input is also electrically connected to the input of the second fan speed controller and the input of the second power converter. The output of the first fan speed controller is electrically combined with the output of the second fan speed controller to provide a combined fan speed control signal. The combined fan speed control signal is electrically connected to the plurality of fans.

Abstract: A pump control system incorporates a programmed processor and responds to input from multiple floats. The programmed processor can respond to detected float failures in real time by reassigning control, lag, or lead functions from a failing float to one of the remaining functioning floats. Pump alternating functionality can be provided if any two of a plurality of four or more floats continue to function as expected.

Abstract: An intelligent fan system includes a microcontroller having memory and an interface which provides a connection to a host computer system. The host computer system dynamically provides a plurality of controlled instructions to the microcontroller which are stored in the memory of the microcontroller. The system also includes a temperature sensing device which is connected to the microcontroller. A fan responsive to the communication signal provided by the microcontroller adjusts the speed of the fan in accordance with the plurality of control instructions.

Abstract: A filtration and subsurface distribution system having a vaulted splitting device (e.g., dosing vault) in a recirculating pump tank. The recirculating pump tank houses a sand filter pump and the dosing vault houses a dosing pump. The dosing vault and the dosing pump may be housed outside and remote from the recirculating pump tank which ensures that effluent will not be mixed within the dosing vault. The sand filter pump doses a sand filter with the septic effluent via a feed line. The effluent is then filtered by the sand filter and returned to the dosing vault via a filtrate return. When the filtrate reaches a certain predetermined level within the dosing vault, the drip pump is enabled and turned “on”. In this manner, the filtrate is dosed or dripped into a drain absorption field without mixing with the septic effluent.

Abstract: A compressed air production facility includes at least one variable speed compressor and a plurality of constant speed compressor, which are connected in parallel with one another. The variable speed compressor and the plurality of constant speed compressors are capacitively controlled with the use of a pressure in an air reservoir into which discharge air from these compressor are led. Both upper limit pressure at which the variable speed compressor is turned into its load operation mode into its unload operation mode and a lower limit pressure at which the variable speed compressor is turned into its unload operation mode into its load operation mode are set between an upper limit change-over pressure at which all of the plurality of constant speed compressors are turned into their load operation into their unload operation and a lower limit change-over pressure at which all of the plurality of constant speed compressors are changed over from their unload operation into their load operation.

Abstract: A hybrid vehicle includes: a metal V-belt type infinitely variable gear-change mechanism 20 whereby the rotation of an engine E is subjected to change in gear ratio, a forwards clutch 14 and a reverse brake 15 that perform engagement/disengagement control of the engine and the infinitely variable gear-change mechanism, and a second motor generator 50 capable of driving the drive wheels arranged parallel with the engine. The control device is provided with a first hydraulic pump 3 for engine drive, a second hydraulic pump 56 that is driven by an electric motor 55 for pump drive, and a forwards/reverse clutch control valve 73 that performs changeover control of supply of working hydraulic pressure to the forwards clutch 14 etc.

Abstract: A multiple fan system including at least two simultaneously operated fans. Each of the fans are operable as a constant speed fan and as an oscillating speed fan. Not more than one of the fans is operated as a constant speed fan. Each fan not being operated as a constant speed fan is operated as an oscillating speed fan. A fan controller operates each oscillating speed fan in a mode whereby a respective acoustic emission having a range of frequency different than any other oscillating speed fans is produced.

Abstract: A multiple fan system including at least two simultaneously operated fans. Each of the fans are operable as a constant speed fan and as an oscillating speed fan. Not more than one of the fans is operated as a constant speed fan. Each fan not being operated as a constant speed fan is operated as an oscillating speed fan. A fan controller operates each oscillating speed fan in a mode whereby a respective acoustic emission having a range of frequency different than any other oscillating speed fans is produced.

Abstract: A method for regulating coolant flow rate to a heat exchanger in an automotive vehicle is described. The method includes the steps of providing a main fluid pump for providing a source of fluid under pressure to the vehicle engine and the heat exchanger and providing a reversible flow auxiliary pump between the main fluid pump and the heat exchanger. The method further includes the steps of generating an engine speed signal and an ambient temperature signal. The auxiliary pump forces fluid against the flow from the main fluid pump when the engine speed signal is greater than a threshold value and forces fluid to the heat exchanger when the ambient temperature signal is below a predetermined value and the engine speed signal is less than the threshold value and within predetermined values. A system is also disclosed for accomplishing the method.

Abstract: A multiple fan system including at least two simultaneously operated fans. Each of the fans are operable as a constant speed fan and as an oscillating speed fan. Not more than one of the fans is operated as a constant speed fan. Each fan not being operated as a constant speed fan is operated as an oscillating speed fan. A fan controller operates each oscillating speed fan in a mode whereby a respective acoustic emission having a range of frequency different than any other oscillating speed fans is produced.

Abstract: A compression system includes a sequencing switch movable between a first switch position and a second switch position for alternating a first compressor and a second compressor between a lead mode and a lag mode so that one of the compressors is always in the lead mode and one of the compressors is always in the lag mode. The compression system includes a first compressor including a first microcontroller having a data entry device for establishing a lead mode pressure range and a lag mode pressure range. The first compressor includes a first pressure gauge for sensing the pressure level of compressed fluid discharged therefrom and for relaying the sensed pressure level to the first microcontroller. The first microcontroller continuously monitors the pressure level of the compressed fluid discharged from the first compressor and compares the pressure level of the compressed fluid to the lead mode pressure range and the lag mode pressure range.

Abstract: A well pump storage and delivery assembly includes at least one collecting tank coupled to at least one source of water being derived from an underground well having a well pump therein. The collecting tank has an upper water level measuring member capable of detecting and measuring an upper level of water collected within the collecting tank and a lower water level measuring member capable of detecting and measuring a lower level of water collected within the collecting tank. A pressurization pump is connected to the collecting tank and is capable of receiving water therefrom. The pressurization pump is connected to a pressurized storage tank.

Abstract: A multistage vacuum pump unit having a plurality of separate single-stage pumps connected in series with each other by exhaust pipes, the exhaust pipes each connecting a suction port of one of the adjacent single-stage pumps with an exhaust port of another of the adjacent single-stage pump; motors for driving the separate single-stage pumps respectively; driving device for varying a revolution of one of the single-stage pumps that is at least in contact with an atmospheric side; driving current detection device for detecting a driving current of the motor for driving the single-stage pump that is in contact with the atmospheric side; pressure detection device for detecting a pressure at a vacuum-side inlet; and control device for controlling revolutions of the motors of the single-stage pumps based on the pressure detected by the pressure detection device.

Abstract: A fluid pump speed controller apparatus for ensuring adequate system fluid pressure while minimizing energy consumption. The fluid pump speed controller has an adjustable frequency motor drive and control circuits to vary fluid pump motor speeds based on system fluid demand, monitored by a sensor. The control circuits set the pump speed, based on input from the sensor. The control circuits also set parameters in the control circuit logic, and are capable of self calibration and controlling multiple fluid pumps.

Abstract: First liquid pumping apparatus for containing a first quantity of first liquid, second liquid pumping apparatus for containing a second quantity of second liquid and control apparatus for alternately connecting the first liquid pumping apparatus and second liquid pumping apparatus to pressurized liquid utilization apparatus and for causing the first and second liquid pumping apparatus to alternately deliver the respective liquids to the liquid utilization apparatus at a substantially constant flow or substantially constant pressure; the first and second liquids may be the same liquid or different liquids.

Abstract: A vacuum pump control system is used for controlling a plurality of vacuum pumps comprising at least one type of cryopump, turbomolecular pump, cryoturbo pump, and dry pump such as a Roots type vacuum pump. The vacuum pump control system for controlling a plurality of vacuum pumps, comprises a host computer; a plurality of vacuum pump controllers connected respectively to said vacuum pumps; and a network control unit for transmitting information between the host computer and the vacuum pump controllers. The vacuum pump controllers are connected in parallel to the network control unit by respective communication lines.

Abstract: A pump unit includes a first plunger pump including a suction port arranged at an end of the first pump distant from a camshaft and a discharge port arranged at another end thereof near the camshaft, and a plunger second pump including a suction port arranged at an end of the second pump near the camshaft and a discharge port arranged at another end thereof distant from the camshaft. The first and second pumps are arranged in parallel with each other along the camshaft so that plungers of the first and second pumps contact corresponding cams of the camshaft. The first and second pumps are connected in series so that the discharge port of the first pump communicates with the suction port of the second pump.

Abstract: A fluid delivery method and apparatus implementing active phasing to actively restore the substantially exact mechanical positions of driven components in a delivery system in order to precisely reproduce the mechanical signature and hydraulic characteristics of the system from run to run without perturbing output flow. The delivery system is configured to intelligently drive pump pistons to a known position and to deliver fluid(s) at a known pressure, and includes a plurality of pump modules each including motor driven syringes having respective pistons configured to reciprocate under control of a control mechanism. Pump phasing is accomplished through a mechanism of compensation delivery of the syringes. An independent, motor-driven syringe of any given pump in a plurality of pumps in a system has the ability to act as a delivering syringe to maintain a prescribed output flow while one other syringe of each of the plurality of pumps is repositioned under load.

Abstract: A safety device for avoiding entrapment at a water reservoir drain by using a vacuum operated switch to interrupt power to the reservoir pump and by using a pressure pump to generate a positive pressure to dislodge the obstruction from the drain should a blockage occur. In addition, a manual reset switch requires human intervention to re-activate the reservoir pump once the blockage condition is removed.

Abstract: A fluid dispensing system is provided which has first diaphragm pump means, a filter connected to receive the discharge of said first pump, and accumulator/second diaphragm pump means connected to receive the discharge of said filter. Hydraulic fluids pumped by cylinder/piston/stepper assemblies independently actuate each of the diaphragm pumps, providing accurate, controllable and repeatable dispense of the subject fluid.

Abstract: A method and apparatus for evacuating a vacuum system which includes an evacuating portion comprising first and second vacuum pumps which are connected in series. The method and the apparatus are characterized in that the first vacuum pump is operated in a range from reverse rotation to forward rotation, and the second vacuum pump is rotated unidirectionally, thereby enabling pressure control of the vacuum system over a wide range.

Abstract: Balancing the load between compressors is not trivial. An approach is disclosed to balance loads for compression systems which have the characteristic that the surge parameters, S, change in the same direction with rotational speed during the balancing process. Load balancing control involves equalizing the pressure ratio, rotational speed, or power (or functions of these) when the compressors are operating far from surge. Then, as surge is approached, all compressors are controlled, such that they arrive at their surge control lines simultaneously.

Abstract: A method and apparatus are disclosed for controlling a multicompressor station so that the overall work requirement of the station is minimized while maintaining the compressors in a non-surge conditions. The apparatus includes interconnected control loops for controlling the turbine speed of variable speed compressors or the throttling valves of constant speed compressors that determine a set of criterion for computing the value and sign of the first derivative of work performed by the station. The speed of each compressor is then set to reduce overall system work while maintaining discharge pressure of the station and maintaining the compressors in a non-surge operating format. The method includes the steps of computing the criterion, computing the value and sign of the first derivative of the work function and adjusting the compressor speed to minimize station work while maintaining the compressors in a non-surge condition.

Abstract: The pump station control system and method monitors and displays a time history of the operating parameters of a pump station. Sensed operating parameters are transmitted to an operator in real time and are stored at predetermined time intervals over a predetermined period of time. A real-time cost parameter of the system is calculated that provides a measure of the cost per throughput of the material being pumped. The system can be optimized for the cost parameter by controlling system variables such as pump speed in response to the level of fluid.

Abstract: A pumping system for continuously delivering fluid at a selected flow rate to a receiving system. The system includes at least a first and a second pumping unit, each of the individual units comprises a syringe and a valve. The syringe comprises a piston and a piston actuator, cylinder, and pressure sensor. The valve comprises a positively-actuated zero switching volume valve and valve actuator. The first and second pumping units are in fluid communication with one another and are capable of independent actuation. The individual valves are arranged to isolate either the first syringe or the second syringe, respectively, from the receiving system while at least one of the syringes remains in fluid communication with the receiving system whereby system pressure can be continuously monitored and the selected system flow rate maintained.

Abstract: Evaporative cooler apparatus includes two pumps, a primary pump which pumps water to an evaporative medium and a secondary pump for pumping water from the bottom of the cooler to drain the cooler. The secondary, or drain pump includes a timer so that it is only on to drain water from the bottom of the cooler for a predetermined time, and after a predetermined number of hours of operation of the primary pump. That is, there is a direct relationship between the operation of the cooler apparatus as evidenced by the primary pump, and the draining of the water at the bottom of the cooler by the secondary, or drain pump. The efficiency of the pumps is increased to allow them to pump with a very low water level without cavitation problems by virtue of an impeller design which includes vanes on the bottom of the impeller disk and vanes on top of an impeller disk.