Abstract: A device including a first discharge passage from a first rotor assembly to an engine, a first return passage that returns to an intake side of the first rotor assembly, a second discharge passage from a second rotor assembly to the engine, a second return passage that returns to an intake side of the second rotor assembly, and a pressure control valve whose valve main body is provided between a discharge port from the second rotor assembly and the first discharge passage. The first discharge passage and the second discharge passage are coupled, and a flow passage control is executed in each of: a low revolution range; an intermediate revolution range; and a high revolution range.

Abstract: A variable capacity rotary compressor is provided, in which a vane may be restricted by a pressure difference generated between both side surfaces of the vane when the compressor performs in a saving driving mode. The vane may be restricted quickly and stably by rapidly decreasing a pressure of a vane chamber by leaking a discharge pressure of the vane chamber to an inlet via a low pressure passage and thereby increasing a pressurizing force applied to a side surface of the vane relatively greater than a supporting force applied to a rear surface thereof. In this way, the vane may be prevented from being vibrated due to a weak restriction force of the vane when a power driving mode of the compressor is switched into the saving driving mode, which prevents noise from increasing due to design conditions, thereby enhancing a comfort feeling of a user.

Abstract: A pump apparatus configured with a first pump for pumping working fluid in accordance with a reciprocation of a piston using a space between a first open/close valve for suction and a second open/close valve for discharge as a pump chamber. The pump apparatus is also configured a first flow passage for supplying the working fluid from a supply source to an operation subject via the first open/close valve, the pump chamber, and the second open/close valve in accordance with an operation of the first pump. A second flow passage supplies the working fluid pumped by a second pump, which is different from the first pump, to the pump chamber. A selector is configured to select either the first flow passage or the second flow passage.

Abstract: Disclosed is a variable capacity type rotary compressor, in which a refrigerant sucked via one suction pipe can be alternately sucked into each compression space via a communication passage between a plurality of cylinders so as to reduce the number of components and the number of assembly processes, thereby remarkably reducing a fabricating cost, a refrigerant within an idling cylinder can be prevented from flowing back into another cylinder so as to improve the performance of the compressor, a welding space can be ensured when connecting connection pipes so as to realize a welding automation, thereby further reducing the fabricating cost, and a mode switching valve can be stably fixed to an appropriate position so as to attenuate noise due to vibration of the compressor.

Abstract: An oil pump assembly includes a plurality of pump chambers constituting a plurality of oil pumps, respectively, a plurality of rotors are fitted into the pump chambers, respectively, with a single driving shaft carrying the plurality of rotors to form a single body. Oil pumped up from an oil pan is supplied under pressure to different associated destinations with the relief valves being arranged compactly to reduce the size of the oil pump assembly. Oil pumps are provided with respective relief valves provided to pass oil discharged from the corresponding pump chambers therethrough and the axes of the relief valves are arranged parallel to the driving shaft. A driving shaft is provided on which a plurality of the inner rotors are carried concentrically and integrally. The rotors are connected to the driving shaft and changed depending on discharge oil pressures, thereby preventing the driving shaft from increasing its diameter.

Abstract: An electrical driven pump unit having two hydraulic pumps and two electric motors that are fitted in such a way as to make it possible to obtain the unit's power by adding together the power of the two motors.

Abstract: A compressor control system includes at least one variable compressor, at least one fixed-capacity compressor, and a controller. The controller modulates the variable compressor based on a suction pressure reading of the variable compressor. In addition, the controller selectively toggles the fixed-capacity compressor between a run mode and a shutdown mode based on an operating parameter of the variable compressor.

Abstract: If a hydraulic system has several modes of operation, in particular a mode with a high pressure demand (II) and a mode with a high fluid flow demand (II), the hydraulic fluid pump has to be built with an accordingly high fluid flow output. Such a pump is expensive. Therefore it is suggested, to provide two pumps. I.e. a controllable main pump (2) is provided, which supplies the hydraulic consumer (6) during phases (I) of high pressure demand. During phases (II) of high fluid flow demand, normally, relatively low pressures are sufficient. Therefore, it is suggested to provide a parallel boost pump (9), which supplies the hydraulic consumer (6) in addition to the high pressure pump (2), if a high fluid flow is needed. Excess fluid flow output is avoided by controlling the fluid output flow of main pump 2.

Abstract: A fuel delivery system for a combustion engine is provided. The fuel delivery system includes an exhaust treatment device, a fuel injection unit, a fuel supply, and a fuel pump. The fuel pump includes at least one inlet configured to receive fuel from the fuel supply. A first fixed-output pumping element is configured to generate a first fuel flow at a first pressure and a first flow rate. A second fixed-output pumping element is configured to generate a second fuel flow at a second pressure and a second flow rate. At least one of the second pressure and the second flow rate is different from the first pressure and the first flow rate. A first outlet is configured to direct the first fuel flow to the fuel injection unit. A second outlet is configured to direct the second fuel flow to the exhaust treatment device.

Abstract: Apparatus for establishing and controlling a low pressure gas mixture in a vacuum enclosure (8) comprises at least one secondary pump (9) of the molecular, turbomolecular, or hybrid type, followed by at least one primary pump (10), with first control and adjustment means (22) such as a regulation valve (24) for controlling and adjusting the total gas pressure of the mixture of gases in the vacuum enclosure (8) as a function of a total pressure setpoint (27). The apparatus further comprises second control and adjustment means (28) such as a second regulation valve (29a) downstream from the secondary pump (9). The second regulation valve (29a) is controlled as a function of a delivery pressure setpoint (32) to modify the delivery pressure of the secondary pump (9) and thus to adapt its pumping capacity in selective manner.

Abstract: A modular system for the control of at least one compression system for the compression a fluid medium, said compression system comprising compressors (C1-C7) and their controllers (A1-A7) for the compression of the fluid medium, secondary treatment devices for the treatment of the medium delivered from the compressors, and piping systems (17-19, 23) for conducting the fluid medium to a place of consumption (16, 22), said control system comprising a control unit (3) containing a data processing system (34) for controlling the compression system, a user interface (35) including a display associated with it and transmission means for the transmission of control data between the control unit, the controllers and pressure sensors. The transmission means consist of data communication buses, preferably serial communication buses (30-32) and a data communication port unit (33) serving to connect the bus to the control unit (34). The controllers and pressure sensors are connected to common data communication buses.

Abstract: The invention relates to a switching device for a hydraulic high-pressure system, particularly for operating hydraulic screw-tightening devices, comprising: a directional seat valve (17), which is subjected to the action of high pressure in the closing direction; a control piston (22), which can be subjected to the action of low pressure and which displaces the directional seat valve in the opening direction, and, a control valve (23), which either establishes or interrupts a connection to a pressureless low-pressure return flow line.

Abstract: A pump (10) includes a housing, a stator (20) supported in the housing, and a rotor assembly (30). The rotor assembly (30) includes a rotor (32) supported in the housing for rotation relative to the stator (20) about an axis (12). The rotor assembly (30) also includes a first impeller (34) operatively coupled to a first axial end of the rotor (32) for rotation with the rotor about the axis (12). The rotor assembly further includes a second impeller (36) operatively coupled to a second axial end of the rotor (32), opposite the first axial end, for rotation with the rotor about the axis (12). The rotor assembly (30) is movable along the axis (12) relative to the housing to adjust hydraulic performance characteristics of the pump (10).

Abstract: When the pressure in a main fluid supply channel is lower than a no-load operation start pressure, the spool moves against the biasing force of a biasing member, and the area of opening of a auxiliary fluid supply channel is reduced with regards to opening of the internal flow channel. When the pressure in the main fluid supply channel rises and reaches a no-load operation start pressure, the area of opening in the auxiliary fluid supply channel with regards to opening of the internal flow channel becomes smaller and while connected to the main fluid supply channel, the auxiliary fluid supply channel is connected to the return flow channel. When the pressure in the main fluid supply channel rises above the no-load operating start pressure and reaches a no-load operation pressure, the auxiliary fluid supply channel is cut off from the main fluid supply channel.

Abstract: A fixed displacement binary pump is provided for a powertrain on a vehicle. A hydraulic system is operatively connected with first and second discharge ports of the pump and is operable to alternately permit fluid flow through both discharge ports (i.e., full displacement or volumetric output of the pump) or permit flow through only the first discharge port (i.e., partial displacement or volumetric output of the pump). The pump may be packaged in a front support of the transmission. An auxiliary pump may be provided that is operable to supplement the output of the binary pump or to be used when the binary pump is off. A method of operating the binary pump and auxiliary pump is provided.

Abstract: The present invention generally relates to hemodialysis and similar dialysis systems, including a variety of systems and methods that would make hemodialysis more efficient, easier, and/or more affordable. One aspect of the invention is generally directed to new fluid circuits for fluid flow. In one set of embodiments, a hemodialysis system may include a blood flow path and a dialysate flow path, where the dialysate flow path includes one or more of a balancing circuit, a mixing circuit, and/or a directing circuit. Preparation of dialysate by the preparation circuit, in some instances, may be decoupled from patient dialysis. In some cases, the circuits are defined, at least partially, within one or more cassettes, optionally interconnected with conduits, pumps, or the like. In one embodiment, the fluid circuit and/or the various fluid flow paths may be at least partially isolated, spatially and/or thermally, from electrical components of the hemodialysis system.

Abstract: A piston pump includes a first piston pump including a first piston and a first pump chamber, a second piston pump including a second piston and a second pump chamber, the second piston operating to follow the first piston, a pressure release passage formed in communication with the second pump chamber, and a relief valve provided at the pressure release passage and defining an upper limit discharge pressure of the second piston pump. When a discharge pressure of the second piston pump is equal to or smaller than the upper limit, a discharge fluid of the second piston pump is added to that of the first piston pump so as to flow into an outlet port. When the discharge pressure exceeds the upper limit, the discharge fluid is released to the pressure release passage and the discharge fluid of the first piston pump only flows to the outlet port.

Abstract: An automotive engine oil pump assembly having first and second pump mechanisms contained within a common housing. A shaft rotatably supported in the housing drives the pump mechanisms in a conventional manner. The pump mechanisms are offset in phase to reduce flow pulsations through the housing and limit pump noise and vibration. The first pump mechanism communicates with a common inlet and first outlet of the housing. The second pump mechanism communicates with the common inlet and second outlet of the housing. A common reservoir connected to inlets of the first and second oil pump mechanisms provides a supplemental oil source to balance oil pressures at the pump inlets to prevent pump cavitation and further reduce pump noise and vibration.

Abstract: A system and method for providing pressurised oil during non-feathered in-flight shutdown conditions in a variable-pitch aircraft propeller engine. A secondary pump provides pressurised oil substantially independent of an engine main oil circuit.

Abstract: A multiple stage pump having valves downstream from each respective pump in a same line thereof. The respective lines then merge into a common line. The multiple stage pump prevents pressure variations and shot to shot fuel variations.

Abstract: A hydraulic control circuit for a radial piston engine with two speeds. The changeover between the speeds takes place through the alteration of the absorption volume, the delivery side being connected to the discharge side with a bypass connection by a valve arrangement for a selected number of engine pistons. The control circuit provides a space-saving way of ensuring that the changeover between speeds occurs smoothly and in such a manner to preserve the individual components as far as possible. To this end, at least one intermediate switching position, in which the delivery side is throttled to the discharge side, i.e. connected by a diaphragm-type arrangement, is provided in front of valve arrangement between the two end switching positions. The valve arrangement is preferably driven such that a valve body can be moved through the intermediate switching position at a controlled speed.

Abstract: In a multistage oil pumping system for an oil supply system of a motor vehicle comprising at least two oil pumps arrange axially in side-by-side relationship, each of the oil pumps is connected to a separate drive so that the oil pumps can be operated independently of one another.

Abstract: The invention is a device and method in a high-pressure chromatography system, such as a supercritical fluid chromatography (SFC) system, that uses a pump as a pressure source for precision pumping of a compressible fluid. The preferred exemplary embodiment comprises a pressure regulation assembly installed downstream from a compressible fluid pump but prior to combining the compressible flow with a relatively incompressible modifier flow stream. The present invention allows the replacement of an high-grade SFC pump in the compressible fluid flow stream with an inexpensive and imprecise pump. The imprecise pump becomes capable of moving the compressible fluid flow stream in a precise flow rate and pattern. The assembly dampens the damaging effects of an imprecise pump, such as large pressure oscillations caused by flow ripples and noisy pressure signals that do not meet precise SFC pumping requirements.

Abstract: A multiple stage pump having valves downstream from each respective pump in a same line thereof. The respective lines then merge into a common line. The multiple stage pump prevents pressure variations. The multiple stage pump includes a first pump in a first stage and a second pump in a second stage. At least one valve is downstream from one of the first pump and the second pump in at least one of the first stage and the second stage. A common branch line connects the first stage and the second stage to a common hydraulic system.

Abstract: A multiple stage pump having valves upstream from each respective pump in a same line thereof. The respective lines then merge into a common line. The multiple stage pump prevents pressure variations. The multiple stage pump includes a first pump in a first stage and a second pump in a second stage. At least one valve is upstream from one of the first pump and the second pump in at least one of the first stage and the second stage. A common branch line connects the first stage and the second stage to a common hydraulic system.

Abstract: An exemplary oil delivery system comprises a dual pump system configured for reducing the buildup of pressure by unloading one or both pumps, thus reducing the buildup of heat within the hydraulic system. The dual pump system is configured for delivering oil in combination to a single hydraulic system or to two completely separate hydraulic systems. In addition, the oil delivery system can also be configured to unload one or both of the pumping sections at a pre-determined speed to again limit the flow to any existing open centered hydraulic system. As a result, the oil delivery system recirculates oil back to the reservoir and/or the inlet to the pump in the absence of a buildup of pressure, and thus an absence in the buildup of heat to conserve energy.

Abstract: A cooling system includes a compressor rack, a controller, a gateway, and a system master. The compressor rack includes a plurality of compressors. A controller is dedicated to each compressor and includes a memory storing configuration data for the compressor. A gateway is in communication with each controller and allows the system master to command the controller to send the configuration data to the system master, whereby the system master stores a copy of the configuration data for each compressor.

Abstract: A cooling system includes a compressor rack having a plurality of compressors and a controller associated with each compressor. Each controller is associated with a communication gateway and monitors operational characteristics of its respective compressor and communicates with an internet web server through the gateway.

Abstract: A multi-stage variable speed compressor includes a pressure detector provided for each compressor on and after the second stage for detecting a discharge pressure of a compressor of a stage preceding the corresponding compressor or a suction pressure of the corresponding compressor, wherein the control device controls the rotational speeds of the compressor of the first stage using a deviation of discharge pressure from a desired target pressure, and controls the rotational speed of each compressor on and after the second stage based on the discharge pressure of the compressor in a stage before each compressor or the suction pressure of each compressor, using a pressure signal from the pressure detector provided for each compressor on and after the second stage for detecting a discharge pressure of a compressor of a stage preceding the corresponding compressor or a suction pressure of the corresponding compressors.

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: An internal combustion engine (30) has a fueling system comprising fuel injectors (36) that utilize oil under pressure to force fuel into engine combustion chambers. Oil is pumped to an oil rail (44) by an engine-driven pump (42) whose effective displacement can be varied. A control system (32) processes certain data, such as engine speed and load, for controlling the effective displacement of the pump. The pump has a larger stage (42B) and a smaller stage (42A). The control system selects and de-selects the stages to control pump displacement.

Abstract: A high pressure pump and delivery system mating to LNG storage and suited for natural gas powered trucks and buses, but also suitable for other cryogenic liquid fuels. The reciprocating pump is comprised of a liquid pumping portion and a vapor compressing portion, operating in concert so that it is possible to locate the pump above a source of saturated LNG and to reliably supply high pressure LNG. The delivery system provides a method of utilizing both the pumped LNG and the compressed NG in a Diesel type fuel injection system, and also to scavenge NG vapor from the LNG storage container so as to extend it's storage life. While especially useful for trucks and buses, the present invention is not limited thereto, as it is also useful for locomotives, automobiles and other vehicles designed to operate through combustion of natural gas, as well as stationary applications.

Abstract: A more efficient compressor control system and a more efficient method of operating a multiple throttled inlet rotary screw compressor system includes the method and control system which are a function of both the actual system pressure and volumetric flow rate. Specifically, a throttled inlet rotary screw compressor is loaded or unloaded from the compressor system after sensing the actual system pressure and calculating the system's actual volumetric flow rate. The control system calculates the system's volumetric flow rate by sensing each loaded throttled inlet rotary screw compressor's inlet pressure and converting those inlet pressures to outlet volumetric flow rates. The aggregate of the loaded compressors' volumetric flow rates represents the actual system flow rate.

Abstract: The invention relates to a heating system, particularly for motor vehicles, in which a heat exchange arrangement operating in the manner of a heating member can be thermally coupled by means of a hydraulic heat transfer circuit, particularly a water circuit, to a first heat source, in particular an internal combustion motor serving to drive the motor vehicle, and also to a second heat source, in particular a burner operable independently of the first heat source, wherein a control arrangement can be changed over, in dependence on the operating state of a first pump allocated to the first heat source, between a first state, in which the heat transfer medium or at least a greater portion of it is conducted over both heat sources, and a second state, in which the heat transfer medium is conducted by a further, hydrodynamic pump, only or preponderantly over the second heat source.

Abstract: A fluid system for plural motor driven pumps is disclosed. The fluid system includes a control valve which provides for unloading one or more pumps by diverting the flow of operating fluid from the pump back to the reservoir whenever the load pressure or the motor speed exceeds pre-selected levels.

Abstract: A control system is provided for load sharing between a plurality of compressors. The control system determines the actual coefficients of export flow for the compressors, compares the actual coefficients of export flow with a common or individual coefficients of export flow setpoints generated by one or more central controllers, and then generates control signals for adjusting the operating points of the compressors in order to load balance the compressors.

Abstract: In a pump equipment having one or more rotary pumps for hydraulic circuit, the intake port is communicated with the shaft hole for inserting the drive shaft and fluid flows through the shaft hole to a fluid groove provided in inner surfaces of the pump room for the purpose of lubrication. To prevent fluid leakage to outside, first and second oil seals are disposed for filling the clearance between the drive shaft and the shaft hole and, preferably, a communicating conduit is provided between the first and second oil seals to transmit the fluid leaked through the first oil seal to a low pressure fluid conduit of the hydraulic circuit. In particular, in the pump equipment having plural rotary pumps, the respective discharge ports of the rotary pumps are located at the points which are nearly symmetrical with respect to the center axis of the drive shaft to counterbalance each other, the reaction forces against the drive shaft to be produced by the high pressure at the respective discharge ports.

Abstract: A pump assembly which comprises a vane pump and a second hydraulic pump driven together with this vane pump. The vane pump has a suction region in which first pressure spaces between the vanes and second, rear pressure spaces behind the vanes become larger and a pressure region in which the pressure spaces become smaller and in which the pressure spaces are fluidically connected to a pressure outlet. This vane pump is intended particularly for supplying operating cylinders of a hydromechanical transmission of a motor vehicle with pressure fluid under relatively high pressure. The second hydraulic pump has positively driven displacement elements and is intended for supplying a circuit having a relatively low system pressure, in particular a lubricating-oil circuit of the motor vehicle, with pressure fluid.

Abstract: A pump system is provided where low pressure (4) and high pressure (6) pumps are coaxially mounted to receive motive power from a shared drive (300). The drive shafts are arranged such that one extends within a void in the other and both have shear regions such that, in the event of torque overload, either shaft can shear so as to disconnect the drive to it's associated pump while the other pump and shaft can continue to work.

Abstract: A control system for providing load sharing between a plurality of compressors. The control system determines the actual coefficients of export flow for the compressors, compares the actual coefficients of export flow with a common or individual coefficients of export flow setpoints generated by one or more central controllers, and then generates control signals for adjusting the operating points of the compressors in order to load balance the compressors.

Abstract: The present invention is a more efficient compressor control system and a more efficient method of operating a multiple throttled inlet rotary screw compressor system because the method and control system are a function of both the actual system pressure and volumetric flow rate. Specifically, a throttled inlet rotary screw compressor is loaded or unloaded from the compressor system after sensing the actual system pressure and calculating the system's actual volumetric flow rate. The control system calculates the system's volumetric flow rate by sensing each loaded throttled inlet rotary screw compressor's inlet pressure and converting those inlet pressures to outlet volumetric flow rates. The aggregate of the loaded compressors' volumetric flow rates represents the actual system flow rate.

Abstract: A plurality of autonomously controlled valves and pumps in a fluid distribution system are interconnected by a data communication network. The system also includes fluid flow sensors which report to the system by way of the network. The autonomous controllers include information as to their neighbors or environment sufficient to determine malfunctions such as a leak or break in an associated path, or flow-related problems, and can take autonomous action. The actions are established by the autonomous controllers regardless of the existence of a connection to the network, so that even if the network connection fails or is damaged, the valve or pump can still respond with predetermined “intelligent” actions.

Abstract: The present invention is a more efficient compressor control system and a more efficient method of operating a multiple compressor system because the method and control system are a function of both the system pressure and the volumetric flow rate capacity of the system. Specifically, a compressor is loaded or unloaded from the compressor system after sensing the actual system pressure and volumetric flow rate capacity. The inventor(s) of the present invention have discovered that it is more efficient to control the compressors upon sensing both the pressure and volumetric flow rate capacity of the fluid. Moreover, controlling the compressor system in response to sensing both the pressure and volumetric flow rate capacity of the fluid insures that the appropriate blend of compressors is loaded to the system in order to produce the most suitable pressure and volumetric flow rate capacity.

Abstract: The present invention is a more efficient compressor control system and a more efficient method of operating a multiple compressor system because the method and control system are a function of both the system pressure and the volumetric flow rate capacity of the system. Specifically, a compressor is loaded or unloaded from the compressor system after sensing the actual system pressure and volumetric flow rate capacity. The inventor(s) of the present invention have discovered that it is more efficient to control the compressors upon sensing both the pressure and volumetric flow rate capacity of the fluid. Moreover, controlling the compressor system in response to sensing both the pressure and volumetric flow rate capacity of the fluid insures that the appropriate blend of compressors is loaded to the system in order to produce the most suitable pressure and volumetric flow rate capacity.

Abstract: An electronic control system is disclosed to control and to prevent damage to a standalone or a network of oil free, two stage compressor packages. The electronic control system uses pressure and temperature sensors to detect actual shutdown conditions or predict shutdown conditions based on the operating state of the compressor package and the current temperatures or pressures of the air at strategic locations in the compressor package. It has been determined through experimentation that, if the pressure at the inlet of the stage two compressor is less than the discharge pressure of the stage two compressor by more than an allowable value, then a high temperature condition will occur in the stage two compressor and cause the compressor to seize.

Abstract: A multiple stage pump having valves upstream from each respective pump in a same line thereof. The respective lines then merge into a common line. The multiple stage pump prevents pressure variations and shot to shot fuel variations.

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: A pumping system for selectively activating the stages of a multi-stage centrifugal pump is provided. The pumping system has a first stage impeller for receiving fluid into the system and imparting rotational energy into the fluid. The system also has a second stage impeller for centrifugally imparting additional rotational energy into the fluid after the first stage impeller. A valve selectively closes an inlet to the second stage impeller so that the system operates as a single stage centrifugal pump while the second stage impeller remains wetted.

Abstract: The present invention provides a vacuum pump allowing process pressure control with high responsiveness and miniaturization and cost reduction of the overall apparatus, as well as reduction of the running cost. A second pump mechanism portion is equipped on the way of an exhaust passage communicating an exhaust side out of a first pump mechanism portion with a gas outlet. The second pump mechanism portion is constructed to be capable of changing the pump speed of rotation independently of the first pump mechanism portion. When the pump speed of rotation of the second pump mechanism portion is changed, the pressure of the exhaust side out (backing pressure) of the first pump mechanism portion changes. Therefore, efficiency of gas suction from a gas inlet to the first pump mechanism portion side is increased or decreased, and the pressure in a process chamber is changed.

Abstract: Disclosed is a backup heat-dissipating system having a serial fan which can be assembled easily, fastly and conveniently, and can effectively eliminate the interference between fans and prevent the air leakage resulting from the failed fan unit. The backup heat-dissipating system includes a main frame, a first rotor device disposed in the main frame and including a first control device, and a second rotor device disposed in the main frame to be coupled with the first rotor device in series along an axial direction of the main frame and including a second control device. When the first rotor device is failed, the first control device will output a signal to the second control device for driving the second rotor device to rotate at a relatively higher speed.