A method of operating an exhaust gas recirculation pump for an internal combustion engine including: providing an EGR pump assembly including an electric motor coupled to a roots device having rotors, the EGR pump operably connected to an internal combustion engine; providing an EGR control unit lined to the EGR pump assembly; providing sensors linked to the EGR control unit; determining if a motor speed is within a predetermined target (step SI), wherein when the motor speed is within the predetermined target then; determining if a motor torque is within a predetermined target (step S2) wherein when the motor torque is within the predetermined target then; determining if a motor temperature is within a predetermined target (step S3) wherein when the motor temperature is within the predetermined target then; maintaining operation of the exhaust gas recirculation pump.

A Roots-type blower may include first and second meshed, lobed rotors disposed in first and second chambers of a housing. Each lobe may have first and second axially facing end surfaces defining a twist angle that may be a function, at least partially, of the number of lobes on each rotor. A blower housing may include a bearing plate that may include one or more internal pressure relief ports. A pressure relief port may be configured to relieve fluid pressure from a trapping area that may form between first and second meshed rotors.

A blower drive system for a vehicle such as a vacuum truck includes a blower including a blower input shaft and a blower housing; a transfer case operably connected to transfer drive from the vehicle engine driveline to the blower input shaft; a frame bracket assembly including one or more connections to the vehicle chassis frame and one or more connections to the blower housing. The frame bracket assembly mounts the blower housing in a specified fixed angle with respect to ground and mounts the bottom of the blower housing in a specified fixed height above the vehicle chassis frame.

A vacuum system having a condenser and a root vacuum pump set includes an independent inlet condenser set having an inlet end for receiving vapor inputted from an output of an air cooling power generator condenser of a generator; air in the vapor being condensed, and the surplus air is outputted; a root vacuum pump set including a plurality of root vacuum pumps; the root vacuum pump set further including an input end and an output end; the input end being connected to the independent inlet condenser set; air outputted from the independent inlet condenser set being inputted to the plurality of root vacuum pump for compression and then the compressed air being outputted from the output end; and a backing pump connected to the output end of the root vacuum pump set by using an output pipe; the backing pump serving to receive air outputted from the root vacuum pump set.

The present teachings generally include a composite rotor assembly comprising a shaft and a rotor body mounted to the shaft. The rotor body can include a core structure including a cured polymeric material wholly or partly defining plurality of lobes joined by adjacent root portions. The rotor body can also include a support structure continuously extending the length of the core structure to provide additional structural integrity to the rotor body. The support structure can be wholly or partially embedded within the core structure and can also be wrapped around the exterior of the core structure. In one example, the core structure includes an epoxy resin and the support structure includes a carbon fiber material.

A pump includes a first housing part defining a first portion of a bore extending within the first housing part and shaped to receive a rotor; and a second housing part defining a second portion of the bore extending within the second housing part and shaped to receive the rotor. The first housing part has a first face abutable against an opposing second face of the second housing part to position the first portion of the bore with the second portion of the bore to receive the rotor. The first portion of the bore has a first circular cross-section portion centered along the first face and the second portion of the bore having a second circular cross-section portion centered, within the second housing part, at a distance from the second face.

A multistage Roots pump comprise a plurality of pump chambers in a pump housing. They constitute respective pump stages, wherein each pump stage comprises two two-toothed rotary pistons. The pump stages are separated from each other by partition walls. In the partition walls essentially radially extending connecting ducts are arranged. The connecting ducts are connected with an inflow chamber whose inflow opening has a larger cross-section than the connecting ducts.

A vacuum booster assembly includes, but is not limited to, a booster housing defining a booster chamber and including a gas inlet and a gas outlet; a first rotor positioned within the booster chamber and adapted for rotation therein, the first rotor including a first shaft and at least two lobes defining a first lobe profile; and a second rotor positioned within the booster chamber and adapted for rotation therein, the second rotor including a second shaft and at least two lobes defining a second lobe profile, wherein the first and second rotors are formed from a metal having a coefficient of thermal expansion from about 1 (10.sup.−6 in/in*K) to about 13 (10.sup.−6 in/in*K), and wherein at least one of the outer surface of the first rotor, the outer surface of the second rotor, or the booster chamber includes a coating.

A motor-driven compressor is installed in a fuel cell vehicle to supply air to a fuel cell. The motor driven compressor includes a rotation shaft, an electric motor, a compression unit that compresses air, a housing that includes a motor chamber and a compression chamber, and a seal member that restricts a flow of a fluid between the motor chamber and the compression chamber. The housing includes an inlet and an outlet. The inlet draws, into the motor chamber, the air-conditioning refrigerant that has passed through the evaporator but has not reached the air-conditioning compressor as a low-temperature refrigerant. The outlet discharges the low-temperature refrigerant, which is drawn from the inlet into the motor chamber, out of the motor chamber.

A housing for a rotary vane pump includes a suction flange and a discharge flange having a multi-angular cross-section with at least two sides extending parallel to each other, cooling ribs provided on an outer surface of the housing, with the number of cooling ribs in the region with a high internal pressure being greater than a number of cooling ribs in the region with a low internal pressure, inlet and outlet, with the inlet cross-section being greater than the outlet cross-section, and connection elements provided on the housing and each having two installation surfaces connected by a connection surface.