A motor-driven Roots pump includes a housing, a drive shaft and a driven shaft that have axial lines parallel with each other, and a gear chamber. The housing includes a first partition that has a first defining surface, a second partition having a second defining surface, and a relief recess. An addendum circle of the drive gear and an addendum circle of the driven gear intersect with each other at a first intersection point. A plane that includes both the axial lines is defined as an imaginary plane. The first intersection point is located on a side of the imaginary plane on which the drive gear and the driven gear start meshing with each other. An opening of the relief recess is opposed to the first intersection point and is arranged in a region on a side of the imaginary plane on which the first intersection point is located.

A vane pump (101) for an automatic transmission includes a suction-side behind-vane pressure duct (112) and a pressure-side behind-vane pressure duct (111). The suction-side behind-vane pressure duct (112) is connected to the pressure side (116) of the vane pump (1). A valve device (113, 114) is connected to the pressure-side behind-vane pressure duct (111). During operation of the vane pump (101), a pressure-side behind-vane pressure (p DH) can be set in the pressure-side behind-vane pressure duct (111) with the valve device (113, 114).

The invention relates to a method for controlling a start-up of an electric vacuum pump for a vacuum system of a vehicle, wherein the start-up can occur according to at least two different start-up modes, i.e., according to a standard mode and according to at least one special mode, wherein in the standard mode the vacuum pump is connected to a supply voltage in a non-clocked manner and in the special mode the vacuum pump is connected to a supply voltage in a dynamically clocked manner.

A crankcase heating control system for a heat pump system includes a data receiving module and a power control module. The data receiving module is configured to receive: data indicative of a temperature of a compressor of the heat pump system; and data indicative of an ambient temperature. The power control module is configured to: selectively apply power to a heater of a crankcase of the compressor; and disable the heater when all of: a period since the compressor was last turned is greater than a predetermined period; the ambient temperature is less than a predetermined temperature; and the temperature of the compressor is less than the predetermined temperature.

A scroll compressor includes a shaft being rotated by a drive source, an eccentric bush including a recess part into which the shaft is inserted and an eccentric part being eccentric to the shaft, an orbiting scroll configured to perform an orbiting motion in interlock with the eccentric part, a fixed scroll tooth-engaged with the orbiting scroll, and a buffer member configured to prevent an outer periphery of the shaft and an inner periphery of the recess part from coming in contact with each other, wherein the buffer member is formed to be able to perform a relative motion with respect to the shaft and the recess part. Accordingly, the scrolls are prevented from being damaged, an impact sound is prevented from being generated, and an increase of an inertial force and an unbalance force of a rotating body is suppressed.

Vacuum pump (1), comprising a housing (2) having an inlet (4) and an outlet (6) and defining a chamber (8) within the housing (2), a rotor (10) for rotational movement about a rotational axis (AR) within the chamber (8), and at least a first and a second vane (22, 24) received in respective first and seconds slots (16, 18) formed in the rotor (10). The first and second slots (16, 18) are substantially parallel to each other, and a length (L.sub.V) of each vane (22, 24) is larger than a length (L.sub.S) of the respective slot. Production method of such a vacuum pump.

An adjustable vane pump, in particular an oil pressure pump, with a suction side and a pressure side, with a housing and a rotor supported in the housing so as to be rotatable about a rotor axis. At least one vane is supported for movement in a radial direction. The housing comprises a housing floor and a housing cover transversely to the rotor axis, and an adjustment cage is arranged between the housing floor and the housing cover.

A heat pump device includes a compressor including a motor, a heat exchanger, an inverter, and an inverter control unit. The inverter control unit generates a drive signal for the inverter. When the compressor is heated, the inverter control unit applies, to the motor, a high-frequency voltage with which the motor cannot be rotationally driven; estimates a magnetic pole position indicating a stop position of a rotor of the motor; determines an amplitude and a phase of a voltage command based on an estimation result of the magnetic pole position and a necessary amount of heat, and generates a drive signal.

A thermal energy recovery device includes: a circulation line having an evaporator, an expander, a condenser, and a pump; a power recovery machine; a first on-off valve; a thermal energy introduction line configured to introduce a gas phase working medium into a post-expansion space; a second on-off valve; and a control unit. Until an evaporation condition that a liquid phase working medium accumulated in the post-expansion space has reached an amount equal to or smaller than a reference amount is met, the control unit closes the first on-off valve and opens the second on-off valve, and drives the pump in a state where the expander is stopped, and when the evaporation condition is met, the control unit opens the first on-off valve and closes the second on-off valve, and drives the expander.

A back pressure chamber forming portion forms a back pressure chamber configured to accumulate a high pressure refrigerant discharged from a working chamber and thereby generate a refrigerant pressure, which urges a movable scroll against a stationary scroll. A balancer is placed at an inside of the back pressure chamber and is configured to be rotated by a rotatable shaft. The back pressure chamber forming portion has a discharge hole that communicates between a radially outer side of the back pressure chamber, which is located radially outward in a radial direction of an axis of the rotatable shaft, and a suction chamber to discharge a liquid phase refrigerant from the back pressure chamber into the suction chamber when the liquid phase refrigerant flows from the working chamber into the back pressure chamber.