A belt drive system includes a drive sheave and a driven sheave. A drive motor turns the drive sheave when the drive motor is activated. A drive belt is connected to the drive sheave and the driven sheave so that the driven sheave is turned when the drive motor is activated. The drive motor is mounted upon a shuttle and the shuttle is slidingly mounted on a base. A drive system moves the shuttle when the adjustment motor is activated so that a position of the drive sheave relative to the driven sheave may be adjusted so as to increase a tension in the drive belt. A controller activates the adjustment motor when slippage of the drive belt on either the drive sheave or the driven sheave is detected.

An exhaust gas recirculation pump for an internal combustion engine that includes an electric motor assembly having an electric motor disposed within an electric motor housing. A roots device is coupled to the electric motor. The roots device includes a housing defining an internal volume. Rotors are disposed in the internal volume and connected to the electric motor. A bearing plate is attached to the housing wherein the bearing plate and an outer cover attached to the bearing plate defines an oil cavity. A transmission assembly is positioned on an opposing side of the housing relative to the electric motor and in the oil cavity.

A rotary screw compressor includes a compressor assembly and a drive motor assembly. The compressor assembly includes a compressor housing, a first screw rotor and a second screw rotor installed in the compressor housing and engaged with each other. An end of the first screw rotor is an engaging end. The drive motor assembly includes a motor housing, a motor rotor, a motor stator and a centering bushing installed in the motor housing, and the motor stator installed on an outer side of the motor rotor and capable of driving the motor rotor to rotate, and the centering bushing is passed and connected to the inner circumference of the motor rotor and has an end sheathed on the engaging end, so that the motor rotor can drive the first screw rotor to rotate through the centering bushing and the engaging end.

A transmission between a drive shaft and a driven shaft comprises a housing and at least a driven gearwheel that is mounted on the driven shaft and a drive gearwheel that is mounted on a drive shaft. The housing comprises two separated chambers, i.e. a first chamber that is connected to the driven shaft and a second chamber which is separate from the first chamber, whereby the first chamber is connected via a channel with the second chamber, whereby around the drive gearwheel or driven gearwheel the second chamber is formed, whereby the form of the second chamber is such that when the gearwheel in question rotates, a gas flow is created around this gearwheel which causes a negative pressure in the channel by the venturi effect.

The invention relates to a displacement machine according to the spiral principle, in particular a scroll compressor or scroll expander, with a high-pressure chamber, a low-pressure chamber and an orbiting displacement spiral, which engages in a counter-spiral such that chambers are formed between the displacement spiral and the counter-spiral for receiving a working medium, wherein a counter-pressure chamber is formed between the low-pressure chamber and the displacement spiral. According to the invention a pressure regulating device which is fluidically connected to the counter-pressure chamber sets a pressure difference between the counter-pressure chamber and the low-pressure chamber by means of a set value specified by the computing unit.

Disclosed is a crank shaft, including a central rotation shaft, a first eccentric component, a second eccentric component, a disc partition plate and an annular partition plate, wherein the disc partition plate is disposed between the first eccentric component and the second eccentric component, and is integrally formed with the central rotation shaft, and the annular partition plate is sleeved outside the disc partition plate. The crank shaft can prevent the occurrence of leakage between the partition plate and a roller while increasing an eccentricity of the crank shaft and improving operating performances of a compressor. Further disclosed are a pump body assembly having the crank shaft and a compressor.

A dry vacuum pump is provided, including two shafts, respectively supporting at least one pumping rotor being configured to synchronously rotate in reverse in order to convey a gas to be pumped from an intake of the dry vacuum pump to an outlet; and a synchronous motor configured to rotate one shaft of the two shafts, the synchronous motor including a rotor coupled to the shaft, a first stator with windings arranged around the rotor, and at least one second stator with windings arranged around the rotor, the windings of the stators being configured to be supplied individually or simultaneously in order to adapt a power of the synchronous motor to a pumping load. A method for controlling a synchronous motor of a vacuum pump is also provided.

Disclosed are a cylinder, a pump body assembly, a compressor, and a temperature adjusting device. The cylinder includes a cylinder body, and a first cavity and a second cavity are formed in an axial direction of the cylinder body, wherein the first cavity is in communication with the second cavity, and an inner diameter of the first cavity is greater than that of the second cavity; and when the cylinder body operates, the first cavity forms a first working cavity, and the second cavity forms a second working cavity. With such an arrangement, multiple working cavities are formed inside one cylinder body, which simplifies an installation process of the pump body assembly, and enables a pump body with the cylinder to be installed more conveniently and easily, thereby improving installation reliability of the pump body assembly.

A screw compressor includes a housing, a first rotor rotatable about a first axis relative to the housing, and a second rotor rotatable about a second axis relative to the housing. The second rotor is enmeshed with the first rotor. A motor is embedded within the first rotor such that the motor is coaxial with the first axis.

The invention relates to an external gear machine (1) in particular an external gear pump or an external gear motor, having at least two gears (3, 4) that mesh with each other in external engagement, wherein the gears (3, 4) are surrounded by a housing (10), wherein one gear (4) has at least one bearing journal (7, 8) and the other gear (3) has a driving or driven journal (5), which are in each case mounted in a bearing bushing (38) so as to respectively be rotatable about a rotation axis (13, 14), wherein a bearing sleeve pp with an anti-twist element is arranged in the bearing bushing (38). In order to improve the external gear machine, in particular with regard to the materials that can be used for producing the bearing bushings and/or the service life, the anti-twist element of the bearing sleeve is arranged in a through-hole of the bearing bushing and is combined with a filter device and/or throttle device via which a working medium of the external gear machine (1) reaches the bearing sleeve.