A method for expulsion of a fluid inside a compressor at start-up including the steps: applying a first signal to the motor windings for a first duration of time to align the motor rotor to the initial position; applying a second signal to the motor windings to start rotation of the compressor shaft; applying a third signal to the motor windings for a second duration of time to hold the compressor shaft in place; and applying a fourth signal to the motor windings to accelerate the motor to an operational speed.

A vacuum pump having a housing which limits a working space and having a rotor, rotatably mounted in the housing about a rotor axis, the rotor guides a vane being movably mounted in the radial direction, the vane has a transverse extent, and the vane divides the working space into a suction side having a suction inlet and a pressure side having a pressure outlet, the housing has at least one oil outlet, the oil outlet is closed by a relief valve, the relief valve assumes an open position, when a limit pressure lying above a nominal pressure is exceeded in the working space, and the transverse extent of the vane is large enough that when the vane passes the oil outlet, the oil outlet is closed by the vane, so that there is no fluid connection between the suction side and the pressure side over the oil outlet.

A multiple lobe vane fluid pump having enhanced under-vane cavity pressurization for cold start priming includes a pressure plate having a first flow passage and a second flow passage, the first flow passage being configured to allow fluid flow between a primary under-vane cavity and a primary discharge port, the second flow passage being configured to allow fluid flow between the primary discharge port and a secondary under-vane cavity. Additionally, the pump includes a thrust plate including the primary under-vane cavity, a first adjacent under-vane cavity having one open end in fluid communication with a first end on the primary under-vane cavity, and a second adjacent under-vane cavity having one open end in fluid communication with a second end of the primary under-vane cavity.

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.

A vane pump includes a rotor; a plurality of slits that are formed in the rotor, the plurality of vanes being respectively inserted into the plurality of slits in a slidable manner; a cam ring that has a cam face on which tip-ends of the vanes slide by the rotation of the rotor; and pump chambers that are defined by the rotor, the cam ring, and an adjacent pair of the vanes. The plurality of vanes have a plurality of first vanes that are formed by applying a DLC coating on a base material and second vanes that are formed such that the base material is exposed, the first vanes being respectively inserted into at least two adjacent slits of the plurality of slits.

The invention relates to a pump, having a contour ring, having a rotor, having vanes, having side plates, having a housing and a housing cover, having under-vane grooves for supplying the lower vane faces with pressure, the vanes being arranged radially displaceably in the rotor and extending under the vanes as a result of the pressure and being pressed against the contour ring. Furthermore, the invention relates to a system for supplying oil to a consumer.

A vane pump that employs one or more less restricted vanes (or looser vanes) within its rotor is described herein. The less restricted vane(s) are configured to radially move outwardly before the remaining vanes during startup. In one case, for example, at least one vane has a different thickness (e.g., thinner) as compared to the thickness of the remaining vanes. In another case, at least one slot has a different width (e.g., wider) as compared to the width of the other slots. The less restricted vane facilitates a cold start in highly viscous oil by allowing easier radial displacement and thus earlier initial build-up of pressure in the pump. The pump may be used with an engine or transmission.

There are described a vane cell pump and a method for operating a vane cell pump. The vane cell pump comprises a hollow-cylindrical contour ring which is arranged between two side plates and which has an inner peripheral face and a rotor which is rotatably supported about a rotation axis which extends parallel with the cylinder axis of the contour ring and which has a plurality of conveying elements which can be displaced radially relative to the rotation axis and which are urged against the inner peripheral face during a rotation of the rotor. The inner peripheral face is formed in such a manner that a number corresponding to the number of flows of the vane cell pump in respect of pump portions are each constructed with an intake region and a pressure region which are passed through by the conveying elements during a rotation of the rotor. Within a pump portion, the radial spacing between the rotation axis and the inner peripheral face increases when viewed in the working rotation direction of the rotor over the intake region in order subsequently to decrease toward the end of the pressure region again. A narrow location, during the passage through which the conveying elements (are displaced radially inward toward the rotation axis to the greatest extent, is located between a pressure region) and a subsequent intake region when viewed in the working rotation direction. The rotor has, radially inside the conveying elements, expulsion regions which are at least partially connected to at least one pressure region via a fluid path in order to expel the conveying elements against the inner peripheral face. By applying only a part-stroke, an auxiliary start contour which is arranged between the rotation axis and the inner peripheral face radially inside the conveying elements in the region of at least one pump portion displaces conveying elements which are previously displaced at a narrow location to the greatest extent radially inwardly toward the rotation axis as a result of a maximum of temporary contact into the pump portion.

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 variable-displacement lubricant pump includes a first plunger. A control ring is pushed by the first plunger in a high pumping volume direction. The first plunger is arranged in a first control chamber with a side wall. A first pressure conduit connects a pump outlet port with the first control chamber. A pumping volume limitation unit is arranged so that the first plunger covers and closes an outlet opening arranged in the side wall in a lower pumping volume position of the control ring. A thermostatic element actuates a temperature controlled valve based on lubricant temperature. The thermostatic element pushes a shiftable valve body against a retraction spring to an extended closed end position when the lubricant has an operation temperature. The shiftable valve body is in a retracted closed end position at a cold lubricant temperature and in an intermediate open position at an intermediate lubricant temperature.