A novel rotating body, its material, and manufacturing method thereof, shortening a distance for cutting a bore surface in its axial direction, reducing processing costs, enabling lower-cost manufacture of inner rotor. A metallic rotating body 11 has a bore surface 12 for press-fitting a shaft thereinto, including a cutting-processed portion 13 at first end and an unprocessed portion 14 at second end. The processed portion 13 has an inner diameter formed smaller than the unprocessed portion 14. A chamfer 15 at first end of the bore surface 12 is cut, while a chamfer 6 at the second end not. A bore surface 2 of material 1 processed into the rotating body 11 includes a small-diameter portion 3 at first end and a large-diameter portion 4 at second end. A step 5 is formed between the small- and large-diameter portions 3, 4, with the chamfer 6 formed at second end.

Compressor assembly including a motor having a motor shaft which drives at least one compressor rotor of a compressor element as well as an oil-pump, in which a compressor rotor includes a compressor rotor part which is mounted on a compressor rotor shaft which is connected to the motor shaft by means of a direct coupling so to form a composed driving shaft and wherein-in which the oil-pump is mounted directly on the composed driving shaft or on another compressor rotor shaft.

Compressor assembly including a motor having a motor shaft which drives at least one compressor rotor of a compressor element as well as an oil-pump, in which a compressor rotor includes a compressor rotor part which is mounted on a compressor rotor shaft which is connected to the motor shaft by means of a direct coupling so to form a composed driving shaft and wherein-in which the oil-pump is mounted directly on the composed driving shaft or on another compressor rotor shaft.

A motor pump unit comprises an electric motor and a reversible internal gear machine. The latter has a multi-part housing in which an externally toothed pinion and an internally toothed hollow gear are arranged. A free space, in which a multi-part filler element is arranged, is configured between the gears. The filler element comprises radially movable sealing segments, between which a radial gap is configured. An axially movable sealing plate is arranged between axial faces of the gears and a housing part. This has a sealing plate control groove that is open to the faces of the gears and that can be pressurized, and which is open to the radial gap and located directly opposite thereto. The pinion segment and/or hollow gear segment has a radial sealing segment control channel that can be pressurized and extends transversely, is open to the radial gap, and ends directly in the radial gap.

The subject matter of this specification can be embodied in, among other things, a method that includes a gear pump includes gears having a gear root diameter and teeth having an addendum and pressure angle. A housing includes a fluid inlet and discharge, bearings configured to position the gear teeth in intermeshing contact across a fluid dam. The fluid dam includes a first face arranged at an angle to a split line, spaced apart from a center line at the split line a first distance towards the inlet, and extending from the first gear root diameter away from the center line to the first gear root diameter, and a second face arranged approximately perpendicular to the split line, spaced apart from the center line at the split line a second distance towards the outlet, and extending between the first gear root diameter and the second gear root diameter.

The subject matter of this specification can be embodied in, among other things, a method that includes a gear pump includes gears having a gear root diameter and teeth having an addendum and pressure angle. A housing includes a fluid inlet and discharge, bearings configured to position the gear teeth in intermeshing contact across a fluid dam. The fluid dam includes a first face arranged at an angle to a split line, spaced apart from a center line at the split line a first distance towards the inlet, and extending from the first gear root diameter away from the center line to the first gear root diameter, and a second face arranged approximately perpendicular to the split line, spaced apart from the center line at the split line a second distance towards the outlet, and extending between the first gear root diameter and the second gear root diameter.

A compressor having a compressor wall that has an interior surface that defines a compression chamber, in which a rotor or pair of rotors operates to compress a fluid. To do so, the rotors are in operative communication with the interior surface. The compressor also includes an injection port in the compressor wall and opening into the compression chamber, the injection port being in fluidic communication with a second fluid. The compressor can also include an insert in operative communication with the injection port, wherein the insert and the injection port define therebetween a gap through which the second fluid enters the compression chamber.

Provided is a fluid-pump inner rotor that can be easily fitted to an outer rotor. This fluid-pump inner rotor includes a rotor member having a through hole along a rotational axis and a shaft member fitted in the through hole. Fitting strength between a first hole region provided in an inner face of the through hole of the rotor member which region extends along a rotational axis of the rotor member from one of end faces thereof perpendicular to this rotational axis and a first shaft region provided in an outer face of the shaft member is set greater than fitting strength between a second hole region provided in the inner face of the through hole of the rotor member and a second shaft region provided in the outer face of the shaft member.

Provided is a fluid-pump inner rotor that can be easily fitted to an outer rotor. This fluid-pump inner rotor includes a rotor member having a through hole along a rotational axis and a shaft member fitted in the through hole. Fitting strength between a first hole region provided in an inner face of the through hole of the rotor member which region extends along a rotational axis of the rotor member from one of end faces thereof perpendicular to this rotational axis and a first shaft region provided in an outer face of the shaft member is set greater than fitting strength between a second hole region provided in the inner face of the through hole of the rotor member and a second shaft region provided in the outer face of the shaft member.

A rotary fluid machine has an inner rotor and an outer shell held by a stationary support structure, arranged so that sealing points on the inside of the shell interact in a sealing arrangement with the outer surface of the rotor to define working chambers, such that in use the relative motion of the rotor to the shell causes fluid to be moved through ducts in the rotor and rotor shaft, between the working chambers and a point where the rotor shaft interacts with the support structure.