A screw spindle pump, including a housing and a drive spindle accommodated therein and at least one running spindle which meshes with the latter and which has in each case two terminal end surfaces. A stop surface is provided axially adjacent to at least one end surface of the running spindle, wherein the running spindle is accommodated displaceably with an axial clearance perpendicular to the stop surfaces.

In a scroll compressor (1) provided with a fixed scroll (3) and an orbiting scroll (5), an inclined portion is provided in which the inter-facing surface distance (L) between an end plate (3a) and an end plate (5a) that face each other decreases continuously from the outer peripheral side towards the inner peripheral side. The inclined portion is configured from wall inclined portions (3b1, 5b1) in which the height of a wall (3b, 5b) decreases continuously from the outer peripheral side towards the inner peripheral side, and end plate inclined portions (3a1, 5a1) in which a tooth bottom surface is inclined in accordance with the incline of the wall inclined portions (3b1, 5b1). The inclined portion is provided across a range of no less than 180° around the center of the spiral.

In order to improve a machine for depressurizing or compressing substantially gaseous media, comprising a machine casing and at least one screw rotor, which is arranged in a screw rotor bore in the machine casing, extends between a low-pressure side and a high-pressure side of the screw rotor bore, cooperates with the substantially gaseous medium and is mounted on both sides in the machine casing by means of a respective bearing set, and a motor/generator unit that is coupled or couplable to the at least one screw rotor, it is proposed that the at least one screw rotor should be provided with at least one axial support bearing that axially supports the at least one screw rotor such that a high-pressure end face of the at least one screw rotor is guided, without making contact, to an end wall, which faces this end face, of the machine casing that receives the at least one screw rotor.

A screw pump, including a housing with a running bore having at least two intersecting bores, each of which receives a spindle, wherein the spindles have worm screw profiles which intermesh in portions and in operation bend in a defined bending direction under a hydraulic bending pressure, wherein each bore is configured as a slot with a longer first axis of symmetry and a shorter second axis of symmetry standing orthogonally thereto, wherein the longer first axis of symmetry runs in the bending direction.

Some embodiments of a disclosure provide a piston limiting structure, a compressor, and a heat exchange apparatus. The piston limiting structure includes: a cylinder, having a piston hole perpendicular to an axial direction of the cylinder and penetrating the cylinder, wherein a projection of the piston hole in a penetrating direction is circular; a piston, disposed in the piston hole and slid in the piston hole, wherein a side wall of the piston is provided with a limiting surface, and the limiting surface does not penetrate two ends of the side wall of the piston along an axial length of the piston; and a limiting member, wherein the cylinder is provided with a limiting hole penetrating from an outer wall of the cylinder to the piston hole, the limiting member is mounted in the limiting hole , and the limiting member abuts against the limiting surface.

A pump arrangement (1) at least comprising a pump (2) having a pressure side (3) and an intake side (4) and a drive unit (5) for the pump (2) which are arranged in a common housing (6), wherein the drive unit (5) is an axial flow electric drive which comprises a stator (7) which is connected to the housing (6) in a rotationally secure manner and a rotor (8) which is arranged so as to be able to be rotated with respect to the housing (6), wherein the rotor (8) is arranged with a first end face (9) opposite the stator (7) in an axial direction (10) and forms an outer conveying means (11) of the pump (2) and has with spacing from the first end face (9) on an inner circumferential face (12) a first conveying profile (13), wherein in a radial direction (14) inside the rotor (8) there is arranged an inner conveying means (15) of the pump (2) which has on an outer circumferential face (16) a second conveying profile (17) which cooperates with the first conveying profile (13) in order to convey a fluid (18).

Some embodiments of a disclosure provide a piston limiting structure, a compressor, and a heat exchange apparatus. The piston limiting structure includes: a cylinder, having a piston hole perpendicular to an axial direction of the cylinder and penetrating the cylinder, wherein a projection of the piston hole in a penetrating direction is circular; a piston, disposed in the piston hole and slid in the piston hole, wherein a side wall of the piston is provided with a limiting surface, and the limiting surface does not penetrate two ends of the side wall of the piston along an axial length of the piston; and a limiting member, wherein the cylinder is provided with a limiting hole penetrating from an outer wall of the cylinder to the piston hole, the limiting member is mounted in the limiting hole, and the limiting member abuts against the limiting surface.

An apparatus includes a position adjustment circuit to receive a gap setpoint and a gap feedback signal corresponding to a gap width between a pair of meshing gear teeth of a first gear and a second gear. The position adjustment circuit outputs a gap adjustment signal corresponding to a difference between the gap setpoint and the gap feedback signal. The apparatus includes a motion control circuit to provide a first speed demand signal to the first motor that drives the first gear and a second demand signal to the second motor that drives the second gear, and dynamically synchronize position between the pair of meshing gear teeth such that the gap width between the pair of meshing gear teeth is within a predetermined range of the gap setpoint by adjusting at least one of the first speed demand signal or the second speed demand signal.

A fixed scroll wrap (52) includes a fixed spiral portion (57) having a spiral shape and a fixed arcuate portion (58) having an arcuate shape. A movable scroll wrap (62) includes a movable spiral portion (67) having a spiral shape and a movable arcuate portion (68) having an arcuate shape. An arcuate portion side surface clearance (GA) is defined by the fixed arcuate portion (58) and one of the movable spiral portion (67) and the movable arcuate portion (68), or is defined by the movable arcuate portion (68) and one of the fixed spiral portion (57) and the fixed arcuate portion (58). A spiral portion side surface clearance (GI) is defined by the fixed spiral portion (57) and the movable spiral portion (67). The arcuate portion side surface clearance (GA) is larger than the spiral portion side surface clearance (GI).

A screw pump, including a housing with a running bore having at least two intersecting bores, each of which receives a spindle, wherein the spindles have worm screw profiles which intermesh in portions and in operation bend in a defined bending direction under a hydraulic bending pressure, wherein each bore is configured as a slot with a longer first axis of symmetry and a shorter second axis of symmetry standing orthogonally thereto, wherein the longer first axis of symmetry runs in the bending direction.