The invention relates to an impeller (1), in particular for a side channel machine, comprising blades (5) arranged distributed in the circumferential direction and formed in each case by a blade wall (6), which blades form open blade chambers (4) in a plan view onto the impeller (1), wherein a blade wall (6) in the plan view starts at a first radius dimension (r.sub.1) related to the geometrical impeller rotation axis (x), which first radius dimension (r.sub.1) corresponds to half or more than half of a second radius dimension (r.sub.2), which second radius dimension (r.sub.2) defines a circumferential rim edge (9) of the impeller (1), and wherein the radius dimension (r.sub.1) defines a radially inner boundary wall (7) of the blade chamber (4), wherein furthermore a blade wall (6) comprises an exposed upper terminating edge, which runs correspondingly radially on the inside into the inner boundary wall (7) and ends radially on the outside in plan view, wherein an imaginary connecting line (V) can be drawn between a run-in point of the terminating edge (12) into the inner boundary wall (7) and a radially outer end of the terminating edge (12) and the terminating edge runs normal to the connecting line (V) with a different offset dimension, wherein a greatest offset dimension results. For the advantageous development, in particular with regard to improved efficiency, it is proposed that the greatest offset dimension corresponds to 0.1 times or more the difference between the second (r.sub.2) and the first radius dimension (r.sub.1).

An improved vacuum pump mechanism is described in which an intersecting solid or perforated element is arranged to intersect a channel member. Relative movement of the intersecting solid or perforated element and channel member causes gas molecules to be urged from inlet to an outlet of the pump. Gas molecules are constrained within the channel member and interaction of the gas molecules with the flat and smooth surfaces of the intersecting solid or perforated member influence momentum of the gas molecules so that they are directed towards the outlet. In one embodiment, the channel member is formed as a helix and the intersecting solid or perforated elements are disk-shaped. An alternative embodiment is provided having the channel member configured as a spiral and the perforated elements as cylindrical skirts. The pump provides significant improvements in pump capacity, reduced power consumption and size of pump.

A rotator may be configured to be accommodated in a casing of a pump for sucking a fluid into the casing and discharging the fluid outside of the casing. The rotator may comprise an insert portion configured to insert a rotating shaft and one or more communicating openings. The one or more communicating openings may be disposed in a vicinity of the insert portion, and pierce the rotator in a direction along the rotating shaft. The rotator may be made of resin. A flow direction of the resin located around the insert portion and the one or more communicating openings may extend at least in the direction along the rotating shaft.

A fluid working machine comprises a rotor (7) with a blading (10) comprising 40 to 65 blades that radially project out of a body central and are suitably circumferentially offset on a plane normal to the axis of symmetry of the rotor, according to an appropriate spacing rule that can eliminate or appreciably attenuate the acoustic emission components that are mostly annoying to the human ear or at frequencies close to the resonance frequencies of other parts of the working machine.

An impeller for a fluid pump includes a hub having an outer surface; an outer ring which is concentric with the hub and having an inner surface; and a plurality of blades extending from a root at the outer surface to a tip at the inner surface. Each of the blades has a first leg and a second leg which meet at a vertex such that a concave side of the blades faces toward a rotational direction and such that a convex side of the blades faces away from the rotational direction. The concave side of each one of the plurality of blades forms a draft angle with the convex side of another one of the plurality of blades which is immediately adjacent thereto in the rotational direction. The draft angle at the inner surface is less than or equal to 10% of the draft angle at the outer surface.

An impeller for a side channel flow machine has impeller blades. An inlet region of the impeller blade is off-set from the outlet region. The inlet region is connected to the outlet region via a sloped transition region. The impeller allows a high degree of efficiency of the side channel flow machine and can be produced at particularly low cost.

A fluid pump includes an inlet for introducing fluid into the fluid pump and an outlet for discharging the fluid from the fluid pump A motor is included having an armature which rotates about an axis. The motor also has a stator which circumferentially surrounds the armature such that a fluid passage is defined radially between the armature and stator through which the fluid flows from the inlet to the outlet. A pumping arrangement is rotated by the armature and pumps the fluid from the inlet to the outlet. A flow impedance member extends axially in the fluid passage which impedes circumferential flow of the fluid within the fluid passage, thereby generating a pressure gradient circumferentially within the fluid passage which applies a lateral force to the armature.

An outer wall surface of an output end portion includes a pair of first plane surfaces which are formed at different positions in its circumferential direction. An inner wall surface of a fitting hole includes a pair of second plane surfaces which are formed at different positions in the circumferential direction. A clearance between one of the pair of first plane surfaces and one of the pair of second plane surfaces is made larger from one side toward the other side in an axial direction in a state that a rotary shaft and an impeller are concentric with each other.

An impeller may include a plurality of blades disposed along a rotation direction in an outer circumferential portion of at least one end surface of two end surfaces of the impeller; a plurality of blade grooves; and an outer circumferential wall disposed at an outer circumferential edge and closing the plurality of grooves. The housing may include an opposing groove opposing a blade groove region and extending along the rotation direction of the impeller. In a plan view of the one end surface of the two end surfaces of the impeller, each of the plurality of the blades may be curved, and a central portion of each of the blades may be positioned frontward in the rotation direction of the impeller than both ends of the blade.

A fluid pump includes an inlet for introducing fluid into the fluid pump and an outlet for discharging the fluid from the fluid pump. A motor is included having an armature which rotates about an axis The motor also has a stator which circumferentially surrounds the armature such that a fluid passage is defined radially between the armature and stator through which the fluid flows from the inlet to the outlet. A pumping arrangement is rotated by the armature and pumps the fluid from the inlet to the outlet A flow impedance member extends axially in the fluid passage which impedes circumferential flow of the fluid within the fluid passage, thereby generating a pressure gradient circumferentially within the fluid passage which applies a lateral force to the armature.