In one form, a compressor system includes a compressor, and an annular ring disposed downstream of the compressor and structured to reduce pressure fluctuations in the pressurized air discharged by the compressor. The annular ring may include an internal passage for conducting the pressurized air. The annular ring may include at least one resonator in fluid communication with the internal passage. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.

In one form, a compressor system includes a compressor, and an annular ring disposed downstream of the compressor and structured to reduce pressure fluctuations in the pressurized air discharged by the compressor. The annular ring may include an internal passage for conducting the pressurized air. The annular ring may include at least one resonator in fluid communication with the internal passage. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.

An internal gear pump includes a pump rotor (4) in which a meshing point between an inner rotor (2) having n teeth and an outer rotor (3) having (n+1) teeth is located rearward, in a rotational direction of the rotor, relative to an eccentric axis (CL) along which a center (O.sub.I) of the inner rotor and a center (O.sub.O) of the outer rotor are disposed. A tooth-surface curve of the outer rotor (3) near a meshing section thereof is formed by duplicating thereto a tooth-surface shape of the inner rotor (2) near a meshing section thereof.

An internal gear pump includes a pump rotor (4) in which a meshing point between an inner rotor (2) having n teeth and an outer rotor (3) having (n+1) teeth is located rearward, in a rotational direction of the rotor, relative to an eccentric axis (CL) along which a center (O.sub.I) of the inner rotor and a center (O.sub.O) of the outer rotor are disposed. A tooth-surface curve of the outer rotor (3) near a meshing section thereof is formed by duplicating thereto a tooth-surface shape of the inner rotor (2) near a meshing section thereof.

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.

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.

A cooling pump assembly has a cooling pump, a mount, a shaft, and a driving set. Wherein, a driving unit of the driving set is configured to connect a device to be cooled and has a central hole fluidly communicating with an interior of the cooling pump. The shaft is inserted in the cooling pump, the mount, and the driving unit. The shaft is connected to the driving unit and the cooling pump. The shaft has a channel fluidly communicating with the device to be cooled and fluidly communicating with the channel and the central hole via multiple guiding holes of the shaft. Therefore, the cooling pump assembly and the device to be cooled can be driven by a same motor.

An electric motor, in particular for a vacuum pump, with two magnetically coupled shafts. A correction force can be set on each shaft by means of adjusting magnet devices, whereby negative effects due to errors in the magnetic coupling can be compensated.

An electric motor, in particular for a vacuum pump, with two magnetically coupled shafts. A correction force can be set on each shaft by means of adjusting magnet devices, whereby negative effects due to errors in the magnetic coupling can be compensated.