The present invention relates to a rotor for a vacuum pump 150 having a roots pumping mechanism, the rotor comprising at least two hollow lobes 160, 162, 164, 166, each lobe having an outer wall 208 which defines a lobe profile, a hollow cavity 210 generally inward of the outer wall, and at least one strengthening rib 226 located in the cavity to resist stress on the lobes generated during rotation.

A first rotor configured to rotate adjacent to a second rotor is disclosed. The second rotor includes a circular main body with a first axis of rotation and a vane extending radially from the main body. The first rotor includes a first curved surface that corresponds to a curve swept at a constant radius about a second axis of rotation, a second curved surface that corresponds to a curve swept by a leading edge of the vane when the second rotor is simultaneously rotated about the first axis of rotation and the second axis of rotation, a third curved surface that corresponds to a curve swept by a trailing edge of the vane when the second rotor is simultaneously rotated about the first axis of rotation and the second axis of rotation, and a vane-receiving groove disposed between the second curved surface and the third curved surface.

A rotary device includes a first rotor rotatable about a first axis and having at its periphery a recess bounded by a curved surface, and a second rotor counter-rotatable to the first rotor about a second axis, parallel to the first axis, and having a radial lobe bounded by a curved surface, the first and second rotors being coupled for intermeshing rotation, wherein the first and second rotors of each section intermesh in such a manner that on rotation thereof, a transient chamber of variable volume is defined, the transient chamber having a progressively increasing or decreasing volume between the recess and lobe surfaces, the transient chamber being at least in part defined by the surfaces of the lobe and the recess; the ratio of the maximum radius of the lobe rotor and the maximum radius of the recess rotor being greater than 1.

An engine system is provided, including a housing, multiple shafts in alignment and in parallel with each other, vertically penetrating through the housing, multiple wing sections integratively attached around the multiple shafts, respectively, and configured to engage with each adjacent one to drive axial rotation, and multiple ducts attached to the housing and communicating with inside of the housing, each duct being for use for passing an air-fuel mixture or outputting exhaust gases. The air-fuel mixture is collected in at least two open sections associated with the first wing section, and the collected air-fuel mixture is compressed and ignited for combustion when each of the at least two open sections has a minimum volume. Chemical energy generated by the combustion is used to drive the axial rotation of each wing section, thereby individually rotating the multiple shafts to transmit power.

A rotary device is disclosed that includes a rotor comprising a main body and plurality of protrusions extending radially from the main body. At least a pair of voids are provided adjacent to each other in the main body of the rotor between each adjacent pair of the plurality of protrusions, and each pair of voids is spaced from each adjacent pair of voids by a distance greater than that between each adjacent void in each pair of voids.

A first rotor configured to rotate adjacent to a second rotor is disclosed. The second rotor includes a circular main body with a first axis of rotation and a vane extending radially from the main body. The first rotor includes a first curved surface that corresponds to a curve swept at a constant radius about a second axis of rotation, a second curved surface that corresponds to a curve swept by a leading edge of the vane when the second rotor is simultaneously rotated about the first axis of rotation and the second axis of rotation, a third curved surface that corresponds to a curve swept by a trailing edge of the vane when the second rotor is simultaneously rotated about the first axis of rotation and the second axis of rotation, and a vane-receiving groove disposed between the second curved surface and the third curved surface.

A power transmission system comprises a transmission device, and a power supply device which powers the transmission device, wherein the transmission device comprises a cavity having a body, covers, an inlet and an outlet; at least a pair of rotors and a gear set that are assembled in the cavity; and a transmission shaft pivotally connected with the pair of rotors and the gear set; the power supply device comprises a power equipment available for transmitting a working fluid; shaft adapters connected with the inlet and the outlet of the cavity; and a connecting pipe connected between the power equipment and the shaft adapter; the working fluid is transmitted by the connecting pipe from the power equipment to the inlet of the cavity to provide the pair of rotors with normal force for radial motion in a reverse rotation direction and make pressure in the cavity increased.

A Roots-type device can include a housing assembly having a first opening and a second opening in fluid communication with an internal cavity; a pair of identical rotors oppositely arranged within the housing internal cavity, each of the pair of rotors having a longitudinal axis and plurality of lobes, each of the lobes defining an end face extending between a first longitudinal side of the rotor lobe and a second longitudinal side of the rotor lobe; and a recess port defined within the housing assembly and being axially spaced from the end faces of the rotor lobes, the recess port placing the first longitudinal side of one of the rotor lobes in fluid communication with the second longitudinal side of the rotor lobe such that the housing first opening is placed in fluid communication with the housing second opening. The device can also be provided be provided with an inlet nozzle structure in fluid communication with the first opening, the inlet nozzle tapering towards the first opening and being configured such that a nozzle velocity of a working fluid passing through the nozzle is at least equal to the rotor mesh axial lead velocity.