Abstract: A method of designing a supercharger that yields a high isometric efficiency based on a fixed pressure ratio, a plurality of rotor leads and a plurality of rotor operating speeds is provided. An efficiency map is generated of rotor lead versus rotor operating speeds for the fixed pressure ratio. A rotor lead value is determined based on the fixed pressure ratio and rotor speed combination from the efficiency map that yields a high isometric efficiency. A supercharger is provided having the determined rotor lead and that is configured to operate with the fixed pressure ratio and the determined rotor operating speed.

Abstract: A method of designing a supercharger that yields a high isometric efficiency based on a fixed pressure ratio, a plurality of rotor leads and a plurality of rotor operating speeds is provided. An efficiency map is generated of rotor lead versus rotor operating speeds for the fixed pressure ratio. A rotor lead value is determined based on the fixed pressure ratio and rotor speed combination from the efficiency map that yields a high isometric efficiency. A supercharger is provided having the determined rotor lead and that is configured to operate with the fixed pressure ratio and the determined rotor operating speed.

Abstract: A supercharger constructed in accordance to one example of the present disclosure includes a housing, first and second rotors, a bearing plate and a pair of sleeves. The first and second rotors are received in cylindrical overlapping chambers of the housing, the first rotor supported by a first rotor shaft, the second rotor supported by a second rotor shaft. The bearing plate is coupled to the housing and has an oil cavity side and an air cavity side. The bearing plate is formed of aluminum. The pair of sleeves can be received by the bearing plate and support respective bearings rotatably supporting respective first and second axle shafts. The pair of sleeves are formed of steel.

Abstract: A method of optimizing performance of a supercharger for a given application includes determining a desired pressure ratio of supercharger operation for the given application. One of a rotor lead and a rotor speed can be determined based on the given application. The other of the rotor lead and the rotor speed can be determined based on the pressure ratio and the one of the rotor lead and rotor speed. According to other features, the other of the rotor lead and the rotor speed can be determined based on a peak efficiency map.

Abstract: A method of designing rotors for a Roots blower comprising a housing having cylindrical chambers, the housing defining an outlet port (19). The blower includes meshed, lobed rotors (37,39) disposed in the chambers, each rotor including a plurality N of lobes (47,49), each lobe having first (47a,49a) and second (47b,49b) axially facing end surfaces. Each lobe has its axially facing surfaces defining a twist angle (TA), and each lobe defines a helix angle (HA). The method of designing the rotor comprises determining a maximum ideal twist angle (TAM) for the lobe as a function of the number N of lobes on the rotor, and then determining a helix angle (HA) for each lobe as a function of the maximum ideal twist angle (TAM) and an axial length (L) between the end surfaces of the lobe.