Supercharger with reduced noise and improved efficiency
First Claim
1. In a rotary blower of the backflow-type including a housing defining two parallel, tranversely overlapping, chambers having cylindrical wall surfaces;
- an inlet port and an outlet port openings having longitudinal and transverse boundaries defined in opposite sides of the housing with the transverse boundaries of each port disposed on opposite sides of a plane defined by the intersections of the chambers;
meshed, lobed rotors disposed in the chambers with the lobes of each rotor having top lands sealingly cooperating with the cylindrical wall surfaces of the associated chamber and operative to traverse the port boundaries disposed on the associated side of the plane for effecting transfer of volumes of compressible inlet port fluid to the outlet port via spaces between adjacent, unmeshed lobes of each rotor;
the lobes being formed with a helical twist, whereby each land is helical and has a lead end and a trailing end inthe direction of rotor rotation;
the improvement comprising;
the inlet port opening skewed toward the lead ends of the lands;
the outlet port opening skewed toward the trailing ends of the lands, whereby said inlet and outlet port openings are skewed toward opposite ends of said rotors to maximize the number of rotational degrees that the helical lands of each transfer volume sealing cooperate with the cylindrical wall surface of their associated chamber; and
means defined by said helical lands and intersecting portions of said outlet port longitudinal and transverse boundaries on either side of said plane for controlling back flow rate of relatively high pressure outlet port fluid to the transfer volumes during initial traversal of said portions by the helical lands and for reducing travel distance of the backflow fluid, said intersecting portions disposed transverse to said helical lands while being traversed and initial traversal of said intersecting portions providing first communication between said high pressure outlet port fluid and said transfer volumes, and the intersection of said intersecting portions disposed substantially midway between the ends of said helical lands and traversed by said helical lands prior to traversal of said plane by the leads ends of said helical lands.
1 Assignment
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Accused Products
Abstract
An improved supercharger or blower (10) of the Roots-type with reduced airborne noise and improved efficiency. The blower includes a housing (12) defining generally cylindrical chambers (32, 34) containing meshed lobed rotors (14, 16) having the lobes (14a, 14b, 14c, 16a, 16b, 16c) thereon formed with an end-to-end helical twist according to the relation 360°/2n, where n equals the number of lobes per rotor. In one embodiment, blower housing (12) also defines inlet and outlet ports (36, 38). The inlet port includes longitudinal boundaries defined by housing wall surfaces (20f, 20h) and transverse boundaries defined by housing wall surfaces (20g, 20i). The transverse boundaries (20g, 20i) are disposed substantially parallel to the helical lobes. The outlet port includes longitudinal boundaries defined by housing surfaces (20m, 20r) and a transverse boundaries defined by housing surfaces (20p, 20s). The inlet and outlet port openings are skewed in opposite directions to increase the time top lands of the lobes are in sealing relation with cylindrical walls (20a, 20b) of chambers (32, 34). Expanding orifices (42, 44) defined by the intersection of transverse boundaries (20p, 20s) and longitudinal boundary (20m) are disposed substantially midway between ends (14g, 14h and 16g, 16h) of the lobe lands to reduce backflow noise.
48 Citations
13 Claims
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1. In a rotary blower of the backflow-type including a housing defining two parallel, tranversely overlapping, chambers having cylindrical wall surfaces;
- an inlet port and an outlet port openings having longitudinal and transverse boundaries defined in opposite sides of the housing with the transverse boundaries of each port disposed on opposite sides of a plane defined by the intersections of the chambers;
meshed, lobed rotors disposed in the chambers with the lobes of each rotor having top lands sealingly cooperating with the cylindrical wall surfaces of the associated chamber and operative to traverse the port boundaries disposed on the associated side of the plane for effecting transfer of volumes of compressible inlet port fluid to the outlet port via spaces between adjacent, unmeshed lobes of each rotor;
the lobes being formed with a helical twist, whereby each land is helical and has a lead end and a trailing end inthe direction of rotor rotation;
the improvement comprising;the inlet port opening skewed toward the lead ends of the lands; the outlet port opening skewed toward the trailing ends of the lands, whereby said inlet and outlet port openings are skewed toward opposite ends of said rotors to maximize the number of rotational degrees that the helical lands of each transfer volume sealing cooperate with the cylindrical wall surface of their associated chamber; and means defined by said helical lands and intersecting portions of said outlet port longitudinal and transverse boundaries on either side of said plane for controlling back flow rate of relatively high pressure outlet port fluid to the transfer volumes during initial traversal of said portions by the helical lands and for reducing travel distance of the backflow fluid, said intersecting portions disposed transverse to said helical lands while being traversed and initial traversal of said intersecting portions providing first communication between said high pressure outlet port fluid and said transfer volumes, and the intersection of said intersecting portions disposed substantially midway between the ends of said helical lands and traversed by said helical lands prior to traversal of said plane by the leads ends of said helical lands. - View Dependent Claims (2, 3, 4)
- an inlet port and an outlet port openings having longitudinal and transverse boundaries defined in opposite sides of the housing with the transverse boundaries of each port disposed on opposite sides of a plane defined by the intersections of the chambers;
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5. In a rotary blower of the backflow type including a housing defining first and second parallel, transversely overlapping, cylindrical chambers having cylindrical and end wall surfaces;
- an inlet port and an outlet port openings having longitudinal and transverse boundaries defined in opposite sides of the housing with the transverse boundaries of each port disposed on opposite sides of a plane defined by the intersections of the chambers;
first and second meshed, lobed rotors respectively disposed in the first and second chambers with the lobes of each rotor having top lands sealingly cooperating with the cylindrical wall surfaces of the associated chamber and operative to traverse the port boundaries disposed on the associated side of the plane for effecting transfer of volumes of compressible inlet port fluid to the outlet port via spaces between adjacent, unmeshed lobes of each rotor;
the lobes being formed with a helical twist, whereby each land is helical and has a lead end and a trailing end in the direction of rotor rotation, the improvement comprising;the inlet port opening skewed toward the lead ends ofthe lands and having the major portion of the transverse boundary on either side of the plane traversed by the lands of the associated lobes prior to the trailing end of each land traversing the plane; and the outlet port opening skewed toward the trailing ends of the lands, whereby said inlet and outlet port openings are skewed toward opposite ends of said rotors to maximize the number of rotational degrees that the heical lands of each transfer volume sealing cooperate with the cylindrical wall surface of their associated chamber; and means defined by said helical lands and intersecting portions of said outlet port longitudinal and transverse boundaries on either side of said plane for controlling bakcflow rate of relatively high pressure outlet port fluid to the transfer volumes during initial traversal of said portions by the helical lands and for reducing travel distance of the backflow fluid, said intersecting portions disposed transverse to said helical lands while being traversed and initial traversal of said intersecting portions providing first communication between said high pressure outlet port fluid and said transfer volumes, and the intersection of said intersecting portions disposed substantially midway between the ends of said helical lands and traversed by said helical lands prior to traversal of said plane by the lands ends of said helical lands. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13)
- an inlet port and an outlet port openings having longitudinal and transverse boundaries defined in opposite sides of the housing with the transverse boundaries of each port disposed on opposite sides of a plane defined by the intersections of the chambers;
Specification