SUPERCHARGER HAVING ROTOR WITH PRESS-FIT STUB SHAFTS
A supercharger constructed in accordance to one example of the present disclosure includes a housing, a first rotor, a second rotor and a rotor shaft assembly. The first and second rotors are received in cylindrical overlapping chambers of the housing. The first rotor has a central longitudinal passage. The rotor shaft assembly rotatably supports the first rotor and includes a first rotor shaft and a separate and distinct second rotor shaft. The first and second rotor shafts are press-fit into the central passage defined in the first rotor.
1 . A supercharger comprising:
a housing;
a first rotor and a second rotor received in cylindrical overlapping chambers of the housing, the first rotor having a central longitudinal passage; and
a rotor shaft assembly rotatably supporting the first rotor and including a first rotor shaft and a separate and distinct second rotor shaft, wherein the first and second rotor shafts are press-fit into the central longitudinal passage defined in the first rotor.
2 . The supercharger of claim 1 wherein the first and second rotor shafts are stub shafts.
3 . The supercharger of claim 1 wherein the first and second rotor shafts are offset from each other in the central longitudinal passage.
4 . The supercharger of claim 1 , further comprising:
a front bearing disposed in the housing that supports the first rotor shaft;
a rear bearing disposed in the housing that supports the second rotor shaft.
5 . The supercharger of claim 4 wherein the first rotor shaft includes a first insertion portion that is received by the central longitudinal passage, an intermediate seal engaging portion configured to be engaged by a seal, a front bearing engaging portion that is supported by the front bearing, and an isolator engaging portion that is configured to engage a timing gear.
6 . The supercharger of claim 5 wherein the second rotor shaft includes a second insertion portion that is received by the central longitudinal passage and a rear bearing engaging portion that is supported by the rear bearing.
7 . The supercharger of claim 6 wherein the second rotor shaft includes a second radial collar that is dimensioned to be nestingly received at a counterbore defined in the first rotor.
8 . The supercharger of claim 7 wherein the counterbore has a first inner diameter and the central longitudinal passage has a second inner diameter and wherein the first inner diameter is greater than the second inner diameter.
9 . The supercharger of claim 5 wherein the first insertion portion incorporates a straight knurl feature.
10 . The supercharger of claim 1 , further comprising a vent configuration collectively formed by:
a first passage defined in the first rotor shaft;
a second passage defined in the second rotor shaft; and
a third passage defined through the housing, wherein air is routed through the vent configuration toward an inlet of the supercharger.
11 . The supercharger of claim 10 , further comprising a front rotor shaft seal that sealingly engages the first rotor shaft.
12 . The supercharger of claim 10 wherein the first passage connects an outer surface of the first rotor shaft with an internal bore of the first rotor shaft.
13 . The supercharger of claim 10 wherein the second passage connects an outer surface of the second rotor shaft with an internal bore of the second rotor shaft.
14 . A supercharger comprising:
a housing;
a first rotor and a second rotor received in cylindrical overlapping chambers of the housing, the first rotor defining a central longitudinal passage; and
a rotor shaft assembly rotatably supporting the first rotor and comprising:
a first rotor shaft having a first insertion portion that is received by the central longitudinal passage, an intermediate seal engaging portion configured to be engaged by a seal, a front bearing engaging portion that is supported by the front bearing, and an isolator engaging portion that is configured to engage a timing gear; and
a second rotor shaft, separate and distinct from the first rotor shaft, the second rotor shaft having a second insertion portion that is received by the central longitudinal passage and a rear bearing engaging portion that is supported by the rear bearing.
15 . The supercharger of claim 14 wherein the first and second rotor shafts are press-fit into the central longitudinal passage defined in the first rotor.
16 . The supercharger of claim 15 wherein the counterbore has a first inner diameter and the central longitudinal passage has a second inner diameter and wherein the first inner diameter is greater than the second inner diameter.
17 . The supercharger of claim 14 , further comprising a vent configuration collectively formed by:
a first passage defined in the first rotor shaft;
a second passage defined in the second rotor shaft; and
a third passage defined through the housing, wherein air is routed through the vent configuration toward an inlet of the supercharger.
18 . The supercharger of claim 17 , further comprising a front rotor shaft seal that sealingly engages the first rotor shaft.
19 . The supercharger of claim 17 wherein the first passage connects an outer surface of the first rotor shaft with an internal bore of the first rotor shaft.
20 . The supercharger of claim 17 wherein the second passage connects an outer surface of the second rotor shaft with an internal bore of the second rotor shaft.