This application is a continuation of International Application No. PCT/US2015/048842 filed on Sep. 8, 2015, which claims the benefit of Indian Patent Application No. 2580/DEL/2014 filed on Sep. 9, 2014. The disclosure of the above application is incorporated herein by reference.
The present disclosure relates generally to superchargers and more particularly to a coupling between an input shaft and a rotor shaft on a supercharger.
Rotary blowers of the type to which the present disclosure relates are referred to as “superchargers” because they effectively super charge the intake of the engine. One supercharger configuration is generally referred to as a Roots-type blower that transfers volumes of air from an inlet port to an outlet port. A Roots-type blower includes a pair of rotors which must be timed in relationship to each other, and therefore, are driven by meshed timing gears which are potentially subject to conditions such as gear rattle and bounce. Typically, a pulley and belt arrangement for a Roots blower supercharger is sized such that, at any given engine speed, the amount of air being transferred into the intake manifold is greater than the instantaneous displacement of the engine, thus increasing the air pressure within the intake manifold and increasing the power density of the engine.
The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
A coupling assembly arranged between an input shaft and a rotor shaft of a supercharger constructed in accordance to one example of the present disclosure includes a coupling hub and a plurality of pins. The coupling hub can have a series of lobes. Adjacent lobes of the series of lobes can define a plurality of openings. The coupling hub can further define a mounting bore therein. The plurality of pins can have first ends and second ends. The first ends can be correspondingly received by the plurality of openings. The second ends can be received by the rotor shaft. The input shaft can be directly mounted into the mounting bore of the coupling hub for concurrent rotation therewith.
According to additional features, the first end of the input shaft can be press fit into the mounting bore of the coupling hub. The second ends of the plurality of pins can be directly received by corresponding openings on the rotor shaft. The series of lobes can consist of three lobes. Additional lobes may be incorporated according to torque transfer requirements for a particular application. The plurality of openings can consist of three openings. The plurality of pins can consist of three pins. Additional pins may be incorporated according to torque transfer requirements.
According to other features, the coupling assembly can further comprise the input shaft. The input shaft can include a first end portion, a second end portion and an intermediate portion. The intermediate portion can connect the first end portion and the second end portion. The first end portion can be coupled to a pulley. The second end portion can be directly mounted into the mounting bore of the coupling hub. The second end portion can have a reduced diameter as compared to the intermediate portion. Each lobe of the series of lobes can have a rib formed thereon, the rib configured to strengthen the coupling hub. The coupling hub can be one-piece. The coupling hub can be formed of over-molded plastic having a metal insert. The metal insert can have a hexagonal outer profile.
According to still other features the metal insert can comprise a series of first planar surfaces that oppose a complementary series of second planar surfaces on the hub body. The first and second planar surfaces cooperate to resist rotation between the hub body and the insert. The insert can further comprise an undercut geometry thereon. The undercut geometry can include a series of insert portions thereon configured to resist axial slip between the insert and the hub body. The plurality of openings can be closed around a circumference of the hub body.
A coupling assembly arranged between an input shaft and a rotor shaft of a supercharger and constructed in accordance to another example of the present disclosure can include a coupling hub and a plurality of pins. The coupling hub can have a series of lobes wherein adjacent lobes of the series of lobes define a plurality of openings. The coupling hub can further define a mounting bore therein. The coupling hub is one-piece and comprises a hub body formed of plastic and an insert formed of metal. The hub body can have a series of first planar portions that oppose a complementary series of second planar surfaces on the hub body. The first and second planar surfaces cooperate to resist relative rotation between the hub body and the insert.
The plurality of pins can have first ends and second ends. The first ends are correspondingly received by the plurality of openings and the second ends are received by the rotor shafts. The input shaft is directly mounted into the mounting bore of the coupling hub for concurrent rotation therewith.
According to other features, the insert includes an undercut geometry thereon. The undercut geometry includes a series of inset portions thereon configured to resist axial slip between the insert and the hub body. The plurality of openings are closed around a circumference of the hub body. The coupling assembly can further include an input shaft that has a first end portion, a second end portion and an intermediate portion that connects the first end portion and the second end portion. The first end portion is coupled to a pulley and the second end portion is directly mounted into the mounting bore of the coupling hub. The second end portion has a reduced diameter as compared to the intermediate portion.
The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:
With initial reference to
The intake manifold assembly 18 can include a positive displacement rotary blower 26, or supercharger of the Roots type. Further description of the rotary blower 26 may be found in commonly owned U.S. Pat. Nos. 5,078,583 and 5,893,355, which are expressly incorporated herein by reference. The blower 26 includes a pair of rotors 28 and 29, each of which includes a plurality of meshed lobes. The rotors 28 and 29 are disposed in a pair of parallel, transversely overlapping cylindrical chambers 28c and 29c, respectively. The rotors 28 and 29 may be driven mechanically by engine crankshaft torque transmitted thereto in a known manner, such as by a drive belt (not specifically shown). The mechanical drive rotates the blower rotors 28 and 29 at a fixed ratio, relative to crankshaft speed, such that the displacement of the blower 26 is greater than the engine displacement, thereby boosting or supercharging the air flowing to the combustion chambers 16.
The blower 26 can include an inlet port 30, which receives air or air-fuel mixture from an inlet duct or passage 32, and further includes a discharge or outlet port 34, directing the charged air to the intake valves 22 by means of a duct 36. The inlet duct 32 and the discharge duct 36 are interconnected by means of a bypass passage, shown schematically at reference 38. If the engine 10 is of the Otto cycle type, a throttle valve 40 can control air or air-fuel mixture flowing into the intake duct 32 from a source, such as ambient or atmospheric air, in a well know manner. Alternatively, the throttle valve 40 may be disposed downstream of the supercharger 26.
A bypass valve 42 is disposed within the bypass passage 38. The bypass valve 42 can be moved between an open position and a closed position by means of an actuator assembly 44. The actuator assembly 44 can be responsive to fluid pressure in the inlet duct 32 by a vacuum line 46. The actuator assembly 44 is operative to control the supercharging pressure in the discharge duct 36 as a function of engine power demand. When the bypass valve 42 is in the fully open position, air pressure in the duct 36 is relatively low, but when the bypass valve 42 is fully closed, the air pressure in the duct 36 is relatively high. Typically, the actuator assembly 44 controls the position of the bypass valve 42 by means of a suitable linkage. The bypass valve 42 shown and described herein is merely exemplary and other configurations are contemplated. In this regard, a modular (integral) bypass, an electronically operated bypass, or no bypass may be used.
With specific reference now to
In one configuration, positive torque is transmitted from an internal combustion engine (of the periodic combustion type) to the input shaft 54 by any suitable drive means, such as a belt and pulley drive system including a pulley 76. Torque is transmitted from the input shaft 54 to the first rotor shaft 58 through the coupling assembly 62. When the engine 10 is driving the timing gears and the blower rotors 28 and 29, such is considered to be transmission of positive torque. On the other hand, whenever the momentum of the rotors 28 and 29 overruns the input from the input shaft 54, such is considered to be the transmission of negative torque.
With additional reference now to
A first timing gear 170 may be mounted on a forward end of the first rotor shaft 158. The first timing gear 170 may define teeth that are in meshed engagement with gear teeth of a second timing gear 172 that is mounted on the second rotor shaft 160. The second rotor shaft 160 can be in driving engagement with the blower rotor 29 (
The input section 148 can include a housing member 150, which forms a forward end of the chambers 28c and 29c (see
The coupling assembly 110 includes a coupling hub 180 and a plurality of pins 182. The coupling hub 180 can be one-piece or unitary. The coupling assembly 110 couples the input shaft 154 to the first rotor shaft 158. The input shaft 154 can include a first end portion 190, a second end portion 192 and an intermediate section 194. In the example shown (see
In one configuration, positive torque is transmitted from an internal combustion engine (of the periodic combustion type) to the input shaft 154 by any suitable drive means, such as a belt and pulley drive system including the pulley 176. Torque is transmitted from the input shaft 154 to the first rotor shaft 158 through the coupling assembly 110. When the engine 10 is driving the timing gears and the blower rotors 28 and 29, such is considered to be transmission of positive torque. On the other hand, whenever the momentum of the rotors 28 and 29 overruns the input from the input shaft 154, such is considered to be the transmission of negative torque.
With reference to
The hub body 310 can further have a plurality of lobes 320, 322 and 324. Additional or fewer lobes may be incorporated according to torque transfer requirements of a particular application. Adjacent lobes 320 and 322 define a first opening or pin receiver 330. Adjacent lobes 322 and 324 define a second opening pin receiver 332. Adjacent lobes 324 and 320 define a third opening or pin receiver 334. The lobes 320, 322 and 324 can include respective ribs 320A, 322A and 324A formed thereon. The ribs 320A, 322A and 324A strengthen the coupling hub 302. The collective pin receivers 330, 332 and 334 are configured to selectively receive first ends of pins 240 (only one specifically shown in
The foregoing description of the examples has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular example are generally not limited to that particular example, but, where applicable, are interchangeable and can be used in a selected example, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.
Number | Date | Country | |
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Parent | PCT/US2015/048842 | Sep 2015 | US |
Child | 15454019 | US |