US1780398A - Air compressor - Google Patents

Description

M. B. MORGAN AIR COMPRESSOR Nov. 4, 1930.

Filed Aug. 24, 1929 23 5 F'Z Z2 6 M 4 6 m 0 m a a 6 w W W 0 L w 7 W 6, a M W w 1 RN /w. a 9 6 Mr Z 6 J Patented Nov. 4, 1930 UNITED STATES PATENT OFFICE MATHEW IB, MORGAN, OF DETROIT, MICHIGAN, ASSIGNOB TO THE TIMBER-DETROIT AXLE COMPANY, OF DETROIT, MICHIGAN, A CORPORATION "OF OHIO AIR COMPRESSOR Application filed August 24,

This invention relates to fluid pumps and is particularly applicable to air compressors. Its principal objects are to devise an air compressor that will be economical to produce, maintain and operate, that will be quiet and positive in action, that will be compact, strong, durable and of large capactaken on the line 11 in Fig. 2,

Fig. 2 is a transverse cross-section on the line 2-2 in Fig. 1,

Fig. 3 isan end elevation with parts shown in transverse section,

Fig. 4. is a longitudinal sectional view of the cam member; and

Fig. 5 is adiagram illustrating a complete cycle of operation for each revolution of the piston around the axis of the shaft.

The present device comprises a short cylindrical or annular member 1, hereinafter called a cam member, with a cylindrical inner surface on which is a continuous rib 2 which is arranged obliquely with reference to the'longitudinal axis of said surface, and constitutes a cam. The sides of said rib are beveled. Each of a number of cylindrical pistons or piston members 3 (four in the construction shown) is provided midway of its length with a circumferential groove 4 with beveled sides and of proper width to roll freely over the cam rib 2. Each end of each piston fits in a cylindrical chamber 5, hereinafter called a piston chamber, formed in the marginal portion of a rotor 6 composed of two. alined counterpart members. 7 of cylindrical form. Each of said cylin- 1929. Serial no. 388,048.

drical members has as many piston chambers as the number of pistons, such chambers being disposed longitudinally in said member and equi-distant from each other.

The inner ends of said cylindrical member 7 abut against each other except at their peripheral portions, where they are recessed sufiiciently to receive the cam member 2 freely between them. The outer ends of said cylindrical members are closed by end caps or closure plates 8 that are clamped firmly together by long threaded bolts 9 that extend through said cylindrical members and are tightened b nuts 10 therein. Said cylindrical mem ers are accurately centered by dowels or pins 11 in their meeting faces, with their piston chambers in alinement; and the outer ends of said cylindrical members have axial openings which fit over centering lugs 12 provided therefor in the inner faces of the closure lates. Each closure plate has a stub sha 13 formed integral therewith.

The two stub shafts 13 are journaled in bushings or antifriction bearings 14 mounted in hubs 15 provided therefor in the ends of a stationary casing 16. The casing is made of two hollow cylindrical members '17 closed at their outer ends and open at their inner ends. The casing members fit over the rotor 6, with their inner ends bearing over and against the cam member 1 whose ends are recessed to receive said casing members. Said casing members 17 are secured together by long bolts 18 that extend endwise through them and the intervening cam member 1 and are provided with nuts 19 on their threaded ends. The closed ends of said casing members are formed into the hubs 15 adapted to receive the bearings 14 for the stub shafts 13 that are inte rotor. ne of said stub shafts is suitably connected to a source of power to be driven thereby.

It is apparent from the foregoing description that when power is applied to the rotor, said rotor is rotated on its axis carrying the several pistons with it. As the pistons continuously engage the cam rib 2, which is 'stationary, the revolution of the pistons about 100 al with the closure plates of the the axis of the shaft causes such pistons to move endwise in their chambers an amount equal to the throw of the cam rib; and it is this reciprocating movement of the piston that is utilized for pumping or compressing.

All of the pistons operate alike; and the timing of one of them is illustrated by the diagram shown in Fig. 5 wherein there is a completecycle of operation for each revolution of the piston around the axis of the shaft.

ed at the opposite end of the same piston, but

the phase of the cycle at one end of the piston-is 180 different from the phase at the other end of said piston In order to rovide for such operation, a radial port 21 1s formed in the side wall of each p ston chamber in position to register with a circumferentially elongated groove 22 (about 135 in the example) in the inner cylindrical surface of the casing, which groove communicates through a passageway 23 in the casing to the source of fluid supply. The portion of the piston opposite said port is of reduced diameter, such reduced portion 24 being of such width that said port is always opposite some portion thereof. Cross bores 25 are formed in the piston in the portion of reduced diameter and communicate with an'axial bore 26 that extends to the end thereof. By this arrangement, the groove 22, which is in communication with the source of fluid supply remains in communication with the admission port of each, piston chamber throughout 135 of its revolution, and during this period the fluid asses from the groove to the radial port 0 the piston chamber and thence through the annular space surrounding the reduced portion of the piston into the cross ports of the piston and thence through the longitudinal bore in the piston into the end of the iston chamber. As soon as the radial port of t e piston chamber passes the end of the groove in the casing, communication with the source of fluid supply is cut off, the fluid charge is trapped in the piston chamber, and the operation of compression thereof begins and continues until the opening of the exhaust port? The exhaust passageway 27 extends longitudinally of the wall of the casing and opens into a circumferentially elongated groove 28 in the inner wall thereof. In the example, this exhaust groove'extends through an angle of about'20. Opposite this exhaust groove is the port or passageway 21 that extends through the wall of the piston chamber opposite the reduced portion of the piston. By

tions of the two cylinderical members 0 the rotor, Where the lubricant is in direct contact with the cam rib,2 and the exposed middle portions of the piston members, including the cam engaging grooves therein. As the cam rib remains stationary while the piston working in engagement therewith revolves around the axis of the shaft, there is enough friction between them to cause rotation of the piston members on their respective axes, Advantage is taken of this fact to overcome the vtendency of the lubricant to get into the charge of fluid. For this purpose, the cylindrical surfaces of each piston member adjacent to the main groove 4 thereof which cooperates with the cam rib are provided with small helical grooves that start at the wall of said main groove and preferably make several turns around the piston member. The two oil grooves are of opposite hand to each other and their lead is such that, as the piston member rotates on its axis in its normal direction, the points of intersection of the two oil grooves with any given longitudinal plane continuously approach each other. Thus their inclination or direction is such that they tend to fling the oil toward the main groove and thus tend to keep the oil or lubricant from creeping into the chamber beyond the end of the piston.

While the device hereinbefore described is especially adapted to be run at high speed for compressing air, it is adapted for use with other compressible fluids; and by properly correlating the intakeand discharge passageways in accordance with common practice, said device may be found used for pumping liquids.

For the purpose of regulating the compressor, provision is made for shifting the cam mem er 1 circumferentially with relation to the other casing members. For this purpose, it is only necessary to loosen and remove the clamping bolts, turn the cam member to bring new holes therein into register with the holes in the casing members, pass the bolts through them and tighten the nuts thereon. Of course, the holes through the cam member are arranged in groups of the same number as the bolts and distributed so that all of the members of each group will simultaneously register with the bolt holes in the cas- It is noted that the device is very compact, that its parts are easy and simple to manufacture and assemble, that the device is well balanced and well adapted to run at high speed, that all of its parts are simple, strong and durable; that its lubrication system is simple and efiicient and protects the fluid charge against contamination with lubricant, that the discharge is subject to considerable range of adjustment, and that there is little likelihood of any of the parts getting out of order.

What I claim is:

1. A pump comprisinga casing having fluid distributing passageways therein and having a continuous cam rib on the interior thereof, a cylindrical rotor rotatable in said casing and having a plurality of piston chambers arranged therein in alined pairs, and a reciprocatable piston member for each pair of chambers, each piston member having a circumferential groove at the middle thereof adapted to receive said cam rib and each piston member having a portion of reduced diameter in each end portion thereof and a passageway from said. reduced portion through the end of said piston member, and the rotor having passageways opening into the respective piston chambers opposite the reduced portions of the piston members and arranged to communicate periodically with said first-mentioned passageways, respectively. 4

2. An air compressor comprising a casing having fluid distributing passageways theren and having a continuous. cam rib on the interior thereof, a cylindrical member rotatable in said casing and having a plurality of piston chambers therein, a reciprocatable piston in each chamber having a circumferential groove near the middle thereof adapted to receive said cam rib and passageways communicating with said first-mentioned passageways, respectively, opening into the respecnve piston chambers, each piston havmg a distributing groove encircling it and a passageway from said groove through the end thereof.

3. A pump comprising a casing having fluid distributing passageways therein and having a continuous cam rib on the interior thereof, and 'a cylindrical rotor rotatable in said casing and having a plurality of piston chambers therein, and a reciprocatable piston in each chamber having a circumferential groove near the middle thereof engaging said cam rib, said rotor having passageways arranged to communicate periodically with said first-mentioned passageways respectively and opening into the respective piston chambers, each piston having a portion of reduced diameter opposite the adjacent rotor passageway and also having a passageway from such reduced portion through the adja cent endof said piston.

4. A pump comprising a casing havin a continuous cam rib on the interior thereo a cylindrical rotor rotatable in said casing and having a plurality of piston chambers therein, and a reciprocatable piston in each chamber having a circumferential groove near'the middle thereof engaging said cam rib, said casing and said rotor and said piston being provided with appropriate passageways for pumping, said casing comprising an annular member on the inner face of which is said cam rib and two cylindrical members abutting against said cam member and having journal bearings on their outer ends for said rotor, and said rotor comprising counterpart cylindrical members adapted to fit in said casing with their inner ends abutting against each other and with the peripheral portions of said inner ends recessed to freely accommodate said cam member, said rotor also comprising end closure plates that are provid ed with shafts that are journalcd in said bearings, and longitudinal clamping bolts clamping said end plates together.

5. A pump comprising a casing having a continuous cam rib on the interior thereof, a cylindrical rotor rotatable in said casing and having a plurality of piston chambers therein, and a reciprocatable piston in each chamber having a circumferential groove near the middle thereof engaging said cam .rib, said casing and said rotor and said piston being provided with appropriate passageways for pumping, said casing comprising an annular member on the inner face of which is said cam rib and two cylindrical members abutting against said cam member and having journal bearings ontheir outer 'ends for said rotor,-said cam member and said end members having longitudinal symmetrically arranged holes and fastening bolts extending through said holes whereby said parts may be adjusted circumferentially with relation to each other, and said rotor comprising counterpart cylindrical members ada ted to fit in said casing with their inner ends a utting against each other and with the peripheral portions of said inner ends recessed to freely accommodate said cam member, said rotor also comprising closure plates that are provided with shafts that are journaled in said bearings.

6. Aipump comprising a casing having a continuous cam rib on the interior thereof, a cylindrical rotor rotatable in said casing and having a plurality of piston chambers therein, and a reciprocatable piston in each chamber having a circumferential groove near the middle thereof engaging said cam rib, said casing and said rotor and said piston being provided with appropriate passageways for pumping, said casing comprising an annular member on the inner face of which is said ting against said cam member and having journal bearings on their outer ends for said rotor and means for securing said members together with said annular member in either of a plurality of different positions of rotary adjustment.

7. A pump comprising a casing havin a continuous cam rib on the interior thereo a cylindrical rotor rotatable in said casing and having a plurality of iston chambers therein, and a reciprocatab e piston in each chamber having a circumferential groove near the middle thereof engaging said cam rib, said casing and said rotor and said piston being provided with appropriate passageways for pumping, said casing comprlsing an annular member on the inner face of which is said cam member and two cylindrical members abutting against said cam member and having journal hearings on their outer ends for said rotor, said cam member and said end members having longitudinal holes, and fastening bolts extending through said holes.

8. A pump comprising a casing having a continuous cam rib on the interior thereof, a cylindrical rotor rotatable in said casing and having a plurality of pistonch'ambers therein, and a reciprocatable piston in each chamber having a circumferential roove near the middle thereof engaging sai cam rib, said casing and said rotor and said'piston being provided with appropriate passageways for pum ing, said casing comprising an annular mem er on the inner face of which is said cam rib and two cylindrical members abutting against said cammember and having journal bearings on their outer ends for said rotor, said cam member and said and members havmg longitudinal s mmetrically arranged holes, and fastening olts extending through said holes whereby said parts may be adjusted circumferentially with relation to each other.

9. A pump comprising a casing having a continuous cam rib on the interior thereof, a cylindrical rotor rotatable in said casing and having a plurality of iston chambers therein, and a reciprocatab e piston in each chamber having a circumferential groove near the middle thereof engaging said cam rib, said casing and said rotor and said piston being provided with appropriate passageways for pum ing, said casing comprising an annular mem r, on the inner face of which is said cam rib, and two cylindrical members abutting against said cam member and having journal bearings on their outer ends for said rotor, said cam member and said end mem: bers having longitudinal symmetrically arranged holes, and fastening bolts extending through said holes whereby said parts may be adjusted circumferentially with relation to each other, and said rotor comprising count-erpart cylindrical members adapted to fit in said casing with their inner ends abutting against each other and with the peripheral portions of said inner ends recessed to freely accommodate said cam merhber, said rotor also comprising closure plates that are provided with shafts that are journaled in said bearings, and longitudinal clamping bolts clamping said end plates together.

10. A pump comprising a casing having a continuous cam rib on the interior thereof, a cylindrical rotor rotatable in said casing and having a plurality of piston chambers therein, and a reciprocatable piston in each chamber having a circumferential groove near the middle thereof engaging said cam rib, said casing and said rotor and said piston being provided with appropriate passageways for pumping, said casing comprising an annular mem er on the inner face of which is said cam rib and two cylindrical members abutting against said cam member and having journal bearings on their outer ends for said rotor, said cam member and said end members having longitudinal symmetrically arranged holes, and fastening bolts extending through said holes whereby said parts may be adjusted circumferentially with relation to each other, and said rotor com rising counterpart cylindrical members a apted to fit in said casing with their inner ends abutting against each other and with the pe- -ripheral portions of said inner ends recessedto freely accommodate said cam member, said rotor also comprising closure plates that are provided with shafts that are journaled in said bearings, and longitudinal clamping bolts clamping said end plates together.

11. A pump of the kind described comprising a casing which comprises an annular cam member having a continuous cam rib on the interior thereof and two alined cylindrical members on opposite sides of said cam member, a cylindrical rotor rotating in said casing and comprising counterpart cylindrical members adapted to fit in said casing with their inner ends abutting against each other and with the peripheral portions of said inner ends recessed to accommodate the cam rib portion, each of said rotor members having a plurality of piston chambers therein alined with the piston chambers of the other rotor members, reciprocatable piston members each having a circumferential groove in the middle thereof engaging said cam rib and with its end portions working in alined piston chambers.

12. A pump of the kind described comprise ing a casing comprising an annular cam member having a continuous cam rib on the interior thereof and two alined cylindrical mem? bers on opposite sides of said cam member, a cylindrical rotor rotating in said casing and comprising alined cylindrical members adapted to fit in said casing with their inner ends abutting against each other and with the peripheral portions of said inner ends recessed to accommodate said cam member, each of said rotor members having a plurality of piston chambers therein alined with the piston chambers of the other rotor members, reciprocatable piston members each having a circumferential groove in the middle thereof engaging said cam rib and with its end portions working in alined piston chambers, said casing having a passageway for lubricant opening into the space adjacent to said cam rib, and said piston member having helical grooves of opposite hand extending from the main groove thereof, the hand of each helical groove being such that its point of intersection with any longitudinal plane approaches the main groove as the piston rotates in normal direction.

13. A pump of the kind described comprising a casing having a continuous cam rib on the interior thereof, a cylindrical rotor rotating in said casing and comprising counterpart cylindrical members adapted to fit in said casing with their inner ends abutting against each other and with the peripheral portions of said inner ends recessed to accommodate the cam rib portion, each of said rotor members having a plurality of piston chambers therein alined with the piston chambers of the other rotor members, reciprocatable piston members each having a circumferential groove in the middle thereof engaging said cam rib and with its end portions working in alined piston chambers, said casing having a passageway for lubricant o ening into the space adjacent to said-cam ri ,and said piston member having helical grooves of opposite hand extending from the main groove thereof, the hand of each helical groove being such that its point of intersection with any longitudinal plane approaches the main groove as the piston rotates in normal direction.

Signed at Detroit, Michigan, this 19th day of August, 1929.

MATHEW B. MORGAN.

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