US3902829A

US3902829A - Rotary power device

Info

Publication number: US3902829A
Application number: US457751A
Authority: US
Inventors: David E Burrowes
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-04-04
Filing date: 1974-04-04
Publication date: 1975-09-02
Anticipated expiration: 1992-09-02

Abstract

A rotary power device, such as a pump or motor, comprises a central rotor member with a shaft mounting the rotor member for rotation about the axis of the shaft, a plurality of vane members carried by the rotor member and arranged to move in planes parallel to, preferably intersecting, the shaft axis, and a stator member surrounding the rotor member and including lobed surfaces which are complementary so that the vane members follow such surfaces during rotation of the rotor member. The stator member is provided with appropriate inlet and outlet ports for admitting and exhausting a working fluid from regions of the chamber defined between the lobed surfaces, the inner and outer side walls of the stator member, and the vanes and supporting walls of the rotor member. The vane members are spaced around the rotor member such that at least one vane is always positioned between the inlet and outlet ports. Each vane member includes separate vane parts following each of the lobed surfaces and loosely joined by a wedge-like key having angled surfaces which are arranged to press the vane parts toward the lobed surfaces as centrifugal force tends to move the key radially outward. The device can be employed as a rotary motor, engine, or pump, using either compressible or noncompressible fluids.

Description

United States Patent 1191 Burrowes 1451 Sept. 2, 1975 1 1 ROTARY POWER DEVICE [76] Inventor: David E. Burrowes, 4466 Silverwood, Dayton, Ohio 45429 [22] Filed: Apr. 4, 1974 [2]] App]. No.: 457,751

52 us. c1. 418/111; 418/148; 418/219; 418/230; 123/833 51 n11.c1. F01C 1/00; F03C 3/00; F04C 1/00; F01C 19/08 [58] Field of Search 418/13, 111, 219, 228-231, 418/148; 123/833, 8.35, 8.23, 8.41

Primary Examiner 1ohn .1. Vrablik Attorney, Age/1!, 0r FirmBiebel, French & Bugg l lhl [57] ABSTRACT A rotary power device, such as a pump or motor, comprises a central rotor member with a shaft mounting the rotor member for rotation about the axis of the shaft, a plurality'of vane members carried by the rotor member and arranged to move in planes parallel to, preferably intersecting, the shaft axis, and a stator member surrounding the rotor member and including lobed surfaces which are complementary so that the vane'members follow such surfaces during rotation of the rotor member. The stator member is provided with appropriate inlet and outlet ports for admitting and exhausting a working fluid from regions of the chamber defined between the lobed surfaces, the inner and outer side walls of the stator member, and the vanes and supporting walls of the rotor member. The vane members are spaced around the rotor member such that at least one vane is always positioned between the inlet and outlet ports. Each vane member includes separate vane parts following each of the lobed surfaces and loosely joined by a wedge-like key having angled surfaces which are arranged to press the vane parts toward the lobed surfaces as centrifugal force tends to move the key radially outward, The device can be employed as a rotary motor, engine, or pump, using either compressible or noncompressible fluids.

4 Claims, 9 Drawing Figures 1 I I I [I1 PATENTEDSEP 2mm 3.902.829

SHEETILUFB M FIG-1 as PATENTED SEP 19 5 SHEET 2 BF 3 ROTARY POWER DEVICE BACKGROUND OF THE INVENTION This invention relates to rotary power devices of the class utilizing reciprocating vanes as part of the mechanism for controlling the in-flow and exhausting of a working fluid from a chamber which increases and decreases in volume. In the well known types of sliding vane devices, a rotor is provided with slots or other suitable mounting arrangements for vanes which extend radially from the rotor into contact with the walls of an outer chamber. and the axis of rotation of the rotor is eccentric with respect to the outer chamber, the vanes move in a generally radial direction to define regions or chambers which increase or decrease in volume as the motion of the rotor and/or the outer member, progresses. It is well known that such devices have various sealing problems, particularly along the walls of the sliding vanes. and by their nature they are somewhat out of balance in rotation due to the generally radial movement of the vane members.

Another form of rotary power device, sometimes referred to as a barrel motor, involves the use ofa plurality of cylinders spaced around an axis of rotation, and a plurality of pistons operating in those cylinders and connected to a wobble plate which extends at a transverse angle to the axis of rotation and is connected to the pistons such that they reciprocate longitudinally in the cylinders as the wobble plates rotate. In such an arrangement it is necessary that both the cylinder and piston members rotate, or else that there be some indirect connection between the pistons and the wobble plate such that these parts can move relative to each other.

A further class of rotary powered devices involves the more recently developed Wankel engine, utilizing a three or more sided rotor which rotates within a specially formed chamber. both about the axis of the rotor, and with that axis also rotating within the chamber. The sealing problems of such devices, and the complexity of the machining operations for forming the various surfaces, are well known and have been the subject of considerable recent discussion and development work.

SUMMARY OF THE INVENTION The present invention provides the advantages of continuous rotary motion, and utilizes the centrifugal forces involved with the moving parts of the device to promote scaling contact, particularly between the vane members of the device and the walls against which these vane members track. The device preferably is formed as a double-acting motor or pump, since such an arrangement is most convenient to provide in accordance with the basic arrangement of parts.

A plate-like rotor member is mounted to rotate with a main shaft, extending outwardly from the main shaft and provided with slots in which vane members are retained in reciprocating motion in planes which are parallel to the shaft axis, preferably intersecting such axis. On opposite sides of the rotor member there are lobed stator parts which are formed with cam-like lobes, one complementary to the other. such that the vane members follow the lobe surfaces of these stator members and reciprocate along the aforementioned planes. The only reciprocating movement, therefore. of rotating parts is in a direction parallel to the shaft, and there is no reciprocation or movement toward and away from the shaft axis, thus minimizing the substantial efi'ect of centrifugal forces, and opposition thereto, on the rotating parts of the device. For example, there is a much less stringentsize and weight limitation, particularly at high speeds (e.g., over 5,000 rev./min. than is present in the radially moving sliding vane motor.

The stator members also provide an inner wall against which the inner edges of the vane members track with both a circular and reciprocating motion, and a surrounding cylindrical casing provides a tracking surface and enclosure for the outer edges of the vane members'Preferably, the vane members comprise independent pieces loosely joined by a wedge-like key, so that when one-vane member follows a rise or lobe of a cam surface, -it imparts motion through the connecting key against the other vane member, causing it to follow the valley or depression of the lobed surface. These keys are provided with an angled edge such that centrifugal force tending to move the key radially outward, presses upon the vane members and their seal parts and promotes sealing against the surfaces which the vane members follow. The vane members follow the inner and outer chamber walls in circular fashion, thus the seal necessary at those contact edges between moving parts is a relatively simple seal, and may be provided in many cases merely by close machining tolerances. However, a construction for enhancing the sealing of the vane members to the inner chamber walls is also provided as an option if desired. The. same is true of the seals required between the vane members and the rotor slots within which they reciprocate. The amount of reciprocating movement can be relatively slight to achieve a rather large displacement, since significant enlargement or displacement can be achieved merely by increasing the diameter of the rotor and stator parts somewhat, and increasing the width of the vane members.

When operating with an elastic working fluid, such as steam or hot gas products of combustion, it may be desirable to providesome valving control of the working fluid, particularly-to the inlet ports of the device. This can readily be achieved by the use of rotating ported valve plates fastened to the shaft and rotating with it, on the outer sides of the lobed stator members, or by the use of multi-part ported vane members.

Also, by changing the contour of the lobed surfaces, it is readily possible to change the rate of expansion of compressible working fluids, and to match this and the rate of compression (if used) to a particular type of fluid, or fluid mixture such as fuel/air.

Accordingly, the primary object of the invention is to provide a novel rotary power device, useful as a pump or motor, which is of relatively simple and inexpensive construction, and which is characterized by the fact that it has vane members which reciprocate only in directions generally parallel to the axis of rotation, which do not reciprocate toward and away from the axis of rotation, yet provide adequate sealing between rotating parts by utilizing centrifugal force on rotating parts to emphasize sealing contact between relatively moving parts; and to provide such a device which is relatively simple in construction, and may be manufactured with relatively straightforward and inexpensive machining operations.

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view of a motor incorporating the features of the invention, with the outside case of the motor shown in cross section, and the shaft and internal parts shown in elevation;

FIG. 2 is a view similar to FIG. 1, but with only a part FIG. 7 is a partial cross-sectional view taken on lines 77 of FIG.

FIG. 8 is a view of another modification; and FIG. 9 illustrates a modified vane member.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1-3, the motor is comprised of a case which includes a cylindrical casing 10 having outwardly extending flanges 12 at its opposite ends, and end plates 14 which are fastened by bolts 15 to the flanges 12. In the central part of each end plate 14 there is a bearing 17, shown in the form of a suitable roller bearing, which supports the main shaft for rotation about an axis which is concentric with the longitudinal axis of the cylindrical case.

Suitable seals

22 and 23 are placed between the end plates 14 and shaft 20, and between the end plates 14 and the internal wall of the cylindrical casing 10.

The rotor section of the motor comprises a central hub 25 which is fixed to the shaft 20, for example by a spline 26, or equivalent connection. This hub has spaced outwardly extending flanges 27 which extend outwardly into close running tolerance with the internal wall of the casing part 10, and these flanges are provided with vane slots 30 which receive vane assembly 32. These are particularly visible in FIG. 3. The vane assemblies include a pair of individual vane members 33 and a connecting rib or key member 34 which appears in greater detail in a broken-away portion at the bottom of FIG. 2. It will be noted that this key member, is somewhat tapered, as are the slots 35 internally of the root portion of the vanes into which the key member projects. When the motor is operating centrifugal force causes the tapered key members 34 to press outwardly, causing the vane members 33 to separate somewhat in a direction longitudinally of the motor (parallel to the shaft) for sealing purposes, as is later explained.

The stator parts of the motor include a pair of complementary stator cam members and 42 which are essentially mirror images of each other. They fit within the casing member 10, and are fastened thereto by bolts 43 as shown in FIGS. 1 and 2. They may comprise a unitary piece, or as shown, for purposes of simplified construction, they may be made of a central part 4011 and 4211 which is essentially a counter bored cylinder, and the surrounding ring-like cam members 40b and 4212. These parts may be suitably attached to one another by any suitable means, not shown. Each of the stator members presents an essentially flat circular face toward the outer ends of the motor, and there its inner face is formed in the shape of a circular cam. This cam surface is indicated particularly in FIG. 3 as including a pair of lobes 42c, and there are similar lobes 400 (FIG. 1) formed on the stator cam member 40.

The lobes on one cam are aligned with the depressions or valleys on the other cam, so that the two cams define between them a space which the vane assemblies 32 sweep or displace as the rotor rotates within the easing. Thus, between the facing walls of the stator member, through which portions of vane members 33 project, and the opposing faces of the cam surfaces of the stator assemblies, there are defined chambers which have regions of larger and smaller volume, progressing around the casing, as shown in generated form in FIG. 6. The tips or edges 33a of the vane members sweep the cam surfaces as the vanes rotate with the rotor. It will be noted particularly in FIGS. 1 and 6 that the vane members preferably present a tapered tip face so that a rather sharp sealing edge is presented on the vane member to engage with the cam surfaces of the stator member.

Various means such as insert strips or equivalent (not shown) can be used to perfect a seal at this edge. It is the only location in the motor where an essentially line contact is needed. The vane assemblies move essentially as a unit, there being only a small amount of play between the individual vane members 33 and the key members 34 which hold them in alignment and transmit thrust from one to another in a direction longitudinally of the motor. The previously mentioned centrifugal force on the key members causes them to tend to wedge the individual vane members 33 apart somewhat, promoting a good seal between the tip 33a of the vane members and the cam surfaces.

Within each of the lobes 40c and 420 there are inlet passages 50 and exhaust passages 52, the latter being upstream from the inlet passages with respect to the direction of rotation of the rotor member, and preferably including elongated port sections 53. As shown in FIG. 6, the inlet and outlet ports are spaced around the stator, and their spacing is somewhat greater than the distance between vane members 33, thus avoiding any direct flow of fluid between the inlet and outlet ports.

A fluid under pressure is admitted through the inlet passages 50 into the expansion chamber which is defined by the trailing edge of a vane member 33, the surface of the stator cam member 40 (or 42), the surface of the rotor flanges 27, and the inner and outer surfaces formed by the central parts 400 (or 42a) of the stator and the inner wall of the casing 10.

In the case of an incompressible fluid, such as hydraulic fluid, the supply of fluid under pressure to the inlets 50 may be continuous, with the resultant force on the trailing sides of vane members 33 causing the rotor member to rotate, until the vane members uncover the outlet ports 52, whereupon the fluid is exhausted through the outlet port 52 and this connection continues as the vane members pass over the extended port section 53. With the twin lobe structure shown, the effect is to have four separate chambers operating, with a substantially continuous flow of hydraulic fluid through the motor. The stroke of each expansion chamber, can be compared to the stroke of a piston in a conventional piston-cylinder motor, and can be varied to suit different requirements by changing the slope of the surfaces of the cam lobes and/or by changing the number of such lobes around the stator member and the number of vane members,

The exhaust ports 52 are connected through suitable openings 54 in the sides of the casing 10, to which a suitable exhaust or return pipe can be connected. This is particularly needed if hydraulic fluid should be used as the source of power, since it should be returned to a pump sump for recirculation.

In the event that the motor is to be used with an expansible fluid, such as high temperature steam, it may be desirable to provide a valving control over the admission of such fluid to the inlet ports 50. In that case, the rotor member also includes a pair of

valve plates

60 and 62, each suitably fastened to shaft 20, and each running respectively in close-fitting relation to the outer or flat faces of the

stator cam members

40 and 42. These valve plates are provided with inlet control ports 64 that are aligned on a radius of the valve plate corresponding to the location of the stator inlet ports hausting the steam as completely. as possible through the outlet ports 52, and connecting this exhaust to a suitable condenser (not shown). In order to assure complete exhaust, the port section 53 may be appropriately extended both upstream and downstream from the port 52, as desired, in order to minimize any compression of steam trapped in front of the vane'members. Similarly, it is possible to utilize other expansible fluids, for example hot gases which might be the products of combustion of a continuously operating burner, or air under pressure from a compressor or from heating to a high temperature by contact with some heat source externally of the motor.

In all cases, however, the major parts of the motor are required only to rotate in a continuous fashion. Only the vane members reciprocate, and this motion is along planes which extend parallel (preferably through) the axis of rotation of the motor shaft. The amount of reciprocation of the vane members is relatively slight for an engine of a given displacement. Centrifugal forces are employed in the vane assemblies to promote good sealing of the moving vane members to the surfaces against which they run. All parts of the motor are relatively simple in construction, and may be machined and/0r cast effectively and inexpensively.

FIG. 9 shows a modified construction of vane members in which identical parts have the same reference numbers as previously used. The vane member has a longitudinal tapered passage 36 receiving a tapered pin 37 which engages the key member 34. The inner edge of the vane member is fitted with a seal strip 38 which contacts a cross-pin 39. The cross-pin in turn is pressed by the tapered pin 37. Thus centrifugal force tends to move both the vane member and key 34 to the left (as viewed), the wedge shape of the key pushes the vane member and pin 37 upward, and the pin pushes the seal strip 38 to the right via the cross pin 39.

In a typical device constructed generally as shown, using a lobular surface of one inch in width and a rise in the order of one-half inch, a four chamber four vane motor having an outer diameter of somewhat less than 5 inches will displace. about 20 cubic inches per revolution. This allows for displacement lost due to the porting of the motor. v

In a larger single lobe (one each side) arrangement with two vane member assemblies, it .is possible to achieve a total displacement of about-452 cubic inches per revolution in a unit having a cam or lobular-surface with an outer diameter of 15 inches, an inner diameter of 9 inches, andvanemembers of 3 inch width moving longitudinally a total of 3 inches. Thus substantial displacement can be achieved within a relatively small outer size of the unit.

Another modification is shown in FIG. 8, wherein one set of chambers is employed for a compression function and the outer'set 'is'utilized for an internal combustion function. The chambe'rs are appropriately interconnected by a dual vane arrangement 80, 81 including passages '82, 83 formed in and through the vanes as shown. 4

One chamber 85 has an inlet port 86 connected to it. The advancing parallel vanes move over this port in relative positions such that the

passages

82, 83 are closed. Air (or mixture) ahead of the vane is compressed. As the vanes slide into the outer chamber88, the

passages

82, 83 register and the compressed fluid transfers into chamber 88 (behind blade 81 through a leaf-type check valve 89, or the like, controlling passage 83. As the blades continue to move,

passages

82, 83 are again closed and the mixture may be ignited by a suitable ignitor 90. The force of the expanding, burning mixture reacts on the blades, and hence is transferred to the rotor structure. When the blades reach the other end of the lobe, they pass anexhaust port 92 from chamber 88, and the products of combustion are exhausted while another charge is entering chamber 85. A

As previously explained, the number of chambers can be appropriately multiplied around the device. In this embodiment the uniflow arrangement of gases is achieved, and the device functions similarly to the fourcycle internal combustion process.

Utilizing a single lobe on each side, and a pair of dual-vane members 180 apart, intake occurs in the lower chamber 85 while combustion is taking place in chamber 88. Mixture can be drawn in through a relatively large port 86, and the compression can be controlled by the length of chamber 85 and the slope of its exit end 85a. The expansion of products of combustion can be controlled by the length of chamber 88. Combustion occurs behind a set of vane members while exhaust occurs through a large port in front of the vane members, and with two sets of vane members this cycle happens twice per revolution.

Using this arrangement in a unit of the large dimensions stated above, an engine of about 226 cubic inch displacement can be provided in a package size of roughly 18 by 18 inches.

While the forms of apparatus herein described constitute preferred embodiments of this invention, it is to be understood that the invention is not limited to these precise forms of apparatus, and that changes may be made therein without departing from the scope of the invention.

What is claimed is:

l. In a rotary power device, having a shaft defining a central axis,

a stator member including a pair of facing comple mentary lobular surfaces extending radially outward around said shaft and spaced apart along the axis of said shaft,

said surfaces terminating at inner and outer edges concentric with said axis,

an inner cylindrical wall mating with said inner edges and an outer cylindrical wall mating with said outer edges,

a rotor member attached to said shaft extending radially outward therefrom between said surfaces and mating with said inner and outer walls to form enclosed chambers which have progressively increasing and decreasing cross-sectional size around said shaft along planes extending radially from said axis,

spaced apart vane assemblies extending through said rotor member along planes which are parallel to said axis and extending generally outward therefrom into contact with said surfaces and said inner and outer walls to divide said chambers into regions between said vanes which move progressively as said shaft and said divider member rotate with respect to said stator member,

and means defining ports opening into opposite ends of said chambers and controlled by movement of said vanes past said ports for supply and exhaust of a working fluid to and from said regions,

said vanes being spaced apart less than the spacing between those ports at opposite ends of said chambers to keep those ports separated at all times by a vane;

the improvement comprising:

each said vane assembly includes a pair of independent vane members having a tip contacting a corresponding one of said lobular surfaces and a root portion slidably supported in said rotor member, and a key member engaging the root portions of the pair of vane members,

said key member and said root portions contacting along lines which converge radially outward of said rotor member whereby said key member transmits thrust between the vane members and centrifugal force on said key member results in sealing force of said vane member tips against said surfaces.

2. A rotary power device as defined in claim 1, including a rotary valve driven member driven from said shaft and cooperating with the supply port to control admission of an expansible fluid into said chamber.

3. A vane assembly for a rotary power device having cooperating inner and outer cylindrical walls and opposed complementary lobular surfaces extending between said walls forming a stator member, a rotary shaft extending concentrically of said stator member and a rotor member having laterally extending surfaces which mate with said walls and portions of said lobular surfaces, said rotor member having a plurality of slots therethrough, pairs of spaced apart vane members mounted for concurrent sliding movement along their length in said slots with the respective tips of said vane members engaging and movable along said lobular surfaces and with the inner and outer edges of said vane members movable along said cylindrical walls, a wedge-shaped reaction key supported between said vane members with a narrower edge located radially outward of said rotor member, and complementary wedge surfaces on each of said vane members engaging the associated key and providing a translation of centrifugal force on said keys into sealing forces urging the tips of said vane members against said lobular surfaces.

4. A vane assembly for a rotary power device, comprising a pair of spaced apart vane members mounted for concurrent movement along their length, a wedge shaped reaction piece supported between 'said vane members,

said vane members and said piece being adapted for simultaneous rotation in a direction such that centrifugal force is directed toward the narrower edge of said piece,

seal strips carried on those edges of said vane members opposite to the narrower edge of said piece, and means transferring force from said piece due to centrifugal force thereon into opposite forces tending to move said strips away from the edges of said vane members on which said strips are carried.

Claims

1. In a rotary power device, having a shaft defining a central axis, a stator member including a pair of facing complementary lobular surfaces extending radially outward around said shaft and spaced apart along the axis of said shaft, said surfaces terminating at inner and outer edges concentric with said axis, an inner cylindrical wall mating with said inner edges and an outer cylindrical wall mating with said outer edges, a rotor member attached to said shaft extending radially outward therefrom between said surfaces and mating with said inner and outer walls to form enclosed chambers which have progressively increasing and decreasing cross-sectional size around said shaft along planes extending radially from said axis, spaced apart vane assemblies extending through said rotor member along planes which are parallel to said axis and extending generally outward therefrom into contact with said surfaces and said inner and outer walls to divide said chambers into regions between said vanes which move progressively as said shaft and said divider member rotate with respect to said stator member, and means defining ports opening into opposite ends of said chambers and controlled by movement of said vanes past said ports for supply and exhaust of a working fluid to and from said regions, said vanes being spaced apart Less than the spacing between those ports at opposite ends of said chambers to keep those ports separated at all times by a vane; the improvement comprising: each said vane assembly includes a pair of independent vane members having a tip contacting a corresponding one of said lobular surfaces and a root portion slidably supported in said rotor member, and a key member engaging the root portions of the pair of vane members, said key member and said root portions contacting along lines which converge radially outward of said rotor member whereby said key member transmits thrust between the vane members and centrifugal force on said key member results in sealing force of said vane member tips against said surfaces.

4. A vane assembly for a rotary power device, comprising a pair of spaced apart vane members mounted for concurrent movement along their length, a wedge shaped reaction piece supported between said vane members, said vane members and said piece being adapted for simultaneous rotation in a direction such that centrifugal force is directed toward the narrower edge of said piece, seal strips carried on those edges of said vane members opposite to the narrower edge of said piece, and means transferring force from said piece due to centrifugal force thereon into opposite forces tending to move said strips away from the edges of said vane members on which said strips are carried.