US3825375A

US3825375A - Rotary driving

Info

Publication number: US3825375A
Application number: US00215544A
Authority: US
Inventors: N Deane
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-01-05
Filing date: 1972-01-05
Publication date: 1974-07-23
Anticipated expiration: 1991-07-23

Abstract

A rotary device of the type comprising a housing defining a first trochoidal internal profile between a pair of end walls and a rotor rotatable within the housing defining at its periphery a second trochoidal surface, the housing profile and rotor surface defining working chambers the volume of which expand and contract during relative rotation of the rotor and housing, and the rotor and housing defining conduits and porting for introducing fluid into the working chambers through the rotor.

Description

United States Patent Deane July 23, 1974 ROTARY DRIVING 3,684,411 8/1972 Cameron 418 42 [76] Inventor: Nicholas B. Deane, 1558 FOREIGN PATENTS OR- APPLICATIONS Massachusetts Ave-a Cambridge, 1,924,380 11/1970 Germany 418/61 Mass- 02138 1,401,998 11/1968 Germany 418 186 Filed: Jan- 1972 1,144,052 2/1963 Germany l23/8.0l

[ PP 215,544 Primary Examiner-Carlton R. Croyle Assistant ExaminerJohn J. Vrablik [52] US. Cl 418/61 A, 418/185, 418/186 [51] Int. Cl...... F01c 1/02, FOlc 21/12, F040 17/02 [57] ABSTRACT [58] Field of Search 418/42, 183, 185, 186-188, A rotary device f the type comprising a housing 418/61 A fining a first trochoidal internal profile between a pair of end walls and a rotor rotatable within the housing [56] References Clted defining at its periphery a second trochoidal surface, UNITED STATES PATENTS the housing profile and rotor surface defining working 824,648 6 1906 I-Iamann 418/42 chambers the v l f which xpand and contract 878,327 2/1908 Adams 418/186 during relative rotation of the rotor and housing, and 1,250,430 12/1917 Case 418/186 the rotor and housing'defining conduits and porting 1,387,949 8/1921 Smith 418/186 for introducing fluid into the working chambers 3,413,961 12/1968 Keylwert... 418/186 through the roton 3,655,303 4/1972 Cotton 418/188 3,671,153 6/1972 Luck 418/188 32 Claims, 12 Drawing Figures PATENTEB 31974 FIG. 1

SHEEIIUFG PATENTEU 3.825.375

' SHEEI 30$ 6 1 ROTARY DRIVING This invention relates to rotary engines.

The so-called Wankel internal combustion engine is well known. It comprises a rotor supported within a housing for relative rotation about an axis eccentric of and parallel to the axis of the rotor. The inner surfaces of the housing include a plurality of arched lobe defining portions symmetrically spaced circumferentially about the axis of the housing. The outer or peripheral surface of the rotor is continuous and includes a plurality of apex portions symmetrically spaced circumferentially about the rotor'axis, each apex portion incorporating an edge surface parallel to the axis of the rotor and engaging the inner surface of the housing.

In the two most common forms of such engines, the inner surface of the housing is in the form of either a 2-lobed or 3-lobed epitrochoid, and the rotorhas a shape approximating the inner envelope of the projections of the epitrochoid on a transverse plane integral with the rotor in all the successive positions of the housing and rotor as they undergo relative movement as determined by the eccentricity of their axes and the ratio of the number of said lobes to the number of said apex portions. For brevity, said inner envelope-is generally referred to as the inner envelope of the epitrochoid and is themaximum permissible outline of the rotor, beyond which interference between the rotor and the peripheral wall of the epitrochoidal cavity of the housing will occur. In the case of a two-lobed epitrochoid housing, the rotor will have three apex portions; in the case of a three-lobed epitrochoid, it will have four apex portions.

It is a primary object of the present invention to provide an external combustion, Wankel-type motorin which inlet to the working chambers is from a housing end wall through the rotor. Other objects include providing three or four-lobed motors in which exhaust may also be through the rotor, which have the minimum practical K factor and high efficiency, are reversible and will start from any position, and whose torque may be controlled by either an internal or external throttle.

The invention features, in a motor of the type having a housing defining a first trochoidal internal profile of M lobes between a pair of equal end walls and a rotor rotatable within the housing defining at its periphery second trochoidal surface of N segments extending between N apexes, the housing profile and the rotor surface defining N working chambers the volume of which expand and contract M times during each complete rotation of the rotor relative to the housing, that improvement wherein the rotor defines N sets of conduits extending therethrough each set being associated with one segment of the rotor peripheral surface and extending from the respective one to at least one rotor end face; the housing end walls define M inlets and M exhausts, one inlet and one exhaust being associated with each lobe of the housing trochoidal surface and all inlet ports being positioned on portions of the housing end walls that are at all times during the relative rotation in face-to-face engagement with the adjacent rotor end faces; at least one of housing end walls and rotor end faces define control porting arranged for permitting communication between a housing inlet and to each working chamber through a respective conduit set during a predetermined portion of the relative rotation of the housing and rotor during which the volume of the working chamber defined by the rotor peripheral surface segment associated with respective rotor conduit set is expanding. In preferred embodiments in which exhaust is through the rotor the complementary porting permits communication between the respective rotor conduit set and a respective housing exhaust during the portion of the relative rotation during which the volume of the working chamber is decreasing and includes generally arcuate porting on one of a rotor end face and housing end wall arranged for overlying a regular port on the other end face and end wall during a portion of the relative rotation, and there is featured starting portion arranged so that, at least at low rotational speed, at least one working chamber'is at all points of the relative rotation in communication with a housing inlet port and means for varying the period of inlet into the working chambers. Particular preferred embodiments further may include various other features such as inlet ports on one, housing wall and outlet ports on the other, rotor conduit sets including one conduit leading from each peripheral segment to one rotor end and a second conduit leading to the other end wall, and complementary porting that issymmetrical for motor reversibility coupled with control means for varying flow through different portions of the symmetrical porting depending on the direction of relative rotation.

Other objects, features, and advantages will appear from the following detailed description of preferred embodiments of the invention, taken together with the attached drawings, in which:

FIG. 1 is a sectional view, taken at l1 of FIG. 2, of a motor constructed according to the present invention;

FIGS. 2 and 3 are sectional views taken, respectively, at 2-2 and 3-3 of FIG. 1;

- FIG. 4 is a perspective view of portions of the motor of FIG. 1;

FIG. 5 is a perspective view of the rotor of the motor of FIG. 1;

FIG. 6 is a plan view, partially in section, of a second motor constructed according to the present invention;

FIG. 7- is a sectional view taken at 77 of FIG. 6;

FIG. 8 is a sectional view of a valve of the motor of FIG. 6;

FIG. 9 is a diagrammatic view of the driving system for the motor of FIG. 6; and

FIGS. 10-12 are sectional views of a third motor embodying the invention.

Referring particularly to FIGS. 1-5 there is shown a rotary engine, generally designated 8, comprising a generally square rotor 10 having convex arcuate sides 11 and eccentrically supported forrotation within a multi-piece outer body 12.

As shown the rotor 10 rotates on an axis 14 that is eccentric from and parallel to the axis 16 of the curved inner surface of the outer body 12. The outer body or housing 12 comprises a peripheral wall 20 that has for its inner surface a curved epitrochoidal inner surface 18 having three arched lobe-defining portions or lobes, and a pair of axially spaced end walls, generally designated 22 and 24 respectively, that are disposed on opposite sides of the peripheral wall 20. The generally square shape of the rotor 10 corresponds in its configuration to the inner envelope or the maximum profile of the. rotor which will'permit interference free rotation of the rotor while the housing 12. The shape of the epitrochoidal profile of inner surface 18 is determined by the ratio between two variables, R and e. R is defined as the distance from the axis of center 14 of rotor 10 to the point at which an apex of the rotor contacts inner surface 18. The other variable, e, is defined as the eccentricity of the rotor axis 14 from the outer body axis 16. This ratio between R and e may conveniently be designated K, or the K factor of the epitrochoid. The K factor of motor 8 is 12, whichto provide for'proper sealing has been found to be the practical lower limit for motors constructed in accord with the present invention in which the epitrochoid of the outer body is three-lobed and porting in the outer body controls the periods of inlet and exhaust.

Housing end walls'22 and 24 support a shaft 26 (diameter 2e) the geometric center of which is coincident with the axis 16 of the outer body 12. An eccentric 28 is rigidly attached to shaft 26, and the rotor 10 is supported upon the shaft eccentric 28 for rotation relative thereto.

As shown in FIGS. 1-3, an intemally-toothed or ring gear 30 (radius 4e) is mounted in a recess 32 at the end face 41 of rotor 10 adjacent end wall 24 and rigidly attached to the rotor. The ring gear 30 is in mesh with an externallytoothed timing gear 34 (radius 3e) rigidly attached to the stationary end wall 24 of the outer body 12. The

gears

30 and 34 do not drive or impart torque to the shaft 26 but merely serves to index or register the position of the rotor 10 with respect to the outer body 12 as the rotor rotates relative to the outer body and removes the positioning load that would otherwise be placed upon the apex portions of the rotor 10.

The gear ratio between rotor ring gear 30 and timing gear 34 is 4:3 and each time the rotor 10 comprises one revolution about its own axis 14, shaft 26 rotates four times about its axis 16.

As shown most clearly in FIGS. 2 and 5, each of the four apex portions of the rotor 10 carries a radially movable gas-seal 38 which is in continuous engagement with the inner surface 18 of the outer body 12 as the rotor 10 rotates within and relative to the outer body 12. In the embodiment of motor8, the rotation of rotor 10 relative to outer body 12 is, as indicated in FIG. 2, clockwise. During rotation of the rotor 10 relative to the outer body 12, four variable volume working chambers 42-1 through 42-4, are formed between the peripheral working faces, 11-1 through 11-4, of the rotor 10 and the inner surface 18 of the outer body 12. Each chamber goes through three complete cycles (expansion to maximum volume followed by contraction to minimum volume) during each complete revolution of the rotor.

As shown in FIGS. 1 and 5, rotor 10 has two

end faces

40 and 41. Each carries an

oil seal

50, 52, respectively in the form of a ring substantially surrounding bore 48. The diameter of seal 50 is slightly greater than that of bore 48; that of seal 52 is slightly greater than that of gear 30. Each

end face

40, 41 also carries a gas seal 54, closely adjacent and extending approximately parallel to the outer peripheral edge of the rotor end faces. Seals 54, thus are peripheral seals very close to theouter peripheral outline (defined by faces 11) of rotor 10. The width of each seal is approximately Vie.

I g In accordance with the present invention, means are provided to inject gaseous fluid (at high pressure and, if steam, at high temperature) from an end wallof housing 12 into and through a conduit in rotor 10 into each of working chambers 42 (at or near the point of which the chamber volume is a minimum), and to exhaust the fluid (after each chamber volume has expanded to its maximum) back through the rotor.

In the relative rotor and outer body position shown in FIG. 2, working chamber 42-1 has just passed its maximum volume and is contracting in size; chamber 42-2 is approaching and nearly to its point of maximum volume. Chambers 42-3 and 42-4 are each effectively divided into two smaller sub-chambers by the contact between rotor working faces 11-3 and 11-4 and portions of surface 18 closely adjacent the surface minor axis. As shown, the smaller sub-chamber of chamber 42-3 (defined by wall 18 and the trailing portion of face 1 1-3 is decreasing in size; the larger sub-chamber (defined by wall 18 and the leading portion of face 11-3) is expanding. Similarly, the leading and smaller sub-chamber of chamber 42-4 is expanding, while the trailing larger sub-chamber is contracting. The housing end wall ports and rotor conduits are arranged so that high pressure fluid will be injected into each working chamber immediately after the leading (in direction of rotation) sub-chamber is formed by the leading apex seal'38 on the rotor face 11 passing the housing minor axis, and that exhaust will begin when the chamber reaches it maximum volume and continue until the trailing sub-chamber reaches approximately zero volume. For efficiency, injection into the chamber continues for less than one-half cycle (a complete cycle including expansion followed by contraction). In the FIG. 2 position, injection of high pressure gas into the leading subchamber of chamber 42-4 has just commenced; exhaust from the smaller trailing sub-chamber of chamber 42-3 will continue until the apex seal 38 at the trailing end of surface 11-3 is closely adjacent the housing minor axis.

' The porting for supplying high pressure gas to and exhausting low pressure gas from the working chambers is provided in the

end walls

22, 24 of housing 10. It should be apparent that, if the motor is to function properly, this porting must not be located in an area of the end walls that will, during any period of rotation of rotor 10, form a portion of a working chamber. Rather, the porting must be located radially inwardly from the radially innermost points of the housing end walls that are swept by rotor gas seals 54 during revolution of the rotor within housing 12. Similarly, the porting must be located in a portion of the end walls that is radially outward from the area that is swept by the oil seals 50, 52. There are such areas on each end wall that are not swept over or encroached upon by either the gas or oil seals, and these areas form a suitable and practical location for the porting. The exact size and shape of the areas varies with the shape (X factor and number of lobes) of surface 18.

Referring particularly to FIGS. 1 and 5, rotor 10 includes an inlet conduit, generally designated 60, extending from each face 11 of rotor 10 to rotor end face 41, and an exhaust conduit extending from each face 11 to rotor end face 40. Each inlet conduit 60 includes a conduit portion 62 extending generally radially inwardly from a port 64, whose leading edge (in the direction of rotor rotation) is spaced some 4 from the leading rotor seal 38, and main and starter conduit portions, designated 66 and 68 respectively, extending from respective, radially aligned,

ports

67, 69 at rotor end face 41 to conduit portion 62. The precise positions of

ports

67 and 69 depends on the locations of the inlet ports on housing end wall 24 with which they communicate. Each exhaust conduit 70 extends from a port 72 spaced some 4 from the trailing end of the particular segment 11 to a port 74 at rotor face 40 arranged to communicate with the exhaust ports on housing end wall 22.

A valve comprising a screw-in valve seat 81, a bias spring 82, and a ball 80 is provided in conduit portion 62

intermediate conduit portions

66 and 68. As shown, spring 82 biases ball 80 towards the valves open position, in which the ball is spaced from seat 81.

Referring now to FIGS. 1 and 3, end wall 22 of housing 12 includes an exhaust port plate 90, mounted in face-to-face engagement with a manifold 92 and defining three generally arcuate exhaust ports 94. Each exhaust port is surrounded by a seal 95 and is associated with one lobe of surface 18. Manifold 92 includes an annular groove 96 in the surface thereof adjacent port plate 90 communicating with ports 94, and an exhaust conduit 98 extending from groove 96 to the periphery of the manifold. The angular extent of each port 94 is such that a rotor exhaust port 74 will communicate with each port 94 from the timein the rotation of rotor that the working chamber 44 defined by the segment 11 and lobe of surface 18 associated with the respective rotor and exhaust ports reaches its maximum volume until the trailing apex seal on the segment 11 defining the chamber reaches the next housing minor axis. In the FIG. 3, embodiment, each port 94 subtends an arc of approximately 102, commencing 18 (measured in the direction of rotor rotation) from the minor axis of the epitrochoid of inner surface 18.

End wall 24 (FIGS. 1 and 2) includes, mounted in respective 'face-to-face engagement, a port plate 100 and a manifold 102. Port plate 102 defines three sets of inlet ports, each set comprising a generally arcuate starter port 104 surrounded by a seal 105 and, radially outwardly therefrom, a main inlet port 106 surrounded by a seal 107. Each starter port is of sufficient extent to communicate with a rotor port 69 through (360 MN where M is the number of faces of rotor 10 and N is the number of lobes of the epitrochoid of surface 18) of rotor rotation commencing when the leading apex seal of the rotor segment 11 defining a working chamber passes a housing minor axis. As illustrated in FIG. 2, each starter port 104 extends from a point approximately 6 (in the direction of rotor rotation) from the epitrochoid minor axis through an arc, clockwise as shown, of 24. Each main inlet port 106 extends through an arc of approximately 10 (again clockwise as shown) from a point radially aligned with the extreme counterclockwise end of the starter port 104 with which it is associated.

Referring now to FIGS. 1 and 4, a circularly arcuate recess 110 having a height slightly greater than that of ports 106 and an angular extent of approximately 30 is provided overlying each port 106 on the side of plate 100 adjacent manifold 102. A slide 108 is mounted in each recess 110 and is movable, as described hereinafter, between a fully closed position in which the slide completely overlies the port 106 to which it is adjacent,

, of one of pins 124 and to the outer wall of the manifold.

6 and a fully open position in which the slide is spaced to one side of the port.

An annular groove 112 is provided in the end face of manifold port plate 102 and communicates with ports 106. An inlet conduit 114 extends from groove 112 to the outer periphery of the manifold. A starter conduit 116 extends from groove 112, adjacent each of ports 106, to the associated one of ports 104. As shown, a tab 109 attached to each slide 108 projects outwardly into groove 112 in position for closing the associated starter conduit 1 16 when the slide is in its fully closed position.

other to a respective slide 108, project from the slide outwardly through respective annular slots 126 in manifold 102, ride inrespective generally radial slots 128 in ring 120. A double acting control actuator 130 is at tached, by loose swivels, to an extended outer portion A hydraulic control system responsive to the motor throttle, operates actuator 130 and moves ring 120 (and thus slides 108) relative to the manifold.

In operation, gaseous fluid (such as steam) is supplied to the motor at high pressure through inlet conduit 114 and is exhausted, at low pressure through exhaust conduit 98. With slides 108 in their fully closed position, no high pressure fluid is permitted to flow through

inlet ports

104 and 106, and the motor is stopped. For starting, actuator 130 is actuated to move slides 108 (clockwise as shown in FIG. 4) to their open position, uncovering main-ports 106 and the conduits 116 leading to starter ports 104. The high pressure fluid then passes from

ports

104, 106 into the communicating ones'of therotor

inlet ports

67, 69 and thence through the rotor conduit 60 into the working chambers. In the working chambers, the fluid expands, forcing rotor 10 to rotate relative to the outer body 12. As each working chamber reaches its maximum volume, the exhaust conduit port 74 associated therewith enters into communication with one of exhaust ports 94 in end wall 22; the expanded fluid is then exhausted through rotor exhaust conduit to port 94 and from the housing.

As should be evident, the fact that each of starter ports 104 "is in communication with rotor inlet conduit 60 through 30 of rotor rotation insures that high pressure fluid can be supplied to one of the working chambers regardless of the position of the rotor. For starting, this is necessary. At higher speeds, however, efficient operation requires that high pressure. fluid be introduced only during a short initial portion of the period of working chamber volume expansion. At these highspeeds, centrifugal force causes the ball of the valves in conduit 62 to set firmly on seats 81, thus preventing gas from starter ports from flowing through

conduits

68 and 62 to the working chambers, and thereby increasing motor efficiency. The main inlet flow, from ports 106 through conduit 66, provides the working force.

Reference is now made to FIGS. 6-9 which illustrate a second motor, generally designated 200, constructed in accord with the invention. As shown, motor 200 includes a generally triangular rotor 210, having three convex arcuate sides 211, mounted for rotation on an axis 214 eccentric from and parallel to the axis 216 of the curved two-lobed epitrochoidal surface 218 of a multi-piece outer body 212. As with motor 8,. the distance between

axes

216 and 214 is the effective eccentricity (e) of motor 200, and the shape of rotor 210 corresponds to the inner envelope. The K factor of motor 200 is 8, the minimum practical factor for a twolobed device with extended housing end wall ports. Outer body 212 includes a peripheral wall 220 defining two-lobed epitrochoidal inner surface 2l8 and a pair of axially

spaced'end walls

222, 224 supporting a shaft 226 (diameter 2e) concentricly with axis 216. Rotor 210 is mounted for rotation on shaft eccentric 228 (diameter 4e) rigidly attached to shaft 226. Internally toothed ring gear 230, (radius 3e) rigidly attached to rotor 210 and externally toothed timing gear 234 (diameter 2e) rigidly attached to end wall 222 index the rotor and outer body with respect to each other. The gear ratio between

gears

230 and 234 is 3:2, shaft 226 completing three revolutions per revolution of rotor 210.

Each of the apex portions of rotor 210 carries a gas seal 238 in engagement with surface 218. During rotation of rotor 210 relative to outer body 212, three variable working chambers 242 are formed between rotor faces 211 and inner surface 218. Each chamber expands and contracts in volume twice, i.e., completes two cycles, duringeach complete rotor revolution. To prevent division of working chambers 242 into subchambers during the initial and concluding portions of each cycle, each rotor face 211 is provided with a central concave channel 213 that permits gases freely to pass from the portion of the working chamber defined by one lobe of the epitrochoidal surface to the portion of the chamber defined by the other lobe.

Rotor 210 has two end faces 240 and 241, respectively, which are in facing engagement with end walls 222and 224 respectively, and a bearing bore 244 extending generally axially through the rotor. A'radially inwardly extending flange 246 is provided at the end of bore 244 adjacent end face 224. Each

end face

240, 241 carries an

oil seal

248, 250, respectively in the form of a ring substantially surrounding bore 244. The diameter of seal 248 is slightly greater than that of gear 230; that of seal 250 is slightly greater than the inner diameter of flange 246.

' Each

end face

240, 241 also carries a gas seal 252, mounted adjacent and approximately parallel rotor faces 211 and thus providing a peripheral seal which is very close to the outer peripheral edge or outline of rotor 210.

Outer body end wall 224 includes a port plate 221 in a manifold 223. The porting'for connection with a rotor port andsupplying fluid to and exhausting fluid from working chambers 242 is defined by port plate 221. As

previously discussed with reference to motor 8, such end wall porting must be located in an area that is not swept or encroached upon by either the gas seals adjacent the rotor periphery, or the oil seals adjacent the rotor bore. ln motor 200, a permissible area of greater size than that available in most two-lobed motors of equivalent K factor, is provided by flange 246 of the rotor, which permits the diameter of the oil seal 250 surrounding the tlange'to be of significantly smaller diameter than either rotor bore 244 or ring gear 230.

Referring particularly to FIGS. 6 and 7, rotor 210 includes three tunnels or conduits 260, each extending from a po'rt262 at the center of a concave portion 213, to a port 264 at the rotor end face 241, radially aligned with port 262 and approximately midway between the surface of the segment and the rotor center.

Port plate 221 includes two sets of inlet and exhaust ports, one set being associated with each lobe of the outer body. As shown, the two sets are symmetrical about motor axis 216. Each set is symmetrical about major axis b-b and includes a total of six ports;

ports

274, 276 nearest the major axis,

ports

278, 280 nearest the minor axis a-a, and

ports

282, 284 intermediate, respectively

ports

274 and 278 and

ports

276 and 280. Each port is surrounded by a seal 273 and lies on the path traced by the ports 264 of rotor tunnels 260'during rotation of rotor 210.

Adjacent ports are spaced from each other by a distance slightly greater than the diameter (W,) of rotor ports 264. Thus, each of

ports

278, 280 are at their I nearest point, a distance of W,J2 from the housing minor axis, and the nearest point of approach of

ports

274, 276 to the major axis is also W,l2. The total arc subtended by

ports

278, and 282, and accordingly also by

ports

280 and 284, is such that rotor port 264 will be in communication with one of the ports (except for the instant it is between ports) from the point in rotor rotation that the volume of the working chamber 242 associated with the particular rotor port is a minimum through the next 60 of rotor rotation. Port 274 subtends an arc such that it will communicate with the rotor port during the next 30 of rotation.

For supplying high pressure gas, typically steam, from a source 290 to motor 200 and exhausting the gas after expansion from the motor to reservoir 292, a system of conduits, shown diagrammatically in FIG. .9, is provided in manifold 223 of housing wall 224. A main inlet line 294, in which a throttle 291 is provided, extends from source 290 to a three position valve 296; an exhaust line 298 extends from valve 296-to reservoir 292. Two lines, designated 300, 302, extendfrom valve 296 to

respective ports

304, 306 in the outer surface of manifold 223.

As diagrammatically shown, internal conduits in manifold 223 extend from main port 304 to each of

ports

274, 278 and 282 in port plate 221; other conduits extend from each of

port plate ports

276, 280 and 284 through manifold 223 to manifold port 306. The conduits between ports 278 and port 304, and between ports 280 and port 306 are unrestricted. A valve 308 is provided inthe conduit between each of

ports

282, 284 and the respective one of

manifold ports

304, 306. A similar valve 310 is provided between

manifold ports

304, 306 and each respective one of

port plate ports

274 and 276.

As shown in detail in FIG. 8, each valve 308 comprises a cylindrical sleeve 312 mounted in a bore extending through manifold 223. One end of sleeve 312 is flush against the adjacent surface of port plate 221 with the sleeve bore overlying one of the port plate ports (such as port 282 shown). A threaded plug 314 closes the other end of the sleeve bore. A port 316 in the cylindrical wall of sleeve 312 provides communication between the valve and the internal conduits of manifold 223. Within sleeve 312 is a ball 318 which is urged toward a valve seat 320 (at the end of the sleeve adjacent port plate 221) by a spring 322. A retaining ring 324, holding spring 322 in place, is together with seat 320 threaded into position within sleeve 312. The

surface of valve seat 320 engaging ball 318 is grooved to permit slow flow through the valve when the ball 318 is seated. Full flow through the valve occurs when the ball is lifted off the seat.

Valves 310 are identical to valves 308, except that the valve seats in valves 310 have no grooves so that there will be no flow through valves 310 when the valve balls are seated.

When valve 296 is in the position shown in FIG. 9, with the A section of the valve providing communication between the motor and the

lines

294, 298 rotor 210 is driven clockwise (as viewed in FIG. 6). Source 290 provides high pressure steam to manifold port 304; expanded steam is exhausted from the motor to reservoir 292 through manifold port 306. The steam, at high temperature and pressure, is admitted into each of the motor working chambers 242 during the period of rotor rotation that the rotor conduit 260 associated with the respective working chamber communicates with a main inlet port 278. The steam expands, causing rotor rotation, until the working chamber reaches its maximum volume, and is then exhausted from the chamber through

ports

276, 280 and 284.

Most of the steam expanded in each chamber is injected through main inlet 'ports 278, which as previously indicated are unrestricted. A relatively small amount of steam is injected through starter ports 282, during the period of rotation immediately following the main inlet flow. The purpose of this smaller flow, the magnitude of which is of course limited by valves 308, is to insure that the motor can be started regardless of the position of the rotor.

During clockwise rotation, the valves 310 associated with port plate ports 274 are closed by the high pressure steam which, together with the valve springs, urges their balls firmly against the valve seats. The expanded steam is exhausted through all of

ports

276, 280 and 284. The pressure of the steam within the working chambers lifts the balls of the

valves

310 and 308 associated with

ports

276, 284 off their respective seats (the working chamber pressure being greater than the pressure on the side of the valves connected to reservoir 292), and permits full flow through

ports

276, 284 to manifold port 306. Flow through ports 280 is, of course, never restricted.

For counterclockwise rotor rotation, section B of valve 296 is moved into between the motor and

lines

294, 298 which high pressure steam is applied to manifold port 306 and expanded steam is exhausted through manifold port 304. With valve 296 in this position, the

valves

308 and 310 associated with

port plate ports

282, 274 are open. Main inlet flow is through ports 280; starter inlet flow is through ports 284 (flow being restricted by now-closed valves 308); and the valves 310 associated with ports 276 are fully closed.

The motor speed, for rotation in either direction, is controlled by throttle 291.

To stop the motor, valve 296 is moved into its third position, in which valve section C prevents flow from source 290 into the motor, and both of

manifold ports

304, 306 are connected to reservoir 292.

A third motor, constructed in accord with the present invention and generally designated 338, is shown in FIGS. 10 through 12. As illustrated, motor 338 includes a generally triangular rotor 340 mounted for retation on an eccentric 342, the axis 343 of which is eccentric from and parallel to the axis 344 of the curved 10 epitrochoidal surface 346 of a multipiece outer body 348. A shaft 350, to which eccentric 342 is rigidly attached, extends through outer body 348.

Outer body 348 includes a peripheral wall 352 defining two-lobed epitrochoidal surface 346, and a pair of

end walls

354, 356 which support shaft 350. A ring gear 358 attached to rotor 340 and a timing gear 360 attached to outer body 348 index the outer body and rotor with respect to each other. The gear ratio between

gears

358, 360 is 3:2.

Rotor 340 includes three convex arcuate peripheral faces 362, each having in the central portion thereof a concave channel 364. Each apex 366 of the rotor carries a gas seal in engagement with epitrochoidal surface 346. During relative rotation, three variable volume working chambers 368 are formed between rotor faces 362 and epitrochoidal surface 346. The axially facing end faces 370, 372 of rotor 340 are in facing engagement with, respectively, outer body end

walls

354, 356.

For introducing high pressure gas into and exhausting expanded gas from motor 338, a pair of inlet ports 374 extend through end wall 354 and a pair of exhaust ports 376 extend through end wall 356. Each of

ports

374, 376 are of the same diameter and are spaced from the adjacent minor axis aa of surface 346 by a distance equal to slightly more than the port radius. As shown in FIGS. 11 and 12, respectively, ports 374 are spaced from the axis in the direction of rotation of rotor 340; ports 376 are spaced in the opposite direction.

A total of three drilled conduits 380, each associated with one of and aligned with the midpoint of the respective face, rotor peripheral faces 362 extend through rotor 340 in position for communicating with

ports

374 and 376 during rotor'rotation. A radially extending conduit 382 extends from each of conduits 380 to the respective concave channel 364.

For providing communication between conduits 380 and

ports

374, 376 during the desired portion of rotor rotation, each of rotor end faces 370, 372 defines three generally arcuate grooves, designated 384, 386 respectively. One end of each of

grooves

384, 386 overlies the adjacent end of one of conduits 380. Each of grooves 384, in end face 370 is arranged to overlie inlet ports 374 in housing end wall 354 from the point in rotor rotation that the volume of the working chamber 368 associated with respective groove 384 is at its minimum through the next (approximately) ten degrees of rotor rotation. Each of grooves 386 at rotor end face 372 is arranged to overlie a housing end wall outlet port 376 through the of rotor rotation that the volume of the respective working chamber 368 is decreasing.

As in

motors

8 and 200, it is important that the porting in the housing end wall be located in an area that does not, during any period of rotor rotation, form a portion of the working chamber, In

motors

8 and 200, the extent of the arcuate porting in the housing end walls, together with sea] width, required the motors to have relatively high K factors. In motor 338, the only housing end wall ports are the circular inlet and exhaust ports; the arcuate porting for controlling the period of inlet into and exhaust from the working chambers is provided in the rotor end aces. Accordingly, even with extensive oil, gas and port seals, which have been omitted for purposes of clarity, it is possible to construct practical motors such as motor 338 with K factors as low as six.

The operation of motor 338 is similar to that of

motors

8 and 200, previously described. High pressure gas is introduced into the motor through ports 374, expanded in working chambers 368, and then exhausted through ports 376.

ln other embodiments, operation may be different. For example, two motors (each having a three lobed housing and four working surface rotor, such as those of motor 8) may be mounted on a common eccentric and operated using the Stirling thermodynamic cycle. For such operation, one of the motors is a hot motor in which the hot gas is expanded; the other a cold motor into which the gas is compressed. The expanded gas is cooled in a heat exchanger before compression in the cold motor; and then heated before expansion in the hot motor. Other embodiments, and methods of operation utilizing them, are within the scope of the following claims and will occur to those skilled in the art. I

What is claimed is:

1. In a rotary device of the type having a housing defining a first trochoidal internal profile of M lobes between a pair of spaced, axially-facing end walls, and a rotor rotatable within the housing defining at its periphery a second trochoidal surface of N segments extending respectively between N apexes, the housing profile and the rotor peripheral surface defining-N working chambers the volume of each of which expands and contracts M times during each complete rotation of the rotor relative to the housing, that improvement wherein: f l

the rotor defines N sets of conduits extending therethrough, one of the sets being associated with each segment of the rotor peripheral surface and including a conduit extending from a port at the respective each segment to a port at at least one axiallyfacing end face of the rotor; and, I the housing end walls define M inlets and M exhausts,

one of said inlets and one of said exhausts being associatedwith each of the M lobes of the housing profile,

each-of said inlets and each of said exhausts being at least one port at a respective housing end wall, all portsof said inlets and of said exhausts being located on portions of the housing end walls that are at all times during the relative rotation of the rotor and housing in face-to-face engagement with the respective adjacent rotor end face,

each of the inlets successively communicating with eahc of the rotor conduit sets during relative rotation of the rotor and housing,

each of the exhausts successively communicating with each of the rotor conduit sets during relative rotation of the rotor and housing,

1 than said second level.

all flow of fluid between the inlets and the working chambers and between the exhausts and the working chambers being through the rotor conduit sets,

at least some time during the respective portions of the relative rotation in which the volume of a respective working chamber is contracting the porting permits flow of fluid from the respective working chamber to a respective housing exhaust,

at least some time during the respective portions of the relative rotation in which the volume of a respective working chamber is expanding the porting prevents flow of fluid from the respective working chamber to the housing exhausts, and

at least some time during the respective portions of the relative rotation in which the volume of a respective working chamber is contracting the porting prevents flow of fluid to the respective working chamber from the housing inlets.

2. The device of claim 1 in which said control porting permits flow from each working chamber substantially throughout the portion of the relative rotation in which the volume of the respective each working chamber is contracting.

3. The device of claim 1 in which said control portion permits flow at a first level into each working chamber during an initial period when the volume of said-each chamber is expanding, and pennits flow into said each working chamber at a second level during a period when the volume thereof is expanding subsequent to said initial period, said first level being a greater flow 4. The device of claim 3 wherein said control porting permits flow into each working chamber during substantially 360 MN degrees of the relative rotation after the'volume of the respective each working chamber commences to expand.

5. The device of claim 4 wherein said initial period is less than 360 MN degrees.

6. The device of claim 5 wherein said control porting includes, associated with each of one of said housing inlets and said rotor conduit sets and arranged for communicating with each of the other of said inlets and said sets, a main inlet port and a starter inlet port, said main inlet port permitting flow during said initial period and said starter port permitting flow during said period subsequent. V

7. The device of claim 6 wherein said device includes means for permitting greater flow through said starter ports in one direction than in the other direction.

8. The device of claim 4 wherein each of said rotor conduit sets includes a main conduit extending from the rotor peripheral surface and a pair of secondary conduits extending from the main conduit to respective ports at a rotor end face, and each of said housing inlets defines a main inlet port and a starter inlet port, each of said main inlet ports and starter inlet ports being arranged for communicating with a respective one of the ports defined by each of said pairs of secondary conduits.

9. The device of claim 8 including means responsive to the speed of said relative rotation for permitting flow to said working chambers from said starter ports at low speeds and preventing such flow at high speeds.

10. The device of claim 8 including a movable slide valve associated with and movable relative to. each of said main inlet ports for varying the angular extent of said each main inlet ports.

11. The device of claim 10 wherein each of said slide valves is movable between a closed position in which said each valve prevents flow through the main and starter ports associated therewith and an open position in which said each valve permits such flow.

12. The device of claim 11 wherein said housing defines an intermediate conduit extending from adjacent each said main inlet port to the said starter port associated therewith, and said valves close said intermediate conduits in said closed positions.

13. The device of claim 1 in which each of said rotor conduits includes a first conduit portion extending from a point midway the length of a respective one segment generally radially of said rotor and a second conduit portion extending from said first conduit portion to said one end face.

14. The device of claim 13 in which said inlets and said outlets are defined by the housing end wall adjacent said one end face.

15. The device of claim 13 in which each said second conduit portions extends between the end faces of said rotor, said inlets are defined by the housing end wall adjacent one rotor end face, and said outlets are defined by the housing end wall adjacent the other housing end face.

16. The device of claim 1 in which each of said sets of rotor conduits includes an inlet conduit extending from adjacent one end of the respective one segment of the rotor peripheral surface to a rotor end face, and an exhaust conduit extending from adjacent the other end of the respective one segment to a rotor end face.

17. The device of claim 16 in which said conduit porting permits flow to the working chamber defined by each 9 respective one segment commencing at about the point of the relative rotation that the one end of the respective one segment is adjacent a minor axis of the housing peripheral surface and permits flow from such working chamber until at about the point of the relative rotation that the other end of the respective one segment is adjacent the minor axis.

18. The device of claim 16 wherein said inlet conduits extend to one rotor end face and said exhaust conduits extend to the other rotor end face.

19. The device of claim 18 wherein each of said inlets includes a main inlet port and a starter inlet spaced radially of said housing therefrom, and each of said inlet conduits defines at said one end face a first port arranged for communicating with said main inlet ports and a second port arranged for communicating with said starter inlet ports.

20. The device of claim 1 wherein said porting at said housing end walls includes an arcuate inlet port and an arcuate outlet port associated with each of said lobes, each of said inlet and outlet ports being arranged for communicating with each of said rotor conduit sets.

21. The device of claim 20 wherein said porting at said rotor end faces includes an arcuate inlet port and an arcuate outlet port associated with each of said rotor conduit sets, each of said inlet ports being arranged for communicating with each of said M inlets and each of said outlets being arranged for communicating with each of said M exhausts.

22. The device of claim 1 wherein said control porting is arranged in sets, each set including an arcuate inlet port and an arcuate exhaust port, and the ports of said each set being arranged symmetrically about the mid point of said each set.

23. The device of claim 22 wherein said control porting is defined by an end wall of said housing each said set is symmetrical about a major axis of the first trochoidal profiles and adjacent sets are symmetrical about minor axes of the first trochoidal profile.

24. The device of claim 23 wherein each of said sets comprises six arcuate ports.

25. The device of claim 24 wherein each of said rotor conduit sets defines a single port at said one face, said single port being arranged for communicating with each of said ports of said control porting sets.

26. The device of claim 24 including valving for preventing flow through a first port of each of said sets during relative rotation in one direction and permitting flow through said first port and preventing flow through a second port of each of said sets during relative rotation in another direction.

27. The device of claim 26 including other valving for permitting flow at one rate through a third port of each of said sets during relative rotation in said one direction and permitting full flow through said third port and restricting flow through a fourth port of each of said sets during relative rotation in said another direction.

28.-The device of claim 27 wherein said third and fourth ports of each said set are adjacent a respective major axis.

29. The device of claim 1 wherein siad rotor includes a bore extending axially therethrough and a radially inwardly extending flange at one end of said bore defining a portion of the rotor end face at said one end, at least some of said control porting being adjacent said one end.

30. The device of claim 1 wherein one of M and N is 3, theother of M and N is 4, and the ratio of the maximum radius of the rotor to the distance between the axis of the rotor and the axis of the housing is not less than 12.

31. The device of claim 1 wherein one of M and N is 2, the other of M and N is 3, and the ratio of the max,- imum radius of the rotor to the distance between the axis of the rotor and the axis of the housing is not less than 8.

32. The device of claim 1 wherein each of said rotor conduit sets includes a first rotor conduit extending inwardly from a respective segment of the peripheral surface of said rotor and a second rotor conduit extending axially through said rotor and communicating with said first rotor conduit,

one of said housing end walls defines each of said ports of said M inlets, the other of said housing end walls defines each of said ports of said M outlets,

said M exhaust during said relative rotation.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 825 375 Dated July 23, 197 4 lnventofls) Nicholas B. Deane It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as' shown below:

Column 2, line 1 4, "portion" should be --porting--; Column 6, line 58, "set" should be ---seat--; Column 8, line 21, "w lz" should be --w /2- Column 10, line 56, "chamber," should be --chamber.--,

line 6'4, "aces" should be,--faces--;

Claim 1, column 11, line 52, "eahc" should be --each--; v

line 62, "defined" should be --de fining---;

Claim 3, column 12, line 21, "portion" should be --porting--;

Claim 17, column 13, line 32, delete "9"; 4

Claim 29, column 14, line 28, "siad" should be --said--.

Signed and sealed this8th day of October 1974.

(SEAL) Attest:

McCOY M.- GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents F OHM FLU-I050 (IO-1L9)

Claims

1. In a rotary device of the type having a housing defining a first trochoidal internal profile of M lobes between a pair of spaced, axially-facing end walls, and a rotor rotatable within the housing defining at its periphery a second trochoidal surface of N segments extending respectively between N apexes, the housing profile and the rotor peripheral surface defining N working chambers the volume of each of which expands and contracts M times during each complete rotation of the rotor relative to the housing, that improvement wherein: the rotor defines N sets of conduits extending therethrough, one of the sets being associated with each segment of the rotor peripheral surface and including a conduit extending from a port at the respective each segment to a port at at least one axially-facing end face of the rotor; and, the housing end walls define M inlets and M exhausts, one of said inlets and one of said exhausts being associated with each of the M lobes of the housing profile, each of said inlets and each of said exhausts being at least one port at a respective housing end wall, all ports of said inlets and of said exhausts being located on portions of the housing end walls that are at all times during the relative rotation of the rotor and housing in face-to-face engagement with the respective adjacent rotor end face, each of the inlets successively communicating with eahc of the rotor conduit sets during relative rotation of the rotor and housing, each of the exhausts successively communicating with each of the rotor conduit sets during relative rotation of the rotor and housing, all flow of fluid between the inlets and the working chambers and between the exhausts and the working chambers being through the rotor conduit sets, the ports at the housing end walls and the rotor end faces defined control porting arranged such that at least some time during each of the respective portions of the relative rotation in which the volume of a respective working chamber is expanding the porting permits flow of fluid from a respective housing inlet to the respective working chamber, at least some time during the respective portions of the relative rotation in which the volume of a respective working chamber is contracting the porting permits flow of fluid from the respective working chamber to a respective housing exhaust, at least some time during the respective portions of the relative rotation in which the volume of a respective working chamber is expanding the porting prevents flow of fluid from the respective working chamber to the housing exhausts, and at least some time during the respective portions of the relative rotation in which the volume of a respective working chamber is contracting the porting prevents flow of fluid to the respective working chamber from the housing inlets.

3. The device of claim 1 in which said control portion permits flow at a first level into each working chamber during an initial period when the volume of said each chamber is expanding, and permits flow into said each working chamber at a second level during a period when the volume thereof is expanding subsequent to said initial period, said first level being a greater flow than said second level.

4. The device of claim 3 wherein said control porting permits flow into each working chamber during substantially 360 Divided by MN degrees of the relative rotation after the volume of the respective each working chamber commences to expand.

5. The device of claim 4 wherein said initial period is less than 360 Divided by MN degrees.

6. The device of claim 5 wherein said control porting includes, associated with each of one of said housing inlets and said rotor conduit sets and arranged for communicating with each of the other of said inlets and said sets, a main inlet port and a starter inlet port, said main inlet port permitting flow during said initial period and said starter port permitting flow during said period subsequent.

10. The device of claim 8 including a movable slide valve associated with and movable relative to each of said main inlet ports for varying the angular extent of said each main inlet ports.

28. The device of claim 27 wherein said third and fourth ports of each said set are adjacent a respective major axis.

30. The device of claim 1 wherein one of M and N is 3, the other of M and N is 4, and the ratio of the maximum radius of the rotor to the distance between the axis of the rotor and the axis of the housing is not less than 12.

31. The device of claim 1 wherein one of M and N is 2, the other of M and N is 3, and the ratio of the maximum radius of the rotor to the distance between the axis of the rotor and the axis of the housing is not less than 8.

32. The device of claim 1 wherein each of said rotor conduit sets includes a first rotor conduit extending inwardly from a respective segment of the pEripheral surface of said rotor and a second rotor conduit extending axially through said rotor and communicating with said first rotor conduit, one of said housing end walls defines each of said ports of said M inlets, the other of said housing end walls defines each of said ports of said M outlets, one of said rotor end faces includes a respective arcuate groove in said one end face communicating with each of said second rotor conduits and arranged to communicate with each of said ports of said M inlets during said relative rotation, and the other of said rotor end faces includes a respective arcuate groove in said other end face communicating with each of said second rotor conduits and arranged to communicate with each of said ports of said M exhaust during said relative rotation.