US3151528A

US3151528A - Swashplate engine

Info

Publication number: US3151528A
Application number: US73456A
Authority: US
Inventors: David P Eastman
Original assignee: Clevite Corp
Current assignee: Clevite Corp
Priority date: 1960-12-02
Filing date: 1960-12-02
Publication date: 1964-10-06
Anticipated expiration: 1981-10-06

Description

Oct. 6, 1964 p. P. EASTMAN SWASHPLATE ENGINE 4 Sheets-Sheet 1 Filed Dec. 2, 1960 Illil/l/l/l/l/l/ now INVENTOR. DAVID P. EASTMAN Oct. 6, 1964 n. P. EASTMAN SWASHPLATB ENGINE 4 Sheets-Sheet 2 INVENTOR. DAVID P EASTMAN ATT NEY x I 1/ i m? 2? Filed D60. 2, 1960 Oct. 6, 1964 o. P. EASTMAN 3,151,528

SWASHPLATE ENGINE Filed Dec. 2, 1960 4 Sh ets-Sheet 3 so (Q) INVENTOR.

DAVID P. EASTMAN 2 F'IG.3 BY

AT ORNEY Oct. 6, 1964 D. P. EASTMAN SWASHPLATE ENGINE 4 Sheets-Sheet 4 Filed Dec. 2, 1960 INVENTOR. DAVID P. EASTMAN %ORNEY United States Patent 3,151,528 SWASHPLATE ENGINE David P. Eastman, Novelty, Ohio, assignor to Clevite Corporation, a corporation of Ohio Filed Dec. 2, 1960, Ser. No. 73,456 Claims. (Cl. 91175) This invention generally relates to an improvement in swashplate type engines and more particularly concerns static and dynamic balancing of such engines to reduce mechanical vibration.

A swashplate engine of the type herein referred to is disclosed in copending US. application Serial No. 60,- 746, filed October *5, 1960, which is assigned to the same assignee.

As used herein, a swashplate engine is taken to mean an engine having a plurality of pistons and cylinder assemblies with their stroke axis parallel to and symmetrically disposed to a power output shaft, the pistons coacting with an eccentric swashplate on the shaft so as to impart rotary motion to the shaft in response to staggered linear reciprocation of the pistons in their respective cylinders. By virtue of this arrangement, and in order to construct an engine of this type compatible with a vibration sensitive environment, it is necessary to counterbalance the forces causing such vibration. Principally, we are concerned with forces acting in three different directions. First, an axially directed force produced by the reciprocating motion of the pistons and pants connected thereto. A centrifugal force exerted upon the eccentric mass of the swashplate member, and a force created by the inertia of the reciprocating pistons. These three forces acting in combination are associated with the scquential orientation of the swashplate during the operation of the engine, and the rotation of the swashplate. All three forces change direction and in effect thus rotate with the inner shaft. Rotation of these forces acting ultimately on the vehicle in which the engine is mounted, such as a torpedo, sets up a vibration which influences the operating characteristics of the vehicle.

As aforestated the forces are not confined to a single plane of excitation and therefore produce what is known as a dynamic unbalance. A force which is confined to a single transverse plane normal to the rotational axis, conventionally referred to as a static unbalancing, can be counter-balanced only by a single weight placed with its mass diametrically opposite to the mass producing the force and lying in the same plane therewith. On the other hand dynamic unbalance produces a moment or torque that can be suitably counter-acted only by another pair of forces acting oppositely to each other and lying in planes separated by a substantial distance. It is for (this reason that the arrangement in accordance with the invention requires a first and a second counter-balancing weight which are spacedly secured with respect to each other.

It is the primary object of this invention to provide a swashplate engine which is free of mechanical vibration, or in which such vibration is minimized to an acceptable degree.

It is a further object of this invention to advantageously employ counter-balancing members for achieving the aforementioned objectives and advantages.

To facilitate a better understanding of the present invention, together with other and further objects thereof, reference is bad to the following description taken in connection with the accompanying drawings, and its scope will be pointed out in the appended claims.

FIGURE 1 is a longitudinal partly sectional view through the aft section of a torpedo incorporating the invention;

3,151,528 Patented Got. 6, 1964 FIGURE 2 is a longitudinal partly sectional view through the swashplate engine taken along line 22 of FIGURE 3;

FIGURE 3 is a front view of the engine spider member;

FIGURE 4 is a cross-sectional view of the spider member taken along line 22 of FIGURE 3;

FIGURES 5 and 6 are enlarged side and end views of the conical valve member;

FIGURE 7 is an exploded perspective view of major engine components including the forward counter-balancing member; and

FIGURE 7a is a sectional view of the latter member.

Introduction Referring now to the drawings and more particularly to FIGURE 1, there is illustrated a conventional afterbody 1 of a torpedo adapted to rotatably support swashplate engine 3. For ease of description end 5 of the afterbody 1 is designated the forward section and end 7 the aft section. The swashplate engine 3 comprises a housing 19 containing a fluid pressure responsive mechanism 145 (FIGURE 2) of the reciprocatory piston type, a rotatably mounted inner power take-off shaft 22 and a swashplate conversion assembly mounted to the inner shaft 22 and connected to the fluid pressure responsive mechanism for converting the reciprocatory substantially linear motion of the fluid pressure responsive mechanism 145 into rotary motion, transmitting the rotary motion to the inner shaft 22 and simultaneously utilizing the torque reaction caused by the reciprocatory movement of pistons 146 to contra-rotate an outer second power takeoff shaft 16 which is substantially integral with segments of the housing 10. A fluid pressure supply tube 200 is connected to the housing 10 and is adapted to cooperate with a rotary valve 176 and related components hereinafter described, which sequentially opens and closes flow communication between the fluid pressure supply tube 200 and the fluid pressure responsive mechanism 145 to effect a supply of fluid under pressure to piston heads 146 and to discharge the fluid after the same has functioned to impart reciprocatory movement to the pistons. A forward counter-balancing sleeve 300 is secured to the inner power take-off shaft 22 immediately forward of the swashplate conversion assembly 95. An aft counter-balancing element 330 acting in conjunction with the forward counter-balancing sleeve is mounted to the inner shaft 22 at the aft end thereof and more particularly to a propeller mechanism assembly 28.

Housing The housing as illustrated herein comprises a plurality of

independent sections

12, 34, 44, 52 and 64 which are secured together to form the housing. The

sections

12, 44 and 64 are connected by means of bolts 13 arranged in circular array about the central axis of the housing 10 and extending through

sections

44 and 64 and into threaded engagement with section 12. The housing section 12 is formed of a semi-spherical hollow body or casing 14 and the integral outer or second tubular power take-off shaft 16. The outer power take-off shaft 16 has a cylindrical outer surface portion 18 adapted to provide a rotatable support means to carry a conventional propeller mechanism assembly 20, as partially shown in FIGURE 1. Outer power take-off shaft 16 is adapted to receive radial load ball bearings 8, (9) to rotatably mount the shaft to the torpedo after-body. The hollow interior of the outer power take-off shaft 16 is adapted to carry rotatably and coaxially the inner tubular power take-off shaft 22. The inner shaft extends into the hollow housing portion 14 and mates therein with conical valve member 176. At the opposite end the inner tubular shaft 22 extends beyond the axial extremity of the outer shaft 16 to provide a rotatable support 26 for carrying coaxially a second propeller mechanism assembly 28. The assembly 28 can thus be rotated independent of the first propeller mechanism assembly 29.

With exceptions hereinafter noted, the first and second propeller mechanism assemblies are composed of substantially identical materials. A blade 28a (29a) is integrally connected to a blade hub 28b (b), both of such members are formed of conventional corrosion resistant materials.

The aft counter-balancing member 330 is an elongated rod, or substance, primarily comprised of a material having a higher specific weight than that from which the propeller assembly 28 is made.

The rod or substance for instance the latter being composed of lead, is inserted into a bore 332 drilled through the propeller hub 28b. See FIGURE 1. The bore 332 is positioned parallel to the central axis of the shaft, and arranged in this manner the aft counterbalancing member provides a center of mass positioned eccentrically with respect to the rotational axis of the engine unit 3.

A metal cooling jacket 34, see FIGURE 2 and/or 3, is spaced around the engine casing 14 to provide a cooling water passage 36. Water conduits 38 are suitably arranged in the casing as shown, to discharge the coolant from the cooling passage as hereinafter further described. The cooling jacket 34 is attached to the casing by means of suitable screws (not shown) and O-rings 4t) radially received in peripherally arranged annular grooves 42 in the casing 14 engage the jacket 34 to prevent water leaks. The section 44 of the housing 10, see detail drawing FIG- URE 4, forms a cylindrical spider member, portions 46 of which are received in the hollow cylindrical casing housing 14, and opposite ends of spider member portions 48 are adapted to receive the hollow cylindrical housing section 52, which forms a cooling jacket and is arranged in the same manner as cooling jacket 34. The spider member is peripherally grooved to receive O-rings 48a and b which are adapted to sealingly engage the cooling jacket 52 and the casing member 12. The connection between

members

44, 12 and 52 is conveniently accomplished by suitably matching the diameter of the annular recess 50 or shoulder 51 of each respective member, so as to register the cooling jacket 34 and the casing member 12 to the spider member 44 with a press-fit.

The spider member 44 is formed with six openings 54, see FIGURE 3, positioned in circular array about the central axis of the spider, the central axis of each of the openings being substantially parallel to the central axis of hollow cylinders 56, see FIGURES 4 and 5. Each of such spider openings 54 is adapted to rigidly receive an end portion 58 of the piston carrying cylinder 56. Each cylinder 56 is a hollow cylindrical casing and one axial end 58 of each cylinder is mounted to the spider member as aforesaid, and the opposite end 62 is secured to housing section 64 forming a circular engine head. To seal the cylinder into position, an O-ring 40c is secured into an annular groove 410 of the engine head, and an O-ring 40d is secured into an annular groove 41d in the spider member, the O-r-ings :being adapted to peripherally surround the cylinder 56 at its respective ends. A central bore of the spider is adapted to suitably receive a tubular sleeve which has an annular recess 74 to receive and retain a graphitic annular seal 72. The seal 72 is coaxially and rotatably mounted about rotary valve 176. The forward end of the tubular sleeve 70 is formed with a plurality of slots 76 and is mounted in an annular bore portion of the engine head 64. The spider member 44 and the engine head 64 are thus spacedly connected and are further secured together by means of tubular cooling jacket 52 which attaches to the respective ends of

members

44, 64.

Internal Mechanism The inner tubular power take-off shaft 22 is rotatably and coaxially carried within the semi spherica-l hollow body portion 14 of casing 12 by means of a ball bearing assembly 86, of which an annular outer race 88 is secured with a press-fit to an internal annular support shoulder 90 of the casing 12, and an inner annular race 92 of the bearing 86 surrounds an annular sleeve 94 interposed between the inner race 92 of the bearing and the shaft 22. The sleeve 94 has an outwardly radially extending flange 96 which is adapted to take up longitudinal thrust from a swashplate cam 93.

The swashplate cam 98 is rigidly secured to the inner shaft 22. An annular ball bearing retaining ring 100 carried on the outer peripheral surface 192 of the cam 98 provides a plurality of radially extending openings 104 adapted to receive in each opening a bearing ball 106. An annular swashplate ring 112 is coaxially mounted to the bearing retaining ring 100. The bearing balls 106 ride in a ball bearing race formed in the shape of an annular groove 108 in the swashplate cam and in a corresponding groove 110 provided in the annular ring 112. The annular swashplate ring 112 is suitably connected to the reciprocating piston rods 148, as hereinafter further described, and the pistons operating in sequence force the swashplate ring 112 into wobble motion causing a torque action on the swashplate cam 98 which is translated to the inner power take-off shaft 22 causing it to rotate. Reaction to the positive torque causes a negative torque reaction which effects contra-rotation of the fluid pressure responsive mechanism 145 and all other components which are in fixed relationship to fluid pressure responsive mechanism 145 such as housing 16, particularly note power take-off shaft 16.

The swashplate cam 98 is secured to the inner shaft 22 by means of a key (not shown) fitting into key slot 120, and at the aft end the cam abuts against the radially outwardly extending flange 96 of the sleeve member 94. At the forward end the cam is secured against a forward vibration counter-balancing member 300 of a generally annular form of which the end adjacent to the cam extends partially into an annular pocket 81 of the swashplate cam 98 to rigidly limit the axial freedom of the latter. The swashplate cam comprises essentially two

annular sleeve portions

128 and 130, which are integrally superimposed upon one another in a relationship permitting annular sleeve 128 to form a skew angle with respect to the central axis of the cam, as is shown in FIG- URE 8. The cylindrical outer surface of the sleeve 128 is eccentrically arranged with respect to the central axis of the cam 98 and provides a radial groove 108 to receive partially therein bearing balls 106 which are disposed to carry a combination thrust and radial load and convert the reciprocatory movement of the pistons 146 into rotary movement of the shaft 22. The ball retaining ring 100 is a substantially annular ring and is formed so as to permit an alignment of the axial center of each aperture 194 with the corresponding axial center of the annular groove 1%, 110 of the swashplate cam 98 and ring member 112, respectively.

The annular swashplate ring 112 is provided with six bores 134 arranged in circular array about the central axis of the swashplate ring 112 to receive and secure in each of such openings a bronze ball socket joint 136, by means of which the ring 112 is connected to the reciprocating pistons.

A circular face gear plate 138 is integrally arranged with the ring 112 and its teeth 14%) are adapted to mesh with teeth 142 of the bevel gear 143 mounted about the inner shaft and connected to the spider member 44 by an annular flange portion 141 which extends into central bore 60 of the spider member. The engagement of the teeth of

members

138 and 143 serves to maintain the position of the swashplate ring in suitable relationship with the outer housing 10 and the connecting rods 148.

The interaction of the gear teeth balances the forces imposed on the swashplate ring 112 by the fluid pressure responsive mechanism 145. The gear meshing arrangement between bevel gear 1 -13 and gear plate 138 is of angular nature and while one segment of the gear teeth 140 continuously meets with another segment of the gear teeth the opposite end of such teeth are angularly removed from each other. The space created thereby is advantageously utilized by securing between

gears

143, 138 the aforementioned forward counter-balancing member 300.

The counter-balancing member 300 is an annular sleeve upon which an annular region 304 of about 180 is peripherally superimposed. This region 304 forms an cecentric mass with respect to the inner shaft with its center of mass substantially diametrically opposed to the center of mass of the swashplate cam 98. A semi-cylindrical groove 306 in the annular region 304 extending substantially parallel with the outer periphery thereof, facilitates machining of the sleeve 381) to provide the eccentric concentration of the mass in the region 304. An annular nut 308 with an inside thread 310 is fitted into opening 312 of the sleeve with a press-fit and at its aft end abuts against shoulder 314. The nut threadedly secures the sleeve to the inner shaft and against the swashplate cam 98. A spanner range fits into openings 389 of the nut to effect a tight connection. An annular casing 316 is an integral part of the sleeve 300 and surrounds the inner shaft in a radially spaced relationship. The casing 316 has a pair of radial flanges 318 (314) extending from the spaced portion to sealingly connect the casing to the inner shaft. A radial slot 320 in the casing is in a registering position with opening 322 in the shaft to which a vent tube 258 is internally mounted, the vent tube extends radially from the opening toward the central axis of the inner shaft, see FIGURE 2, the interior tube being thus positioned to enable fluid fiow between the interior of the hollow shaft and the hollow casing 12 through slot 320. Any coolant, described below present in the shaft 22 is prevented from rising or flowing into the casing while the shaft rotates, since the coolant is centrifugally pressured in a radial direction whereby a free breathing zone is created near the axial center of the shaft, i.e., in the proximity of opening 259 of vent 258.

Essentially the fluid pressure responsive mechanism 145 comprises a cylindrical piston 146 which is of suitable annular dimension to slide within the cylinder casing 56. The piston has an integrated socket joint 149 receiving a spherelike end 150a of a piston rod member 148 which connects the piston 146 to the swashplate ring 112 by way of the ball end portion 150]; which is received in bronze ball socket joint 136. The piston may be formed of aluminum or other suitable material. As shown in FIGURE 8 the outer cylindrical surface 152 of the piston 146 has a number of annular grooves of which

grooves

154 and 156 each receive a metallic or plastic ring 162 therein, and groove 158 is adapted to receive an O-ring 160. The O-ring 160 has a multiple function to perform, acting first as an oil control ring to wipe excess lubricant from cylinder wall as the piston descends to prevent lubricants from penetrating into the fluid supply conduits and from coming into contact with combustible gases. The O-ring 169 further serves to lend a certain degree of radial resiliency to the reciprocating piston member 146. The radial resiliency of the piston reduces frictional abrasion caused in some instances by deposition of solid combustion products in the cylinder casing 56. Radial resiliency of the O-ring 160 is also important in another aspect The piston head performs reciprocatory linear motion during operation of the propulsion unit 3. However, since the central axis of the piston rods are not at all times parallel with respect to the central axis of the device 3, the force of the piston acting upon the connecting rods produces a slightly radial component of force tending to push the piston against the cylinder wall. Another source of radial interference relates to the centrifugal action arising from contra-rotation of the cylinder structure. Hence, the O-ring carries at least a portion of this side burden and protects the metallic parts from frictional damage to pro vide proper sliding action of the piston in the cylinder. A slight radial clearance is provided between the inside diameter of the cylinder 56 and the outside diameter of the piston, particularly at the location of the piston head. It may be advantageous to use chemical fuel to produce the fluid under pressure in the cylinders. In this event to reduce buildup of solids on the cylinder walls it has been found advantageous to use metallic piston rings 162 capable of lightly scraping the cylinder walls during the reciprocatory motion.

Fluid Flow Control, and Passages Hot gas, or other suitable fluid, flows from a combustion chamber, or equivalent (not shown), into a tubular conduit 164 and a hot gas seal assembly 166 and then enters into and through a rotary valve assembly 174. The rotary valve assembly 174 comprises the rotary valve 176 and an annular conical seat 178 of graphitic or other suitable heat resistant material, secured in a cylindrical pocket 188 of the engine head, and into which a conical valve head portion 182 of the valve 176 is partly inserted. The hot gas seal assembly 166 includes a sealing member 168 encased by an annular steel sleeve 170, movable within a hot gas nozzle 172 to provide the fluid communication means between the hot gas supply chamber and the valve 176.

The valve 176 has a conical valve head 182 and a tubular body portion 184 extending coaxially from the conical head 182. The valve head 182 is substantially hexagonal in cross-section, see FIGURES 2 and 5. This configuration avoids difficulties usually encountered with cylindrically shaped valves, such as binding in the cylindrical seat as the valve expands when the temperature increases. The angle across the conical portion of head 189 adjacent to valve seat 178 is preferably approximately within the range of 55 to 65. An angle of 60 works particularly well. The double conical valve head as shown in FIG- URES 2, 5 and 6 has the advantage of small surface contact and is preferred when particularly high temperatures are encountered. The outside diameter of the tubular portion 184 is the same as the outside diameter of the inner shaft 22 and is adapted, by means of axially protruding teeth 186, to mate with similarly protruding teeth 187 of the inner shaft 22. The interlocking of these teeth establishes a connection between the two members so that when the inner shaft 22 is caused to rotate the conical valve 176 member rotates in unison with the shaft. The conical portion 182 of the valve 176, see FIGURE 2, is formed with inlet and

outlet ports

188, 190. The ports provide, in conjunction with

ports

192, 194 which are formed in the valve seat and the engine head respectively, a communicating passageway between the hot gas seal 166 and the small chamber 191 in the engine head 64, and a flow connection between the cylinders and the tubular portion 184 of the valve.

The sealing member 168 is substantially tubular and preferably made of heat resistant material such as graphi-te. The stainless steel sleeve is in essence a protective casing around the sealing member. The seal and the surrounding sleeve are tightly attached to each other and are movable within tubular passageway 196 of nozzle 172 toward and away from the valve head 182. However, the sealing member 168 is limited in its freedom of rotary motion. The sealing member is keyed (not shown) to the hot gas nozzle by installing a pin in the wall of the hot gas nozzle, the pin projecting inwardly through the wall of the sealing member, a rectangular slot is cut into the outer circumference of the sealing member for engagement with the pin, the slot enables axial movement but prevents rotation. A spring member 198 concentrically surrounds a feed tube 200 within the passageway 196 of the hot gas nozzle, the spring 198 is positioned to engage an internal annular shoulder 201 of the nozzle and reacts against an inwardly extending flange 262 portion of sleeve 1'79, biasing the hot gas seal to maintain initial contact between the sealing members and the conical valve head. The feed tube 200 registers coaxially with the central aperture 206 of the conical valve head. A small connecting tube 295 of suitable material is interposed therebetween.

A hollow cylindrical bearing support member 2*38 spacedly surrounds the nozzle and one end thereof forms a radially outwardly extending flange 212 mounted to the engine head. A radial load bearing 214 is mounted to the outer surface 216 of bearing support member 208. The feed tube 2% is cooled by a cooling fluid which is introduced into the engine through the space 218 defined by the internal diameter of the bearing support member 208 and the circumference of the tubular nozzle. The nozzle has an outwardly extending flange 222 which is provided with suitable apertures to secure the same either directly to the combustion chamber (not shown) or to other fluid communicating means.

In operation gas moves through the feed tube 200 and enters the inlet port 188 of the valve 176. This port sequentially registers with one of six combination inlet and

outlet ports

192, 194 distributed in circular array around the central axis of the valve seat and the engine head, and leading to and from the cylinder head end 58. The gas drives the piston downwardly in its cylinder and the gas is thereafter discharged through

ports

192, 194 into passage 190 and into the hollow shaft portion 184 of the conical valve from which the exhaust gas is permitted to escape through the hollow shaft of the second or inner power take-off shaft 22.

The proper port selection takes place in accordance with a predetermined cycle, which permits the single inlet passage 183 of the conical valve to be swept across each of the six cylinder ports 192 during one revolution, and, further, the valve is so timed that fluid is admitted through the inlet ports 192 of the seat and the engine head port 194 to each cylinder when the piston of the cylinder is approaching top dead center. The valve is also timed to close olf the passage to any one cylin der at an appropriate time in the piston cycle. Thus gas passage 190 in the valve is arranged to register with the cylinder ports 192 so that at the appropriate time in the cycle the port 194 to the cylinder is opened to the exhaust passage and the hot gas remaining in the cylinder, when the piston is above bottom dead center, is expelled from the cylinder through the

outlet ports

194, 192, 190 respectively.

Preferably a coolant, such as water, is used for the preservation of metal parts which are subjected to high temperatures arising from the combustion products. Such a coolant is introduced, see FIGURE 2, into the device through the annular space 218 formed by sealing member 246 surrounding the tubular hot gas nozzle 172. A face seal ring 250 secured to member 246 is provided to seal the water within space 218. Where the engine unit is adapted solely for uni-directional rotation the bearing support 208, as shown, may be utilized as part of the stationary structure and can be joined to the hot gas nozzle 172. Water can then be introduced to the annular space through an opening in the support 208 with a fixed connection. The coolant then flows from the space 218 through an annular space 219 located around the hot gas nozzle as shown in FIGURE 2, to an annular opening 252 circumscribed on one side by the bearing support member 208, and on the other side by rotary valve head 182 and thereafter the coolant is directed to flow into annular pocket 299.

A plurality of flow channels 68 are drilled into the engine head 64 to deliver the coolant entering annular pocket 299 to the forward and aft section of the device. For forward section cooling the coolant flows from channel 68 into and through narrow slots 69 provided in a cylindrical ring 71 to deflect the coolant onto cylinder 58, the remainder flowing to cooling jacket space 66 bounded by cooling jacket 52. The tubular sleeve 70 surrounding the tubular stem 184 of the rotary valve, forms the inner boundary for the water jacket space 66. The slots '76 of the tubular sleeve, aforedescribed, are provided as a discharge opening for water leaving the space 66. Thus the coolant enters through the slot 76 and passes through the annular space 78 surround ing the valve stem from which point the coolant is free to flow into the tubular interior of the rotary valve by passing through apertures 81 provided in the stem portion 184 of the valve.

For aft section cooling, a channel not shown, connects the annular pocket 209 of the supporting member 208 to annular pockets 211 surrounding portions of bolts 13. The annular pocket 211 is drilled from the aft end into the engine head and O-rings 225 disposed within annular pockets 211 about bolts 13 prevent coolant from penetrating into the space 66. The annular pockets are in flow communication with radial bores 15a of the bolts. The bores 15a communciate flow from pockets 211 to radial bores 15c drilled in the casing 12, by means of intermediate bores 15b drilled through part of the central axes of the bolts 13. Thus, the coolant flows along the axes of the bolts through bores into cooling jacket space 36 bounded by jacket 34. From space 36 the coolant is fed through passageways 38 and finally through radial apertures 213 into inner power take-off shaft 22. Two

annular seals

215, 217 are mounted about the shaft 22 oppositely adjacent to apertures 213.

Once the coolant is in the hollow confines of the tubular stem of the inner power take-off shaft, the coolant joins the exhaust gas where it serves the function of cooling the exhaust for the protection of engine components along the exhaust path. In instances where the fluid is of a nature producing extremely high temperatures, the valve head is partly cooled by channeling a portion of the coolant from space 219 through axial channel 253 in the rotary valve head 182. The channel 253 thus provides for cooling the interior of the valve head and establishes flow communication between space 219 and inner shaft 22, the latter also permits gases which may have escaped the hot gas seal to be expelled through the channel.

The coolant is expelled through shaft 22 either directly out into the open or into and through specially adapted discharge lines which are not illustrated in the drawings.

Cooling is also effected by efficient utilization of lubricants in casing 12. By action of the swashplate and the reciprocating motion of the pistons, the lubricant is rapidly turned within the cylindrical body portion 14 and forced in and out of the open ends of the cylinders 58. In operation, the rapid movement of lubricant brings it alternatively in contact with the exposed surfaces of the pistons 146 and the socket joints 136 whereby considerable heat is removed by contact. To retain the lubricant within casing 12 a lubricant seal 254 is disposed in annular pocket 256 of spider member 48. To prevent clogging of the vent tube 253 by the lubricant and loss of lubricant, the forward vibration counter-balancing member and more particularly the annular casing 316, aforedescribed, co-acts with vent tube 258 permitting only gas, such as may have accumulated in the casing through leakages, to escape through the vent. The arrangement, by means of centrifugal and accelerative forces, causes the gas to separate from the lubricant and the latter is thrown back into the casing.

A vent tube 260 similar to tube 258 is positioned in the inner shaft at a location further aft. Vent 260 maintains the annular space between inner and outer shaft at exhaust pressure and channel 262 drilled through the outer shaft 16 communicates the pressure with external areas. An annular seal unit 264 is arranged with a bronze 9 retainer 264a and O-rings 264k for sealing between the inner and outer shaft to prevent foreign substances to enter into the casing 12.

While there have been described what at present are considered to be the preferred embodiments of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is aimed, therefore, in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

I claim as my invention:

1. A swashplate engine comprising, in combination: a rotatably mounted cylinder housing member having a plurality of cylinder bores extending parallel to and being arranged in circular array about the central axis of the member; piston means slidably disposed for reciprocation in each cylinder bore; a power take-off shaft coaxially and rotatably mounted with respect to said housing; swashplate means secured to said shaft and operatively associated with the reciprocable piston means to convert the reciprocatory motion into an angular force component and to exert the latter upon said shaft to rotate the shaft in one direction and causing said housing member to be rotated in the opposite direction; fluid supply and exhaust conduits in said housing member connecting each of said cylinder bores to a fluid fuel source; a rotatably mounted valve in coaxial engagement with said shaft and rotatable in unison therewith to sequentially open and close fluid flow communication between said conduits and said cylinder bores; and a first and second counter-balancing means connected to said shaft having a center of mass disposed eccentrically to the axis of rotation of said shaft, said first counter-balancing means being axially spaced with respect to said second counterbalancing means and, in combination, said first and second balancing means having centers of mass diametrically opposite to the center of mass of the swashplate means.

2. A swashplate engine comprising, in combination: a rotatably mounted cylinder housing member having a plurality of cylinder bores extending parallel to and being arranged in circular array about the central axis of the member; piston means slidably disposed for reciprocation in each cylinder bore; a power take-off shaft coaxially and rotatably mounted with respect to said housing; swashplate means secured to said shaft and operatively associated with the reciprocable piston means to convert the reciprocatory motion into an angular force component and to exert the latter upon said shaft to rotate the shaft in one direction and causing said housing member to be rotated in the opposite direction; fluid supply and exhaust conduits in said housing member connecting each of said cylinder bores to a fluid fuel source; a rotatably mounted valve in coaxial engagement with said shaft and rotatable in unison therewith to sequentially open and close fluid flow communication between said conduits and said cylinder bores; a first dynamic balancing means axially disposed about said shaft and formed of an annular sleeve having an eccentric peripheral portion; means mounting said balancing means to said shaft; and a second dynamic balancing means connected to said shaft and having a center of mass disposed eccentrically to the axis of rotation of said shaft and axially spaced with respect to said eccentric peripheral portion of said first balancing means.

3. A swashplate engine comprising, in combination: a rotatably mounted cylinder housing member having a plurality of cylinder bores extending parallel to and being arranged in circular array about the central axis of the member; piston means slidably disposed for reciprocation in each cylinder bore; a power take-off shaft coaxially and rotatably mounted with respect to said housing; swashplate means secured to said shaft and operatively asso ciated with the reciprocable piston means to convert the reciprocatory motion into an angular force component and to exert the latter upon said shaft to rotate the shaft in one direction and causing said housing member to be rotated in the opposite direction; fluid supply and exhaust conduits in said housing member connecting each of said cylinder bores to a fluid fuel source; a rotatably mounted valve in coaxial engagement with said shaft and rotatable in unison therewith to sequentially open and close fluid flow communication between said conduits and said cylinder bores; a first and second propeller hub, said first propeller hub being connected to said housing member, and said second propeller hub being coaxilly mounted to said shaft; a portion of said second hub arranged eccentric relative to the axis of said shaft and formed of a material having a specific weight higher than the majority of the remainder material forming said hub; and a dynamic balancing means connected to said shaft and having a center of mass disposed eccentrically to the axis of rotation of said shaft and spaced relative to said portion of said hub.

4. A swashplate engine comprising, in combination: a rotatably mounted cylinder housing member having a plurality of cylinder bores extending parallel to and being arranged in circular array about the central axis of the member; piston means slidably disposed for reciprocation in each cylinder bore; a power take-off shaft coaxially and rotatably mounted with respect to said housing; swashplate means secured to said shaft and operatively associated with the reciprocable piston means to convert the reciprocatory motion into an angular force component and to exert the latter upon said shaft to rotate the shaft in one direction and causing said housing member to be rotated in the opposite direction; fluid supply and exhaust conduits in said housing member connecting each of said cylinder bores to a fluid fuel source; a rotatably mounted valve in coaxial engagement with said shaft and rotatable in unison therewith to sequentially open and close fluid flow communication between said conduits and said cylinder bores; an annular sleeve mounted about said shaft, said sleeve having an annular region superimposed upon portions of the sleeves radial periphery forming an eccentric mass with respect to said shaft; an annular casing integral with said sleeve and partly radially spaced with respect to said shaft, said casing having a pair of radial flanges connecting the radially spaced casing to said shaft; a radial slot in said casing, one of said flanges being axially forward and another being axially rearward of said slot; means securing said sleeve to said shaft; a vent tube mounted to said shaft and extending toward the axial center of the shaft; said shaft having a radially extending fluid passageway proximate to said slot; and a dynamic balancing means connected to said shaft and having a center of mass disposed eccentrically to the axis of rotation of said shaft and spaced relative to said sleeve.

5. A swashplate engine comprising, in combination: a rotatably mounted cylinder housing member having a plurality of cylinder bores extending parralel to and being arranged in circular array about the central axis of the mem ber; piston means slidably disposed for reciprocation in each cylinder bore; a power tak-ofr shaft coaxially and rotatably mounted with respect to said housing; swashplate means secured to said shaft and operatively asso ciated with the reciprocable piston means to convert the reciprocatory motion into an angular force component and to exert the latter upon said shaft to rotate the shaft in one direction and causing said housing member to be rotated in the opposite direction; fluid supply and exhaust conduits in said housing member connecting each of said cylinder bores to a fluid fuel source; a rotatably mounted valve in coaxial engagement with said shaft and rotatable in unison therewith to sequentially open and close fluid flow communication between said conduits and said cylinder bores; an annular sleeve mounted to said shaft, said sleeve having an annular region super- 1 1 imposed upon portions of the sleeves radial periphery forming an eccentric mass with respect to said shaft; an annular casing integral with said sleeve and partly radially spaced with respect to said shaft, said casing having a pair of radial flanges connecting the radially spaced casing to the shaft; a radial slot in said casing, one of said flanges being axially forward and the other being axially rearward of said slot; means securing said sleeve to said shaft; a vent tuoe mounted to the shaft and extending toward the axial center of the shaft; said shaft having a radially extending fluid passageway proximate to said slot; 21 first and second propeller hub, said first propeller hub being connected to said housing means, and said second propeller hub being coaxially mounted to said shaft; and a portion of said hub arranged eccentric relative to said axis of said shaft and formed of a material having a specific weight higher than the majority of the remainder material forming said hub and spaced relative to said sleeve.

References Cited in the file of this patent UNITED STATES PATENTS 355,814 Esty Jan. 11, 1887 630,767 Beadle Aug. 8, 1899 1,152,004 Canton Aug. 31, 1915 1,378,855 Gollings May 24, 1921 1,885,323 Duryea Nov. 1, 1932 2,097,138 Steele Oct. 26, 1937 2,713,829 Bwcham July 26, 1955 2,964,234 Loomis Dec. 13, 1960 FOREIGN PATENTS 137,552 Great Britain Jan. 22, 1920