GB2216600A

GB2216600A - Reciprocating piston, reciprocating and orbital cylinder machine

Info

Publication number: GB2216600A
Application number: GB8905391A
Authority: GB
Inventors: Haim Rom
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-03-10
Filing date: 1989-03-09
Publication date: 1989-10-11
Also published as: IT8983354A0; IT1234187B; KR890014927A; IL85694A0; GB8905391D0; JPH02112601A; AU3119189A; ZA891796B; DE3906912A1; FR2628479A1

Description

IMPROVEMENTS IN AND RELATING TO INTERNAL COMBUSTION ENGINES AND THE LIKE

This invention-relates to internal combustion engines and the.like / such as compressors and the like power/wnrk machines.

Countless attempts have been made to remedy the inherent drawbacks of the conventional I.C. engines. The necessity to use a crankshaft, connecting rods and toggle arms, in order to convert the to- and-fro piston motion into a useful rotational motion; excessive and uneven wear due to side thrust of the piston against the cylinder wall; static and dynamic unbalance; vibrations and noisy operation; lubrication problems; poor space utilization; and relatively low speed limits -- are some of the major deficiencies of the conventional design, which the present invention aims to overcome.

is According to the invention there is provided a reciprocating cylinder and piston assembly for internal combustion engines, compressor$ and the like power/work machines. The cylinder and the piston are coupled to each other by a transmission system effecting, in combination, reciprocating movements of both the piston and the cylinder in opposite directions, and a translational movement of the cylinder about a circular orbit relative to a support of the transmission system.

The piston is preferably double-sided, defining compression chambers at each side thereof, the total stroke of the piston relative to the cylinder equalling four times the radius of the said circular orbit.

These and further aspects, constructional details, advantages and applications of the invention will be more fully comprehended in the light of the ensuing description of various preferred embodiments thereof, given merely by way of example, and for the better evaluation of the various aspects of the present invention, with reference to the accompanying drawings, wherein - Fig. 1 is a schematic elevation of a piston and cylinder assembly according to a first, basic embodiment of the invention; is Fig. 2 is a section taken along line II-II of Fig. 1; Fig. 3 is a further embodiment of the invention; Fig. 4 is a further embodiment of the invention; Fig. 5 is a section taken along line V-V of Fig. 4; Fig. 6 is a further embodiment of the invention; Fig. 7 is a further embodiment of the invention; _.:Fig. 8 is a further embodiment of the invention; Fig. 9 is a further embodiment of the invention; Fig. 10 is a further embodiment of the invention; Fig. 11 shows a cylinder head construction applicable to the design according to the invention; Figs. 12a and 12b illustrate a detail of the cylinder head shown in Fig. 11; Figs. 13a and 13b illustrate another detail of the cylinder head shown in Fig. 11; Fig. 14 is a still further developed embodiment of the invention; and Fig. 15 shows the application of the invention to a work machine.

In Figs. 1 and 2 there are schematically shown basic elements and components of an engine featuring the principles of the present invention. Hence, a double-sided piston 10 is reciprocable within cylinder 12, while both are movable along their common axis in opposite directions on the one hand, and, on the other hand, perform together, as a unitary body, a translational, parallel to itself rotational movement about a circular orbit.

The piston 10 is rotationally coupled to crank pin 14 constituting the power-takeoff of the engine. The crank pin 14 has its central shaft portion 14' journalled by a bearing, and its off-center shaft portion 14" is rotatably coupled to the piston 10 by bearing 10' located at the center thereof. The portion 14" projects into the piston 10 through an axially extending slot 16 formed at the respective location of the wall of the cylinder 12, 25namely along a generatrix thereof.

The cylinder 12 is provided at its two opposite ends with bearings 12' and 12". A first crank pin 18, with central shaft portion 18' and off-center shaft 18" is coupled to the bearing 12', and a second crank pin 20, with shafts 20' and 20" is coupled to the bearing 12". The eccentricity or "throw" of the shafts 14", 18" and 20", marked S in Fig. 1, is the same, however, the direction of the shaft 14" throw is initially fixed in a mirror-image opposite direction with respect to that of the shafts 18" and 20", the latter being directed in the one and same direction.

The shafts 14', 18' and 20' are coupled to each other by three identical gear wheels 14"', 18"' and 20"', respectively, so that the above described directional relationship is kept.

The engine is accommodated within a housing 22 with only the crank pin central shaft portion 14' projecting for coupling thereto the driven component of the engine (not shown).

For sake of clarity, all other parts and components necessarily incorporated to enable the performance as a two-stroke or four-stroke Otto cycle internal combustion engine, (spark plugs, valves and the like auxiliary systems and accessories), have been omitted from the drawings.

The operation of the engine is as follows. It will be noted that two compression chambers are formed, denoted Al and A2.

Once started, the crank pins 18 and 20 will rotate, say, in the counter-clockwise direction, and crank pin 14 in the clockwise direction. The cylinder 12 and the piston 10 will thus perform oppositely directed linear motions.

It will further be noted that. due to the crank pins being dimensioned and assembled in the relationship as described above -- the cylinder and the piston move in unison, performing a translational motion about the respective central axes of the shafts 14', 18' and 20', while kept parallel to their common longitudinal axis (or to the plan X-X defined by said three central axes).

A simple analysis of this combined motion will show that the respective volumes of the compression chambers A1 and A2 will vary alternately between a maximum and a minimum directly proportional to a stroke of 4xS in one and in the other direction, relative to the central plane of symmetry Y-Y of the engine structure, upon every complete revolution of the crank pins.

It will be further readily understood that rather than having the cylinder and piston assembly translated in relation to the transmission system, i.e. the gear train associated with cranks 14. 18 and 20 affixed to the housing 22 -- the cylinder may be held stationary and the housing allowed to perform the translatory motion therearound.

Turning to Fig. 3, an engine according to a modified embodiment is shown. Piston 24 and cylinder 26, defining compression chambers B1 and B2, are-coupled to each other via crank pin 28, with central shaft 28' and eccenter shaft 28", gear wheel 30, gear wheel 32 and crank pin 34 with shafts portions 34' and 3C, as shown.

The movement of the eccenter shaft 28" is guided within slot 36 formed in the side wall of the cylinder 26.

A pair of counter-weights 38 and 40 are affixed to the wheels 30 and 32, respectively.

The nature of the piston and cylinder periodical positive reciprocating movement, towards and away from each other, on the one hand, in combination with the parallel to itself unison movement of the piston and cylinder assembly as a unitary body, on the other hand, is is assured by the coupling arrangement as described above, as the wheels 30 and 32 rotate in opposite directions.

The counter-weights 38 and 40 serve to balance the traverse, upanddown movement of the piston and cylinder assembly.

The embodiment of Figs. 4 and 5 comprises piston 42 and cylinder 44, which is provided with air-cooling fins 46.

The piston 42 is coupled to crank pin 48 comprising shaf ts 48' and 4V. The cylinder 44 is coupled to crank pins 50 and 52 with shafts 50', 5V and 52', 52". the latter being seated in bearings SO" and 52"', formed on suitable lugs 54 and 56 extending from the opposite sides of the cylinder 44.

The crank pins 48, 50 and 52 are connected to each other by means of identical, meshing gear wheels 58, 60 5 and 62, respectively.

A slot 64 is formed in the side wall of the cylinder 44, allowing the passage of the the eccenter shaft 48" into bearing 66 provided at the center of the piston 42, as well as its guided back-and-forth movement therealong.

The mode of operation of the engine is substantially the same as described in conjuction with Figs. 1 and 2, in relation to compression chambers C1 and C2.

Referring now to Fig. 6, piston 64 is centrally supported by eccenter shaft 66" of a crank pin, which, in the instant caset is constituted by gear wheel 66 meshing with wheels 68, 70, 72 and 74.

Cylinder 76 is provided with a pair of lugs 78, 80, with bearings 68"' and 70"' for the shafts 68" and 70", respectively. The cylinder 76 is designed to perform a two-stroke cycle. To this end inlet or suction port 82 and discharge port 84 are provided in the cylinder jacket.

An internal passage 86 communicates between compression chambers D1 and D2. A spark plug 88 is 25installed at the cylinder head.

According to the instant embodiment of the invention, an additional (and possibly more) piston and cylinder assembly is readily annexed, connected "in parallel" to the first mentioned system. Hence, the wheels 72 and 74 serve to carry another cylinder 90 (only partly shown in Fig. 6), preferably in an off-set relationship with respect to the first assembly (cylinder 76), for attaining a better balanced overall structure..

The embodiment exemplified in Fig. 7 aims to achieve a two-stroke combustion cycle engine incorporating a discharge rotary valve which is operated in the same fashion-as the piston and cylinder components. The system comprises a piston 92 and a cylinder 94 with lugs 96 and 98.

Crank pin and wheel assemblies generally denoted 100, 102 and 104 are employed, similar to the arrangement of Fig. 5, apart from that sprocket or toothed wheels, with sprocket chain or timing belts 106 are presented rather than a gear mesh engagement.

The chain 106 is drivingly coupled to a fourth crank pin and wheel assembly 108, provided with a partly hollow, or slotted eccenter shaft 108', thus constituting an exhaust gas rotary valve, operable in synchronization with the piston and cylinder combined motion.

The piston and cylinder are of a differential configuration, i.e. where the front, working side is of a smaller diameter than the intake, rear side. Thus, the cylinder 94 is configured to function in a supercharged two-stroke Otto cycle, comprising an inlet port 110 at chamber E2 and passage 112 leading to chamber El, which also communicates with the valve 108' through port 114, next to spark plug 116.

Fig. 8 illustates the employment of the principles of the present invention for the design of a double-side, two-stroke I.C. engine.

Differential piston 120 and cylinder 122 are provided, operatively coupled by crank pin assemblies 124 (at the piston side) and 126, 128, 130 and 132 (at the cylinder side).

Compression chambers F1 and F2 are interconnected by passages 122' and 122", in opposite directions, as shown, with intake and exhaust port 136 for chamber F1 and similar port 138 for chamber F2.

is The operation of the engine is directly analogous to that of the embodiment of Fig. 7 with respect, however, to both sides of the piston 120.

Turning now to Fig. 9, piston 140 and cylinder 142 are coupled to each other in the familiar manner, namely, crank pin and gear assemblies generally denoted 144, 146 and 148, respectively.

Eccenter shafts 146' and 148' are each further provided with additional gear wheels 146" and 148", constantly in mesh with respective, identical gear wheels 150 and 152. Wheel 150 is mounted on cylinder head 154 by a shaft 156. The shaft has a cam 156' for operating -i.e. opening and closing -- a spring loaded valve 158 of a generally conventional design. A cylinder head 160 is provided at the opposite side of the cylinder 142. Shaft 162 of the wheel 152 constitutes a rotary valve, as in the preceding embodiment.

Obviously, the provision of the valves of different types is shown for illustration purposes only, emphasizing the versatility of design possibilities according to these further aspects of the present invention.

In Fig. 10 further variations of design are exemplified. Thus, piston 164 is differently coupled to cylinder 166, i.e. by a pair of radially extending lugs 164' and 164" carrying bearings 164"'and 164"" of crank pin assemblies 168and 168". Suitable elongated slots 166' and 166" are made in the respective wall portions of the cylinder 166 to allow the oppositely directed reciprocable movements of the piston and the cylinder generated by piston crank pin assemblies 168', 168" (interconnected by an additional, direction changing gear 167) and crank pin assemblies 170, 172.

Two sets of piston seal rings, designated 174 and 176, are provided (as in all of the previous cases) at the opposite sides of the double-acting piston 164.

A housing 178 encloses the complete engine when used, e.g. as a stationary electric power generator, driven by one of the shafts associated with crank pins 168', 168"j, 170 or 172.

This configuration is particularly advantageous and unique, in that the piston on the one hand, and the cy linder on the other hand, are independently supported by the housing 178. Therefore, the piston reciprocating movement is no longer slidable within and guided by the cylinder wall, but is rather "contactless" moved thereinside, without any radial friction forces present. Close precision fitting of the piston into the cylinder, as well as intensive lubrication of the cylinder, are not required, entailing a considerable saving of production and maintenance costs.

This feature may also be considered important from another aspect. Due to the minimal mechanical stresses between the piston and the cylinder, the latter can be is made of ceramic materials -- rather than of metal -which will allow the operation of the engine under elevated temperature conditions.

A particular design detail is illustrated in Fig. 11, which is generally applicable to any one of the preceding embodiments.

There are partly shown piston 180, cylinder 182, housing 184 and overhead valve assembly 186.

In more detail, bearing in mind the kinematics of the system, certain specific problems must be satisfactorily 25solved in order to reduce the invention into practice, such as the supply and exhaust of the combustible mixture, and the inlet and outlet of the cooling water.

To this end, the use of hollow crank pins such as shown in Figs. 12 and 13, is proposed, in the following manner. The valve head 186 contains an intake manifold section 188 and exhaust manifold 200, which have to be connected to the outside of the housing 184, namely, with respect to the section 188 -- to opening 202 (and from section 200 to an opposite opening - not shown).

A rotatable crank pin 204, clearly shown in Figs. 12a and 12b, is mounted, partly in a bearing socket 206 formed at the housing section 184, in axial alignment with the opening 202, and partly in socket 208 provided in the cylinder head 186. Suitable linings and gaskets are incorporated.

Thanks to a throughgoing bore 210, communication is established and constantly maintained albeit the up and down movement of the cylinder head 186 relative to the fixed housing 184.

As for cooling fluid circulated through opening 212 into and out of void 214 in the cylinder 182, a similar arrangement is used. Hollow crank pin 216, illustrated in Figs. 13a and 13b, with internal passage 218 is mounted, coupled to the respective parts as shown. Another assembly arrangement, for a double- side, four-stroke engine configuration is shown in Fig 14. 25 For each side of the piston 220 and cylinder 222, there is provided a valve assembly, generally denoted 224 and 226.

Both valve assemblies are installed in a common structure 228, as a part of the engine outer casing 230.

The respective inlet/outlet ports of the cylinder 222, designated 232 and 234, must become alternately aligned with the valve assemblies 224 and 226, respectively, i.e.

towards and during the end of every stroke regarding compression chambers H1 and H2.

The structure 228 is fixed, and comprises a right-hand cam shaft section 236' and a left-hand section 236", both rotatable (in opposite directions) by a spur gear transmission comprised of pinion 238 and gears 240, 242. The pinion 238 is driven by central crank pin 244, whose off-center shaft 244' passes through the piston 220.

Suitable guide strips and seals 246, 248 are used to facilitate the movement of the cylinder 222 within its casing 230.

Fig. 15 schematically represents a still further method of coupling to each other a centrally located piston 250 associated with crank shafts 250' and 250" - and a pair of cylinder 252 crank pins 252', 252" and 254', 254".

Hence, each of the cylinder crank pins is provided with an additional eccentric shaft 252"' and 254"', projecting to the outside of the structure (i.e. opposite to the off-centered shafts directly coupled to the cylinder).

A tie-rod 256 is coupled by its ends to the shafts 252" and 254", and is passed through a linear bearing block 258 which is coupled to eccenter shaft 250" of the piston crank pin.

The piston 250 is differential, particularly for acting as a four-stage compressor, namely in conjunction with non-return valves 260, 262, 264 and 268.

1 is

Claims

CLAIMS:

1. A reciprocating cylinder and piston assembly for internal combustion engines, compressors, and the like powerlwork machines, characterized in that the cylinder and the piston are coupled to each other by a transmission system effecting. in combination, reciprocating movements of both the piston and the cylinder in opposite directions, and a translational movement of the cylinder about a circular orbit relative to a support of the said transmission system.

2. An assembly as claimed in Claim 1, wherein the piston is double-sided, defining compression chambers at each side thereof. the total stroke of the piston relative to the 1 cylinder equalling four times the radius of the said circular orbit.

3. An assembly as claimed in Claim 2, wherein the transmission system comprises: first, second and third fixed mounting seats for rotatably supporting first, second and third axial shafts, respectively; each axial shaft being associated with an off-center, crank shaft whose axis extends parallel to and at the same distance from the axis of its respective axial shaft; the first crank shaft being pivotally coupled to the piston in a direction normal to the longitudinal axis thereof, at a certain angular direction with respect to the axial shaft axis; the second and third crank shafts being pivotally coupled to the cylinder with their angular direction forming a mirror image of the first crank shaft angular direction; means being provided for coupling the first axial shaft to the second and to the third axial shafts for the common rotational movement thereof by the same angular velocity while the direction of the first shaft is opposite to the direction of the second and third shafts.

4. An assembly as claimed in Claim 3, wherein the axial shaft(s) and its respective crank shaft(s) is integrally formed, as crank pin(s).

5. An assembly as claimed in Claim3, wherein the axial shafts are coupled to each other by gear wheels.

6. An assembly as claimed in Claim 3,wherein the axial shafts are coupled to each other by a sprocket chain or a timing belt.

7. An assembly as claimed in Claim 3, wherein the first crank shaft. extends through a slot formed in the wall of the cylinder. extending along a generatrix thereof.

8. An assembly as claimed in Claim Cwherein at least one of the second or third crank pins is partly hollow to serve as a rotary valve for the inlet/outlet of combustible/exhaust gases.

9. An assenbly as clain-ed in Claiin 3 and further corrpris_ing a fourth axial and crank shaft, the first and fourth crank shafts being coupled to the piston at opposite sides thereof externally of the cylinder.

- An assembly as claimed in Claim 9, wherein the said crank shafts are coupled to the piston intermediate a pair of lugs radially projecting therefrom through axial slots formed in the respective locations of the cylinder wall, the first and fourth axi 1. shafts being coupled to each other by an idler gear wheel.

11. An assembly as claimed in Claim 3,wherein the first axial shaft is drivingly coupled to a cam shaft for operating inlet and outlet valves associated with the cylinder.

12, An assembly as claimed in Claim 4, wherein the second and third crank pins comprise an additional oppositely projecting off-center crank shaft, coupled to each other by a tie-rod, the first crank pin being provided with linear a bearing block through which the rod is passed.

13. A reciprocating cylinder and piston assembly substantially as hereinbefore described with reference to and as shown in any one of Figures 1 to 15 of the accompanying drawings.

14. An internal combustion engine or power/work machine incorporating as assembly as claimed in any preceding claim.

Published 1989 atThe Patent Office, State House, 55.71 High Holborn, London WClR4TP. Further copies maybe obtainedfrom The Patentoffice. Sales Branch, St Maz7 Cray, Orpington, Kent BR5 3RD. Printed by Multiplex techniques ltd, St Marv Cray, Kent, Con- 1187