Crankless Reciprocating Machine

Abstract

A crankless reciprocating machine which is provided with a mechanism other than a conventional crank mechanism for converting a reciprocating motion into a rotary motion or vice versa. The mechanism comprises at least one pin firmly connected to a piston or pistons so as to be immovable relative thereto and extending radially outwardly therefrom, and an endless cam mounted in a fixed part or a rotating part, said pin and said cam operatively connecting the reciprocating motion of said piston or pistons with the rotary motion of said rotating part.

Parent Case Text

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of application Ser. No. 717,518, filed Apr. 1, 1968, and now abandoned.

Description

BACKGROUND OF THE INVENTION

The present invention relates to reciprocating machines, and in particular to a crankless reciprocating machine which is provided with a novel mechanism for converting a rotary motion into a reciprocating motion or vice versa.

Conventional reciprocating piston machines require a crank mechanism for converting a reciprocating motion into a rotary motion. The crank mechanism has disadvantages in that it entails a serious loss of energy by friction or otherwise, in addition to causing noises and vibrations in operation. Accordingly, there is much to be desired in the operational efficiency of conventional reciprocating machines. Further, the crank mechanism tends to cause the cylinder to be deformed into an egg shape because of wear, resulting in a shorter effective life of the machines themselves.

In the crank mechanism, vibrations may increase as the number of revolution increases. This is due primarily to an imbalance of the structure involving connecting rods and crank arms. A further increase in the number of revolutions may cause the breakage of bolts securing connecting rods and the scattering of balance weights, resulting in a serious damage to the side cover or the frame.

The aforementioned disadvantages of conventional reciprocating piston machines stem from an imbalance in structure inherent in the crank mechanism. Therefore, the aforementioned disadvantages of conventional reciprocating machines can only be obviated to a degree within certain limitations, so long as the conventional crank mechanism is employed.

In conventional internal combustion engines of the reciprocating piston type, thermal efficiency of the engines depends to a great extent on the timed opening and closing of suction or intake valves and discharge or exhaust valves. High precision machining is thus required in producing these valve means. Being exposed to exhaust gases of high temperature, the exhaust valves are particularly liable to be damaged. It is not possible, therefore, to ensure that the valves will function properly over a long period of time in service.

SUMMARY OF THE INVENTION

The present invention obviates all the disadvantages of conventional reciprocating piston machines referred to above. The principal object of the invention is to provide a crankless reciprocating machine provided with a novel mechanism which ensures that a reciprocating motion is converted into a rotary motion and a rotary motion into a reciprocating motion in balanced operation.

Another object is to provide a motion conversion mechanism which comprises at least one pin firmly connected to a piston or pistons so as to be immovable relative thereto and extending radially outwardly therefrom, and an endless cam mounted in a fixed part or a rotating part, said pin and said cam operatively connecting the reciprocating motion of said piston or pistons with the rotary motion of said rotating part.

In one type of embodiments of the present invention, the rotating part comprises a cam means formed with a cam groove on its inner side surface, and a rotary shaft, said rotary shaft being supported by a fixed cylinder in which a piston is reciprocably mounted. In another type of embodiments, the rotating part includes a cylinder means having a piston mounted therein and a rotary shaft or shafts firmly fixed to said cylinder means, said rotary shaft or shafts being supported by a fixed casing which is formed with an endless cam groove on its inner surface.

Other objects and advantages of the invention will become apparent from consideration of the following description when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a longitudinal sectional view of one embodiment of the crankless reciprocating machine according to this invention;

FIG. 2 is a side view of a hollow cylindrical member forming a cam groove;

FIG. 3 is a longitudinal sectional view of a second embodiment of this invention;

FIG. 4 is a transverse sectional view along the line IV-IV of FIG. 6 showing a third embodiment of this invention;

FIG. 5 is a developmental sectional view along the circle a of FIG. 4;

FIG. 6 is a longitudinal sectional view along the line VI-VI of FIG. 4;

FIG. 7 is a sectional view of a fourth embodiment of this invention, and which is a modification of the third embodiment;

FIG. 8 is a longitudinal sectional view of a fifth embodiment of this invention which includes two machines of the third embodiments arranged in back to back relation;

FIG. 9 is a longitudinal sectional view of a sixth embodiment of this invention having a pin extending both inwardly and outwardly in the radial direction;

FIG. 10 is a longitudinal sectional view of a seventh embodiment of the invention constructed as an internal combustion engine;

FIG. 11 is a longitudinal sectional view of an eighth embodiment of this invention in which the cam means and the rotary shaft are connected to each other through a gearing;

FIG. 12 is a perspective view of a cam means formed with a cam for controlling suction and discharge valves on one end surface, and with a gear on the outer circumferential surface;

FIG. 13 is a longitudinal sectional view of a ninth embodiment of this invention in which the rotary shaft extends through a fixed cylinder block;

FIG. 14 is a longitudinal sectional view of a tenth embodiment of this invention in which two pistons are arranged in face to face relation;

FIG. 15 is a longitudinal sectional view of an eleventh embodiment of this invention;

FIG. 16 is a sectional view showing a buffer device disposed between the pin and antifriction means;

FIG. 17 a to f are developmental views in explanation of various forms of cam grooves;

FIG. 18 is a longitudinal sectional view of a twelfth embodiment of this invention;

FIG. 19 is a longitudinal sectional view of a thirteenth embodiment of this invention;

FIG. 20 is a longitudinal sectional view of a fourteenth embodiment of this invention constructed as a rotary pump;

FIG. 21 is a sectional view along the line XXI-XXI of FIG. 20;

FIG. 22 is a longitudinal sectional view of a fifteenth embodiment of this invention; and

FIG. 23 is a longitudinal sectional view of a sixteenth embodiment of this invention.

The invention will now be explained in detail with reference to a first to an eleventh embodiments illustrated in FIGS. 1 to 17, each of which has a rotating part comprising a cam means and a rotary shaft, said rotary shaft being supported by a fixed cylinder.

In FIG. 1, a piston 3 secured to one end of a piston rod 4 is mounted in a cylinder 2 of a fixed cylinder block 21 in such a manner that said piston is slidable in said cylinder but restrained against rotation relative to the cylinder. Secured to the other end of the piston rod 4 for slidable movement in the cylinder 2 like the piston 3 is a pin mounting portion 7 to which is secured a pin 8 extending radially outwardly and adapted for converting a reciprocating motion into a rotary motion or vice versa. A cam means 20 mounted concentrically with the cylinder 2 is secured to a rotary shaft 1 and immovable relative to said rotary shaft. The cam means encloses that portion of the cylinder 2 in which said pin 8 operates. The rotary shaft 1 is rotatably mounted on the cylinder block 21 through bearing 17. The cam means 20 comprises two hollow cam members 6 and 6' which form a cam groove 18 on the inner surface of the cam means. The pin 8 extends through a slot formed in the cylinder block 21, and its outer end is loosely fitted in said cam groove 18.

The cam groove 18 forms a closed or endless curve on the inner surface of the cam means 20. The cam means 20 is constructed such that the piston 3 makes at least one reciprocating motion for each complete revolution of the cam means.

The cam members 6 and 6' are hollow cylindrical members each having a curved end, and the curved ends of the two hollow cylindrical cam members 6 and 6' are complementary to each other as shown in FIG. 2. The two cam members 6 and 6' disposed as shown in FIG. 2 are fitted in the cam means 20 in such a manner that the two members are spaced apart a predetermined distance from each other so as to provide the cam groove 18 of desired width.

When energy is supplied to an operation chamber 19 defined by the cylinder 2 and the piston 3 of the machine shown in FIG. 1, the piston moves in reciprocating motion. The movement of the piston 3 causes the pin mounting portion 7 to move in reciprocating motion in the cylinder, so that the pin 8 received in the cam groove 18 also moves axially of the piston. This forces the cam means 20 and the rotary shaft to rotate. Conversely, when the cam means 20 is rotated through the rotary shaft 1 by some external force, the cam groove 18 rotates, and the pin 8 received in the cam groove 18 causes the pin mounting portion 7, and hence the cylinder 3, to move in the cylinder 2 in reciprocating motion, whereby the volume of the operating chamber 19 can be varied.

It will be evident that when the machine is used as an internal combustion engine or an expansion engine the rotary shaft 1 serves as an output shaft, but when the machine is used as a pump or a compressor the rotary shaft 1 serves as an input shaft.

The machine illustrated in FIG. 1 can be constructed such that a plurality of cylinders are disposed in the machine. One example of such construction is shown in FIG. 3 as a second embodiment of the invention. In the figure, two piston rods 4 each having a piston 3 connected to one end are connected at the other end to a common pin mounting portion 7, with the pistons 3 facing opposite directions. Two units of this piston-pin mounting portion combination are mounted coaxially in a fixed cylinder block 21. In the embodiment illustrated, the cylinder 2 is in the form of an elongated cylinder in the cylinder block, with the two piston-pin mounting portion combinations forming a common operating chamber therebetween. Cam means 20 corresponding in number to the piston-pin mounting portion combination units are mounted concentrically in the cylinder 2 for rotation. Each cam means 20 is formed with a gear 22 on its outer circumferential surface, said gear 22 being in meshing engagement with a gear 23 secured to the rotary shaft 1. Accordingly, the reciprocating motion of the pistons 3 causes the cam means 20 to move in rotary motion through the pin 8 received in the cam groove, and the rotary motion of the cam means causes in turn the rotary shaft 1 to rotate through the gears 22 and 23 in meshing engagement with each other. It will be evident from the figure that the two units of piston-pin mounting portion combination form a mirror image with respect to the central transverse section of the cylinder block 21. It is to be understood that the number of the aforementioned units arranged coaxially in the cylinder is not limited to two as shown, and that the number of units that can be mounted is indefinite theoretically.

It will be evident that the aforementioned units of piston-pin mounting portion combination can be mounted not only coaxially but also parallel to and circumaxially about the axis of the rotary shaft 1. A plurality of the machines shown in FIG. 1 can be arranged circumaxially about the axis of the rotary shaft 1 and parallel thereto. This arrangement is shown in FIGS. 4 to 6. The machine shown in these figures comprises six cylinders 2 mounted circumaxially about the rotary shaft 1 and parallel thereto. The cam means 20 is formed with a cam groove 18 which receives therein all the pins 8 each of which is mounted on the pin mounting portion 7 of each unit of piston-pin mounting portion combination and extends radially outwardly. In this arrangement, the cylinders 2 need not be disposed circumaxially about the rotary shaft on one circle; they may be arranged such that they are disposed on a plurality of concentric circles as shown in FIG. 7. In this case, units of piston-pin mounting portion combination disposed on different circles may conveniently be combined with each other and the pin mounting portions of these units may be fixedly connected together, so that the pin of the unit disposed on the circle of the largest diameter can extend radially to be received in the cam groove. It will be evident that the units of piston-pin mounting portion combination having their pin mounting portions fixedly connected together can move as a unit in reciprocating motion.

FIG. 8 shows a machine which comprises two sets of the machine of FIG. 6 arranged in end to end relation with respect to the end plate of the cam means 20 which is formed integrally. In this construction, the pistons are arranged symmetrically with respect to the cam means 20. If two cam grooves 18 are formed symmetrically with respect to the center face of the cam means 20, the pistons 3 will move symmetrically with respect to the center face of the cam means. A fully balanced construction can thus be obtained in a reciprocating machine.

The machine shown in FIG. 9 has a boss 24 enclosing the rotary shaft 1. The boss 24 is formed with a cam groove 15 in the form of a closed or endless curve on its outer circumferential surface. The pin 8 extends not only radially outwardly to be loosely fitted in the cam groove 18, but also through the pin mounting portion 7 and radially inwardly to be loosely fitted in the cam groove 15. Like the cam groove 18, the cam groove 15 is formed by arranging the curved ends of two hollow cylindrical members 5 and 5' in spaced relation from each other.

The cam grooves 15 and 18 are constructed in such a manner that each pin 8 is maintained normal to the axis of the piston at all times when the pistons move in reciprocating motion. The machine illustrated in FIG. 9 has antifriction means, such as roller bearings, for example, attached to the portion of the pin 8 which extends through the slot 16, so that the thrust created when the pin 8 moves along the curved surfaces of the cam grooves 15 and 18 can be borne by said antifriction means.

Each of the pins 8 of the machine shown in FIG. 9 has two ends received in the cam grooves 15 and 18 respectively and supported therein. This arrangement permits no couple of forces or bending force to be applied to the pistons 3, so that the pistons can be restrained against scratching the inner surface of the cylinder. Since the force applied by the piston 3 is divided and directed to the opposite ends of the pin 8, each end of the pin 8 carries substantially half the force applied to one end of the pin when only one end of the pin is received in the cam groove. This is one advantage offered by the invention in designing machines of this type.

A device is known in which a piston has a pin projecting therefrom and received in a groove formed in a cylinder whereby the piston can move in rotary motion in the cylinder as the former moves in reciprocating motion in the latter. In this known device, the piston and the cylinder move in rotary motion besides moving in reciprocating sliding motion relative to each other. This makes it impossible to provide an effective seal to the machine even if a piston ring is used. However, since the piston and the cylinder do not move in rotary motion relative to each other in the machine constructed according to this invention, the machine can be sealed as effectively as if the piston ring were used in the crank mechanism. Moreover, an added advantage of the machine provided by this invention lies in the fact that it is free from an imbalance in operation occurring in motion conversion which has plagued the machine relying on the conventional crank mechanism.

FIG. 10 shows a seventh embodiment of this invention in which the crankless reciprocating machine is constructed as an internal combustion engine. This machine has a fixed cylinder block, so that it is possible to incorporate most of the elements of a conventional internal combustion engine in the machine without any modification.

In FIG. 10, each of the pistons 3 is mounted in one of the cylinders 2 formed in the cylinder block 21 secured to an outer casing 13 and immovable relative thereto. Each piston 3 has a pin 8 secured thereto and extending radially therefrom, the end of each pin 8 being received, through a double antifriction means 9, the cam groove 18 formed on the inner surface of the cam means 20.

The cam means 20 is secured to the rotary shaft 1 through a flange 12, the cam means 20 and the rotary shaft 1 rotating as a unit. The rotary shaft 1 is not journaled directly by the cylinder block 21; the rotary shaft 1 is supported by a shaft 14 secured to the cylinder block 21 through a bearing 28 mounted in the flange 12. The cam means 20 is rotatably supported by the outer casing 13 through roller bearings 17. Each pin 8 is received in the cam groove 18 through an antifriction means or roller bearing 9 mounted on its outer end far from the piston 3. It will be evident that all the forces applied to the pistons 3 are carried by the pins 8, and that the forces acting on the pistons in the axial direction can effectively be converted into a turning force operating along the cam groove 18. The larger the distance between the cam groove and the axis of rotation of the rotating part, the larger will be the moment of rotation of said turning force. In other words, the force carried by the cam groove and pins will be reduced per unit area. This offers an advantage in designing the machine. Preferably, the antifriction means may have a largest possible diameter. It will be evident that the larger the diameter of the antifriction means, the lower is the number of revolutions of the antifriction means about the pin 8.

Mounted on the end surface of the cam means 20 opposite to the end surface on which the rotary shaft 1 is connected are cam means 10 and 11 which are formed with cam faces 29 and 30 respectively (FIG. 12). The fixed cylinder block 21 is formed with tappets 34 and 35 which are disposed such that they are positioned on the paths of cam faces 10 and 11 respectively. The tappets actuate oscillating arms 62 and 53 through push rods 37 and 38 respectively, thereby opening and closing suction and discharge valves 26. 36 designates ignition plugs and 25 is a cylinder head in which a suction and discharge duct is formed.

The cam groove of the embodiment shown in FIG. 10 is in the form of a curve shown in FIG. 17b. FIG. 10 is a view in section showing the machine in two planes normal to each other and taken through the center axis of the machine.

The eighth embodiment shown in FIG. 11 represents a development of the second embodiment shown in FIG. 3. The cylinder block 21 is formed with a plurality of cylinders 2 extending therethrough in each of which are mounted two pistons 3 secured to opposite ends of a piston rod 4. Formed in the center portion of each piston rod 4 is a pin mounting portion 7 from which a pin 8 extends radially outwardly. The end of each pin 8 is received, through a double antifriction means 9, in the cam groove 18 formed in the cam means 20 as is the case with the embodiment shown in FIG. 10. In the embodiment of FIG. 11, each cylinder 2 is provided with a suction and discharge valve 26 and an ignition plug 36, the valves and plugs being disposed on opposite end surfaces of the cylinder block 21.

The cam means 20 is provided with a gear 22 on its outer circumferential surface which is in meshing engagement with a gear 23 keyed to the rotary shaft 1 rotatably journaled by the fixed cylinder block 21. As is the case with the embodiment shown in FIG. 3, the reciprocating motion of the pistons 3 is converted into the rotary motion of the cam means 20 through the pin-cam arrangement, which is converted in turn into the rotary motion of the rotary shaft 1 through the gearing, thereby developing power.

This embodiment is provided with ignition plugs 36 as aforementioned. It is readily apparent that if the engine is provided with ejection pumps and nozzles the engine can be made to operate in a diesel cycle. The cam groove of the embodiment of FIG. 11 is in the form of a curve shown in FIG. 17b. FIG. 11 is a view in section showing the machine in two planes normal to each other and taken through the center axis of the machine.

FIG. 12 shows the cam portions 10 and 11 and their respective cam faces 29 and 30. These cam portions 10 and 11 are disposed on the opposite end surfaces of the cam means 20 of FIG. 11. The gear 22 is mounted on the outer circumferential surface of the cam means 20.

The ninth embodiment shown in FIG. 13 is a modification of the embodiment shown in FIG. 10, in which the rotary shaft 1 extends through the fixed cylinder block 21. The mechanism for operating the valves, pistons, cam means and cam groove of this embodiment are identical with those of the embodiment shown in FIG. 10, except for the fact that the cam means 20 is not journaled by an outer casing but is connected to the rotary shaft 1 and immovable relative thereto, said rotary shaft 1 being rotatably supported by the cylinder block 21 through bearings 17. This arrangement is advantageous when the machine is rotated at a high speed, for the peripheral speed of the cam means will be greatly increased as the rate of revolution of the machine is increased, making it difficult to support the cam means on its outer surface. The bearings 17 are preferably provided with thrust bearing surfaces 31.

The tenth embodiment shown in FIG. 14 has two pistons 3 disposed in face to face relation in a single cylinder 2. The two pistons in one cylinder have a stroke which is twice as great as the stroke of a single piston, and the space between the two pistons changes its volume at a rate twice as high as the rate at which the space would change its volume if only one piston were used. This permits to achieve a high resistance to heat in operation. Cam means 20 are rotatably mounted within the cylinder block 21 in its opposite end portions. Each cam means 20 is formed with a cam groove 18 on its inner surface. Opposite ends of the pins 8 extending radially outwardly from the pin mounting portion 7 which, being connected to pistons 3 and piston rods 4 and immovable relative thereto, is in the form of sliding blocks 40, are received in cam grooves 18 through antifriction means 9. Each cam means 20 has mounted on its outer circumferential surface a gear 22 which is in meshing engagement with a gear 23 keyed to the rotary shaft 1.

Said sliding block 40 is slidably mounted within a bush 39 connected to the cylinder block 21 and immovable relative thereto. The bush 39 is formed with a slot 16 through which the opposite ends of the pin 8 extend.

From the foregoing description and the disclosure in the figure, it will be understood that each pin is received and supported in a cam groove 18 at its opposite ends. The cam grooves 18 of the machine shown in FIG. 14 are in the form of a curve shown in FIG. 17b. Although the machine is thus provided with a cam groove for a 4-cycle operation, the machine is so constructed that two explosions occur during one rotation of the rotary shaft 1, and suction and discharge valves are also constructed for a 2-cycle operation. Accordingly, the machine can develop a higher output than machines of the same volume. As is evident from the foregoing description, the bush 39 and the sliding block 40 do not move in rotary motion relative to each other but move in sliding motion relative to each other. The pin 8 has mounted on its ends roller bearings 9 as are the case with the embodiments shown in FIGS. 10, 11 and 13. A bearing 41 for supporting the piston rod 4 is mounted on the inner end of the bush 39.

Each bush 39 and said sliding block 40 serve as a cylinder and a piston in a way and constitute a means for supplying an air-fuel mixture to the cylinder 2. The bearing 41 is formed with a duct 44 therethrough, in which is mounted a valve 43 under the influence of a spring 48. Said spring normally urges the valve 43 to close the duct 44. When the pressure in an operation chamber III is increased and the pressure in a chamber II in the cylinder 2 becomes negative, the valve 43 is opened so as to deliver an air-fuel mixture from chamber III to chamber II. The sliding block 40 is provided with a valve 42 and a spring 49 which act as a check means. Said check means operates in such a manner that an air-fuel mixture is supplied into the operation chamber III from outside when the pressure in said chamber is negative, and when the pressure in said chamber is increased as a result of the sliding movement of the sliding block 40, the valve is closed so as to prevent the air-fuel in the operation chamber III from flowing backwardly. The sliding block 40 is formed with a main duct 51 for air-fuel mixture supply and a branch duct 50 branching off from said main duct to open in the operation chamber III and having said valve 42 mounted therein.

The air-fuel mixture in the operation chamber III begins to be compressed when the slot 16 is completely closed and sealed by the sliding block 40. The volume in the operation chamber III is larger than that in the operation chamber 1 in the cylinder, so that a sufficiently large quantity of air-fuel mixture can be supplied to the chamber III.

As the pistons 3 move outwardly in sliding motion as illustrated and discharge ports 32 are opened in an explosion stroke, exhausts are vented through said ports 32. Suction ports 47 are also opened, permitting the compressed air-fuel mixture in the chambers II to flow into the chamber I through passages 45 and 46 and said suction ports 47. The valve 43 for each passage 44 remains closed. 31 designates air supply lines.

FIG. 15 shows an embodiment which combines the fifth embodiment shown in FIG. 8 with the sixth embodiment shown in FIG. 9 and functions as an internal combustion engine. In the present embodiment, the dam means 20 having the shape shown in FIG. 5 is provided with a boss 24, through which the rotary shaft 1 extends and is immovable relative thereto. The rotary shaft is rotatably mounted on the cylinder block 21 through the bearings 17. The cam grooves 18 formed by the hollow cylindrical members 6 and 6' are disposed on the inner surface of the boss 24 of the cam means 20, while the cam grooves 15 formed by the hollow cylindrical members 5 and 5' are disposed on the outer surface of the boss 24. Each pin 8 extending through each piston 3 and projecting radially outwardly and inwardly has opposite ends which are received in the cam grooves 18 and 15 respectively through an antifriction means 9. The cam grooves 18 and 15 are disposed relative to each other in such a manner that the pin 8 having its opposite ends received in said cam grooves is correctly disposed radially. Each pin 8 is provided with antifriction means 25 at the portion where the pin 8 extends through the slot 16, in order to carry the thrust applied to the pin when the reciprocating motion of the piston is converted into the rotary motion of the cam means 20. The forces required for the conversion of motion are distributed to the opposite ends of the pin, thereby reducing the forces applied to each end of the pin and the side surfaces of the cam grooves. This arrangement is very advantageous in designing the machine.

In the present embodiment, the cam portions 10 and 11 for controlling the suction and discharge valves 26 are disposed on the end surfaces of the hollow cylindrical members 5' which is disposed over the boss 4 in enclosing relation. The cam means which constitutes the rotating part is rotatably supported by the rotary shaft 1, so that the construction lends itself to high speed rotation.

In the embodiments shown in FIGS. 10, 11, 13 and 15, the antifriction means mounted at opposite ends of the pin 8 are in the form of double roller bearings. This arrangement permits to withstand a heavy load, and at the same time to distribute speed to the two roller bearings and reduce the relative speed of the outer ring and the inner ring of each roller bearing when the machine rotates at high speed.

A buffer means for absorbing shock may be mounted between the pin and the antifriction means, in order to reduce the shock to which the pin 8 is subjected. This buffer means may be one which relies on oil or is formed of rubber. The embodiment shown in FIG. 16 relies on oil. As shown, the pin 8 has at its end a grooved disc 54 in which is fitted an outer disc 55 split into two portions and having projections positioned against the grooves of the disc 54. Positioned between the grooves of the disc 54 and the projections of the outer disc 55 is a space 56 in which oil is sealed. In this case, the shock applied by the antifriction means is not transmitted directly to the pin but attenuated by the oil in the space 56, thereby preventing damage to the pin 8. 57 designates 0 rings for preventing the leak of oil.

It should be noted that the cam groove 18 of the crankless reciprocating machine according to this invention may vary its shape and configuration depending on whether the machine is used for a 2-cycle operation or a 4-cycle operation. Since the surface of the cam means which is large in area can be used to accommodate the cam groove, it is possible to provide for not only a 2-cycle or 4-cycle operation as aforementioned but also a 6-cycle operation when required. In machines of this type, it has hitherto been customary that the piston can make only one reciprocating motion during one rotational motion. The present invention permits the piston to make one to three reciprocating motions or more during one rotational motion, thereby increasing the output accordingly. FIG. 17 is a developmental view showing the shape and configurations of the cam groove 18 for each application. In the figure, the piston 3, piston rod 4, pin 8, antifriction means 9 and cam groove 18 are shown schematically. FIG. 17a shows the cam groove for a 2-cycle operation used with a compressible fluid. FIGS. 17b and 17c are the cam grooves for 4-cycle operation and a 6-cycle operation respectively. When an internal combustion engine is operated at high speed, the cooling poses an important problem. The cam groove for the cycle provided with a cooling stroke is shown in FIG. 17d. In this case, the cooling cycle is provided in order to directly remove heat from the surfaces of piston and cylinder by drawing air by suction and discharging same as well as to completely scavenge the cylinder. The piston need not cover the whole stroke distance in the cooling stroke; the usual practice is for the piston to move in reciprocating motion only a part of the stroke distance as shown in FIG. 17d. It is thus one of the advantages of the present invention that the piston can be arranged to move in reciprocating motion through a part of the stroke distance when required.

The aforementioned feature of the present invention makes this crankless reciprocating machine useful as an expansion machine. When an expansible material is caused to operate in the operation chamber to provide a turning force, it is desirable that the expansion stroke of the piston be lengthened. It is thus advantageous to arrange that an angle of rotation of 180.degree. is used as an expansion stroke and the remaining angle of 180.degree. is used for exhaust, suction and compression strokes. The cam groove suitable for use with this application is shown in FIG. 17e.

The cam groove for a two cycle operation using a noncompressible fluid is shown in FIG. 17f.

From the foregoing description, it will be appreciated that the crankless reciprocating machine according to this invention can be adapted for all types of operation in which the length of effective stroke of the piston and the time interval required for the piston to cover the stroke distance can be varied as desired. Specifically, the machine can be constructed in such a manner that the piston moves in quick feed and slow return or stops for a predetermined time interval.

Now the embodiments of this invention will be described with reference to FIGS. 18 to 22 in which the rotating part includes a cylinder means having a piston mounted therein and a rotary shaft or shafts firmly fixed to said cylinder means, and an endless cam groove is formed on the inner side surface of a fixed casing.

In FIG. 18, rotary shafts 61 concentric with each other are connected to opposite ends of a cylinder means 80 and immovable relative to each other. These parts which constitute the rotating part are rotatably mounted in a fixed casing 81 by bearings 77 which support said rotary shafts 61. A cylinder 62 is formed in the cylinder means 80. Slidably mounted in said cylinder 62 is a piston 63 to which a piston rod 64 is secured at one end. The piston rod 64 is firmly connected at the other end to a pin mounting portion 67 slidable in the cylinder 62 together with the piston 63 as a unit and mounting a motion conversion pin 68 projecting radially outwardly of the cylinder. The pin 68 extends through a slot 76 formed in the cylinder means 80, and the outer end of the pin 68 is received and moveable in a cam groove 78 formed by two cam members 66 and 66' disposed on the inner surface of the fixed casing. Said cam groove is in the form of a closed curve on the inner surface of the fixed casing, and the piston 63 makes at least one reciprocating motion while the cylinder means 80 makes one complete revolution.

The cam members 66 and 66' are hollow cylindrical members each having a curved end as is the case with the cam members 6 and 6' of FIG. 2. At least one of the rotary shafts 61 aligned axially and immovable relative to each other extends through one of the end walls of the fixed casing 81 and functions as an output shaft when the machine is used as an internal combustion engine or an expansion engine. It functions as an input shaft when the machine is used as a pump or a compressor.

In the machine illustrated in FIG. 18, when the piston 63 is moved in reciprocating motion by the energy supplied to the operation chamber 79 defined by the cylinder 62 and piston 63, the pin mounting portion 67 also moves in reciprocating motion in the cylinder 62 because of its connection with the piston through the piston rod 64. This forces the pin 68 to move along the cam groove 78. The movement of pin 68 in turn causes the piston 63 and cylinder means 80 and hence the rotary shafts 61 to rotate. Conversely, when the cylinder means 80 is caused to rotate by a force applied from outside to the rotary shafts 61, the pin 68 will move along the cam groove 78, resulting in the pin mounting portion 67 and piston rod 64 forcing the piston 63 to move in reciprocating motion in the cylinder 62 to thereby vary the volume of the operation chamber 79.

The machine shown in FIG. 18 can be arranged such that multiple cylinders may be mounted. One example of this adaptation is shown in FIG. 19 as a thirteenth embodiment of the invention. In FIG. 19, two pistons 63, and 63 each connected to one end of each of the piston rods 64 and 64 which are connected at the other end to opposite sides of a common pin mounting portion 67, are disposed in back to back relation and form a unit. Two units are illustrated as being mounted coaxially in the cylinder means 80. The cylinders 62 are in the form of an elongated cylinder in the cylinder means, two pistons in the center and the cylinder wall defining a common operation chamber. Two cam grooves 78 and 78 are formed on the inner surface of the fixed casing 81. As can be seen from the figure, the two units form a mirror image with respect to the center transverse section of the cylinder means 80. It is to be understood that the invention is not limited to the number and the arrangement of units described and illustrated herein, and that the number of units that can be arranged in the cylinder is infinite theoretically as is the case with the second embodiment illustrated in FIG. 3.

It is also to be understood that the multiple units of cylinders can be arranged not only coaxially as shown in FIG. 19 but parallel to and circumaxially about the axis of the rotary shaft like the third embodiment shown in FIGS. 4, 5 and 6 and on a plurality of concentric circles as shown in FIG. 7.

The fourteenth embodiment shown in FIG. 20 is constructed as a rotary pump. The cylinder means 80 including cylinders 62 arranged parallel to and circumaxially about the axis of the rotary shaft 61, spacer collar 82, piston rod rest 74, spacer ring 83 and bearing disc 72 are all keyed to the rotary shaft 61 for rotation therewith as a unit. The bearing disc 72 is rotatably supported by the fixed casing 81 through a thrust bearing 84, and formed with bearing openings 73 each for supporting a piston rod at one end. Each piston rod 64 is supported at the other end by one of the bearing members 65 each constituting the bottom of a cylinder 62. The bearing members 65 also serve to center the pistons 63 with respect to the cylinders 62. Formed substantially in the center portion of each piston rod 64 is the pin mounting portion 67 through which a pin 68 extends radially outwardly and inwardly. The pin 68 has a radial outer end which is received in the cam groove 78 through an antifriction means 69 in the form of a roller bearing. Forces acting on the piston 63 will be concentrated on the pin 68. It will be evident that by providing the pin with the antifriction means as aforementioned, forces acting on the piston rods in the axial direction can effectively be converted into forces acting on the pin to urge the same to rotate along the cam groove.

The piston rest 74 is formed with a slot 76 disposed axially of the piston rod 64 for receiving therein the inner end portion of the pin 68 extending radially inwardly. The slot 76 serves to guide said inner end portion of the pin 68 which moves in reciprocating motion with the piston 63 as a unit. The outer surface of the piston rest 74 in the vicinity of the slot 76 serves to support the smooth surface of the pin mounting portion 67 and prevent the axial deflection of the piston rod 64. The inner surface of the piston rest 74 in the vicinity of the slot 76 serves to support a slider means 75 mounted on the inner end of the pin 68. The slider means 75 is supported by an antifriction means consisting of four rollers 70, for example, on four points on said inner end of the pin (See FIG. 21). This arrangement ensures that the pin 68 is supported in such a manner that it is positively and precisely aligned axially at all times. It will readily be apparent that it is significant to maintain the pin in a position in which it is positively aligned axially at all times, because the antifriction means 69 will tend to slip out of the cam groove 78 unless the pin 68 is positively aligned axially.

The cam groove 78 is generally inclined relative to the direction of reciprocating motion of the piston rod 64. The provision of said slider means 75 is conducive to preventing the deflection of the piston rod 64 caused by the arrangement set forth hereinabove and the deflection of the piston rod 64 caused by centrifugal forces applied thereto as the number of revolution of the machine increases. The cam groove 78 will tend to apply to the pin a force directed axially of the piston rod 64. This force acts at the same time to cause the pin 68 to rotate parallel to the plane of the figure about the pin mounting portion 67. The provision of the slider means 75 is also conducive to preventing this action. The frictional dragging of the piston rod 64 on the piston rod rest 74 can be reduced by the rollers 70 of the slider means 75.

In FIG. 20, the fixed casing 81 is provided with a front cover 93 which is fixed thereto, said cover 93 being formed with a suction port 91 and a discharge port 93. In this case, the cam groove is in the form of a curve of FIG. 17f for a two cycle operation. The distance between the suction port 91 and the discharge port 92 should be selected such that the spacing is larger than the diameter of the cylinder 62 in order to prevent said two ports from being short-circuited through one of the cylinders 62 when said particular cylinder is released from indexing with the suction port and moved to be indexed with the discharge port. Since the cylinder 62 is sealed completely by the front cover between said two ports, it is advantageous to suspend the operation of the pistons in this transition period, because the machine handles a noncompressible fluid in such a case. According to this invention, this end can be attained readily by selecting the curve of the cam groove in such a manner that the portion in the curve corresponding to the suspension of the operation of piston is disposed at right angles to the axis of the piston rod. In conventional mechanisms, it is impossible to stop the compression operation of pistons at this time, so that damage to the machine has often resulted. It is common practice to provide a relief valve whereby a fluid under high pressure is directed to either of the ports in order to prevent damage. The disadvantage of this arrangement is that there is a limit to the high pressure that can be obtained because of this relief action.

The advantages of the crankless reciprocating machine according to this invention can be summarized as follows:

1. The invention permits the machine to mount multiple cylinders arranged either coaxially or circumaxially about the axis of the machine, thereby increasing the output or the capacity of the machine;

2. The arrangement that the rotating part is balanced in construction and operation permits the machine to be rotated at a high speed, no damage occuring due to the imbalance of the rotating part during a high speed rotation;

3. The invention permits to provide an airtight seal to the operation chamber or chambers which can vary in volume, because there is less likelihood of gas leak than in conventional machines of the same type;

4. The invention permits the machine to operate in two or more cycles as desired during one revolution by properly selecting the shape of the cam groove; and

5. The invention provides latitude in selecting the ratio of one stroke to another during one cycle of operation.

Claims

What I claim is:

1. A crankless reciprocating machine comprising, in combination, a fixed cylinder; at least one piston reciprocal in said fixed cylinder; rotatable means, including at least one substantially cylindrical cam means and a rotary shaft, journaled for rotation about an axis, each cam means being formed with an endless cam groove in its radially inner surface; at least one pin fixed to and extending radially outwardly from each piston and engaged in a cam groove in a cam means to interconnect each piston and the rotatable means for rotation of said rotatable means upon reciprocation of each piston and reciprocation of each piston upon rotation of said rotatable means; and pin supporting and guiding means interiorly of said cam means and providing for axial movement of each pin while preventing rotation of the connected piston; said machine including a plurality of working chambers each defined by a cylinder and a piston, extending parallel to the axis of said cam means shaft and arranged circumferentially about the axis of said rotary shaft; the axis of rotation of said cam means differing from the axis of rotation of said rotary shaft; and gear means interconnecting the axis of said rotary shaft and the axis of said cam means for conjoint rotation.

2. A crankless reciprocating machine, as claimed in claim 1, including a plurality of variable volume working chambers arranged axially of said fixed cylinder and each defined by the cylinder and a piston.

3. A crankless reciprocating machine, as claimed in claim 1, including a plurality of variable volume working chambers, each defined by a cylinder and a piston, said working chambers being arranged circumferentially about the axis of said shaft.

4. A crankless reciprocating machine, as claimed in claim 3, in which said working chambers are arranged on plural concentric circles concentric with the axis of said shaft.

5. A crankless reciprocating machine, as claimed in claim 1, in which the radially outer end of each pin carries an antifriction means engaged in the cam groove.

6. A crankless reciprocating machine, as claimed in claim 5, including buffer means between each pin and the associated antifriction means.

7. A crankless reciprocating machine, as claimed in claim 5, in which said pin supporting and guiding means comprises a slot in said fixed cylinder and extending parallel to the axis thereof.

8. A crankless reciprocating machine, as claimed in claim 1, wherein each endless cam groove is contoured so that the associated respective piston performs one complete reciprocation during each complete revolution of said rotating part.

9. A crankless reciprocating machine, as claimed in claim 1, in which each endless cam groove is so contoured that the associated piston performs plural complete reciprocations during the time said rotating part makes one complete revolution.

10. A crankless reciprocating machine, as claimed in claim 1, wherein said endless cam groove is contoured so that the distance covered per unit of time by said piston varies in each stroke.

11. A crankless reciprocating machine, as claimed in claim 1, including two pistons positioned in said fixed cylinder in facing relation to form an opposed piston means.

12. A crankless reciprocating machine comprising, in combination, a fixed cylinder; at least one piston reciprocal in said fixed cylinder; a rotatable part including at least one substantially cylindrical cam means and a rotary shaft journaled by said fixed cylinder, each cam means being formed with an endless cam groove in its radially inner surface; at least one pin fixed to and extending diametrically through the associated piston and having opposite ends received in respective cam grooves to interconnect each piston and the rotatable part for rotation of said rotatable part upon reciprocation of each piston and reciprocation of each piston upon rotation of said rotatable part; and pin supporting and guiding means interiorly of said cam means and providing for axial movement of each pin while preventing rotation of the connected piston; said machine including a plurality of working chambers, each defined by a cylinder and a piston, extending parallel to the axis of said cam means and arranged circumferentially about the axis of said rotary shaft.

13. A crankless reciprocating machine, as claimed in claim 12, including a plurality of variable volume working chambers arranged axially of said fixed cylinder and each defined by the cylinder and a piston.

14. A crankless reciprocating machine, as claimed in claim 12, including a plurality of variable volume working chambers.

15. A crankless reciprocating machine, as claimed in claim 12, in which the radially outer end of each pin carries an antifriction means engaged in the cam groove.

16. A crankless reciprocating machine, as claimed in claim 15, including buffer means between each pin and the associated antifriction means.

17. A crankless reciprocating machine, as claimed in claim 12, in which said pin supporting and guiding means comprises a slot in said fixed cylinder and extending parallel to the axis thereof.

18. A crankless reciprocating machine, as claimed in claim 12, wherein each endless cam groove is contoured so that the associated respective piston performs one complete reciprocation during each complete revolution of said rotating part.

19. A crankless reciprocating machine, as claimed in claim 12, in which each endless cam groove is so contoured that the associated piston performs plural complete reciprocations during the time said rotating part makes one complete revolution.

20. A crankless reciprocating machine, as claimed in claim 12, wherein said endless cam groove is contoured so that the distance covered per unit of time by said piston varies in each stroke.

21. A crankless reciprocating machine, as claimed in claim 12, including two pistons positioned in said fixed cylinder in facing relation to form an opposed piston means.