GB2038937A

GB2038937A - Reciprocating Piston Engine

Info

Publication number: GB2038937A
Application number: GB7900272A
Authority: GB
Original assignee: SUZUKU K
Current assignee: SUZUKU K
Priority date: 1979-01-04
Filing date: 1979-01-04
Publication date: 1980-07-30

Abstract

In a cylinder 41 a piston 1 is reciprocable and is connected to a transmission member 3 having a circular bore 4, in which a rotary member 11 is rotatably received, the rotary member having an eccentric bore 12 defined therein and a shaft extending through said eccentric bore and having an eccentric 21 integrally formed with the shaft so that the reciprocating movement of the piston is converted into a rotational movement of the shaft 20 through the eccentric bore 12 and eccentric 21. A member 30 is fitted on the shaft 20 and has a surface 31, Fig. 6, which co- operates with a projection 15 on the rotary member 11 to ensure that the rotary member 11 and the shaft 20 rotate in opposite directions. The transmission member 3 may join two pistons 1 and 2 together. <IMAGE>

Description

SPECIFICATION Reciprocal Engine This engine relates to an engine and more particularly, to a reciprocal engine which eliminates the use of the so-called connecting rod.

A variety of gasoline engines have been proposed and practically employed and in any of the prior art gasoline engines, the arrangement is so designed that the piston is moved upwardly and downwardly or vertically in response to the explosion of compressed fuel within the combustion chamber and the reciprocal movement of the piston is transmitted to the crank shaft through the connection rod which connects between the piston and crank shaft to thereby rotate the crank shaft. However, in the prior art gasoline engine of the above type, the engine body is substantially larger in size as compared with the combustion chamber and the prior art engine fails to meet the recent demands for small size, light weight and high output engines.And the prior art gasoline engine of the above type presents the problem that in the operation of the engine, the movement amount of the piston and that of the crank shaft are not equal to each other.

Since the movement amount of the piston and that of the crank shaft are not equal to each other as described hereinabove, in order to solve the problem, in the prior art gasoline engine of the above type, the crank shaft has a large and heavy fly wheel attached thereto to rotate the crank shaft smoothly. However, the attachment of the fly wheel to the crank shaft increases the weight of the crank shaft by the weight of the fly wheel resulting in waste of energy required for rotating the crank shaft. And when the engine is designed as having a plurality of cylinders arranged in the horizon, the cylinders have to be arranged occupying a relatively large floor space so that the cylinders will not interfere with the rotation of the crank shaft.

Therefore, the purpose of the present invention is to provide a novel and improved reciprocal engine which can eliminate the problems inherent in the prior art engine by the arrangement in which the upward and downward reciprocal movement of the piston is converted into a rotational movement of the crank shaft to thereby reduce the size, weight, oscillation and production cost of the engine and yet provide a high output in the engine.

In order to attain the above purpose, according to the present invention, a pair of upper and lower pistons are received within the respectively associated cylinders for upward and downward movement, the pistons are connected together by means of a substantially hollow connection member which defines a circular bore therein, a rotary member having an eccentric bore defined therein is rotatably received in the circular bore in the connection member and a shaft extends through the eccentric bore in the rotary member and has an eccentric wheel integrally formed therewith adjacent to one end of the shaft and rotatably received in the eccentric bore by means of bearings.

According to the present invention, there has been provided a reciprocal engine which comprises a pair of cylinders defined in a single cylinder block, a pair of pistons reciprocally received in the respectively associated cylinders and connected together through a substantially hollow connection member having an outwardly bulged portion provided with a circular bore the center axis of which intersects the center axis of the connection member body and a pair of diametrically opposite slides on the opposite outer surfaces, said pistons and connection member forming a piston unit, a rotary member rotatably received in the circular bore of the connection member through bearings and having an eccentric bore therein and a projection on one side, a shaft extending through the eccentric bore in the rotary member and having an eccentric wheel integrally formed therewith and rotatably received in the eccentric bore through bearings, an annular anti-racing member surrounding the shaft adjacent to the eccentric wheel and having a boss on one side thereof facing the projection on the rotary member, said boss having diametrically opposite upper and lower arcuate faces, said arcuate faces being adapted to engage the projection on the rotary member when the rotary member and shaft rotate in the same direction and are out of engagement with the projection when the rotary member and shaft rotate in the opposite directions, whereby the reciprocal movement of the piston unit is imparted to the shaft as a rotational movement.

The above and other objects and attendant advantages of the present invention will be more readily apparent to those skilled in the art from a reading of the following detailed description in conjunction with the accompanying drawings which show one preferred embodiment of the invention for illustration purpose only, but not for limiting the scope of the same in any way.

Fig. 1 is a fragmentary elevational view in section of the cylinder piston assembly of a preferred embodiment of the improved reciprocal engine constructed in accordance with the present invention; Fig. 2 is an elevational view of the piston unit showing the piston unit in the position turned by 900 from the position of Fig. 1; Fig. 3 is an end elevational view of the rotary member as shown in Fig. 1; Fig. 4 is a crosssectional view taken along substantially the line A-A of Fig. 3; Fig. 5 is a schematic elevational view of the anti-racing member; Fig. 6 is a cross-sectional view taken along substantially along the line B-B of Fig. 5; Fig. 7 is a side elevational view of the shaft as shown in Fig. 1 with a portion thereof broken away;; Fig. 8 is a cross-sectional view taken along substantially the line C-C of Fig. 7; Fig. 9 is a cross-sectional view taken along substantially the line D-D of Fig. 7; Figs. 10, 11, 12 and 13 are cross-sectional views on a reduced scale showing the reciprocal engine of the present invention in different operative positions; and Fig. 14 is an elevational view of a second embodiment of the reciprocal engine of the invention.

The present invention will be now described referring to the accompanying drawings which show one preferred embodiment of the reciprocal engine of the invention for illustration purpose. In Fig. 1, reference numerals 1 and 2 denote a pair of pistons which are integrally connected together in end-to-end relationship by means of a substantially hollow connection member 3 to provide a piston unit 9. The connection member 3 bulges outwardly on the opposite sides to form a hollow cylindrical portion 4 the center axis of which intersects the center axis of the connection member 3 at right angles in a horizontal plane.

The hollow cylindrical portion 4 is reduced in diameter at one end to form a first engaging projection 5 and has on the opposite sides with a pair of diameterically opposite slides 6, 6 for the purpose to be described hereinafter.

Reference numerals 41 and 42 denote a pair of opposite cylinders defined in a cylinder block and the above-mentioned pistons 1 and 2 are reciprocally received in the cylinders 41 and 42, respectively. A piston ring 7 is mounted about the piston 1 and a similar piston ring 8 is mounted about the piston 2. An operation chamber 43 is also defined in the cylinder block 40 between the cylinders 41 and 42 and the inner surfaces of the opposite side walls 44, 44 which define the operation chamber 43 are in slidable contact with the above-mentioned slides 6 and 6 on the connection member 3 so that the piston unit 9 is allowed to slide vertically along the walls 44, 44, but prevented from rocking laterally as the piston unit moves reciprocally.

A cylindrical rotary member 11 is rotatably received in the cylindrical portion 4 in the connection member 3 by means of bearings 50 and provided with an eccentric bore 12 therein. A second engaging portion 13 is integrally formed on one side of the rotary member 11 and extends radially and outwardly from the outer periphery of the rotary member and the eccentric bore 12 is reduced in diameter on the side of the rotary member 11 opposite to the second engaging projection 13 to form a third engaging portion 14.

The first and second engaging portions 5 and 13 cooperate with each other to retain the bearings 50 in position.

A shaft 20 extends through the eccentric bore 12 and has an eccentric wheel 21 integrally formed therewith adjacent to one end of the shaft and rotatably received in the eccentric bore 1 2 through bearings 51. The eccentric wheel 21 has an annular projection or fourth engaging portion 22 extending radially and outwardly of the periphery of the eccentric wheel on one side thereof. As more clearly shown in Fig. 7, the shaft 21 is also formed with a recess 23 on one side thereof (the lower side as seen in Fig. 7) extending along an intermediate portion of the shaft between opposite ends thereof including the eccentric wheel 21. An annular anti-racing member 30 is fitted on the shaft 20 surrounding the portion of the recess 24 except for the portion of the recess 24 defining the under surface of the eccentric wheel 21.The anti-racing member 30 is provided on one side (the right-hand side as seen in Fig. 6) with a boss having upper and lower arcuate surfaces 31, 31. The anti-racing member 30 also has a center through bore 33 by means of which the anti-racing member is fitted on the shaft 20. The third and fourth engaging portions 14 and 22 cooperate with each other to retain the bearings 51.

When the eccentric wheel 21 assumes the intermediate height positions between the highest and lowest positions within the eccentric bore 12 in the rotary member 11 as shown in Figs. 11 and 13, the eccentric wheel 21 and rotary member 11 rotate in the same direction and tend to race. Thus, in order to prevent such racing of the eccentric wheel 21 and rotary member 11, the anti-racing member 30 cooperates with a projection 1 5 threaded in and projecting from the side of the rotary member 11 opposite to the second engaging portion 1 3. That is, when the rotary member 11 and eccentric wheel 21 rotate normally (the rotary member 11 and eccentric wheel 21 rotate in the opposite directions), the projection 1 5 describes the elliptical locus 60 as shown by the two-dot-chain line in Fig. 5.Therefore, as the rotary member 11 rotates so that the projection 1 5 moves describes the elliptical locus 60, the upper and lower arcuate surfaces 31, 31 of the boss on the antiracing member 30'will not contact the projection 1 5 so that the projection 1 5 is allowed to smoothly move describing the elliptical locus. If the rotary member 11 and eccentric wheel 21 race (the rotary member and eccentric wheel rotate in the same direction), the projection 1 5 describes the circular locus as shown by the onedot chain line 61 in Fig. 5. Thus, the projection 1 5 abuts against the upper and lower arcuate surfaces 31, 31 of the anti-racing member boss and the rotary member 11 ceases to move momentarily and thereafter, the rotary member resumes the movement so that the projection 1 5 describes the two-dot chain line locus 60.

In operation, when compressed fuel within the cylinder 41 is exploded by a conventional ignition means (not shown) such as an ignition plug or fuel injection pump (as seen in Fig.10), the piston unit 9 is caused to move downwardly to thereby rotate the rotary member 11 in the counterclockwise direction as seen in Figs. 10 and 11.

The rotation of the rotary member 11 in the counter-clockwise direction rotates the eccentric wheel 21 and accordingly, the shaft 20 integral with the eccentric wheel within the eccentric bore 12 in the rotary member as seen in Figs. 10 and 11. As the upper piston 1 approaches the lower point and the lower piston 2 approaches the upper dead point, that is, the compression stroke approaches the termination (as seen in Fig. 12) whereupon compressed fuel within the cylinder 42 explodes and as a result, the piston unit 9 moves upwardly to impart a rotational movement force to the shaft 20 in the clockwise direction through the eccentric bore 12 in the rotary member 11 and the eccentric wheel 21.In this case, since the slides 6 and 6 on the opposite sides of the connection member 3 slidably move along the inner surfaces of the opposite side walls 44, 44 of the operation chamber 43, the connection member 3 and accordingly the piston unit 9 is prevented from rocking in the lateral direction whereby the transmission of any oscillatory force from the moving piston unit 9 to the shaft 20 is eliminated.

It is essential that when the upper and lower pistons 1 and 2 assume the intermediate positions between the upper and lower dead points as shown in Figs. 11 and 13, the center axis of the rotary member 11 and the center axis of the shaft 20 having the integral eccentric wheel 21 lie in the same horizontal plane.

Assuming that the distance between the upper surface of the fourth engaging portion 22 on the eccentric shaft 21 and the center axis of the shaft 21 is a and the distance between the bottom of the recess 24 in the shaft 21 and the center axis of the shaft 21 is b, respectively, then the stroke of the eccentric wheel 21 can be expressed by (a-b)x2 and therefore, it will be appreciated that the greater the value of (a-b) is, the greater the stroke of the eccentric shaft is.

Fig. 14 shows the second embodiment of the invention and the second embodiment is substantially similar to the first embodiment except for the piston arrangement. The cylinder block has only one cylinder 41 defined therein and a piston 1 is reciprocally received in the cylinder for upward and downward movement and has a movement transmission member 3 connected thereto which has a circular bore 4 defined therein. The construction and arrangement of the parts of the second embodiment are similar to those of the corresponding parts in the first embodiment.

Although the present invention has been described hereinabove in connection with the instance in which the same is applied to a gasoline engine, the invention is also equally applicable to a Diesel engine, a two-cycle engine and a four-cycle engine. And when the upper and lower pistons 1, 2 which are reciprocally received in the cylinders 41,42, respectively, are integrally connected together by means of the connection member 3 to form the integral piston unit 9 as described hereinabove, and as the piston unit moves upwardly and downwardly, the explosion of compressed fuel occurs in the upper and lower cylinders alternately to thereby provide a high engine output.

As mentioned hereinabove, according to the present invention, the upward and downward movement of the piston unit is directly converted into a rotational movement of the shaft through the eccentric bore in the rotary member and the eccentric wheel integral with the shaft, the waste amount of energy is minimized and the entire engine can be manufactured having a small size and as a result, the weight of the engine can be reduced.

While only one specific embodiment of the present invention has been shown and described in detail, it will be understood that the same is for illustration purpose only and not to be taken as a definition of the invention, reference being had for this purpose to the appended claims.

Claims

1. A reciprocal engine comprising at least one cylinder defined in a cylinder block, at least one piston reciprocally received in said cylinder, a movement transmission member connected to said piston for movement together with the piston and having a circular bore defined therein a rotary member rotatably received in said circular bore in the connection member and having an eccentric bore defined therein, and a shaft extending through said eccentric bore in the rotary member and having an eccentric wheel integrally formed adjacent to one end of the shaft and rotatably received in said eccentric bore in the rotary member whereby the reciprocal movement of said piston is transmitted to said shaft as a rotational movement.

2. A reciprocal engine comprising upper and lower cylinders defined in a cylinder block, upper and lower pistons reciprocally received in said upper and lower cylinders for upward and downward movement, respectively and integrally connected together through a substantially hollow connection member having a circular bore defined therein to form a piston unit, a circular rotary member rotatably received in said circular bore in the connection member and having an eccentric bore defined therein, and a shaft extending through said eccentric bore in the rotary member and having an eccentric wheel integrally formed adjacent to one end of the shaft and rotatably received in said eccentric bore in the rotary member whereby the reciprocal movement of said piston unit is transmitted to said shaft as a rotational movement.

3. The reciprocal engine as set forth in Claim 2, in which said rotary member is rotatably received in said circular bore in the hollow connection member through bearings and said eccentric wheel on the shaft is rotatably received in said eccentric bore in the rotary member through bearings.

4. The reciprocal engine as set forth in Claim 2, in which said circular bore is defined by a circular portion formed by outwardly bulging said connection member on the opposite sides and has the center axis intersecting the counter axis of the connection member at right angles in a horizontal plane.

5. The reciprocal engine as set forth in Claim 4, in which said circular portion has a pair of diametrically opposite horizontal slides on the outer surfaces of the opposite side walls thereof so that said piston unit is allowed to slidably move along said cylinder block vertically, but prevented from rocking laterally.

6. The reciprocal engine as set forth in Claim 2, said shaft is provided on the undersurface with a recess in an intermediate portion between the opposite ends including a portion which defines the undersurface of said eccentric wheel, and annular anti-racing member surrounds said recessed intermediate portion of the shaft except for said undersurface of the eccentric wheel and has a boss provided with upper and lower arcuate faces and said rotary member has a projection on the side facing said boss on the anti-racing member whereby when said rotary member and said,shaft rotate in the same direction, said arcuate faces on the boss of the anti-racing member engage the projection to temporally stop the rotation of the rotary member whereas when the rotary member and shaft rotate in the opposite directions, the arcuate faces are out of engagement with the projection to allow the rotary member to continue to rotate.

7. The reciprocal engine set forth in Claim 6, in which when said rotary member and shaft rotate in the same direction, said projection describes a circular locus whereas when the rotary member and shaft rotate in the opposite directions, the projection describes an elliptical locus.

8. A reciprocal engine substantially as herein described with reference to, and as shown in, the accompanying drawings.