JP2006104996A - Engine power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an efficient engine power transmission device with less vibration as a power source and reduced sliding resistance of a piston caused by side thrust.
A power transmission device that converts a reciprocating motion from an engine (1) having a cylinder (3) and a piston (4) into a rotational motion of a crankshaft (1), one end of which is connected to the piston (4) and the other end is connected. A connecting rod 5 that reciprocates on the center line C of the cylinder 3 together with the piston 4 and a cam mechanism 10 that converts the reciprocating motion of the other end of the connecting rod 5 into a rotational motion and transmits it to the crankshaft 1. It was.
[Selection] Figure 1

Description

  The present invention relates to a power transmission device that transmits driving force from an engine to an output shaft.

  Patent Document 1 discloses a mutual conversion device for reciprocating motion and rotational motion of a piston. The device of Patent Document 1 attempts to prevent unnecessary side thrust other than driving force by providing a lever member between a piston and a rotating shaft and slidably forming a fulcrum and a force point of the lever member.

  However, in the apparatus of Patent Document 1, the support structure for the lever member is complicated, and the lever member is provided in a direction substantially perpendicular to the cylinder axis, so that the apparatus becomes large and requires a large installation space. If such a conversion device is applied between a piston and a crankshaft of a normal engine, a problem occurs in the configuration of the piston and the connecting rod, and it cannot be applied as it is.

  On the other hand, as a conventional engine used in an aircraft such as a helicopter, a star engine as shown in FIG. 18 in which reciprocating engines are arranged radially around a crankshaft is known.

  This is a reciprocating type engine 102 such as a four-cycle engine composed of a cylinder 103 and a piston 104 slidably provided in the cylinder 103 around the crankshaft 101 serving as an output shaft, and arranged radially at equal intervals. It is. The piston 104 and the crankshaft 101 are connected via a connecting rod 105 and a crankrod 106 so that the reciprocating motion of the piston 104 is converted into a rotational motion and the driving force is transmitted to the crankshaft 101. It is configured.

FIG. 19 shows one cylinder portion of this conventional 4-cycle reciprocating engine. As described above, this engine has a structure in which the connecting rod 105 and the crank rod 106 are connected to each other in order to convert the reciprocating motion of the piston 104 moving up and down in the cylinder 103 into the rotational motion of the crankshaft 101. ing. Reference numerals 107 and 108 in the figure indicate a connecting portion (crank pin) between the connecting rod 105 and the crank rod 106 and a connecting portion (piston pin) between the piston 104 and the connecting rod 105, respectively. It is connected freely.

A side thrust of the piston 104 is known as one of the major factors that hinder the output efficiency of the conventional 4-cycle reciprocating engine.

Hereinafter, an enlarged view of the engine 102 is shown in FIG. 20, and the side thrust will be described. Due to the expansion force of the explosion in the cylinder 103, the piston 104 moves upward in the figure with the force f, and tries to rotate the crankshaft 101 via the connecting rod 105 and the crank rod 106. On the other hand, a reaction force indicated by F in the figure acts on the piston 104 from the connecting rod 105. If the angle between the moving direction of the piston 104 and the connecting rod 105 at this time is θ, the vertical reaction force Fcosθ and the lateral reaction force Fsinθ act on the piston 104. This lateral reaction force Fsinθ acts as a side thrust and acts on the inner wall of the cylinder 103 from the piston 104. That is, the side thrust force is a biasing force due to a lateral deflection during the reciprocating motion of the piston 104. Note that the vertical reaction force Fcosθ is substantially equal to f.

When the piston 104 reciprocates along the center line C in the cylinder 103, the side thrust is reciprocated while the connecting rod 105 is inclined with respect to the piston 104 via the piston pin 108, that is, the center of the cylinder. This occurs in order to reciprocate the line C while changing the angle θ with respect to the line C. Therefore, it can be understood that in order to eliminate the side thrust (Fsinθ), it is sufficient to always set θ = 0 during the reciprocating motion of the piston or to apply a force to cancel Fsinθ. That is, in the connecting portion between the connecting rod 105 and the piston 104 (in this example, the piston pin 108), the reaction force acting on the piston 104 from the connecting rod 105 always acts in the direction that coincides with the center line C, and in the lateral direction. If it does not act, side thrust is not generated.

For this purpose, the connecting rod 105 is reciprocated on the center line C with θ = 0 fixed with respect to the piston 104, or another reciprocating motion is performed with respect to the connecting rod 105 while being inclined symmetrically, for example. A connecting rod may be provided to generate a lateral force of −Fsinθ, thereby canceling both side thrust forces.

Even if the connecting rod 105 reciprocates at θ = 0, if a lateral force acts on the tip of the connecting rod 105 as will be described later, a lateral force also acts on the piston 104. The influence on the piston 104 can be eliminated by releasing the lateral force at the tip or receiving it with a separate member.

Thus, in the conventional reciprocating engine, a side thrust is generated between the cylinder 103 and the piston 104, resulting in energy loss. For this reason, countermeasures have been desired from the aspect of fuel consumption.

The influence of this side thrust not only causes energy loss but also causes piston cracking and chipping due to the side contact between the cylinder 103 and the piston 104.

Moreover, in order to improve the airtightness between the cylinder 103 and the piston 104, the function of the piston ring 109 provided in the piston 104 is also affected, and the gas leakage generated from the piston ring 109 cannot be completely sealed. This also hinders energy efficiency.

Furthermore, since the reciprocating motion of the piston 104 of each engine is transmitted to the swinging connecting rod 105, even if the opposing engine 102 is driven in synchronism, the vibration due to the swinging of the connecting rod 105 is seen for each engine. It is difficult to cancel completely.

JP-T 8-510038 Publication

  The present invention has been made in consideration of the above-described prior art, and an object of the present invention is to provide an efficient engine power transmission device that has less vibration as a power source and reduces sliding resistance of a piston caused by side thrust.

In order to achieve the above object, the invention of claim 1 is a power transmission device for converting a reciprocating motion from an engine including a cylinder and a piston sliding in the cylinder into a rotational motion of a crankshaft. A connecting rod whose one end is connected to the piston and whose other end reciprocates on the center line of the cylinder together with the piston, and a cam which converts the reciprocating motion of the other end of the connecting rod into a rotational motion and transmits it to the crankshaft. An engine power transmission device is provided.

The invention of claim 2 is characterized in that, in the invention of claim 1, the cam mechanism is formed by an elliptical cam that is in contact with the other end of the connecting rod and is driven to be pressed from the other end. .

The invention of claim 3 is characterized in that, in the invention of claim 1, the cam mechanism is formed by a cam formed of an elliptical groove portion into which the other end of the connecting rod is fitted.

According to a fourth aspect of the present invention, in the first aspect of the invention, the cam mechanism is formed by a star-shaped cam such as a cross that is in contact with the other end of the connecting rod and is driven to be pressed from the other end. It is characterized by.

The invention of claim 5 is characterized in that, in the invention of claim 1, the cam mechanism is formed by a cam comprising a star-shaped groove portion into which the other end of the connecting rod is fitted.

According to a sixth aspect of the present invention, in the first aspect of the present invention, the cam mechanism includes an extending portion having a groove portion substantially perpendicular to the center line provided at the other end of the connecting rod, and a groove portion of the extending portion. And at least a pair of rotating members that rotate symmetrically with respect to the center line.

The invention of claim 7 is characterized in that, in the inventions of claims 1 to 6, a guide for reciprocating the connecting rod on the center line is provided.

The invention according to claim 8 is an engine power transmission device for converting a reciprocating motion of a piston sliding in a cylinder into a rotational motion of a crankshaft, and having a plurality of connecting rods, one end of which is connected to the piston. The other ends of the plurality of connecting rods are arranged so as to reciprocate while approaching and separating symmetrically with respect to the center line of the cylinder, and engage with the other ends of the connecting rods with respect to the center line. An engine power transmission device comprising a plurality of rotating members that rotate symmetrically is provided.

A ninth aspect of the invention is characterized in that, in the first to eighth aspects of the invention, a pair of engines are arranged opposite to each other on the center line of the piston, and the cam mechanism or the rotating member is arranged between the two engines.

The invention of claim 10 is characterized in that, in the inventions of claims 1 to 9, the cylinders are arranged radially.

According to the first aspect of the present invention, a connecting rod that has one end connected to the piston and reciprocates on the center line of the cylinder along with the reciprocating motion of the piston, and the reciprocating motion of the other end of the connecting rod is converted into a rotational motion. The following effects can be obtained.

1. In the connecting rod, one end and the other end connected to the piston reciprocate on the center line of the cylinder, and the connecting rod does not tilt with respect to the piston. That is, the connecting rod reciprocates with its long axis coinciding with the center line of the cylinder. Therefore, the inclination angle θ with respect to the cylinder center line is zero. Therefore, the above-described side thrust Fsinθ = 0 and no side thrust force is generated. Thus, since it can suppress that a side thrust force acts on a piston, a vibration of an engine can be suppressed.
2. Since side thrust force can be prevented, energy efficiency can be improved and output efficiency can be improved.
3. Since the frictional energy due to the side thrust can be reduced, the rotational resistance of the engine can be kept low even during idling, and fuel consumption can be suppressed.
4). Since the contact between the cylinder and the piston is suppressed, the risk of the piston being cracked or chipped is reduced.
5. Gas leakage generated from the piston ring due to the lateral vibration of the piston can be minimized, and the output efficiency can be further improved.
According to the invention of claim 2, since the cam mechanism is formed by an elliptical cam that is in contact with the other end of the connecting rod that reciprocates on the center line of the cylinder, the reciprocating motion is rotationally moved with a simple structure. Can be converted to

According to the invention of claim 3, since the cam mechanism is formed by, for example, an elliptical groove provided in the disk-like member that fits with the other end of the connecting rod, the cam mechanism is reliably connected with a simple structure. Reciprocating motion can be converted into rotational motion while maintaining This also realizes driving with less vibration in the cam mechanism.

According to the invention of claim 4, since the cam mechanism is formed by a star-shaped cam such as a cross contacting the other end of the connecting rod, a plurality of engines can cooperate with each other with a simple structure and efficiently. A common output shaft can be rotated.

According to the invention of claim 5, since the cam mechanism is formed by a star-shaped groove provided on, for example, a disk-shaped member that fits to the other end of the connecting rod, a plurality of the cam mechanisms can be surely provided with a simple structure. The common output shaft can be efficiently rotated by cooperating the engines.

According to the invention of claim 6, the cam mechanism includes an extending portion having a groove portion substantially orthogonal to the center line at the other end of the connecting rod that reciprocates on the center line of the cylinder. Since it is formed from at least a pair of rotating members that fit into the groove and rotate symmetrically with respect to the center line, it is possible to reciprocate without swinging the connecting rod with a simple structure, and the pair of rotating members Rotation output can be obtained by rotating symmetrically. As a result, driving with less vibration in the cam mechanism can be realized.

According to the invention of claim 7, since the guide comprising a roller for guiding the connecting rod along the center line is provided, for example, a roller, the connecting rod surely reciprocates on the center line and vibrates. Can be prevented.

According to the invention of claim 8, the plurality of connecting rods reciprocate while flattening symmetrically with respect to the cylinder center line (that is, while changing the inclination angle θ in the opposite direction), For example, when looking at a pair of connecting rods, the aforementioned side thrusts Fsinθ and -Fsinθ are generated. For this reason, the side thrusts of both connecting rods cancel each other, thereby preventing lateral deflection.

According to the ninth aspect of the present invention, a pair of engines cooperate with each other to reciprocate the pistons on the cylinder center line, for example, so that both the pistons are arranged between them (Claims 1 to 7). Or a rotating member (Claim 8) can be driven, and a high output can be obtained efficiently.

According to the invention of claim 10, since a plurality of pairs of engines can be arranged radially, a high output can be obtained more efficiently.

A power transmission device to which the present invention is applied and an engine using the same are slidable around a crankshaft, which is an output shaft, as a star engine used in an aircraft such as a helicopter. A four-cycle reciprocating engine consisting of pistons provided in a cylinder is arranged radially, and the piston and crankshaft are connected via a connecting rod and a cam mechanism, so that the reciprocating motion of the piston is rotated. This is converted to transmit the driving force to the crankshaft. Hereinafter, each embodiment will be described in detail with reference to the drawings.
In the following embodiments, the same parts are denoted by the same reference numerals, and redundant description is omitted as much as possible.

(First embodiment)
FIG. 1 is a first embodiment showing a power transmission device 100 to which the present invention is applied. In the first embodiment, the cylinder is a single cylinder.
Reference numeral 1 denotes a crankshaft as an output shaft, and the crankshaft 1 is provided with an elliptical cam 11 having the same rotation center.
Reference numeral 5 denotes a connecting rod, one end of which is provided with a roller 12 provided so as to be in contact with the cam 11 so as to be rotatable, and the other end is integrally connected to the piston 4. In this first embodiment, a cam mechanism 10 is constituted by a cam 11 mounted on the crankshaft 1 and a roller 12 provided at the end of the connecting rod 5.

  Guides 14 made of rollers are provided on both sides of the connecting rod 5 and supported so that the connecting rod 5 does not swing when the piston 4 reciprocates and can move smoothly. With this guide 14, the connecting rod 5 always reciprocates on the center line C without being inclined with respect to the center line C of the cylinder 3 as the piston 4 reciprocates. As a result, lateral vibration associated with the reciprocating motion of the piston 4 is prevented, and side thrust is eliminated.

  In addition, the code | symbol 8 in a figure shows a piston pin, and the code | symbol 9 has shown the piston ring provided in piston 4 in order to improve the airtightness between the cylinder 3 and the piston 4. FIG.

FIG. 2 is an enlarged view of a contact point between the cam 11 and the roller 12 of FIG.
An upward force f is generated in the piston 4 due to the explosion in the cylinder 3. When the force f is transmitted to the cam 11 through the roller 12 provided at one end of the connecting rod 5, the force f is a component force f in the vertical and horizontal directions with respect to the tangential direction as shown in FIG. _1, is divided into _{f 2.} The cam 11 is rotated by this component force f ₁ and converted into a driving force.

On the other hand, a lateral force with respect to the connecting rod 5 is generated by the component force f ₂ , and this lateral force is released by the rotation of the cam 11 and the roller 12. Further, the remaining lateral force is received by the guide 14 and absorbed by the reaction force. Therefore, no lateral vibration is caused to the piston 4.

By adopting the above-described configuration, it is possible to suppress the side thrust force from acting on the piston 4 and to suppress engine vibration.
By preventing the side thrust force in this way, energy efficiency can be improved and output efficiency can be improved.

Further, since frictional energy due to side thrust can be reduced, engine rotation resistance can be kept low, and fuel consumption can be suppressed.
Further, since the contact between the cylinder 3 and the piston 4 is suppressed, the risk of the piston being cracked or chipped is reduced.

Further, gas leakage generated from the piston ring 9 due to the lateral vibration of the piston can be minimized, and the output efficiency can be further improved.
In particular, as described above, since the guides 14 are disposed on both sides of the connecting rod 5, the connecting rod 5 is reliably reciprocated on the center line C of the cylinder without tilting to prevent engine vibration. be able to.

(Second embodiment)
FIG. 3 is a second embodiment showing a power transmission device 200 to which the present invention is applied, and shows a two-cylinder type in which two cylinders 3 are arranged facing each other in the vertical direction as compared with the first embodiment. Yes. By operating the pistons 4 of these two cylinders 3 in synchronism, the same effects as in the first embodiment can be obtained, and a higher output driving force can be obtained.

  Further, as indicated by phantom lines, a higher output driving force can be obtained by using a star engine in which a plurality of cylinders 3 are arranged radially and equidistantly around the crankshaft 1 (cam mechanism 10). It is also possible.

(Third embodiment)
FIG. 4 is a third embodiment showing a power transmission device 300 to which the present invention is applied. In this third embodiment as well, two cylinders 3 are arranged facing each other in the vertical direction in the same manner as the second embodiment. A two-cylinder type is shown.
In this third embodiment, instead of the cam 11 of the first and second embodiments described above, an elliptical groove portion 16 into which a roller 12 provided at the other end of the connecting rod 5 is fitted is used as the cam mechanism 10. The groove cam 15 formed on the shaped member is used.

FIG. 5 shows an enlarged view of the groove cam 15. In FIG. 5, reference numeral 17 denotes a shaft hole into which the crankshaft 1 is inserted, and 16a and 16b denote an outer peripheral wall and an inner peripheral wall of the groove portion 16, respectively. .
According to the configuration of the third embodiment, in addition to the effects of the first and second embodiments described above, the roller 12 at the end of the connecting rod 5 is fitted into the groove portion 16, so that the connecting rod 5 and the groove cam The connection state of 15 is reliably maintained. In addition, the cam mechanism 10 has less vibration and can be driven with less vibration.

Further, since the roller 12 provided at the other end of the connecting rod 5 is fitted in the groove portion 16, the outer peripheral wall 16a and the inner peripheral wall 16b of the groove portion 16 are concentrically similar to each other. Even if the synchronization between the roller 12 and the groove cam 15 is shifted within a slight range, the roller 12 can be held between the outer peripheral wall 16a and the inner peripheral wall 16b of the groove portion 16, so that the roller 12 can be removed from the cam portion. It can be prevented from leaving.

(Fourth embodiment)
FIG. 6 shows a star engine 400 in which the power transmission device 300 of FIG. 4 to which the present invention is applied is arranged radially around the crankshaft 1 (cam mechanism 10) and a plurality of cylinders 3 are arranged at equal intervals. This is an example of four cylinders in which eight cylinders 3 are arranged radially. By operating the pistons 4 of the eight cylinders 3 in synchronism, the same effects as in the third embodiment described above can be obtained, and a higher output driving force can be obtained.

(5th Example)
FIG. 7 shows a power transmission device to which the present invention is applied, and shows a fifth star engine 500 in which six cylinders 3 are arranged radially and equidistantly around the crankshaft 1 (cam mechanism 10). This is an example.

The fifth embodiment is different from the other embodiments described above in that the cam mechanism 10 is formed by a star-shaped cam 18 such as a cross that contacts the roller 12 at the end of the connecting rod 5. .

With such a structure, the same effects as those of the power transmission devices 100 and 200 of the first and second embodiments described above can be obtained, and the shape of the cam 18 (the number of protrusions, the inclination or size of protrusions and depressions) Etc.) according to various conditions, it is possible to efficiently drive the common crankshaft 1 by cooperating a plurality of engines with a simple structure.

FIG. 8 is a diagram showing a combustion cycle of the star engine 500 of FIG. 7. In the star-shaped cam 18, particularly the cross-shaped cam 18 according to the fifth embodiment, A to D and a to The four steps as shown in d are performed twice.

Here, each process of a general 4-cycle engine will be described with reference to FIG.
A, a (intake step): The roller 12 moves from the convex portion of the cam 18 along the concave portion, and the piston moves to the bottom dead center. At this time, an intake valve (not shown) is opened, and mixed air in which fuel and air are mixed is sucked into the cylinder 3 from the intake side.

B, b (compression process): The roller 12 moves from the concave portion of the cam 18 along the convex portion, and the piston moves to the top dead center. As a result, the mixed air in the cylinder 3 is compressed, and when the piston 4 reaches near the top dead center, the mixed air in the cylinder 3 is exploded by being ignited by a spark plug (not shown).

C, c (expansion step): The roller 12 moves from the convex portion of the cam 18 along the concave portion, and the piston moves to the bottom dead center. The cam 18 is rotated via the roller 12 by the explosion energy of the mixed air in the cylinder 3.

D, d (exhaust step): The roller 12 moves from the concave portion of the cam 18 along the convex portion, and the piston moves to the top dead center. At this time, an exhaust valve (not shown) is opened, and exhaust is performed from the exhaust side.

(Sixth embodiment)
FIG. 9 is a power transmission device to which the present invention is applied, and shows a star engine 600 in which six cylinders 3 are arranged radially at equal intervals around the crankshaft 1 (cam mechanism 10). This is an example. In this sixth embodiment, as the cam mechanism 10, a star-shaped groove portion 20 having a star-shaped groove portion 20 having eight projections and depressions fitted to the roller 12 provided at the end portion of the connecting rod 5 is formed in a disk-shaped member. The point using the groove cam 19 is different from the other embodiments described above.

As a result, the same effects as those in the first to fifth embodiments described above can be obtained at the same time, and the common crankshaft 1 can be efficiently rotated by cooperating a plurality of engines with a simple structure. it can.

(Seventh embodiment)
FIG. 10 is a seventh embodiment showing a power transmission device 700 to which the present invention is applied, and is a two-cylinder type in which two cylinders 3 are arranged facing each other in the vertical direction as in the second embodiment.

In the seventh embodiment, the ends of the connecting rod 5 of the opposing engine 2 are integrally coupled via a common extending portion 40 having a groove portion 21 orthogonal to the center line C. In this example, a pair of left and right rotating members 23 having a connecting pin 22 slidably fitted in the groove portion 21 are provided.

When the piston 3 reciprocates, as the connecting rod 5 moves, the pair of rotating members 23 are rotated symmetrically in the direction of the arrow by the connecting pin 22 fitted in the groove 21. At this time, the reciprocating motion of the piston 3 can be converted into the rotational motion by connecting one of the rotation center shafts 24 that rotate integrally with the rotating member 23 to the crankshaft 1.

As a result, the same effects as those of the second embodiment can be obtained, and driving with less vibration can be realized.

(Eighth embodiment)
FIG. 11 is an eighth embodiment showing a star engine 800 in which six cylinders 3 are arranged radially at equal intervals around the crankshaft 1 with respect to the power transmission device 700 of the seventh embodiment. FIG. 12 is a sectional view thereof. However, in the eighth embodiment, the connecting rod 5 having the groove portion 21 of the extending portion 40 is formed in a T shape, and one is provided for each cylinder 3.

In addition, a driving force is not directly obtained from the rotation center shaft 24 that rotates together with the rotation member 23, but a gear is formed on one rotation center shaft 24 and meshed with the rotation center shaft 24 of each cylinder 3. A driving force is taken out by providing a gear 25 and connecting the crankshaft 1 to the center of the connecting gear 25 so as to be integrally rotatable. Reference numeral 26 in FIG. 12 indicates a part of the case connecting these members, and reference numeral 27 indicates a connecting pin that connects the rotating member 23 and the rotation center shaft (gear) 24 to connect to the case 26. Reference numeral 28 denotes a guide for holding the crankshaft 1 in the case 26 in a rotatable manner.

Here, gears are used to further reduce the drive loss. However, the present invention is not limited to this. Needless to say, the present invention can be implemented in place of a power transmission mechanism in a normally conceivable range such as a connecting belt.
As a result, the same effect as in the seventh embodiment can be obtained.

(Ninth embodiment)
FIG. 13 is a ninth embodiment showing a power transmission device 900 to which the present invention is applied. Like the second and sixth embodiments, a two-cylinder type in which two cylinders 3 are arranged facing each other vertically in the figure. It is.

In this example, a pair of connecting rods that are symmetrically inclined with respect to the center line C are connected to each piston in order to cancel the side thrust Fsinθ of FIG. In this example, two cylinders 3 are provided facing each other, but only one single cylinder type may be used.

In the ninth embodiment, each engine 2 is provided with a pair of connecting rods 5 which are connected to the piston 4 at one end via a piston pin 29 and are arranged along the center line C of the cylinder 3. A pair of rotating members 23 are provided between the engines 2 and 2 and connected to the other end of the connecting rod 5 via a connecting pin 22 or the like and rotate symmetrically.

Since the ninth embodiment is a two-cylinder type in which two cylinders 3 are arranged facing each other in the vertical direction in the figure, the connecting rod 5 connected to both pistons 4 is connected to the same rotating member 23.

With this configuration, when the piston 4 reciprocates, the pair of rotating members 23 rotate symmetrically in the direction of the arrow as the connecting rod 5 moves. At this time, the reciprocating motion of the piston 4 can be converted into the rotational motion by connecting one of the rotation center shafts 24 that rotate integrally with the rotating member 23 to the crankshaft 1.

As a result, it is possible to obtain the same effect as in the above-described embodiment, and to realize driving with less vibration.

(Tenth embodiment)
FIG. 14 is a tenth embodiment showing a star engine 1000 in which four cylinders 3 are arranged radially and equidistantly around the crankshaft 1 with respect to the power transmission device 900 of the ninth embodiment. In the tenth embodiment, since the four cylinders 3 are arranged as described above, the connecting rod 5 connected to each piston 4 is connected to the same rotating member 23 as the adjacent engine 2. Yes.

In the tenth embodiment, as in the star engine 800 of the eighth embodiment described above, the driving force is not directly obtained from the rotation center shaft 24 that rotates integrally with the rotation member 23, but one rotation is performed. A gear is formed on the central shaft 24, a connecting gear 25 that meshes with the rotating central shaft 24 of each rotating member 23 is provided, and the crankshaft 1 is connected to the center of the connecting gear 25 so as to be able to rotate integrally. I'm taking it out.
It is to be noted that, in the same manner as in the eighth embodiment, it can be implemented in place of a power transmission mechanism in a normally conceivable range such as a connection belt instead of the connection gear.
As a result, the same effect as in the ninth embodiment can be obtained.

(Eleventh embodiment)
FIG. 15 shows an eleventh embodiment showing a star engine 1100 to which the present invention is applied, and FIG. 16 shows a cross section of the star engine 1100 of the eleventh embodiment. The eleventh embodiment is a four-cylinder type in which four cylinders 3 are arranged radially and equidistantly around the crankshaft 1 as in the tenth embodiment.

The cam mechanism 10 according to the eleventh embodiment is a type in which the two elliptical cams 11 described in the first embodiment are used in a cross shape, and the two cams 11 rotate in opposite directions. It is comprised so that it may do. The cams 11 are engaged via bevel gears 30 and 31. More specifically, a bevel gear 30 is formed on the opposite side surfaces of the cam 11, and the bevel gear 31 is connected to the carrier 32 via a connecting pin 33 and is allowed to rotate and fixed at that position.

Reference numeral 34 in the drawing denotes a rotation center axis of the cam 11, and one of the rotation shafts is coupled to the crankshaft 1 in the eleventh embodiment.

By doing so, the reciprocating motion of the piston 4 is converted into a rotational driving force by the cam 11 as described above. At this time, the bevel gear 31 meshes with both bevel gears 30 on the opposite sides of the cam 11, and the bevel gear 31 is fixed to the carrier 32 via the connecting pin 33. Rotate in the direction. The driving force is transmitted through the crankshaft 1 that is integrally coupled to the rotation center shaft 34 of the one cam 11.

  Accordingly, the same effects as those of the first and second embodiments described above can be obtained, and the driving force of the cams 11 rotating in reverse to each other is connected via the bevel gears 30 and 31, thereby reciprocating motion. Energy can be accurately converted into rotational driving force without loss.

(Twelfth embodiment)
FIG. 17 is a twelfth embodiment showing a star engine 1200 which is a modification of the eleventh embodiment. In the twelfth embodiment, the cam 11 is not elliptical, but the cross-shaped cam 18 described in the fifth embodiment is used, and the effects of both the fifth and eleventh embodiments can be obtained. Is.

  In each of the above-described embodiments, 1, 2, 4, 6, and 8 engines 2 arranged radially around the crankshaft 1 are shown. However, the present invention is not limited to this.

  In addition, although a four-cycle gasoline engine has been illustrated and described as an engine, it goes without saying that the present invention can be applied to a reciprocating engine such as a two-cycle engine or a diesel engine.

  The power transmission device and star engine to which the present invention is applied can be applied to a small aircraft such as a helicopter, and also uses a reciprocating motion of the engine as a rotational driving force, for example, various vehicles such as vehicles, ships, and generators. Available for things.

It is principal part structure explanatory drawing of 1st Example of the power transmission device with which this invention is applied. FIG. 2 is an enlarged explanatory view of a contact point between a cam and a roller in FIG. 1. It is principal part structure explanatory drawing of 2nd Example of the power transmission device with which this invention is applied. It is principal part structure explanatory drawing of 3rd Example of the power transmission device with which this invention is applied. FIG. 10 is an enlarged explanatory view of a groove cam of a third embodiment. It is principal part structure explanatory drawing of 4th Example of the power transmission device with which this invention is applied. It is principal part structure explanatory drawing of 5th Example of the power transmission device with which this invention is applied. It is explanatory drawing of the combustion cycle which concerns on the star type engine of FIG. It is principal part structure explanatory drawing of 6th Example of the power transmission device with which this invention is applied. It is principal part structure explanatory drawing of 7th Example of the power transmission device with which this invention is applied. It is principal part structure explanatory drawing of 8th Example to which this invention is applied. FIG. 12 is a side sectional view of the star engine of FIG. 11. It is principal part structure explanatory drawing of 9th Example of the power transmission device with which this invention is applied. It is principal part structure explanatory drawing of 10th Example to which this invention is applied. It is principal part structure explanatory drawing of 11th Example to which this invention is applied. FIG. 16 is a side sectional view of FIG. 15. It is principal part structure explanatory drawing of 12th Example which is a modification of 11th Example. It is composition explanatory drawing which shows the conventional star type engine. FIG. 19 is a configuration explanatory view showing a cylinder portion of FIG. 18. It is explanatory drawing about the side thrust which expanded a part of FIG.

Explanation of symbols

1: crankshaft, 2: engine, 3: cylinder, 4: piston, 5: connecting rod, 9: piston ring, 10: cam mechanism, 11: cam, 12: roller, 13: connecting pin, 14: guide, 15 : Groove cam, 16: groove portion, 16a: outer peripheral wall, 16b: inner peripheral wall, 17: shaft hole, 18: cross cam, 19: star-shaped groove cam, 20: groove portion, 21: groove portion, 22: connecting pin, 23 : Rotating member, 24: rotating center shaft, 25: connecting gear, 26: case, 27: connecting pin, 28: guide, 29: piston pin, 30, 31: bevel gear, 32: connecting pin, 33: carrier, 34: rotation center axis, 40: extension, 100, 200, 300, 700, 900: power transmission device, 400, 500, 600, 800, 1000, 1100, 1200: star engine.

Claims (10)

A power transmission device for converting a reciprocating motion from an engine having a cylinder and a piston sliding in the cylinder into a rotational motion of a crankshaft,
A connecting rod having one end connected to the piston and the other end reciprocating on the center line of the cylinder together with the piston;
A power transmission device for an engine, comprising: a cam mechanism for converting a reciprocating motion of the other end of the connecting rod into a rotational motion and transmitting the rotational motion to a crankshaft.   2. The power transmission apparatus for an engine according to claim 1, wherein the cam mechanism is formed by an elliptical cam that is in contact with the other end of the connecting rod and is driven to be pressed from the other end.   2. The engine power transmission device according to claim 1, wherein the cam mechanism is formed by a cam including an elliptical groove portion into which the other end of the connecting rod is fitted.   2. The engine power transmission according to claim 1, wherein the cam mechanism is formed by a star-shaped cam such as a cross that is in contact with the other end of the connecting rod and is driven to be pressed from the other end. apparatus.   2. The engine power transmission device according to claim 1, wherein the cam mechanism is formed by a cam including a star-shaped groove portion into which the other end of the connecting rod is fitted. The cam mechanism includes an extending portion having a groove portion substantially perpendicular to the center line provided at the other end of the connecting rod;
2. The engine power transmission device according to claim 1, wherein the engine power transmission device is formed of at least a pair of rotating members that fit into the groove portion of the extending portion and rotate symmetrically with respect to the center line. 3. The engine power transmission device according to any one of claims 1 to 6, further comprising a guide for reciprocating the connecting rod on the center line. A power transmission device for an engine that converts a reciprocating motion of a piston sliding in a cylinder into a rotational motion of a crankshaft,
One end has a plurality of connecting rods connected to the piston, and the other ends of the plurality of connecting rods are arranged to reciprocate while approaching and separating symmetrically with respect to the center line of the cylinder, A power transmission device for an engine, comprising: a plurality of rotating members that engage with the other end of the connecting rod and rotate symmetrically with respect to the center line.   The engine power transmission device according to any one of claims 1 to 8, wherein a pair of engines are arranged opposite to each other on a center line of the piston, and the cam mechanism or the rotating member is arranged between the two engines. The engine power transmission device according to claim 9, wherein the cylinders are arranged radially.

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