JP7658568B2 - Rotational motion to reciprocating motion converter - Google Patents

Description

The present invention relates to a rotary motion reciprocating motion conversion device that is suitable for use mainly in external combustion engines such as steam engines and Stirling engines, compressors, etc., and converts rotary motion into reciprocating motion in both directions.

Patent Document 1 describes a rotary motion reciprocating motion conversion device that connects a rotary shaft that performs rotary motion to multiple reciprocating members (pistons) that perform linear reciprocating motion via a Z-shaped shaft section (Z crankshaft) and a swinging arm, and can convert the rotary motion of the rotary shaft and the reciprocating motion of the reciprocating members in both directions. In this rotary motion reciprocating motion conversion device, a Z-shaped shaft section (Z crankshaft) consisting of an inclined shaft section and a connecting shaft section is connected to the rotary shaft, multiple swinging arms are protruded from the inclined member provided on the inclined shaft section, and the tip of each swinging arm is connected to the reciprocating movement connecting member (piston rod) of the reciprocating movement member so that it can perform rotary grinding motion. However, this rotary motion reciprocating motion conversion device has a problem that durability and conversion efficiency are reduced because sliding friction occurs at the connecting section between the tip of the swinging arm and the reciprocating movement connecting member.

Patent document 2 describes a rotary motion/reciprocating motion conversion device in which an inclined side connecting member is provided on a swing arm, a reciprocating side connecting member is provided on a reciprocating movement connecting member (piston rod), the inclined side connecting member and the reciprocating side connecting member are connected via an eccentric shaft, and the rotary grinding motion of the inclined side connecting member and the reciprocating side connecting member are converted in both directions.

In both the rotary motion to reciprocating motion conversion devices in Patent Document 1 and Patent Document 2, the tip of the oscillating arm performs a rotary grinding motion (figure-eight motion), which makes the connection with the reciprocating side connecting member complicated.

Figure 7 shows a two-cylinder steam engine 100 with a conventional Z-crankshaft. This two-cylinder steam engine 100 is equipped with a first cylinder 101a and a second cylinder 101b, a swing arm 104 that connects a piston rod 103a connected to a piston 102a of the first cylinder 101a and a piston rod 103b connected to a piston 102b of the second cylinder 101b, an output shaft 105, and a Z-crank member 106 that connects the swing arm 104 and the output shaft 105. The Z-crank member 106 is composed of a tilting member 106a through which the swing arm 104 is inserted, a first connecting member 1066b that connects one end of the tilting member 106a to the output shaft 105, and a second connecting member 106c that is connected to the other end of the tilting member 106a.

In the two-cylinder steam engine 100 of FIG. 7, the pistons 102a, 102b of the first cylinder 101a and the second cylinder 101b reciprocate, and the swing arm 104 performs a reciprocating arc motion, causing the inclined member 106a of the Z-crank member 106 to perform a grinding motion. In order to prevent the first cylinder 101a and the second cylinder 101b from rotating together with the grinding motion of the inclined member 106a of the Z-crank member 106, a vertical member 107 is fixed in the middle of the swing arm 104 in a direction perpendicular to the swing arm 104. Both ends of the vertical member 107 are rotatably connected to the frame 108 of the two-cylinder steam engine 100.

In the two-cylinder steam engine of Figure 7, a hole 109 must be formed in the outer surface of the tilting member 106a through which the vertical member 107 passes, so that the tilting member 106a can perform a figure-of-eight motion. In addition, the vertical member 107 must be attached to the swinging arm 104 through this hole 109 within the narrow interior of the tilting member 106a, which creates the problem of difficult assembly.

Japanese Patent Application Publication No. 11-343923 JP 2010-96140 A

The present invention was made in consideration of the above-mentioned problems with the conventional technology, and aims to provide a rotary motion to reciprocating motion conversion device that simplifies the support structure of the oscillating member, is easy to install, and allows smooth reciprocating arc motion at both ends of the oscillating member.

The inventors noticed that the Z-crank member that performs the miso grinding motion has a part that performs a figure-of-eight motion and a part that performs a reciprocating circular arc motion, and discovered that the support structure for the oscillating member can be simplified by restricting the rotational motion of both ends of the oscillating member in the part that performs the reciprocating circular arc motion.

That is, the present invention is
At least two reciprocating members that perform reciprocating motion;
A rotary motion member that performs a rotary motion;
a swinging member connecting the two reciprocating members;
a Z-crank member connecting the oscillating member and the rotary motion member, the Z-crank member being configured to convert the rotary motion of the rotary motion member and the reciprocating motion of the reciprocating motion member in both directions,
The present invention is characterized in that restraining members are provided at both ends of the oscillating member, which performs reciprocating arcuate motion parallel to the direction of reciprocating motion of the reciprocating member, to allow movement in a direction parallel to the plane of the reciprocating arcuate motion and to restrain movement in a direction perpendicular to the plane of the reciprocating arcuate motion.

It is preferable that the reciprocating member is a piston rod connected to a piston that slides inside a cylinder, the rotating member is a rotating shaft, and the oscillating member is a oscillating arm that connects the piston rod.

The Z crank member is
an inclined member through which the swing member is inserted;
a first connecting member that connects one end of the inclined member and the rotational motion member;
A second connecting member connected to the other end of the inclined member;
It is preferably composed of

As an embodiment of the restraining member,
A pin is inserted through holes at both ends of the swing member;
a bearing mounted on the pin;
two clamping members connected to the reciprocating member for clamping the bearing in a reciprocating direction of the reciprocating member;
two support members connected to the two clamping members and supporting the swinging member in the axial direction of the pin via the bearing;
It is preferable that the actuator further comprises a slide member attached to the support member and slidable in the reciprocating direction of the reciprocating member relative to a rail provided on a frame supporting the reciprocating member and the rotational member.

As another embodiment of the restraining member,
The restraining member includes an arm.
One end of the arm is rotatably connected to both ends of the swinging member,
It is preferable that the other end of the arm is rotatably connected to a frame supporting the reciprocating member and the rotary member, on an axis that passes through the center of the oscillating member and is perpendicular to the plane of the reciprocating arcuate motion.

According to the present invention, both ends of the oscillating member, which performs a reciprocating arc motion parallel to the direction of the reciprocating motion of the reciprocating member, are permitted to move in a direction parallel to the plane of the reciprocating arc motion by the restraining member, and movement in a direction perpendicular to the plane of the reciprocating arc motion is restrained. As a result, it is no longer necessary to attach a vertical member to the middle of the oscillating member inside the narrow interior of the inclined member of the Z-crank member, or to form a hole to prevent interference with the vertical member due to the figure-of-eight motion of the inclined member, as in the conventional method. It is only necessary to attach the restraining members to both ends of the oscillating member, which simplifies the support structure of the oscillating member, makes installation easy, and has the effect of allowing the reciprocating arc motion of both ends of the oscillating member to be performed smoothly.

1 is a partial cross-sectional plan view of a steam engine equipped with a rotary motion reciprocating motion conversion device according to a first embodiment of the present invention, when a piston is at top dead center or bottom dead center. FIG. 2 is a partial sectional plan view of the steam engine of FIG. 1 with the piston at its midpoint; FIG. 3 is a front view of the connection between the piston rod and the swing arm of the steam engine in the state shown in FIG. 2 . 4 is an enlarged cross-sectional view of the Z crank member and a view taken in the directions of arrows A and B. FIG. FIG. 6A is a plan view showing a swing arm and a Z crank member of a device for converting rotary motion into reciprocating motion according to a second embodiment of the present invention, and FIG. 6B is a cross-sectional view taken along line CC. 1A is a partial cross-sectional plan view of a steam engine equipped with a conventional device for converting rotary motion into reciprocating motion, and FIG. 1B is a front view thereof.

An embodiment of the present invention will be described below with reference to the attached drawings.

Figures 1, 2, and 3 show a four-cylinder steam engine 1 equipped with a rotary motion to reciprocating motion conversion device according to the first embodiment of the present invention. This steam engine 1 comprises a main body frame 2, first to fourth cylinders 5 (5a, 5b, 5c, 5d) each having a piston 3 (3a, 3b, 3c, 3d) and a piston rod 4 (4a, 4b, 4c, 4d), a rotating shaft 6, a swinging arm 7, a Z-crank member 8, and two restraining members 9a, 9b. In the following explanation, the direction of reciprocating motion of the piston 3 in the cylinder 5 is referred to as the X direction, the horizontal direction perpendicular to the X direction is referred to as the Y direction, and the vertical direction perpendicular to the X direction is referred to as the Z direction.

The main frame 2 includes a first support plate 2a, a second support plate 2b, and a third support plate 2c arranged at a predetermined interval in the X direction, a connecting rod 2d connecting the first support plate 2a and the second support plate 2b, and a connecting rod 2e connecting the first support plate 2a and the third support plate 2c.

Of the four cylinders 5, the first cylinder 5a and the second cylinder 5b are arranged opposite each other in the X direction, and the third cylinder 5c and the fourth cylinder 5d are arranged away from the first cylinder 5a and the second cylinder 5b in the Y direction and opposite each other in the X direction. The first cylinder 5a and the third cylinder 5c are supported by the first support plate 2a, and the second cylinder 5b and the fourth cylinder 5d are supported by the second support plate 2b. The piston rod 4a of the first cylinder 5a and the piston rod 4b of the second cylinder 5b are connected to each other by the first restraining member 9a, and similarly, the piston rod 4c of the third cylinder 5c and the piston rod 4d of the fourth cylinder 5d are connected to each other by the second restraining member 9b. The piston rod 4 of each cylinder 5 is a reciprocating member that performs reciprocating motion in the present invention.

The rotating shaft 6 is rotatably supported by the third support plate 2c via a bearing 6a between the first cylinder 5a and the third cylinder 5c. One end of the rotating shaft 6 is attached to an output wheel 6b, and the other end is connected to a first connecting member 11 of the Z-crank member 8, which will be described later. The rotating shaft 6 is a rotary motion member that performs the rotary motion of the present invention.

As shown in FIG. 4, the swing arm 7 penetrates the tilt member 10 of the Z-crank member 8 and is rotatably mounted relative to the tilt member 10, with both ends protruding from the tilt member 10 and having holes 7a formed therein. As shown in FIG. 1, one end of the swing arm 7 is connected to the piston rod 4a of the first cylinder 5a and the piston rod 4b of the second cylinder 5b via the first restraining member 9a, and the other end of the swing arm 7 is connected to the piston rod 4c of the third cylinder 5c and the piston rod 4d of the fourth cylinder 5d via the second restraining member 9b.

As shown in FIG. 4, the Z-crank member 8 is composed of an inclined member 10, a first connecting member 11, and a second connecting member 12.

The tilting member 10 has a tilting axis s tilted with respect to the X direction, a first hole 0a is formed at one end on the tilting axis s, a second hole 10b is formed at the other end on the tilting axis s, and a through hole 10c is formed in the center in a direction perpendicular to the tilting axis s. A first mounting base 13 having an engaging protrusion 13a is rotatably attached to the first hole 10a by a bearing 13b. A second mounting base 14 having an engaging protrusion 14a is rotatably attached to the second hole 10b by a bearing 14b. A swing arm 7 passes through the through hole 10c and is rotatably attached by a bearing 7b.

The first connecting member 11 has an engaging recess 11a that engages with an engaging protrusion 13a of the first mounting base 13, and has a mounting portion 11b that is attached to the first mounting base 13 with a screw 15, a shaft portion 11c that is coaxial with the rotating shaft 6, and a connecting portion 11d that connects the mounting portion 11b and the shaft portion 11c. The shaft portion 11c of the first connecting member 11 is rotatably attached to the first support plate 2a via a bearing 11e, and is fixed to the end of the rotating shaft 6 opposite the output wheel 6b.

Similarly, the second connecting member 12 has an engaging recess 12a that engages with an engaging protrusion 14a of the second mounting base 14, and has a mounting portion 12b that is attached to the second mounting base 14 by a screw 16, a shaft portion 12c that is coaxial with the rotating shaft 6, and a connecting portion 12d that connects the mounting portion 12b and the shaft portion 12c. The shaft portion 12c of the second connecting member 12 is rotatably attached to the second support plate 2b via a bearing 12f.

Since the two restraining members 9a, 9b have the same structure, the restraining member 9a shown in Figure 5 will be described. The restraining member 9a is composed of a pin 17, a bearing 18, two clamping members 19, two support members 20, and two slide members 21.

The pin 17 is inserted into holes 7a at both ends of the swing arm 7, with both ends protruding in the Z direction and anti-Z direction.

Two bearings 18 are attached to the upper and lower ends of the pin 17, and are appropriately secured in place with retaining rings or the like.

The two clamping members 19 are rectangular plates and are attached by screws 23 to mounting plates 22 provided at the tips of the piston rods 4a, 4b. The two clamping members 19 are spaced apart by the same distance as the diameter of the bearing 18, and as shown in Fig. 3, clamp the bearing 18 from the X direction and guide it in the Y direction when the swing arm 7 swings. A notch 19a extending in the Y direction is formed on the opposing surfaces of the two clamping members 19, and a part of the swing arm 9 fits into the notch 19a when the swing arm 7 swings, preventing the swing arm 7 from interfering with the clamping members 19.

The two support members 20 are attached by screws 24 so as to connect the upper and lower ends of the two clamping members 19. This allows the piston rod 4a of the first cylinder 5a and the piston rod 4b of the second cylinder 5b to move integrally in the X direction, as shown in Fig. 3. In addition, both ends of the swing arm 7 are supported in the Y direction between the two support members 20 via bearings 18.

The two slide members 21 are composed of a rail 21a attached to a support beam 2f that is provided between the first support plate 2a and the second support plate 2b of the main frame 2 so as to extend in the X direction, and a slider 21b that can slide on the rail 21a. The slider 21b is fixed to the two support members 20.

Next, we will explain the operation of a four-cylinder steam engine 1 equipped with a rotary motion to reciprocating motion conversion device according to an embodiment of the present invention.

As shown in FIG. 1, when the steam engine 1 starts, the piston 3a of the first cylinder 5a moves toward the bottom dead center, the piston 3b of the second cylinder 5b facing the first cylinder 5a is at the bottom dead center, the piston 3c of the third cylinder 5c is at the bottom dead center, and the piston 3d of the fourth cylinder 5d facing the third cylinder 5c is at the top dead center. The piston 3a of the first cylinder 5a moves toward the bottom dead center, the piston 3b of the second cylinder 5b moves toward the top dead center, the piston 3c of the third cylinder 5c moves toward the top dead center, and the piston 3d of the fourth cylinder 5d moves toward the bottom dead center.

Due to the movement of the piston 3 of each cylinder 5, the piston rods 4a, 4b of the first cylinder 5a and the second cylinder 5b move in the counter-X direction, and the piston rods 4c, 4d of the third cylinder 5c and the fourth cylinder 5d move in the counter-X direction. At this time, the bearing 18 of the first restraining member 9a is pressed in the X direction by the clamping member 19, and the bearing 18 of the second restraining member 9b is pressed in the X direction by the clamping member 19, so that the swing arm 7 swings clockwise via the pin 17 from the state shown in FIG. 1 to the state shown in FIG. 2.

When the swing arm 7 swings, both ends of the swing arm 7 perform a reciprocating arc motion, and the inclined member 10 of the Z-crank member 8 performs a miso grinding motion. This causes the first connecting member 11 and the second connecting member 12 of the Z-crank member 8 to rotate, and a rotational force is transmitted from the first connecting member 11 to the rotating shaft 6, causing the rotating shaft 6 to perform a rotational motion.

While both ends of the oscillating arm 7 perform a reciprocating arc motion and the inclined member 10 of the Z-crank member 8 performs a grinding motion, the first restraining member 9a and the second restraining member 9b allow both ends of the oscillating arm 7 to move in the Y and X directions parallel to the plane of the reciprocating arc motion, and restrict movement in the Z direction perpendicular to the plane of the reciprocating arc motion.

In addition, a rotational force acts on the swing arm 7 as a reaction to the rotational motion of the first connecting member 11, the second connecting member 12, and the rotating shaft 6 of the Z-crank member 8. As shown in FIG. 3, this rotational force is transmitted to the support beam 2f of the main frame 2 via the bearings 18, the support member 20, and the slide member 21 of the first restraining member 9a and the second restraining member 9b, so that the cylinder 5 is prevented from rotating together with the rotating shaft 6.

In this embodiment, since the Z-crank member 8 does not have a vertical member as in the past, it is no longer necessary to attach a vertical member to the middle of the swing arm 7 inside the narrow interior of the inclined member 10 of the Z-crank member 8, or to form a hole to prevent interference with the vertical member due to the figure-of-eight movement of the inclined member 10, as in the past. Instead, it is sufficient to attach the first restraining member 9a and the second restraining member 9b to both ends of the swing arm 7, which simplifies the support structure of the swing arm 7 and simplifies installation. In addition, both ends of the swing arm 7 are allowed to move in the Y and X directions parallel to the plane of the reciprocating arc motion, so that the reciprocating arc motion of both ends of the swing arm 7 can be performed smoothly.

In the above embodiment, the restraining members 9a, 9b are provided at both ends of the swing arm 7, at the connection between the swing arm 7 and the piston rod 4, but the restraining members may be provided on the inside or outside of the connection between the swing arm 7 and the piston rod 4.

Figure 6 shows a restraining member consisting of a curved arm 25 provided inside the connection part between the swing arm 7 and the piston rod 4. One end of the curved arm 25 is rotatably connected between the connection part between the swing arm 7 and the piston rod 4 and the tilting member 10 of the Z-crank member 8 via a bearing 26, and the other end of the curved arm 25 is rotatably connected via a bearing 28 to an axis 27 provided on the support beam 2f on the Z-axis passing through the center of the swing arm 7. The middle of the curved arm 25 is outside the trajectory plane drawn by the outer shape of the tilting member 10 performing the miso grinding motion, so as not to interfere with the tilting member 10. In this embodiment, both ends of the swing arm 7 are allowed to move in the Y and X directions parallel to the plane of the reciprocating arc motion by the curved arm 25, and are restrained from moving in the Z direction perpendicular to the plane of the reciprocating arc motion. The curved arm 25 can also be connected outside the connection part between the swing arm 7 and the piston rod 4.

The present invention is not limited to the above-described embodiment, and modifications and variations can be made without departing from the spirit and scope of the invention as defined in the claims.
For example, by making the inclined member 10 of the Z-crank member 8 a hollow sphere made up of a combination of hemispheres, as shown by the two-dot chain line in Figure 6, mass balance is achieved around the rotation axis 6, making the miso grinding motion smoother.

The rotary motion to reciprocating motion conversion device in the above embodiment is adapted to a horizontally opposed four-cylinder engine, but can also be applied to a two-cylinder engine.

In addition, while the rotary motion to reciprocating motion converter in the above embodiment converts the reciprocating motion of a piston and piston rod of a cylinder into the rotary motion of a rotating shaft, it can also be applied to a compressor that converts the rotation of a rotating shaft of a motor or turbine into the reciprocating motion of a piston and piston rod of a cylinder.

1... Steam engine 2... Main body frame 3... Piston 4... Piston rod (reciprocating member)
5... Cylinder 6... Rotating shaft (rotary motion member)
7... Swing arm (swing member)
Reference Signs List 8: Z-crank member 9a, 9b: Restraint member 10: Inclined member 11: First connecting member 12: Second connecting member 13: First mounting base 14: Second mounting base 15: Screw 16: Screw 17: Pin 18: Bearing 19: Clamping member 20: Support member 21: Slide member 22: Mounting plate 23: Screw 24: Screw 25: Curved arm (restraint member)
26 ... bearing 27 ... shaft portion 28 ... bearing

Claims (4)

At least two reciprocating members that perform reciprocating motion;
A rotary motion member that performs a rotary motion;
a swinging member connecting the two reciprocating members;
a Z-crank member connecting the oscillating member and the rotary motion member, the Z-crank member being configured to convert the rotary motion of the rotary motion member and the reciprocating motion of the reciprocating motion member in both directions,
a restraining member is provided at both ends of the oscillating member which performs a reciprocating arc motion parallel to the direction of the reciprocating motion of the reciprocating member, the restraining member allowing movement in a direction parallel to the plane of the reciprocating arc motion and restraining movement in a direction perpendicular to the plane of the reciprocating arc motion ;
The restraining member is
A pin is inserted through holes at both ends of the swing member;
a bearing mounted on the pin;
two clamping members connected to the reciprocating member for clamping the bearing in a reciprocating direction of the reciprocating member;
two support members connected to the two clamping members and supporting the swinging member in the axial direction of the pin via the bearing;
a slide member attached to the support member and slidable in the reciprocating direction of the reciprocating member relative to a rail provided on a frame supporting the reciprocating member and the rotational motion member . At least two reciprocating members that perform reciprocating motion;
A rotary motion member that performs a rotary motion;
a swinging member connecting the two reciprocating members;
a Z-crank member connecting the oscillating member and the rotary motion member, the Z-crank member being configured to convert the rotary motion of the rotary motion member and the reciprocating motion of the reciprocating motion member in both directions,
a restraining member is provided at both ends of the oscillating member which performs a reciprocating arc motion parallel to the direction of the reciprocating motion of the reciprocating member, the restraining member allowing movement in a direction parallel to the plane of the reciprocating arc motion and restraining movement in a direction perpendicular to the plane of the reciprocating arc motion ;
The restraining member includes an arm.
One end of the arm is rotatably connected to both ends of the swinging member,
a rotational motion to reciprocating motion conversion device, characterized in that the other end of the arm is on an axis that passes through the center of the oscillating member and is perpendicular to the plane of the reciprocating arc motion, and is rotatably connected to a frame that supports the reciprocating motion member and the rotational motion member. 3. The device for converting rotary motion into reciprocating motion as described in claim 1 or 2, characterized in that the reciprocating member is a piston rod connected to a piston that slides inside a cylinder, the rotary motion member is a rotating shaft, and the oscillating member is a oscillating arm that connects the piston rod. The Z crank member is
an inclined member through which the swing member is inserted;
a first connecting member that connects one end of the inclined member and the rotational motion member;
4. The device for converting rotary motion into reciprocating motion according to claim 1, further comprising: a second connecting member connected to the other end of the inclined member.

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