JPH03140659A - Rotational motion-reciprocative motion converter - Google Patents

Abstract

PURPOSE:To improve compression ratio, pressure-feed efficiency or the like in a compressor, a pump and so on by constituting an eccentric cam with a shaft attached after shifting its phase, a link slid on this eccentric cam and pivoted free of slide motion and an output rod pivoted on this rod. CONSTITUTION:When a shaft 3 is rotated by a motor 7, eccentric cams 2a, 2b are eccentrically rotated in a state that their turning phase has shifted, acting on a sliding part of a link 5 and thereby rocking this link 5 within a flat surface, thus an output rod 6 pivotally supported on the link 5 reciprocates. A pivot 28 of this output rod 6 comes to reciprocate on a circular arc in consequence but the output rod 6 with a spacer 30 comes to be reciprocated almost vertically. With this constitution, a clearance between an outer edge of the spacer 30 and an inner edge of a bellows 31 can be narrowed, thus the compression ratio can be improved. In addition, any fluid will not be left behind in this portion so that fluid pollution can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a device for converting rotational motion into reciprocating motion;
The present invention relates to a rotational motion to reciprocating motion conversion device that is preferably applied to a driving part of a pump or compressor.

Technical Background of the Invention A bellows pump using bellows is known, for example, from Japanese Patent Application Laid-open No. 47
This is already known from Publication No. 40.208.

The driving parts of this bellows pump are shown below. Fourth
As shown in FIG.
A convex portion 54 is formed at a position eccentric with respect to the base plate. The base of a rod 56 is fitted into this convex portion 54 via a bearing 55, and as a result, as shown in FIG. It is now possible to do this.

A bellows receiver 72 and a spacer 57 are fixed to the tip of the rod 56 by bolts 58, and the lower end of a sealing bellows 59 made of an annular diaphragm is joined to the outer periphery of the bellows receiver 72. On the other hand, bellows 59
The upper end portion of the bellows 59 is joined to a valve receiver 62 in which a suction opening 60 and a discharge opening 61' are opened at a position communicating with the inside (compression chamber) of the bellows 59. The valve receiver 62 is attached to a casing 63 in which a swinging chamber 70 for accommodating the rod 56, the spacer 57, and the bell 59 is formed. The spacer 57 is an annular bellows 59
When the rod 56 is at the top dead center of the eccentric reciprocating motion, it almost contacts the valve receiver 62, thereby causing the bellows 5
The fluid introduced into the compression chamber 9 can be efficiently discharged.

A recess 64 is formed in the center of the valve receiver 62, in which a valve 67 consisting of two gaskets 66 and 66 sandwiching a metal plate 65 is accommodated, and the valve retainer 6
It is fixed at 8. The metal plate 65 and two gaskets 66 and 66 of this valve 67 are provided with through holes that communicate with the suction opening 60 and the discharge opening 61, respectively, and the two through holes formed in the metal plate 65 are A check valve (not shown) is attached to each. As a result, the fluid introduced from the suction opening 60 backflows from the suction opening,
Further, the fluid discharged from the discharge opening 61 is prevented from flowing back from the discharge opening.

Further, the valve holder 68 is also formed with a through hole that communicates with the suction opening 60 and the discharge opening 61, respectively.

With this configuration, when the motor is driven, the base of the rod makes an eccentric movement, and as a result, the spacer attached to the tip of the rod makes a swinging reciprocating movement. Then, when the spacer moves from the top dead center to the bottom dead center, fluid is sucked into the bellows from the suction port, and then when the spacer moves from the bottom dead center to the top dead center, this sucked fluid is transferred to the discharge port. By repeating this process, the air pressure in the space connected to the suction port can be reduced.

However, in the vacuum pump using the bellows mentioned above, since the spacer performs reciprocating motion while swinging due to the swinging reciprocating motion of the rod, a certain amount of clearance is secured between the outer edge of the spacer protrusion and the inner edge of the bellows. This has the disadvantage that this portion becomes a dead space, making it difficult to improve the compression ratio or the ultimate degree of vacuum. Furthermore, if a gap is provided between the outer edge of the protrusion of the spacer and the inner edge of the bellows, there is a risk that fluid will accumulate in this area and the fluid will be contaminated.

Furthermore, since the output shaft of the motor and the base of the rod are eccentric, it is difficult to balance the weight (poor torque balance), the load applied to the output shaft is not constant, and the life of the motor or bearings may be shortened. There was also.

Furthermore, driving multiple rods with one motor,
It has been structurally difficult to apply it to so-called multi-cylinder vacuum pumps.

OBJECT OF THE INVENTION The present invention has been made to eliminate such inconveniences, and by converting rotational motion into approximately linear reciprocating motion, the compression ratio and exhaust ratio of a pump driven by a conversion device, for example, can be improved. It is an object of the present invention to provide a rotary motion to reciprocating motion conversion device that has a structure that improves the performance of the rotor, etc., and has a structure that has less torque fluctuation to the drive part, improved durability, reduced drive energy, and a multi-cylinder arrangement. .

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention has a rotatable shaft to which an eccentric cam is fixed, a sliding part that slides on the outer periphery of the eccentric cam, and an identical shaft that includes the rotation axis of the shaft. It is characterized by having a link that is pivotally supported to be swingable in a plane, and a reciprocating rod that is pivotally supported by the link and reciprocates in the axial direction of the shaft.

In the present invention configured in this way, when the shaft is rotated by rotating the drive section, the eccentric cam rotates eccentrically, and the outer periphery of the eccentric cam slides on the sliding section of the link, respectively. The link is swung within a plane that includes the axis of the shaft.

This swing causes the output rod supported by the link to reciprocate in the axial direction of the shaft.

Therefore, although the axis of the output rod reciprocates on an arc, it reciprocates in a substantially straight line. ratio·
It is possible to improve the exhaust ratio, pumping efficiency, etc. Further, by the configuration in which the output rod approximates a linear reciprocating motion, it is possible to prevent fluid from remaining in the compression chamber formed at the tip of the output rod.

Furthermore, in the present invention configured in this way, the load transmitted to the drive unit via the shaft becomes uniform (torque fluctuation is reduced), thereby improving the life of the drive unit and each component. Drive energy can be reduced.

In addition, an eccentric cam is attached to the shaft, and a link is provided so that the sliding part comes into contact with this eccentric cam, making it possible to arrange multiple links around the shaft, allowing for a multi-cylinder arrangement. This makes it possible to provide compact and high-performance compressors, exhaust machines, pumps, etc.

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 is a partially cutaway side view showing an embodiment of the present invention, and FIG. 2 is a partially cutaway plan view showing the same embodiment.

In this embodiment, the rotary motion to reciprocating motion conversion device of the present invention is applied to a vacuum bellows pump.

First, as shown in FIG. 1, a motor 7 is attached to a base 8, and a first pulley 9 is fixed to a drive shaft 1 of the motor 7. A column 10 (
In this embodiment, the head flange 11 is supported and fixed by three pillars), and as shown in FIG.
3, while these suction ports 12 and discharge ports 13
A suction passage 14 and a discharge passage 15 are formed which communicate with each other. The suction passage 14 and the discharge passage 15 communicate with three compression chambers 16, which will be described later.

A shaft 3 is rotatably supported between the center of the head flange 11 and the base 8 via bearings 17, 17, and a second pulley 18 is attached to the lower end of the shaft 3 to drive the motor 7. First pulley 9 and belt 19 fixed to shaft 1
It is connected by

Therefore, the rotational motion of the drive shaft 1 of the motor 7 is transmitted to the shaft 3 as rotational motion.

This shaft 3 has two eccentric cams 2a.

2b are fixed apart from each other. "20" means eccentric cam 2
The fixing nut "21" in b is a fixing sleeve for the eccentric cam 2a, and "22" is a nut for fixing this sleeve 21. The eccentric cams 2a, 2b are connected to a large number of links 5.
Although it is preferable to have a circular shape for the convenience of disposing around the shaft 3, the shape is not particularly limited to this. Further, the two eccentric cams 2a and 2b are eccentrically attached to the shaft 3 in such a manner that their phases are shifted by a predetermined rotation angle so that a link 5, which will be described later, can swing. In addition, eccentric cam 2
By forming a tapered surface or a convex curved surface with a sharp tip on the outer circumferential side surface of a, 2b, sliding on the sliding parts 4, 4 of the link 5 can be performed more smoothly, and transmission efficiency can be improved. becomes. Further, as shown in FIG. 3, the outer periphery of the sliding portion 4 may be formed into a convex curved shape, and the outer periphery of the eccentric cams 2a, 2b may be formed into a planar shape. In this case, the transmission efficiency is particularly improved.

The link 5 is supported by a pair of support arms 23 attached to the base 8 so as to be swingable within a plane that includes the axis of the shaft 3 . That is, the second
As shown in the figure, connect both ends of the pin 24 to two bearings 2.
The pin 24 is supported by the support arm 23 via the spacer 26.25, and the through hole 5a of the link 5 is inserted through the pin 24.
6 prevents lateral displacement. At both ends of this link 5, sliding parts 4, 4 such as bearings are attached, which contact the eccentric cams 2a, 2b, respectively, described above. Further, as shown in FIG. 2, the base of the output rod 6 is supported by a pin 28 at the tip of the side protrusion 27 protruding from the center of the link 5 so as to sandwich the base of the output rod 6. It is. A bearing 29 is interposed between the pin 28 and the base of the output rod 6, thereby allowing a small circular arc reciprocating motion. In addition, the sliding part 4.4
may be a bearing such as a ball bearing, but may also be a ring that simply slides due to its sliding characteristics.

A bellows receiver 72 and a spacer 30 are fixed to the tip of the output rod 6 with bolts (not shown), and the lower end of a sealing bellows 31 made of an annular diaphragm is joined to the bellows receiver 72. On the other hand, the upper end of the bellows 31 is joined to a valve receiver 32, and the valve receiver 32 has a suction passage 14 and a discharge passage 15, respectively, at a position communicating with the inside of the bellows 31, that is, the compression chamber 16. An opening for communication has been established. The spacer 30 is formed to protrude into the compression chamber 16 of the annular bellows 31, and is configured to substantially contact the valve receiver 32 when the output rod 6 is at the top dead center of reciprocating motion. This allows the fluid introduced into the compression chamber 16 of the bellows 31 to be efficiently discharged.

A recess 33 is formed in the center of the valve receiver 32, in which a valve 36 consisting of two gaskets 35 and 35 with a metal plate 34 sandwiched therein is housed, and the valve 36 is fixed with the head flange 11. .

The metal plate 34 of this valve 36 and the two gas scalers 1-3
5.35, a through hole is provided that communicates with the inlet port 12 and the outlet port 13, and a check valve (not shown) is installed in each of the two through holes provided in the metal plate 34. There is. This prevents the fluid introduced from the suction port 12 from flowing back from the suction port, and the fluid discharged from the discharge port 13 from flowing back from the discharge port.

Next, the action will be explained.

In the vacuum pump according to this embodiment configured as described above, when the shaft 3 is rotated by rotating the motor 7, the eccentric cams 2a and 2b rotate eccentrically with their rotational phases shifted from each other. The eccentric cams 2a+ 2b act on the sliding parts 4, 4 of the link 5, respectively, and the link 5
oscillate in a plane. This oscillation causes link 5 to
The output rod 6, which is pivotally supported, performs reciprocating motion.

At this time, the pivot shaft 28 of the output lot 6 reciprocates on the circular arc, but this reciprocating motion on the circular arc is substantially a linear motion. Therefore, the output lot 6 having the spacer 30 In the figure, it reciprocates approximately vertically.

This makes it possible to narrow the gap between the outer edge of the spacer 30 and the inner edge of the bellows 31, thereby improving the compression ratio. According to the design values, the conventional gap of 0°5III11 can be reduced to about 0.2-.

Further, by narrowing the gap between the outer edge of the spacer 30 and the inner edge of the bellows 31 in this way, no fluid remains in this area, and therefore, contamination of the fluid can also be prevented.

Furthermore, in the vacuum bellows pump according to this embodiment configured as described above, the load on the drive shaft 1 transmitted through the shaft 3 becomes uniform (no torque fluctuation), and as a result, the drive unit and It is possible to improve the life of each component and reduce driving energy.

In addition, as in the vacuum pump according to this embodiment, three links are provided around one shaft, and all the sliding parts of the links can come into contact with the eccentric cam of the shaft. A multi-cylinder compressor can be provided. For example, the suction port 12 and the discharge port 13 of each compression chamber 16
If they are connected in parallel, a high-capacity compressor or pump can be obtained, and if they are connected in series, a high compression ratio or high pumping ratio can be obtained.

The present invention is not limited to the examples and can be modified in various ways.

For example, in the above embodiment, a specific example was explained in which the rotary motion to reciprocating motion conversion device of the present invention was applied to a vacuum bellows pump, but the present invention also applies to a reciprocating piston pump,
It can also be used in compressors, etc. Conversely, it is also expected to be applied to, for example, engines that convert reciprocating motion to rotational motion.

In the above embodiment, two eccentric cams are attached with rotational phases shifted in the axial direction of the shaft 3, but three or more eccentric cams may be attached. In that case, the sliding portion 4 in the link 5 must also be provided accordingly. Further, only one eccentric cam may be provided on the shaft 3. However, in that case, a means (for example, a spring) is required to allow the sliding portion 4 of the link 5 to constantly slide on one eccentric cam.

As described in detail, the rotary motion to reciprocating motion conversion device of the present invention includes a shaft connected to a drive shaft and having eccentric cams attached with a phase shift in the rotational direction, and a shaft connected to a drive shaft, and an eccentric cam attached to the eccentric cam, respectively. Since it has a link that has a sliding part that comes into contact with it and is pivotally supported in a plane so as to be able to swing freely, and an output rod that is pivotally supported by the link, the pivot of the output rod reciprocates on an arc. If applied to a compressor, exhaust machine, pump, etc. that performs linear motion and has a bellows or piston at the end of the output rod, compression ratio, exhaust ratio, pumping efficiency, etc. can be improved. Further, by making the output port approximate linear motion, it is possible to prevent fluid from remaining in the compression chamber formed at the tip of the output rod.

Furthermore, in the present invention configured in this manner, the load transmitted to the drive section through the shaft becomes uniform, thereby improving the lifespan of the drive section and each component and reducing drive energy. Can be done.

In addition, an eccentric cam is attached to the shaft, and a link is provided so that the sliding part comes into contact with this eccentric cam, making it possible to arrange multiple links around the shaft, allowing for a multi-cylinder arrangement. This makes it possible to provide compact and high-performance compressors, exhaust machines, pumps, etc.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view showing one embodiment of the present invention, and FIG.
The figure is a partially broken pressure surface diagram showing the same embodiment, FIG. 3 is a sectional view of main parts showing another embodiment, and FIG. 4.5 is a partially broken pressure surface diagram showing a conventional vacuum pump, and a partially broken pressure surface diagram. FIG. 1... Drive shaft 3... Shaft 5... Links 2a, 2b... Eccentric cam 4... Sliding part 6... Output lot Fig. 3

Claims (1)

[Claims] a rotatable shaft to which an eccentric cam is fixed; a link having a sliding part that slides on the outer periphery of the eccentric cam and is swingably supported in the same plane that includes the rotational axis of the shaft; A rotary motion-reciprocating motion conversion device comprising a reciprocating rod that is pivotally supported by the link and reciprocates in the axial direction of the shaft.