JP2004300933A - Reciprocating piston compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a ring member engaged with a crank pin of a crank shaft and a connecting mechanism of a piston and a connecting rod in a reciprocating piston compressor. <P>SOLUTION: In a sealed type electric compressor, the crank pin 4a is eccentrically provided at an upper part of the rotating crank shaft 4, the ring member 5 engaged with the crank pin 4a is provided with a bracket shaped attachment part 5a on a side part and is provided with an engagement recess part 5b oppositely to the same on a tip thereof. The connecting rod 3c having the piston attached on a front end is inserted to the attachment part 5a from a rear end thereof, and a pair of projections 7 horizontally provided in both side of the rear end are engaged with the engagement recess parts 5b. A spring member formed roughly in M-shape is hooked to tip parts of the projections 7 by roughly ring shaped hook parts 8a provided on tips of both leg parts respectively and is locked to the ring member 5 in such a manner of holding an outer circumference of the ring member 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a reciprocating piston compressor, and more particularly to a reciprocating piston compressor having an improved connection structure between a ring member fitted to a crankpin of a crankshaft and a connecting rod attached to a piston.
[0002]
[Prior art]
Conventionally, various types of reciprocating piston compressors are known, and among them, there is a comparatively small one called a hermetic electric compressor. In the hermetic electric compressor, a compression section and an electric section are usually housed in a closed container, and when power is supplied to the electric section, a crankshaft that is axially mounted on a rotor rotates and is eccentrically provided on the crankshaft. The rotating motion of the crank pin is converted into a reciprocating motion via a scotch yoke mechanism and transmitted to the piston of the compression unit. The reciprocating motion of the piston compresses the gas sucked into the cylinder (for example, Patent Document 1).
[0003]
Also, with respect to the scotch yoke mechanism of the hermetic electric compressor, a technique is disclosed in which a ring member fitted to a crankpin and a connecting rod of a piston are connected via a locking pin or a bifurcated pin (for example, see Patents). Reference 2).
[0004]
[Patent Document 1]
JP-A-6-17755 [Patent Document 2]
Japanese Patent Application Laid-Open No. Hei 10-196537
[Problems to be solved by the invention]
According to the conventional connection structure between a ring member and a connecting rod as described above, a hole for inserting a locking pin or a forked pin must be provided in both the ring member and the connecting rod, and the hole has a high processing accuracy. Is required. For this reason, the manufacturing cost becomes expensive. Further, the connection between the ring member and the connecting rod is performed by inserting an end of the connecting rod into a receiving hole provided in the ring member, aligning the axis of the hole of the ring member with the axis of the connecting rod hole, and inserting a locking pin or a forked pin. Therefore, the connecting operation is troublesome. Further, when the ring member and the connecting rod are connected, the connecting rod can rotate horizontally around the axis of the locking pin, but cannot rotate vertically due to the restriction of the receiving hole. For this reason, the mounting position of the ring member with respect to the crankpin must be adjusted so that the horizontal center axes of the connecting rod and the cylinder are precisely aligned. If the horizontal center axis is displaced, the reciprocating movement of the piston cannot be performed smoothly, so that not only the compression performance is reduced but also the wear of the piston and the cylinder is accelerated.
[0006]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks of the prior art. In connecting a ring member and a connecting rod, the connecting operation can be easily performed, high processing accuracy is not required, and the connecting rod can be manufactured at low cost. It is an object of the present invention to provide a reciprocating piston compressor configured to be able to rotate vertically.
[0007]
[Means for Solving the Problems]
According to one aspect of the present invention, there is provided a ring member fitted to a crankpin of a crankshaft, one end of which is attached to a piston via a pin and the other end of which is connected to the ring member. In the reciprocating piston compressor provided with the connecting rod, the ring member and the connecting rod are connected by a spring member.
[0008]
According to another aspect of the present invention, there is provided a ring member fitted to a crankpin of a crankshaft, and one end attached to a piston via a pin and the other end connected to the ring member. In the reciprocating piston compressor provided with the connecting rod, a bracket-shaped mounting portion is provided on the ring member, an engagement recess is provided at the tip of the mounting portion, and a projection is provided on the other end of the connecting rod. The protrusion is engaged horizontally with the engaging recess, and both ends of the spring member are hooked on the distal end of the protrusion protruding from the engaging recess, respectively, and the outer periphery of the ring member is held by the spring member. The ring member and the connecting rod were connected to each other by being held and locked to the ring member.
[0009]
The spring member is formed in a substantially M-shape by a wire, and a substantially ring-shaped hook portion is provided at the tip of both legs, and a locking portion is provided on the ring member. The member is locked.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment in which the present invention is applied to a hermetic electric compressor will be described with reference to the accompanying drawings. FIG. 1 is a schematic sectional view of a hermetic electric compressor according to the present invention. FIG. 2 is a schematic perspective view showing a connection state between the ring member and the connecting rod.
[0011]
In FIG. 1, reference numeral 1 denotes an airtight container, which is formed by joining upper and lower two-piece metal case members together and welding them. Is placed and housed. The electric unit 2 includes a rotor 2a on which a crankshaft 4 is pivotally mounted, and a stator 2b.
[0012]
The compression section 3 has a cylindrical cylinder 3a, a piston 3b reciprocating in the cylinder 3a, a front end attached to the piston 3b via a pin, and a rear end attached to the crankshaft 4 as shown in FIG. And a scotch yoke type connecting rod 3c engaged and connected via a ring member 5 to a crank pin 4a eccentrically provided.
[0013]
3A and 3B show a state before the connecting rod 3c and the ring member 5 are connected. FIG. 3A is a schematic sectional view and FIG. 3B is a schematic plan view. The ring member 5 is provided with a bracket-shaped mounting portion 5a on the side surface as shown in FIG. 3 (b), and a substantially semicircular engaging recess 5b at the tip of the mounting portion 5a as shown in FIG. 3 (a). Are opposed to each other. 3A, a curved portion 5c is formed on the side surface opposite to the mounting portion 5a. The curved portion 5c is formed in a vertical direction. A portion 5d is provided.
[0014]
The connecting rod 3c has a front end cylindrical portion pivotally supported by a piston 3b via a piston pin 6 so that the connecting rod 3c can be horizontally rotated around the piston pin 6 as a support shaft. As shown in FIG. 3 (b), on both sides of the rear end portion, a round bar-shaped projection 7 is horizontally opposed, and is configured to engage with the engagement recess 5b of the ring member 5, respectively. Further, the rear end face is processed into an R shape as shown in FIG.
[0015]
4A and 4B show an example of a spring member 8 used for connecting the connecting rod 3c and the ring member 5, wherein FIG. 4A is a plan view and FIG. 4B is a front view. The spring member 8 is formed of a heat-resistant and oil-resistant metal wire, for example, a piano wire (SWPA) into a substantially M-shape as shown in FIG. A substantially ring-shaped hooking portion 8a is provided opposite to this.
[0016]
In order to connect the connecting rod 3c and the ring member 5 using the spring member 8, the rear end of the connecting rod 3c is inserted into the mounting portion 5a of the ring member 5, and the projection 7 is engaged with the engaging recess 5b. I do. At this time, the tips of the projections 7 protrude outward from the engagement recesses 5b. From this state, the hook 8a of the spring member 8 is hooked and fitted to the tip of the projection 7 projecting from the engaging recess 5b, and the spring 8 is rotated with the hook 8a as a fulcrum. 2 and the curved convex portion 8b (see FIG. 4 (a)) of the spring member 8 is fitted into the recessed locking portion 5d and locked as shown in FIG.
[0017]
As described above, since the ring member 5 has the curved portion 5c which has been subjected to the R processing, the curved convex portion 8b of the spring member 8 is guided by the curved portion 5c, so that the ring member 5 can be easily fitted into the locking portion 5d. Can be. The order in which the spring members 8 are attached is not limited to this. First, the curved convex portion 8b is fitted into the locking portion 5d so as to hold the outer periphery of the ring member 5, and then the hook portion 8a is attached to the tip of the projection 7. Each may be fitted.
[0018]
By locking the spring member 8 to the ring member 5 in this manner, the spring member 8 can be fixed, and at the same time, the connecting rod 3c and the ring member 5 can be connected. In this case, since the distal end of the projection 7 of the connecting rod 3c and the locking portion 5d of the ring member 5 can be seen from the outside, the connection between the connecting rod 3c and the ring member 5 is performed by aligning the axis of the hole in the conventional hard-to-see portion. It becomes extremely easy as compared with the connection by a locking pin or the like.
That is, the work of attaching the spring member 8 can be easily performed, and the spring member 8 can be securely fixed to the ring member 5. The spring member 8 is not limited to a substantially M-shaped one made of the above-described wire, but may be, for example, a coil spring or a leaf spring.
[0019]
In the case of the present invention, after the connecting rod 3c and the ring member 5 are connected, the connecting rod 3c is turned in the vertical direction (vertical direction) with respect to the bracket-shaped mounting portion 5a of the ring member 5 using the horizontal projection 7 as a fulcrum. It has a structure that can move. As described above, since the rear end face of the connecting rod 3c is formed in an R shape, the turning of the connecting rod 3c can be performed smoothly. For this reason, it is not necessary to adjust the mounting position of the ring member 5 with respect to the crank pin 4a and precisely align the horizontal center axis of the connecting rod 3c with the cylinder 3a as in the related art.
[0020]
The connection structure according to the present invention does not require high processing accuracy as in the related art, and has a certain degree of freedom in relation to the cylinder. The present invention can be easily applied to a mold cylinder. Then, even if the central horizontal axis between the connecting rod 3c and the cylinder 3a is slightly displaced, the reciprocating motion of the piston is performed smoothly, and high compression performance can be maintained and early wear of the piston and the cylinder can be prevented.
[0021]
The configuration of the hermetic electric compressor shown in FIG. 1 will be further described. The compression section 3 and the electric section 2 are fixed to a structure 9 and are elastically suspended on the inner wall of the hermetic container 1 via a spring 10. It is supported at a plurality of places (usually three places). A bearing 9 a for supporting the crankshaft 4 is formed integrally with the structure 9. In this case, the cylinder 3a is formed separately from the structure 9, but may be formed integrally with the structure 9.
[0022]
A spiral groove 4b through which lubricating oil passes is provided on the outer peripheral surface of the crankshaft 4. An oil passage 4c communicating with the lower end of the groove 4b is formed along the axial direction, and the spiral groove 4b is formed. An oil passage 4d is formed from the upper end of 4b to the outer peripheral surface of the crank pin 4a, and a spiral groove 4e communicating from the oil passage 4d to the upper end of the crank pin 4a is formed on the outer peripheral surface. Further, a centrifugal pump member 11 is inserted into the lower end of the crankshaft 4.
[0023]
The centrifugal pump member 11 is provided with a plurality of fin-shaped paddles 11 a inside a cylinder, and the leading end (lower end) is reduced in diameter and inserted into a lubricating oil storage container 12 fixed to the bottom of the sealed container 1. Have been. The lubricating oil storage container 12 is provided with a plurality of holes on a side wall so that the lubricating oil 13 stored at the bottom of the closed container can enter and exit.
[0024]
In the hermetic electric compressor configured as described above, when the electric motor 2 is energized and the rotor 2a rotates, the crankshaft 4 rotates axially and the crankpin 4a performs eccentric rotational movement, and this rotational movement is The gas is converted into a reciprocating motion via a scotch yoke type connecting rod 3c, and the piston 3b reciprocates to compress the gas sucked into the cylinder 3a. The supply of the low-pressure gas to the hermetic electric compressor and the discharge of the high-pressure gas after compression are performed by a supply pipe and a discharge pipe (not shown) connected to the closed vessel 1 as in the conventional case.
[0025]
During operation of the hermetic electric compressor, the rotation of the crankshaft 4 causes the centrifugal pump member 11 to pump up the lubricating oil in the lubricating oil storage container 12. The lubricating oil pumped up by the centrifugal pump member 11 rises on the inner wall of the oil passage hole 4c of the crankshaft 4 and enters the spiral groove 4b, and from this groove 4b passes through the oil passage hole 4d to form the spiral oil. It passes through the groove 4e.
[0026]
Thus, the bearing portion 9a is lubricated because the lubricating oil passes through the groove 4b of the crankshaft 4, and the ring member 5 is lubricated because the lubricating oil passes through the groove 4e of the crankpin 4a. Further, a part of the lubricating oil is radially released from the crank pin 4a to the outside, and thus the sliding portion of the piston 3b is lubricated by the released lubricating oil. The remaining lubricating oil falls and returns to the lubricating oil pool at the bottom of the sealed container 1.
[0027]
In the above-described embodiment, an example of the hermetic electric compressor has been described. However, the present invention is not limited to this, and any reciprocating compressor can be applied.
[0028]
【The invention's effect】
As described above, according to the first aspect of the present invention, a ring member fitted to a crankpin of a crankshaft, and one end is attached to a piston via a pin and the other end is connected to the ring member. In the reciprocating piston compressor provided with the connecting rod, since the ring member and the connecting rod are connected by a spring member, the connecting operation can be easily performed as compared with the conventional connecting using a locking pin or the like, and Since high processing accuracy is not required, manufacturing costs can be reduced.
[0029]
According to the invention of claim 2 according to the present invention, there is provided a ring member fitted to a crankpin of a crankshaft, and a connecting rod having one end attached to a piston via a pin and the other end connected to the ring member. In the reciprocating piston compressor, a bracket-shaped mounting portion is provided on the ring member, an engaging concave portion is provided at the tip of the mounting portion, and a projection is horizontally provided on the other end of the connecting rod, The projection is engaged with the engagement concave portion, and both ends of the spring member are respectively hooked on the distal end portion of the projection protruding from the engagement concave portion, so that the spring member holds the outer periphery of the ring member. Since the ring member and the connecting rod are connected by locking to the ring member, the connecting rod can be rotated vertically after the connection, and the center water between the connecting rod and the cylinder is Without requiring precise adjustments to the axis, a piston and a cylinder of premature wear can be prevented while maintaining high compression performance.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view showing an embodiment in which the present invention is applied to a hermetic electric compressor.
FIG. 2 is a schematic perspective view showing a connection state between a ring member and a connecting rod according to the present invention.
FIGS. 3A and 3B show a state before connection between a ring member and a connecting rod according to the present invention, wherein FIG. 3A is a schematic sectional view and FIG. 3B is a schematic plan view.
4A and 4B show an example of a spring member used for connecting a ring member and a connecting rod according to the present invention, wherein FIG. 4A is a plan view and FIG. 4B is a front view.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Closed container 2 ... Electric part 3 ... Compression part 3a ... Cylinder 3b ... Piston 3c ... Connecting rod 4 ... Crank shaft 4a ... Crank pin 5 ... Ring member 5a ... Mounting part 5b ... Engaging recess 5d ... Locking part 7 ... Projection 8 Spring member 8a Hook

Claims (2)

In a reciprocating piston compressor including a ring member fitted on a crankpin of a crankshaft, and a connecting rod having one end attached to a piston via a pin and the other end connected to the ring member, the reciprocating piston compressor includes: A reciprocating piston compressor, wherein the pistons are connected by a spring member. In a reciprocating piston compressor including a ring member fitted to a crankpin of a crankshaft and a connecting rod having one end attached to a piston via a pin and the other end connected to the ring member, the ring member has a bracket-like shape. A mounting recess is provided at the tip of the mounting portion, a projection is horizontally provided at the other end of the connecting rod, and the projection is engaged with the engagement recess. The both ends of the spring member are respectively hooked on the tips of the projections protruding from the engagement recesses, and the spring member is engaged with the ring member so as to hold the outer periphery of the ring member. And a reciprocating piston compressor.

Images