JP2014101753A - Scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scroll compressor capable of stabilizing a rotary motion of a swing scroll over a long period while minimizing a start-up load.SOLUTION: In a scroll compressor configured by forming spiral wraps respectively on surfaces opposite to each other of end plates of a fixed scroll and a swing scroll, forming a plurality of compression chambers by engaging the wraps with each other, a slide bush 27 having a slide surface 90 of a prescribed angle to a load direction of a gas in the compression chambers, is interposed on an eccentric shaft 23 of a rotating shaft for driving the swing scroll, and eccentricity of the slide bush 27 is increased when the load of the gas in the compression chambers is added, a balancer 71 for making centrifugal force which presses a slide surface to the eccentric shaft 23, act on the slide bush 27, is mounted on the slide bush 27, and when the load of the gas in the compression chambers is increased, the centrifugal force is overcome, and the eccentricity of the slide bush 27 is increased.

Description

  The present invention relates to a scroll compressor in which a plurality of compression chambers are formed by meshing each lap formed on a surface of a fixed scroll and a face plate of an orbiting scroll revolving with respect to the fixed scroll.

  In general, this type of scroll compressor has a fixed scroll and an orbiting scroll that revolves with respect to the fixed scroll, and forms spiral wraps on opposite surfaces of the end plates of the fixed scroll and the orbiting scroll. The wraps are engaged with each other to form a plurality of compression chambers.

A slide bush is interposed on the eccentric shaft of the rotary shaft that drives the rocking scroll. The slide bush has a slide surface that forms a predetermined angle with respect to the gas load direction in the compression chamber, and is configured to increase the eccentric amount of the slide bush when a gas load in the compression chamber is applied. . According to such a configuration, since the amount of eccentricity of the component of the gas load can be increased by the slide surface, it is possible to improve the sealing performance between the wraps of the fixed scroll and the swing scroll, The performance of a compressor can be improved (for example, refer patent document 1). In such a scroll compressor, a spring member is inserted between the slide bush and the eccentric shaft, and the slide bush is pressed against the eccentric shaft by the spring member, thereby reducing the amount of eccentricity at the time of starting and reducing the load at the time of starting. Things are also being developed.
Specifically, the scroll compressor presses the slide bush against the eccentric shaft with a spring member, so that the eccentric amount is small when stopped and the clearance between both laps is large, so the starting load can be reduced. On the other hand, when a gas load is applied, the slide bush moves in a direction in which the amount of eccentricity increases against the biasing force of the spring member, and an appropriate amount of eccentricity can be obtained (see, for example, Patent Document 2).

JP-A-7-71386 Japanese Patent No. 3165153

However, as described above, in the scroll compressor in which the slide bush is pressed against the eccentric shaft by the spring member and the amount of eccentricity of the slide bush is variable, the slide surface of the slide bush and the eccentric shaft are separated during operation. was there. In addition, for example, there has been a problem that the spring member may sag or fatigue breakage due to long-term use.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a scroll compressor that can solve the above-described problems of the prior art and can stabilize the orbiting scroll's orbiting motion over a long period of time while suppressing the starting load. There is.

  The present invention includes a fixed scroll and an orbiting scroll that revolves with respect to the fixed scroll, and forms spiral wraps on mutually facing surfaces of the fixed scroll and the end plate of the orbiting scroll. A plurality of compression chambers are formed by meshing with each other, and a slide bush having a slide surface that forms a predetermined angle with respect to the gas load direction in the compression chamber on the eccentric shaft of the rotary shaft that drives the orbiting scroll. In a scroll compressor configured to increase the amount of eccentricity of the slide bush when a gas load is applied in the compression chamber, the centrifugal compressor presses the slide surface against the eccentric shaft against the slide bush. When a balancer that applies force to the slide bush is attached and the load of gas in the compression chamber increases, the balance And configured to eccentricity of the slide bush is increased by overcoming the centrifugal force.

At the time of startup, the amount of eccentricity of the slide bush may be small.
The balancer may be mounted such that the center of gravity G of the entire part assembled with the slide bush and the balancer is located on the −y axis opposite to the eccentric direction D2 with respect to the center C of the rotation shaft.
The balancer is located on the −y-axis side opposite to the eccentric direction D2 with respect to the center C of the rotation shaft and on the extension line L of the slide surface so that the center of gravity G of the entire part assembled with the slide bush and balancer is positioned. It may be attached.
A lower balancer may be attached to the rotating shaft, and the balance of the entire system may be achieved by the lower balancer and the balancer.

  In these inventions, when the scroll compressor is started, the gas load in the compression chamber is small, so that the eccentric amount of the slide bush is small due to the centrifugal force by the balancer. Therefore, the clearance between the laps of the fixed scroll and the swing scroll is large, the leaked cross of the compressed gas is large, and the gas load does not increase so much. Thereby, the load at the time of starting can be made small. Further, if the operation of the scroll compressor is continued, the gas load in the compression chamber gradually increases, so the component force in the direction along the slide surface of the gas load increases, and this component force is the above-mentioned centrifugal force. When the component force in the direction along the slide surface is overcome, the slide bush slides in a direction that increases the eccentric amount of the slide bush. When this relationship is reached, the clearance between both wraps becomes zero, and the efficiency of the scroll compressor becomes high.

  In the present invention, the eccentric amount of the slide bush is controlled by the balance of universal force using a balancer without relying on the force due to deformation of the spring member or the like as in the prior art. Thus, the orbiting scroll orbiting motion can be stabilized over a long period of time while suppressing the starting load. In addition, since the amount of eccentricity of the slide bush is small when the scroll compressor is started, the clearance between the laps of the fixed scroll and the orbiting scroll is large at the time of startup, the compressed gas leak cross is large, and the gas load is too small. Since there is no increase, the starting torque can be reduced, a small motor can be designed, and high efficiency can be realized.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal side view of an embodiment of a scroll compressor to which the present invention is applied, and FIG. 2 is a plan view of the periphery of a compression element 2.
In FIG. 1, 1 is an airtight container. The hermetic container 1 includes a container body 1A having a vertically long cylindrical shape, and an end cap 1B and a bottom cap 1C each having a substantially bowl shape that are welded and fixed to both ends (upper and lower ends) of the container body 1A. .
A partition plate 10 that partitions the space in the sealed container 1 up and down is provided above the sealed container 1. That is, the inside of the sealed container 1 is partitioned by the partition plate 10 into an upper space 11 and a lower space 12.

In the lower space 12 in the sealed container 1, the compression element 2 is housed on the upper side, and the electric element 3 as drive means for driving the compression element 2 is housed on the lower side. Further, the bottom portion of the space 12 (that is, the inner surface of the bottom cap 1C) 65 is an oil sump in which lubricating oil for lubricating the compression element 2 and the like is stored.
A support frame 4 is accommodated in the sealed container 1 between the compression element 2 and the electric element 3, and a bearing portion 6 and a boss accommodating portion 22 are formed in the center of the support frame 4. The bearing portion 6 is for supporting the tip (upper end) side of the rotating shaft 5 and is formed to project downward from the center of one surface (lower surface) of the support frame 4. The boss accommodating portion 22 is for accommodating a boss 24 of the swing scroll 8 described later, and is formed by recessing the center of the other surface (upper surface) of the support frame 4 downward. An eccentric shaft 23 is formed at the tip (upper end) of the rotating shaft 5. The eccentric shaft 23 is provided so that its center is eccentric from the axis of the rotary shaft 5, and is inserted into the boss 24 via a slide bush 27 and a pivot bearing 28 so as to be pivotable.

  The compression element 2 includes a fixed scroll 7 and an orbiting scroll 8. The fixed scroll 7 includes a disc-shaped end plate 14, an involute erected on one surface (lower surface) of the end plate 14, or a spiral wrap 15 having a curve similar to this, The peripheral wall 16 is provided so as to surround the periphery of the wrap 15, and the flange 17 is provided around the peripheral wall 16 and the outer peripheral edge is shrink-fitted on the inner surface of the container main body 1 </ b> A of the sealed container 1. A discharge hole 18 communicating with the space 11 in the upper sealed container 1 partitioned by the partition plate 10 is formed at the center of the end plate 14 of the fixed scroll 7. In the fixed scroll 7, the protruding direction of the wrap 15 is set downward.

In the configuration of the present embodiment, the end plate 14 of the fixed scroll 7 discharges to the other surface (upper surface) of the end plate 14 and includes a cylindrical protrusion 30 having a discharge hole 18. The protrusion 30 is configured to fit into a holding hole 10 </ b> A formed in the partition plate 10, and the upper surface 30 </ b> A of the protrusion 30 faces the space 11 above the partition plate 10. A discharge valve (not shown) for opening and closing the discharge hole 18 and a plurality of release valves (not shown) are provided adjacent to the discharge valve on the upper surface 30A of the protrusion 30.
The release valve is provided to prevent the refrigerant from being over-compressed, and communicates with a compression space (compression chamber 25), which will be described later, of the compression process via a release port (not shown). Specifically, when the refrigerant pressure in the compression process reaches the discharge pressure before reaching the discharge hole 18, the release valve (not shown) is opened, and the refrigerant in the compression space (compression chamber 25) passes through the release port. It is discharged outside.

  On the other hand, the orbiting scroll 8 is a scroll that revolves with respect to the fixed scroll 7 described above, and has a disc-shaped end plate 20 and an involute shape that is erected on one surface (upper surface) of the end plate 20. Alternatively, it is composed of a spiral wrap 21 having a curve similar to this and the boss 24 described above that protrudes from the center of the other surface (lower surface) of the end plate 20. The oscillating scroll 8 is arranged so that the protruding direction of the wrap 21 is upward and the wrap 21 is rotated 180 degrees to the wrap 15 of the fixed scroll 7 so as to face each other. A space is formed. That is, the wrap 21 of the orbiting scroll 8 is opposed to the wrap 15 of the fixed scroll 7 and meshes so that the front end surfaces of both the wraps 21 and 15 are in contact with the bottom surface of the other party. Since two eccentric wraps 21 and 15 are attached to an eccentric shaft 23 which is eccentric from the shaft center via a slide bush 27, the two spiral wraps 21 and 15 are eccentric to each other and confined in contact with each other on a line in the eccentric direction. A plurality of spaces are created, and each of these spaces becomes a compression chamber 25.

  In the fixed scroll 7, a flange 17 provided around the peripheral wall 16 is fixed to the support frame 4 via a plurality of bolts 37. The swing scroll 8 is supported by the support frame 4 via the Oldham ring 40. The Oldham ring 40 is for revolving the orbiting scroll 8 on the circular orbit so as not to rotate with respect to the fixed scroll 7. The Oldham ring 40 includes a pair of Oldham keys 41 and 41 formed so as to protrude upward at opposite positions. Prepare. The Oldham keys 41 and 41 are slidably engaged with a key groove 42 formed on the lower surface of the fixed scroll 7. In this case, the Oldham rings 40, 40 slide along the extending direction of the Oldham key 41 in the sliding space 43 formed between the fixed scroll 7 and the support frame 4 as the swinging scroll turns. Since the orbiting scroll 8 is eccentric and revolves with respect to the fixed scroll 7, the eccentric direction and the contact position of the two spiral wraps move while rotating, and the compression chamber moves from the outside toward the inside compression chamber 25. Reduce as you move. The low-pressure refrigerant gas that has entered from the outer compression chamber 25 and is confined first moves inward while being adiabatically compressed, and finally becomes a high-temperature and high-pressure refrigerant gas when it reaches the center. The refrigerant gas is sent out to the space 11 through the discharge hole 18.

  On the other hand, the electric element 3 includes a stator 50 fixed to the hermetic container 1 and a rotor 52 that is disposed inside the stator 50 and rotates within the stator 50, and rotates around the center of the rotor 52. The shaft 5 is fitted. The end (lower end) of the rotating shaft 5 is pivotally supported by a bearing 9 disposed at the bottom of the sealed container 1. An oil passage 60 is formed inside the rotating shaft 5 along the axial direction of the rotating shaft 5. The oil passage 60 includes a suction port 61 positioned at the lower end of the rotating shaft 5 and a paddle 63 formed above the suction port 61. The lower end of the rotating shaft 5 is immersed in the lubricating oil stored in the oil sump 65, and the suction port 61 of the oil passage 60 opens in the lubricating oil. The oil passage 60 is formed with an oil supply port 64 for supplying lubrication at a position corresponding to each bearing. With this configuration, when the rotating shaft 5 rotates, the lubricating oil stored in the oil sump 65 enters the oil passage 60 from the suction port 61 of the rotating shaft 5 and is pumped upward along the paddle 63 of the oil passage 60. Then, the pumped lubricating oil is supplied to each bearing and the sliding portion of the compression element 2 through each oil supply port 64 and the like.

  On the other hand, the airtight container 1 is compressed by the refrigerant introduction pipe 67 for introducing the refrigerant into the lower space 12 in the airtight container 1 and the compression element 2 and is sealed via the discharge hole 18. 1 is provided with a refrigerant discharge pipe 68 for discharging the refrigerant discharged into the upper space 11 in the outside. The refrigerant introduction pipe 67 is welded and fixed to the side surface of the container body 1A of the sealed container 1, and the refrigerant discharge pipe 68 is fixed to the side surface of the end cap 1B by welding.

  A slide bush 27 is mounted on the eccentric shaft 23 of the rotating shaft 5 as shown in FIG. As shown in FIG. 4, the slide bush 27 has a slide surface 90 on its inner periphery, and the slide surface 90 forms a predetermined angle with respect to the gas load direction in the compression chamber 25. Is formed. Specifically, in the present embodiment, the slide surface 90 is formed so as to be inclined at a predetermined angle α from an eccentric direction (arrow D2) orthogonal to the gas load direction (arrow D1). According to such a configuration, when a gas load in the compression chamber 25 is applied, the component of the gas load is applied by the slide surface 90 so that the eccentric amount of the slide bush 27 increases (see FIG. 6). Thereby, the sealing performance between the wraps 15 and 21 of the fixed scroll 7 and the swing scroll 8 is improved, and the performance of the scroll compressor can be improved.

In the present embodiment, as shown in FIGS. 3 and 4, an upper balancer (balancer) 71 is integrally attached to the slide bush 27. The upper balancer 71 is integrally provided with a mounting portion 71A and a weight portion 71B, and the slide bush 27 is press-fitted or shrink-fitted into the mounting portion 71A. Then, as shown in FIG. 4, the center of gravity G of the whole part assembled with the slide bush 27 and the upper balancer 71 is positioned on the −y axis opposite to the eccentric direction D2 with respect to the center C of the rotating shaft 5. Further, an upper balancer 71 is attached to the slide bush 27. As shown in FIG. 1, a lower balancer 75 is attached to the rotary shaft 5 so as to face the rotor 52, and the entire balance is achieved by the upper balancer 71 and the lower balancer 75.
According to this configuration, as shown in FIG. 4, when the rotating shaft 5 rotates, the weight portion 71B of the upper balancer 71 rotates integrally, and the centrifugal force f (= mrω ² , m is the weight on the slide bush 27. Part weight.) Acts, and the centrifugal force f causes the slide bush 27 to move in the direction opposite to the eccentric direction D2, and the upper inner surface of the slide bush 27 and the slide surface 90 are pressed against the eccentric shaft 23.

When the scroll compressor is started, the gas load in the compression chamber 25 is small, so that it is controlled by the centrifugal force f = mrω ² and the eccentric amount of the slide bush 27 is small as shown in FIG. Therefore, the clearance between the wraps 15 and 21 of the fixed scroll 7 and the swing scroll 8 is large, and compression work is hardly performed. Thereby, the load at the time of starting can be made small. On the other hand, during operation of the scroll compressor, the gas load (arrow D1 in FIG. 4) in the compression chamber 25 gradually increases, so that the component force of the gas load in the direction along the slide surface 90 increases. When this component force overcomes the component force of the centrifugal force f = mrω ^{2 in} the direction along the slide surface 90 (the component force of the centrifugal force f = mrω ² <the component force of the gas load), the slide bush 27 slides in the direction of increasing the amount of eccentricity, as shown in FIG. When this relationship is reached, the clearance between the wraps 15 and 21 of the fixed scroll 7 and the swing scroll 8 becomes zero, and the efficiency of the scroll compressor becomes high.

In the present embodiment, the upper balancer 71 is used to control the amount of eccentricity of the slide bush 27 by a universal force balance without relying on the force due to deformation of the spring member or the like as in the prior art. Problems such as dragging and fatigue destruction are eliminated, and the orbiting scroll can be stabilized for a long period of time while suppressing the starting load.
In this embodiment, since the amount of eccentricity of the slide bush 27 is small when the scroll compressor is activated, the clearance between the wraps 15 and 21 of the fixed scroll 7 and the swing scroll 8 is large at the time of activation. Since this is hardly done, the starting torque can be reduced, a small motor can be designed, and high efficiency can be realized.

FIG. 7 shows another embodiment. In FIG. 7, the same parts as those in FIGS. 1 to 6 are denoted by the same reference numerals, and the description thereof is omitted.
In this embodiment, the upper balancer 72 is integrally provided with a mounting portion 72A and a weight portion 72B. Then, the center of gravity G of all the parts assembled with the slide bush 27 and the upper balancer 71 is on the −y axis side opposite to the eccentric direction D2 with respect to the center C of the rotating shaft 5, and the extension line L of the slide surface 90 An upper balancer 72 is attached to the slide bush 27 so as to be positioned above.
At the time of start-up, the gas load in the compression chamber 25 is small as in the above embodiment, so that the eccentric amount of the slide bush 27 is controlled by the centrifugal force f.
Therefore, the clearance between the wraps 15 and 21 of the fixed scroll 7 and the orbiting scroll 8 is increased, and compression work is hardly performed. Thereby, the load at the time of starting can be made small.

On the other hand, during operation, the gas load in the compression chamber 25 gradually increases, so the component force of the gas load in the direction along the slide surface 90 increases.
In this embodiment, unlike the above embodiment, since the centrifugal force f = mrω ² acts in the direction along the slide surface 90, the component force in the direction along the slide surface 90 of the gas load is the centrifugal force f = mrω. ² , when it becomes larger than itself (centrifugal force f = mrω ² <component force of gas load), the slide bush 27 slides in a direction to increase the eccentricity, and the fixed scroll 7 and the swing scroll 8 The clearance between the laps 15 and 21 is zero, and the efficiency is increased. According to this, compared with the said embodiment, the weight of the weight part 72B can be designed small and the balancer 72 can be reduced in size. Further, since there is no component force acting on the eccentric shaft 23 as a centrifugal force, the bending stress (deflection due to load) of the eccentric shaft 23 can be minimized.

As mentioned above, although one Embodiment of this invention was explained in full detail, it is clear that this invention is not limited to this. In the above-described embodiment, the center of gravity G of the entire part assembled with the slide bush and the balancer is positioned on the −y axis (see FIG. 4) or on the extension line L of the slide surface 90 (see FIG. 7). However, the present invention is not limited to this, and as shown in FIG. 7, it is located on the −y axis side opposite to the eccentric direction D2 from the center C of the rotating shaft 5 and located at θ between the −y axis and the extension line L. You may let them.
As described above in detail, according to the present invention, the turning motion of the orbiting scroll 8 can be stabilized while suppressing the load at the start. Thereby, the performance of the scroll compressor can be improved and the reliability can be improved.

It is a vertical side view of one Embodiment of a scroll compressor. It is a top view which shows the compression chamber of the scroll compressor of FIG. It is an enlarged view of the principal part of FIG. It is a top view which shows a slide bush. It is a top view which shows the slide bush at the time of starting. It is a top view which shows the slide bush at the time of a driving | operation. FIG. 5 is a view corresponding to FIG. 4 showing another embodiment.

DESCRIPTION OF SYMBOLS 1 Airtight container 2 Compression element 3 Electric element 5 Rotating shaft 7 Fixed scroll 8 Orbiting scroll 15, 21 Wrap 18 Discharge hole 23 Eccentric shaft 25 Compression chamber 27 Slide bush 50 Stator 52 Rotor 71 Upper balancer (balancer)
75 Lower balancer 90 Sliding surface

Claims (5)

A fixed scroll and an orbiting scroll that revolves relative to the fixed scroll, each of which forms spiral wraps on mutually facing surfaces of the fixed scroll and the end plate of the orbiting scroll, and meshes the wraps with each other. A plurality of compression chambers are formed, and a slide bush having a slide surface that forms a predetermined angle with respect to the load direction of the gas in the compression chamber is interposed on the eccentric shaft of the rotating shaft that drives the orbiting scroll, In the scroll compressor configured to increase the amount of eccentricity of the slide bush when a gas load in the compression chamber is applied,
A balancer is attached to the slide bush to apply a centrifugal force that presses the slide surface against the eccentric shaft to the slide bush, and when the load of gas in the compression chamber increases, the eccentric amount of the slide bush is overcome by overcoming the centrifugal force. A scroll compressor characterized by being configured to increase.   2. The scroll compressor according to claim 1, wherein an eccentric amount of the slide bush is small at the time of startup.   The balancer is mounted such that the center of gravity G of the whole part assembled with the slide bush and the balancer is located on the −y axis opposite to the eccentric direction D2 with respect to the center C of the rotating shaft. The scroll compressor according to claim 1 or 2.   The balancer is located on the −y-axis side opposite to the eccentric direction D2 with respect to the center C of the rotation shaft and on the extension line L of the slide surface so that the center of gravity G of the entire part assembled with the slide bush and balancer is positioned. The scroll compressor according to claim 1, wherein the scroll compressor is attached.   The scroll compressor according to any one of claims 1 to 4, wherein a lower balancer is attached to the rotating shaft, and the balance of the entire system is achieved by the lower balancer and the balancer.

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