JP3642604B2 - Scroll compressor - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a scroll compressor used as a compressor constituting a refrigeration cycle of an air conditioner, for example.
[0002]
[Prior art]
For example, in a compressor that constitutes a refrigeration cycle of an air conditioner, motion noise is extremely low compared to a normal rotary compressor, and there is no need for a suction valve or a discharge valve, and the number of parts can be reduced. Scroll compressors with good compression performance tend to be used frequently.
[0003]
This type of scroll compressor accommodates an electric compressor body in which a motor part is connected to one end of a rotating shaft and a compressor part is connected to the other end in a sealed case.
The compression mechanism section includes a fixed scroll and a turning scroll, and meshes the spiral wings of the scrolls, and forms a compression space between the wings and the end plate of each scroll.
[0004]
The orbiting scroll orbits in accordance with the rotation of the rotating shaft, sucks low-pressure gas refrigerant, which is a gas to be compressed, into the compression space, and compresses and discharges the compressed space by reducing the volume of the compression space.
[0005]
[Problems to be solved by the invention]
The problem here is the relationship between the clearance (gap) between the rotating shaft provided with the crank portion that engages with the orbiting scroll and the pivoting means that pivotally supports the rotating shaft via a bearing tool.
[0006]
That is, the support frame that is the pivotal support means includes a bearing hole portion in which a hole is machined, and a bearing tool is fitted therein. A rotary shaft cut into the bearing tool is inserted and the rotary shaft is pivotally supported by the support frame via the bearing tool.
[0007]
Although the support frame and the rotating shaft maintain high processing accuracy, it is inevitable that variations still occur to some extent. The bearing tool itself also has a clearance in the radial direction.
[0008]
As an actual assembled product, the combination of the processing variation of the support frame, the rotating shaft, and the clearance between the bearings causes the rotating shaft to tilt due to different phenomena, leading to the tilt of the orbiting scroll that engages with this crank part. Become.
[0009]
Therefore, Japanese Utility Model Publication No. 4-55272 has been proposed. The scroll compressor is characterized in that at least the upper main bearing of the orbiting bearing and the upper and lower main bearings is a cylindrical roller bearing, and the bearing gap of the cylindrical roller bearing is smaller than the orbiting bearing gap. The goal is to make it less.
[0010]
However, in the scroll compressor disclosed here, the crankshaft portion provided at the uppermost end of the rotary shaft (drive shaft) and the configuration that pivotally supports only the upper portion of the rotary shaft connected to the crankshaft portion, It has a so-called cantilever structure.
[0011]
On the other hand, the rotor of the electric motor is fitted to the lower part of the rotating shaft, and the lower end of the rotating shaft extends downward and is immersed in an oil sump formed at the bottom of the sealed container. It is.
[0012]
As described above, the conventional scroll compressor is pivotally supported only at one end portion of the rotating shaft, and is not pivoted at the other end portion. Therefore, it is not possible to completely and reliably eliminate the tilt of the rotating shaft to achieve stable operation.
[0013]
This compressor is a so-called vertical type in which the axial direction of the rotating shaft is oriented in the vertical direction, and the occurrence of whirling at the free end of the rotating shaft is relatively small . However, in the horizontal type (which is advantageous in terms of installation space of the compressor) (axial direction other than the rotating shaft is horizontal), the rotor of the electric motor is fitted on the free end side. Since this rotor is heavy and is affected by gravity not only at the time of stopping but also at the time of rotation, some kind of treatment is required to maintain reliability.
[0014]
The present invention has been made paying attention to the above circumstances, and the purpose thereof is based on the premise that the rotary shaft is pivotally supported through two bearing means on one end side and is also pivoted on the other end side. Thus, it is an object of the present invention to provide a scroll compressor that improves load distribution to each bearing, prevents tilting of the orbiting scroll due to stable rotation of the rotating shaft, and improves compression performance and reliability.
[0015]
[Means for solving the problems]
In order to satisfy the above object, a scroll compressor according to the present invention includes a fixed scroll provided with wings, a wing that meshes with the wings of the fixed scroll, and a orbiting scroll that forms a compression space therebetween. A rotating shaft that includes a crank portion that is rotatably engaged with the orbiting scroll, the main shaft portion being provided integrally with the crank portion, and a pivoting means that rotatably supports the main shaft portion of the rotating shaft. A scroll type compressor that includes a drive unit that rotationally drives a rotary shaft that is pivotally supported by the pivotal support unit, and orbits the orbiting scroll to suck and compress and discharge the compressed gas into the compression space.
The pivot means includes a main bearing that pivots one end of the main shaft portion of the rotating shaft via a roller bearing as a first bearing tool and a slide bearing as a second bearing tool, and the other end of the main shaft portion. The first bearing tool is provided at a position farther than the second bearing tool with respect to the third bearing tool, and the second bearing tool pivotally supports the first bearing tool. And Ca <Cb, where Ca is the clearance between the rotary shaft and the rotary shaft, and Cb is the clearance between the second bearing tool and the rotary shaft .
[0016]
Further , when the clearance between the second bearing tool and the rotary shaft according to claim 1 is Cb, and the clearance between the third bearing tool and the rotary shaft is Cc, the relationship of Cb> Cc is set.
[0017]
Further, the driving means is an electric motor including a rotor fitted to the rotating shaft and a stator arranged with a narrow gap on the outer periphery of the rotor, and the first bearing tool and the rotating shaft When the clearance of Ca is Ca, a relationship of Ca <75 μm is set.
[0018]
Further, the fixed scroll , the orbiting scroll, the rotating shaft, the pivot support means and the drive means are all horizontally oriented in the axial direction, and are horizontally installed as a compressor .
[0019]
[Action]
According to the present invention , since the compressive load during operation is received by the roller bearing which is the first bearing tool provided in the main bearing and the sub-bearing provided with the third bearing tool, the inclination of the rotating shaft is minimized. There is no lock occurrence.
[0020]
Moreover , even if the rotating shaft is tilted, the motor gap of the electric motor can be properly maintained, and there is no starting failure.
Moreover , although gravity acts on a rotating shaft and other components, the influence of gravity is suppressed to the minimum by the above setting.
[0021]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a horizontal scroll compressor. In the figure, reference numeral 1 denotes a sealed case that is long in the horizontal direction. A support frame 2 as a main bearing is provided on the right side in the figure in the sealed case 1. A stay 20 is attached and fixed to the left side, and an auxiliary bearing 21 is attached and fixed to the extended end of the stay via an attachment bolt 22.
[0022]
The axial direction of both the support frame 2 and the auxiliary bearing 21 is directed to the horizontal direction. The support frame 2 is a rotating shaft that extends in the horizontal direction via a first bearing tool A and a second bearing tool B, which will be described later, and the sub-bearing 21 via a third bearing tool C, which will be described later. 3 is rotatably supported.
[0023]
A compression mechanism unit 4 is connected to the rotating shaft 3 on the support frame 2 side, and an electric motor unit 7 including a stator 5 and a rotor 6 is provided at another position.
The compression mechanism unit 4 includes a turning scroll 11 that is turnably supported on the support frame 2 via an Oldham ring 10, and a fixed scroll 12 that meshes with the turning scroll 11. The Oldham ring 10 regulates the rotation of the orbiting scroll 11 and performs only the orbiting motion.
[0024]
In the rotary shaft 3, a portion on which the rotor 6 is fitted and pivotally supported by the bearings A, B, and C is referred to as a main shaft portion 3 a, and a balancer portion 3 b is provided at a right end portion in the drawing of the main shaft portion. Further, a crank portion 3c is provided integrally with the main shaft portion in an eccentric manner. A boss portion 11c provided integrally with the orbiting scroll 11 is rotatably engaged with the crank portion 3c.
[0025]
The orbiting scroll 11 includes an end plate portion 11a provided with a boss portion 11c, and a spiral wing portion 11b that projects integrally on the upper surface side of the end plate portion 11a.
The fixed scroll 12 includes an end plate portion 12 a and a spiral wing portion 12 b that protrudes integrally on the lower surface side of the end plate portion 12 a and meshes with the wing portion 11 b of the orbiting scroll 11.
[0026]
A pair of compression spaces a is formed by the end plate portions 11a and 12a and the wing portions 11b and 12b of the orbiting and fixed scrolls 11 and 12, and a refrigerant gas that is a compressed gas is taken in from the peripheral end side, and the center portion While moving to the side, the volume is reduced, and the compression action can be performed.
[0027]
A discharge port 13 is provided through the central portion of the fixed scroll end plate portion 12a so as to communicate with the spiral center of the compression space a. A valve cover 14 is attached to the end face of the end plate portion 12 a to form a high-pressure discharge chamber 15 that is a sealed space facing the discharge port 13.
[0028]
A discharge pipe (not shown) is connected to the high pressure discharge chamber 15. The discharge pipe extends through the sealed case 1 and communicates with a condenser of a refrigeration cycle (not shown).
[0029]
Further, in the figure of the sealed case 1, a suction pipe 16 is connected to the upper center and communicates with the internal space of the case 1. The suction pipe 16 communicates with an evaporator of a refrigeration cycle not shown here.
[0030]
The auxiliary bearing 21 is provided with a positive displacement oil pump 17. An oil suction pipe 18 extends from the oil pump 17, and a filter 18 a attached to this end is immersed in the lubricating oil in the oil reservoir 19 formed at the inner bottom of the sealed case 1.
[0031]
Next, the bearing tool will be described in detail.
The said 1st bearing tool A inserted in the site | part adjacent to the balancer part 3b which is the rightmost site | part of the main-shaft part 3a in the rotating shaft 3 is a roller bearing.
[0032]
The second bearing tool B is a sliding bearing which is provided at a portion opposite to the balancer portion 3b with respect to the first bearing tool A and is also called a lead bronze bearing. The third bearing tool C provided in the auxiliary bearing 21 is a ball bearing.
[0033]
From the processing accuracy conditions of the rotating shaft 3 and the support frame 2 and the auxiliary bearing 21, clearances (gap) generated between the bearings A, B, C and the rotating shaft 3 are set to the following conditions.
[0034]
As shown in FIG. 2, the clearance between the roller bearing A and the rotary shaft 3 is Ca, the clearance between the slide bearing B and the rotary shaft 3 is Cb, and the clearance between the ball bearing C and the rotary shaft 3 is When Cc
(1) Ca <Cb
(2) Cb> Cc
(3) Cb <75 μm
It is.
[0035]
Thus, when the motor unit 7 is energized and the compression mechanism unit 4 is driven, the low-pressure refrigerant gas evaporated by the evaporator is introduced into the sealed case 1 via the suction pipe 16 and fills the internal space.
[0036]
This refrigerant gas is sucked into the outer periphery of the compression space a formed by the orbiting scroll 11 and the fixed scroll 12. Then, as the orbiting scroll 11 turns orbits, it is gradually transferred to the center and compressed by reducing the space capacity.
[0037]
When the pressure rises to a predetermined pressure, the high-pressure refrigerant gas is discharged from the discharge port 13 to the high-pressure discharge chamber 15 in the valve cover 14 and is filled. Further, it is led to an external condenser through a discharge pipe communicating with the high pressure discharge chamber 15.
[0038]
In this condenser, the high-pressure refrigerant gas is condensed and converted into a liquid refrigerant, and then adiabatic expansion is performed. Further, the refrigerant is led to the evaporator and evaporated, and the air-conditioned room is cooled. The evaporative refrigerant is again sucked from the suction pipe 16 of the compressor and circulates in the above cycle.
[0039]
As shown in FIG. 3, when the crank part 3c of the rotating shaft 3 engaged with the orbiting scroll receives a compressive load F along with the orbiting motion of the orbiting scroll 11, the rotating shaft is connected to each bearing tool AC. Move within the clearance.
[0040]
As described above, the clearance between the roller bearing A and the rotary shaft 3 is Ca, the clearance between the slide bearing B and the rotary shaft 3 is Cb, and the clearance between the ball bearing C and the rotary shaft 3 is as described above. (1) Ca <Cb and (2) Cb> Cc, the compression load F applied to the rotary shaft 3 is received by the roller bearing A and the ball bearing C.
[0041]
In other words, the rotary shaft 3 receives a compressive load within the range of the clearance between the roller bearing A and the ball bearing C to move the shaft, and the sliding bearing B does not receive the compressive load. In addition, since the roller bearing A and the ball bearing C are pivotally supported at a distance that is as long as possible with respect to the rotating shaft 3, the rotating shaft is not inclined and stable operation is obtained.
[0042]
Even if the rotary shaft 3 receives the maximum compressive load and the rotary shaft 3 is inclined, (3) a motor gap that is a gap between the stator 5 and the rotor 6 can be secured by 0.20 mm or more under the condition of Cb <75 μm. . That is, the motor gap can always be properly maintained under any conditions, and start-up failure is prevented.
[0043]
For the above reasons, the whirling of the rotor 6 can be suppressed to the maximum, the generation of magnetic force is stabilized, and the reduction of the rotational torque is prevented. For example, if the drive torque is smaller than the compression load or thrust load in the compression mechanism section 4, the drive will be defective, and if the whirling of the rotor 6 becomes large, the vibration will also increase, but starting failure can be prevented from the setting described above. There is no contact with the rotor.
[0044]
The rotary shaft 3 is pivotally supported by a roller bearing A that is a first bearing tool and a slide bearing B that is a second bearing tool in a support frame 2 that is a main bearing. Assuming that the ball bearing C, which is a bearing device, is pivotally supported, the setting of the clearances of the bearings A, B, and C with respect to the rotary shaft 3 is as follows:
Limited to Ca <Cb.
[0045]
However, in the actual clearance, in addition to the above condition (1), the relationship of Ca = Cb and Ca> Cb remains.
In the case of Ca = Cb, it is allowed because it is close to the condition of (1), but setting of the condition of Ca> Cb is not allowed at all.
[0046]
In the case of Ca> Cb, as shown in FIG. 4, when the rotary shaft 3 is moved in a state of receiving the compression load F, it does not contact the roller bearing A but contacts the sliding bearing B. Since the plain bearing B is formed by winding a thin plate, which is a lead bronze plate, around a shaft, if it receives a large compressive load, the rotary shaft 3 cannot be pivotally supported and is easily locked.
[0047]
5A specifically shows the clearance condition Ca <Cb of the present invention, and FIG. 5B specifically shows the previous clearance condition Ca> Cb.
Explaining with the actually measured values in FIG. 6A, the ratio of the load applied to each bearing is 122% in the roller bearing A when the compression load F applied to the rotating shaft 3 is 100%, but 0% in the slide bearing. %, 22% for ball bearings.
[0048]
On the other hand, under the condition of Ca> Cb in FIG. 5B, when the compressive load F applied to the rotary shaft 3 is 100%, the ratio of the load applied to each bearing is 0% for the roller bearing A and the slip The bearing B is 137%, and the ball bearing C is 37%.
[0049]
That is, under the condition of Ca> Cb, the roller bearing A does not receive a load and most of it is received by the slide bearing B. Moreover, the slide bearing B at this time receives a load larger than the load received by the roller bearing A under the setting condition (Ca <Cb) of the present invention, and the reliability of the single product is low, so that the rotary shaft 3 is locked. Easy to reach.
[0050]
Further, the rotary shaft 3 is horizontal and is a so-called horizontal type. The rotating shaft 3 is affected by the gravity of the rotor 6 of the motor unit 7, which is heavy in weight along the axial direction.
[0051]
However, in the present invention, the rotating shaft 3 is pivotally supported on the support frame 2 by way of the first bearing tool A and the second bearing tool B at one side of the rotor 6 fitting portion and at the other side. The auxiliary bearing 21 is pivotally supported via the third bearing tool C.
[0052]
That is, the scroll type compressor of the present invention is a horizontal type, and the entire weight of the rotor 6 is applied to the rotary shaft 3 and is affected by gravity. However, since the above structure is adopted, the rotary shaft 3 Stable operation without locking.
[0053]
In addition, although the scroll compressor of the said Example demonstrated as what comprises the refrigerating cycle of an air conditioner, it is not limited to this, It can be used as a compressor which compresses other to-be-compressed gas.
[0054]
【The invention's effect】
As described above, according to the present invention, when the clearance between the first bearing tool and the rotating shaft is Ca and the clearance between the second bearing tool and the rotating shaft is Cb, the relationship Ca <Cb is set. Therefore, the compression load during operation is received by the roller bearing, which is the first bearing tool, and the auxiliary bearing, which is the third bearing tool. The effect which can aim at the improvement of property is produced.
[0055]
Since the clearance between the second bearing tool and the rotating shaft is Cb, and the clearance between the third bearing tool provided on the auxiliary bearing and the rotating shaft is Cc, the relationship Cb> Cc is set. Because the compression load during operation is received by the roller bearing as the first bearing tool and the secondary bearing as the third bearing tool, the tilt of the rotating shaft can be minimized and the lock can be reliably prevented. The effect which can aim at improvement of is produced.
[0056]
Further , when the driving means is an electric motor composed of a rotor and a stator, and the clearance between the first bearing tool and the rotating shaft is Ca, the relationship Ca <75 μm is set. Therefore, even if the rotating shaft is inclined, the motor gap Can be maintained properly, there is no start-up failure, and the reliability can be improved.
[0057]
In addition , since the fixed scroll, the orbiting scroll, the rotating shaft, the pivoting means, and the driving means are all oriented horizontally and the compressor is placed horizontally, the rotating shaft is made horizontal so that the rotating shaft Although gravity acts on other parts, the influence of gravity is suppressed to the minimum, smooth rotation is maintained, and the effect of improving the reliability is achieved.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a horizontal scroll compressor according to an embodiment of the present invention.
FIG. 2 is a diagram schematically illustrating a relationship of each bearing tool with respect to a rotation shaft in the embodiment.
FIG. 3 is a diagram schematically illustrating a relationship in a state where the rotation shaft receives a compressive load in the embodiment.
FIG. 4 is a diagram schematically showing a relationship in a state where a rotating shaft receives a compressive load under conditions different from those of the present invention.
FIG. 5A is a diagram for explaining a load applied to each bearing of the present invention.
(B) is a figure explaining the load concerning each bearing on the conditions different from this invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 12 ... Fixed scroll, 11 ... Orbiting scroll, 3c ... Crank part, 3a ... Main shaft part, 3 ... Rotating shaft, A ... 1st bearing tool (roller bearing), B ... 2nd bearing tool (slide bearing), 2 ... main bearing (support frame), C ... third bearing tool (ball bearing), 21 ... sub-bearing, 5 ... stator, 6 ... rotor, 7 ... motor part.

Claims (3)

A fixed scroll with wings;
A orbiting scroll having a wing portion meshing with the wing portion of the fixed scroll, and forming a compression space therebetween,
A rotating shaft having a crank portion rotatably engaged with the orbiting scroll, the main shaft portion being provided continuously with the crank portion;
Pivoting means for pivotally supporting the main shaft portion of the rotating shaft;
A scroll type compressor that includes a driving unit that rotationally drives a rotary shaft pivotally supported by the pivotal support unit, and orbits the orbiting scroll to suck in the compressed gas into the compression space and compresses and discharges the compressed gas.
The pivot means is
A main bearing that pivotally supports one end of the main shaft portion of the rotating shaft via a roller bearing as a first bearing tool and a slide bearing as a second bearing tool;
It consists of a secondary bearing that pivotally supports the other end of the main shaft part via a third bearing tool,
The first bearing tool is provided at a position farther than the second bearing tool with respect to the third bearing tool,
When the clearance between the first bearing tool and the rotating shaft is Ca, the clearance between the second bearing tool and the rotating shaft is Cb , and the clearance between the third bearing tool and the rotating shaft is Cc ,
Ca <Cb
Cb> Cc
A fluid compressor characterized by being set to a relationship of The driving means is an electric motor including a rotor fitted on a rotating shaft and a stator arranged with a narrow gap on the outer periphery of the rotor,
When the clearance between the first bearing tool and the rotating shaft is Ca,
2. The fluid compressor according to claim 1, wherein a relationship of Ca <75 [mu] m is set. 2. The scroll compressor according to claim 1, wherein the fixed scroll, the orbiting scroll, the rotary shaft, the pivot support means, and the drive means are all horizontally oriented and are horizontally installed as a compressor. .

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