KR102640864B1 - Scroll compressor - Google Patents

Abstract

The scroll compressor is installed between a fixed scroll fixed within the housing, a turning scroll that engages with the fixed scroll, a rotating shaft that supports and turns the turning scroll on an eccentric axis eccentric from the main axis, and a bearing of the turning scroll and the eccentric axis, It includes a slide bush mechanism that changes the pressing force of the orbiting scroll against the fixed scroll by causing the amount of eccentricity to change due to the gas load applied to the orbiting scroll according to the rotation speed of the rotation shaft.

Description

Scroll compressor{SCROLL COMPRESSOR}

The present invention relates to scroll compressors.

The scroll compressor has a fixed scroll and an orbiting scroll that rotates with respect to the fixed scroll, and each of the spiral-shaped wraps is formed on the opposing surfaces of the mirror plates of the fixed scroll and the orbiting scroll, and the laps are engaged with each other to form a plurality of coils. In addition to forming a compression chamber, a slide bush having a slide surface forming a predetermined angle with respect to the load direction of the gas in the compression chamber is interposed on the eccentric axis of the rotating shaft that drives the orbiting scroll, so that the load of the gas in the compression chamber is It is configured so that when applied, the amount of eccentricity of the eccentric shaft increases.

Here, when the load of the gas in the compression chamber is applied, if a configuration is adopted in which the eccentricity of the orbiting scroll increases no matter what the rotation speed of the rotation axis of the orbiting scroll is, for example, if the rotation speed of the rotation axis of the orbiting scroll becomes high speed, There is a problem in which excessive pressing force occurs on the fixed scroll of the orbiting scroll.
Prior document Japanese Patent Publication No. 2009-235991 (title of the invention: scroll compressor, publication date: October 15, 2009) discloses a conventional scroll compressor.

The purpose of the present invention is to suppress the occurrence of excessive pressing force on the fixed scroll of the orbiting scroll.

A scroll compressor according to an embodiment of the present invention includes a fixed scroll fixed within a housing, an orbiting scroll that rotates in engagement with the fixed scroll, a rotation shaft that supports and rotates the orbiting scroll on an eccentric shaft eccentric from the main axis, and the orbiting scroll. A slide bush mechanism that is installed between a bearing and the eccentric shaft and changes the pressing force of the orbiting scroll against the fixed scroll by changing the amount of eccentricity by the gas load applied to the orbiting scroll according to the rotation speed of the rotation shaft. Includes.

The slide bush mechanism suppresses the pressing force of the orbiting scroll against the fixed scroll when the rotation speed of the rotation shaft becomes high, and when the rotation speed of the rotation shaft becomes low, the orbiting scroll can press the fixed scroll. there is.

The slide bush mechanism can suppress the pressing force of the orbiting scroll against the fixed scroll by suppressing the amount of eccentricity on the main axis of the orbiting scroll.

The slide bush mechanism may include a slide bush fitted into the bearing of the orbiting scroll, and an inner bush installed between the slide bush and the eccentric shaft and fitted with the eccentric shaft.

The center of gravity of the slide bush and the inner bush may be at a position delayed in the rotation direction of the rotation shaft from a straight line connecting the center of the main shaft and the center of the eccentric shaft.

The slide bush and the inner bush each have a first slide surface and a second slide surface, and the first slide surface and the second slide surface can be in contact with each other so that the slide bush rotates according to the rotation of the inner bush. there is.

The eccentric shaft may include a stopper that limits rotation of the inner bush, and the inner bush may include a protrusion that contacts the stopper to limit rotation of the inner bush.

A gap is formed between the slide bush and the inner bush, and the first slide surface of the slide bush can slide along the second slide surface with respect to the inner bush by the gap.

A first torque generated by rotation of the bearing of the orbiting scroll and a second torque generated by centrifugal force on the slide bush and inner bush may be applied to the slide bush and the inner bush.

The stopper may include a first stopper that limits counterclockwise rotation of the inner bush and a second stopper that limits clockwise rotation of the inner bush.

When the rotation speed of the rotation shaft is low, the first torque is greater than the second torque, so the inner bush is a horizontal line where a straight line connecting the center of the eccentric shaft and the centers of the slide bush and the inner bush passes through the center of the eccentric shaft. When rotated counterclockwise by 45 degrees, the protrusion may contact the first stopper to limit rotation.

When the inner bush is rotated counterclockwise by 45 degrees, the slide bush moves in a direction in which the eccentricity of the first slide surface increases along the second slide surface by the gap due to the load of gas on the orbiting scroll. The slide can be moved to .

When the rotation speed of the rotation shaft is high, the first torque is smaller than the second torque, so that the inner bush is a horizontal line where a straight line connecting the center of the eccentric shaft and the centers of the slide bush and the inner bush passes through the center of the eccentric shaft. When rotated clockwise by 45 degrees based on , the protrusion may contact the second stopper to limit rotation.

In a state in which the inner bush is rotated clockwise by 45 degrees, the slide bush moves in a direction in which the eccentricity of the first slide surface decreases along the second slide surface by the gap due to the load of gas on the orbiting scroll. Slides can be moved.

The first torque may change as a linear function of the rotation speed of the rotation shaft, and the second torque may change as a quadratic function of the rotation speed of the rotation shaft.

In addition, a scroll compressor according to an embodiment of the present invention includes a fixed scroll fixed within a housing, a turning scroll engaged with the fixed scroll, a rotating shaft supporting and rotating the turning scroll on an eccentric shaft eccentric from the main axis, and the turning scroll. It is installed between the bearing of the scroll and the eccentric shaft, and includes a slide bush mechanism that changes the pressing force of the orbiting scroll with respect to the fixed scroll, and the slide bush mechanism is fitted into the bearing of the orbiting scroll, A slide bush having one slide surface, an inner bush installed between the slide bush and the eccentric shaft so that the eccentric shaft is fitted, and having a second slide surface in contact with the first slide surface so that the slide bush rotates together. It includes, and the first slide surface of the slide bush slides along the second slide surface of the inner bush by the gas load applied to the orbiting scroll according to the rotation speed of the rotation shaft so that the amount of eccentricity changes. .

The slide bush mechanism suppresses the pressing force of the orbiting scroll against the fixed scroll when the rotation speed of the rotation shaft becomes high, and when the rotation speed of the rotation shaft becomes low, the orbiting scroll can press the fixed scroll. there is.

The slide bush mechanism can suppress the pressing force of the orbiting scroll against the fixed scroll by suppressing the amount of eccentricity on the main axis of the orbiting scroll.

At least one of the slide bush and the inner bush may include a switching weight for adjusting the center of gravity of the slide bush and the inner bush.

At least one of the slide bush and the inner bush may include a conversion hole for adjusting the center of gravity of the slide bush and the inner bush.

According to the present invention, it is possible to suppress the occurrence of excessive pressing force on the fixed scroll of the orbiting scroll.

1 is an axial cross-sectional view of a scroll compressor according to this embodiment.
Figure 2 is a top view of the slide bush mechanism.
Figure 3a is a diagram showing the state of the slide bush mechanism when the rotation speed of the rotation shaft is low.
Figure 3b is a diagram showing the state of the slide bush mechanism when the rotation speed of the rotation shaft is high.
Figure 4 is a graph showing changes in bearing torque ( T _sh ) and centrifugal force torque (T _c ) when the rotation speed of the rotating shaft changes.
Figure 5 is a top view of a first modified example of the slide bush mechanism.
Figure 6 is a top view of a second modification of the slide bush mechanism.

이하, 첨부 도면을 참조하여, 본 발명의 실시 형태에 대하여 상세히 설명한다.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Fig. 1 is an axial cross-sectional view of the scroll compressor 1 according to the present embodiment.

The scroll compressor 1 is a compressor widely used for air conditioners, refrigerators, and heat pumps. Figure 1 shows a longitudinal cross-sectional view of a closed scroll compressor used in the refrigerant circuit of an air conditioning device.

The scroll compressor 1 is an example of a compression unit 10 that compresses the refrigerant, a drive motor 20 that drives the compression unit 10, and a housing that accommodates the compression unit 10 and the drive motor 20. It is provided with a casing (30). In addition, the scroll compressor 1 according to the present embodiment is a vertical scroll compressor arranged so that the axial direction of the later-described rotation shaft 23 of the drive motor 20 is the direction of gravity. Hereinafter, the axial direction of the rotation axis 23 may be referred to as the “upward direction,” the upper side as seen in FIG. 1 may be referred to as the “upper side,” and the lower side may be referred to as the “lower side.” In addition, although the description here takes a vertical scroll compressor as an example, the present invention is also applicable to a horizontal scroll compressor.

First, the compression unit 10 will be described.

The compression unit 10 includes a fixed scroll 11 fixed within the casing 30, an orbiting scroll 12 that rotates in engagement with the fixed scroll 11, and a fixed scroll 11 fixed to the casing 30. ) and an Oldham ring 14 that rotates the rotating scroll 12 without rotating it.

The fixed scroll 11 includes a cylindrical cylindrical portion 111, an end plate 112 covering the upper opening of the cylindrical portion 111, and a radial outer portion from the lower end of the cylindrical portion 111. It is provided with a protrusion 113 that protrudes. Additionally, the fixed scroll 11 has a fixed side vortex body 114 that protrudes downward from the lower end of the end plate 112 and is formed in a vortex shape when viewed from below. The material of the fixed scroll 11 may be cast iron, for example, FC250 gray cast iron.

A radial through hole 111a is formed in the cylindrical portion 111. This through hole 111a functions as an intake port for sucking refrigerant into the space surrounded by the cylindrical portion 111, the end plate 112, and the orbiting scroll 12.

A vertical through hole 112a is formed in the central portion of the end plate 112. This through hole 112a functions as a discharge port for discharging refrigerant from the space surrounded by the end plate 112, the fixed side swirl body 114, and the orbiting scroll 12.

The fixed scroll 11 configured as above is fixed to the frame 13 by positioning means such as a bolt or a positioning pin passed through a vertical through hole formed in the protrusion 113.

The orbiting scroll 12 includes a disc-shaped end plate 121, a rotating side vortex 122 that protrudes upward from the upper end of the end plate 121 and is formed in a swirl shape when viewed from above, and an end plate. It is provided with a cylindrical cylindrical portion 123 that protrudes downward from the lower end of 121. The material of the orbiting scroll 12 may be FC material or FCD material.

The swirling side vortex body 122 is a swirling body in a shape that engages with the fixed side swirling body 114 of the fixed scroll 11. And, the orbiting side swirl body 122 and the fixed side swirl body 114 of the fixed scroll 11 are the cylindrical portion 111 and the end plate 112 of the fixed scroll 11 and the orbiting scroll 12. It is disposed in the space formed between the end plates 121 and defines a compression chamber 15. Then, by circularly moving the swirling-side swirling body 122 with respect to the fixed stationary-side swirling body 114, the volume of the compression chamber 15 is reduced and the refrigerant is compressed. In other words, the internal space between the stationary-side swirl body 114 and the rotating-side swirl body 122 contracts toward the center of rotation, compressing the refrigerant.

An eccentric shaft 232, which will be described later, of the rotating shaft 23 is inserted into the cylindrical portion 123 through a sliding bearing. In this way, the cylindrical portion 123 functions as a bearing of the eccentric shaft 232.

The frame 13 includes a cylindrical first cylindrical portion 131 and a cylindrical second cylindrical portion 132 that protrudes downward from the lower end of the first cylindrical portion 131. And, in the frame 13, the outer peripheral surface of the first cylindrical portion 131 is fixed to the central casing 31 of the casing 30, which will be described later. In addition, the rotation shaft 23, which will be described later, of the drive motor 20 is inserted inside the first cylindrical portion 131 and the second cylindrical portion 132 through a journal bearing. In this way, the frame 13 also functions as a bearing that rotatably supports the rotating shaft 23.

On the outer periphery of the first cylindrical portion 131, a protruding portion 131a is provided that protrudes upward from the upper end surface. A female thread is formed in this protrusion 131a, and a bolt passed through a through hole formed in the protrusion 113 of the fixed scroll 11 is fastened to this female thread, so that the fixed scroll 11 is attached to the frame 13. It is installed.

Additionally, the first cylindrical portion 131 is formed with a first concave portion 13lb and a second concave portion 13lc that are concave downward from the upper end surface. In the radial direction, the first concave portion 13lb is formed in the central portion, and the second concave portion 13lc is formed between the first concave portion 13lb and the protruding portion 131a. Then, the cylindrical portion 123 of the orbiting scroll 12 is inserted into the first concave portion 13lb. In the second concave portion 13lc, an Oldham ring 14 is disposed between the frame 13 and the orbiting scroll 12 and prevents the rotation of the orbiting scroll 12.

In addition, the first cylindrical portion 131 is formed with a groove 131d extending in the vertical direction from the center of the outer peripheral portion to the lower portion. Additionally, a radial communication hole 131e is formed in the first cylindrical portion 131 to communicate with the inside of the first concave portion 13lb and the groove 131d.

A rotating shaft 23 is fitted to the inner periphery of the second cylindrical portion 132 via a journal bearing, and the second cylindrical portion 132 functions as a bearing that rotatably supports the rotating shaft 23. .

In addition, the above-described compression section 10 is formed with a discharge passage (not shown) that discharges the refrigerant compressed by the fixed scroll 11 and the orbiting scroll 12. The discharge passage has one end connected to a through hole 112a of the end plate 112 for discharging the refrigerant from the space surrounded by the fixed scroll 11 and the orbiting scroll 12, and the other end is connected to the frame within the casing 30. It is connected to the space below (13).

Next, the drive motor 20 will be described.

The drive motor 20 is fixed to the casing 30 below the compression section 10.

The drive motor 20 includes a stator 21 constituting a stator, a rotor 22 constituting a rotor, a rotation axis 23 that supports the rotor 22 and rotates with respect to the casing 30, and a rotation axis ( It is provided with a support member 24 that rotatably supports 23).

The stator 21 has a stator body 211 and a coil 212 wound around the stator body 211.

The stator body 211 is a laminated body in which multiple electrical steel sheets are stacked, and has a schematic shape of a cylinder. In addition, the diameter of the outer peripheral surface of the stator body 211 is formed to be larger than the diameter of the inner peripheral surface of the central casing 31, which will be described later, of the casing 30, and the stator main body 211 (stator 21) is formed in the central casing. It is inserted into (31) with an interference fit. Examples of methods for fitting the stator body 211 into the central casing 31 include shrink fitting or press fitting.

Additionally, the stator main body 211 has a plurality of teeth (not shown) in the circumferential direction on the inner portion facing the outer periphery of the rotor 22. The coil 212 is disposed in a slot (not shown) existing between adjacent teeth. In the stator 21 according to the present embodiment, the coil 212 may be a concentrated coil inserted into a slot existing between a plurality of adjacent teeth.

The rotor 22 is a laminate in which multiple ring-shaped electrical steel sheets are stacked, and has an overall cylindrical shape. The diameter of the inner peripheral surface of the rotor 22 is smaller than the diameter of the outer peripheral surface of the rotating shaft 23, and the rotor 22 is inserted into the rotating shaft 23 with an interference fit. An example of a method of fitting the rotating shaft 23 into the rotor 22 is press fitting. Then, the rotor 22 is fixed to the rotation shaft 23 and rotates together with the rotation shaft 23. Additionally, the rotor 22 may have a permanent magnet embedded therein.

The diameter of the outer peripheral surface of the rotor 22 is smaller than the diameter of the inner peripheral surface of the stator body 211 of the stator 21, and a gap is formed between the rotor 22 and the stator 21.

The rotating shaft 23 has a main shaft 231 into which the rotor 22 is fitted, and an eccentric shaft 232 that is installed on the upper part of the main shaft 231 and has a shaft that is eccentric from the shaft center of the main shaft 231. .

The lower part of the main shaft 231 is rotatably supported by the support member 24, and the upper part is rotatably supported by the frame 13 of the compression unit 10. Additionally, the eccentric shaft 232 is rotatably supported on the cylindrical portion 123 of the orbiting scroll 12.

And, a through hole 233 is formed on the rotating shaft 23 to penetrate the rotating shaft 23 in the axial direction. In addition, the rotating shaft 23 has a first communication hole 234 that communicates the through hole 233 and the bearing of the support member 24, and a second communication hole that communicates the through hole 233 and the bearing of the frame 13. A third communication hole 236 that communicates the hole 235, the through hole 233, and the bearing of the cylindrical portion 123 is formed in the radial direction.

The support member 24 has a cylindrical first cylindrical portion 241 and a cylindrical second cylindrical portion 242 that protrudes downward from the lower end of the first cylindrical portion 241. . And, the support member 24 is fixed to the central casing 31 so that the outer peripheral surface of the first cylindrical portion 241 faces the inner peripheral surface of the central casing 31 of the casing 30, which will be described later. And, a rotating shaft 23 is inserted inside the first cylindrical portion 241 and the second cylindrical portion 242 through a journal bearing. In this way, the support member 24 functions as a bearing that rotatably supports the rotation shaft 23.

Additionally, a hole (not shown) or a groove (not shown) is formed in the first cylindrical portion 241 to communicate with the space above and below the first cylindrical portion 241 .

A pump 243 for pumping lubricating oil is mounted at the lower end of the second cylindrical portion 242 of the support member 24.

Next, the casing 30 will be described.

The casing 30 includes a cylindrical central casing 31 disposed at the center in the vertical direction, an upper casing 32 covering the upper opening of the central casing 31, and a lower casing covering the lower opening of the central casing 31. It is provided with a casing (33). In addition, the casing 30 has a discharge part 34 that discharges the high-pressure refrigerant compressed in the compression part 10 to the outside of the casing 30, and a suction part 35 that suctions the refrigerant from the outside of the casing 30. ) is provided.

As described above, the frame 13 of the compression unit 10, the stator 21 of the drive motor 20, and the support member 24 are fixed to the central casing 31. Additionally, the discharge portion 34 and the suction portion 35 are constructed by inserting a pipe into a through hole formed in the central casing 31. The suction portion 35 is also installed at a position corresponding to the through hole 111a formed in the cylindrical portion 111 of the fixed scroll 11, and rotates with the fixed scroll 11 from the outside of the casing 30. Refrigerant is sucked into the space surrounded by the scroll (12).

The lower casing 33 is formed in a bowl shape and can store lubricating oil.

Next, the operation of the scroll compressor 1 will be described.

When the drive motor 20 of the scroll compressor 1 is driven, the rotation shaft 23 rotates, and the orbiting scroll 12 inserted into the eccentric shaft 232 of the rotation shaft 23 moves with respect to the fixed scroll 11. Turn. As the orbiting scroll (12) rotates with respect to the fixed scroll (11), low-pressure refrigerant is sucked into the space surrounded by the fixed scroll (11) and the orbiting scroll (12) from the outside of the casing (30) through the suction portion (35). do. Then, this refrigerant is compressed according to the change in volume of the compression chamber 15. The high-pressure refrigerant compressed in the compression chamber (15) flows out downward from the compression section (10).

The high-pressure refrigerant flowing out of the compression section 10 is discharged to the outside of the casing 30 through the discharge section 34 installed in the casing 30. Additionally, in the process of being discharged to the outside of the casing 30, it circulates through the gap between the rotor 22 and the stator 21 or the gap between the stator 21 and the central casing 31. Then, the high-pressure refrigerant discharged to the outside of the casing 30 is sucked in again from the suction section 35 after each cycle of condensation, expansion, and evaporation in the refrigerant circuit.

Meanwhile, the lubricating oil stored in the lower casing 33 of the casing 30 is pumped up by the pump 243 and rises through the through hole 233 formed in the rotating shaft 23. The raised lubricating oil is supplied to each bearing of the rotating shaft 23 through the first communication hole 234, the second communication hole 235, and the third communication hole 236 formed in the rotating shaft 23, or the compression unit 10. It is supplied to the sliding moving part of. In addition, the lubricating oil supplied to the sliding part of the compression unit 10 or the lubricating oil supplied to the bearing of the rotating shaft 23 through the second communication hole 235 and the third communication hole 236 is connected to the frame 13. It returns to the lower casing 33 through the formed communication hole 131e and groove 131d, the gap between the rotor 22 and the stator 21, the axial hole formed in the support member 24, etc., It is stored in the lower part of the casing (30). In this process and the process of distributing the gap between the rotor 22 and the stator 21 before the high-pressure refrigerant is discharged to the outside of the casing 30, the lubricant and refrigerant cool the drive motor 20 and flow to the low-pressure side. It flows. The lubricating oil that circulated with the high-pressure refrigerant is then separated from the refrigerant and stored in the lower part of the casing (30).

However, there are cases where such a scroll compressor 1 is equipped with a slide bush mechanism. The slide bush mechanism is a mechanism that improves the adhesion effect by pressing the orbiting scroll 12 to the fixed scroll 11 using the compressive load of the refrigerant gas sucked through the through hole 111a.

Meanwhile, while wide ranges are being demanded in recent years, it is also required that the rotation speed of the rotation shaft 23 can be set widely from low speed to high speed.

However, in the existing slide bush mechanism, when the rotation speed of the rotation shaft 23 becomes high, excessive pressing force on the fixed scroll 11 of the orbiting scroll 12 is generated under the influence of centrifugal force. Therefore, the existing slide bush mechanism could not be mounted on the scroll compressor 1 where the rotation speed of the rotation shaft 23 is variable.

Therefore, this embodiment is a novel slide bush mechanism that causes the slide bush mechanism to act when the rotation speed of the rotation shaft 23 is low, and prevents excessive pressing force from being generated when the rotation speed of the rotation shaft 23 is high. 40), the scroll compressor 1 that can exert the adhesion effect only when the rotation speed of the rotation shaft 23 is low is realized.

Figure 2 is a top view of the slide bush mechanism 40. FIG. 2 shows the state of the inside of the casing 30 when viewed from above after removing the compression portion 10 of the scroll compressor 1 of FIG. 1.

As shown, the slide bush mechanism 40 includes a slide bush 41 and an inner bush 42 on the main shaft 231 of the rotation shaft 23. The slide bush 41 is an example of a first bush installed on the outermost side around the eccentric axis 232 of the rotating shaft 23 and fitted into the bearing of the orbiting scroll 12. The inner bush 42 is installed between the slide bush 41 and the eccentric shaft 232, and is an example of a second bush into which the eccentric shaft 232 is fitted.

Additionally, the slide bush 41 and the inner bush 42 have a first slide surface 411 and a second slide surface 421, respectively. When the first slide surface 411 and the second slide surface 421 contact each other in the vertical plane, the slide bush 41 rotates according to the rotation of the inner bush 42. For example, the slide bush 41 and the inner bush 42 rotate around the eccentric shaft 232 without being shifted in the circumferential direction. However, the inner bush 42 has a protrusion 422, and its rotation is restricted by contacting the stoppers 232a and 232b of the eccentric shaft 232. Meanwhile, by providing a gap between the slide bush 41 and the inner bush 42, the slide bush 41 has the first slide surface 411 along the second slide surface 421 with respect to the inner bush 42. Slide is possible. For example, the slide bush 41 and the inner bush 42 can be shifted in the gap direction along the first slide surface 411 and the second slide surface 421. In addition, hereinafter, when simply referred to as “bush”, it means a member combining the slide bush 41 and the inner bush 42.

로 한다 (φ,

은 시계 방향을 정으로 한다).Here, as shown, in the top view of the slide bush mechanism 40, the center of the main axis 231 is set to point O, the center of the eccentric axis 232 is set to point E, and the center of the bush 231 is set to point E. Let the center of gravity be point (G). Additionally, the point G is assumed to be at a position that lags the straight line connecting the points O and E in the rotation direction of the rotation axis 23. In addition, let the length of the line segment OG be r, the length of the line segment EG be G _r , the angle formed by the line segment OG with respect to the line segment in the horizontal left direction of the drawing passing through the point (O) be ϕ, and let the point (E) be The angle formed by line segment EG with respect to the line segment in the horizontal left direction of the drawing is

(ϕ,

is assumed to be clockwise).

Additionally, in addition to compressive load and centrifugal load, torque load from two types of torque acts on the bush. One of these two types of torque is the first torque (hereinafter referred to as “bearing torque ( T _sh )”) generated by rotation of the cylindrical portion 123 (see Fig. 1) of the orbiting scroll 12. . Another of these two types of torque is the second torque (hereinafter referred to as “centrifugal torque (T _c ) ”) generated by centrifugal force (indicated by a white arrow in the figure) acting on the center of gravity of the bush.

Next, the state change of the slide bush mechanism 40 when the rotation speed of the rotation shaft 23 increases from low speed to high speed will be explained.

= -45°에서 안정된다. 이 상태에서는, 선회 스크롤(12)에 대한 가스의 압력 및 원심력에 의한 하중(이하, "선회 스크롤 하중(F_Total)"이라 한다)이 슬라이드 부시(41)의 제1슬라이드면(411)이 제2슬라이드면(411)을 따라 편심량이 증대하는 방향(파선 화살표로 나타내는 방향)으로 이동시키고, 선회 스크롤(12)은 고정 스크롤(11)로 가압된다. 이하에서는, 이 상태에서의 이너 부시(42)의 위치를 "포지션1"로 표기하기로 한다. 이 포지션1은, 슬라이드 부시 기구(40)가 기존의 슬라이드 부시 기구와 마찬가지의 구조가 되는 위치이다. 또한, 도3의 (a)의 상태는, 이너 부시(42)가 편심축(232)의 주위를 소정 각도까지 회전한 소정 상태 이외의 상태의 일례이다.FIG. 3A shows the state of the slide bush mechanism 40 when the rotation speed of the rotation shaft 23 is low. In this case, since the bearing torque ( T _sh ) is greater than the centrifugal force torque ( T _c ) , the protrusion 422 of the inner bush 42 is stable while in contact with the first stopper 232a of the eccentric shaft 232. do. in other words,

= Stable at -45°. In this state, the load due to the gas pressure and centrifugal force on the orbiting scroll 12 (hereinafter referred to as “orbiting scroll load (F _Total )”) is applied to the first slide surface 411 of the slide bush 41. 2 It is moved along the slide surface 411 in the direction in which the amount of eccentricity increases (the direction indicated by the broken arrow), and the orbiting scroll 12 is pressed by the fixed scroll 11. Hereinafter, the position of the inner bush 42 in this state will be denoted as “position 1”. This position 1 is a position where the slide bush mechanism 40 has the same structure as the existing slide bush mechanism. In addition, the state in Figure 3(a) is an example of a state other than the predetermined state in which the inner bush 42 rotates around the eccentric shaft 232 to a predetermined angle.

FIG. 3B shows the state of the slide bush mechanism 40 when the rotation speed of the rotation shaft 23 becomes high. In this case, since the centrifugal torque ( T _c ) is greater than the bearing torque ( T _sh ), the bush is along the eccentric axis 232, and the protrusion 422 of the inner bush 42 is aligned with the second axis of the eccentric axis 232. It rotates until it contacts the stopper (232b). As a result, the amount of eccentricity of the slide bush 41 is fixed and is not affected by the centrifugal force or the rotating scroll load on the bush. Here, the direction indicated by the broken arrow is an example of a predetermined direction in which the slide bush 41 can slide so that the amount of eccentricity is reduced by the load on the orbiting scroll 12. Hereinafter, the position of the inner bush 42 in this state will be denoted as “position 2”. This position 2 is a position where the slide bush mechanism 40 has the same structure as the fixed crank structure. 3B is an example of a predetermined state in which the inner bush 42 rotates around the eccentric shaft 232 to a predetermined angle, and 90° is used as an example of the predetermined angle.

In addition, here, as the state of the slide bush mechanism 40, two states are shown in FIGS. 3A and 3B, but it is not limited thereto. For example, the slide bush mechanism 40 may be in three or more states. That is, as the state of the slide bush mechanism 40, at least two states may be used, each state rotating around the eccentric axis 232 to an angle corresponding to each state.

Next, the state change of the slide bush mechanism 40 will be explained in more detail.

First, the bearing torque ( T _sh ) and centrifugal force torque ( T _c ) are expressed as the following equations (1) and (2), respectively.

은 회전축(23)의 회전 속도를 나타낸다. 또한, 도 2에서 나타낸 바와 같이, r은 주축(231)의 중심(O)으로부터 부시의 무게 중심(G)까지의 길이이며, G_r은 편심축(232)의 중심(E)으로부터 부시의 무게 중심(G)까지의 길이이며, φ은 주축(231)의 중심(O)으로부터 부시의 무게 중심(G)으로의 방향을 나타내는 각도이며,

은 편심축(232)의 중심(E)으로부터 부시의 무게 중심(G)으로의 방향을 나타내는 각도이다.Here, m represents the mass of the bush, D represents the diameter of the slide bush mechanism 40, L represents the height of the slide bush mechanism 40, and η represents the amount of lubricating oil supplied to the bearing of the eccentric shaft 232. represents the viscosity, and C represents the bearing radius clearance (length minus the radius of the slide bush 41 from the bearing radius of the eccentric shaft 232),

represents the rotation speed of the rotation shaft 23. In addition, as shown in Figure 2, r is the length from the center (O) of the main axis 231 to the center of gravity (G) of the bush, and G _r is the weight of the bush from the center (E) of the eccentric axis 232. It is the length to the center (G), and ϕ is the angle representing the direction from the center (O) of the main axis 231 to the center of gravity (G) of the bush,

is an angle indicating the direction from the center (E) of the eccentric axis 232 to the center of gravity (G) of the bush.

As can be seen from equations (1) and (2), both the bearing torque ( T _sh ) and the centrifugal force torque ( T _c ) increase as the rotation speed of the rotation shaft 23 increases, but the former increases at the rotation speed. There is a difference in characteristics in that the latter changes as a linear function, while the latter changes as a quadratic function of rotation speed.

이 변화한 경우에 무게 중심(G)은 G_r을 일정하게 유지한 채 E를 중심으로 하여 회전하므로, r 및 φ은

에 의존하는 값으로 된다. 식(1)의 우변에는

도 r도 φ도 없으므로, 베어링 토크(T _sh )는

에 의존하지 않고 일정해지지만, 식(2)의 우변에는

도 r도 φ도 있으므로, 원심력 토크( T _c )는

에 의해 다르다. 따라서, 도4에서는, 원심력 토크( T _c )의 변화를,

의 하한값인 -45° 및

의 상한값인 45°에 대하여 나타내고 있다. 실선이,

= -45°의 경우의 원심력 토크( T _c )이며, 파선이,

= 45°의 경우의 원심력 토크( T _c )이다. 도 4에 굵은 실선으로 나타낸 그래프로부터 알 수 있는 바와 같이, 회전 속도가 약 60(rps)보다도 고속으로 되면, 원심력 토크( T _c )가 베어링 토크(T _sh )보다 커지고, 부시가 편심축(232)을 따라 회전하여 그 위치는 포지션1로부터 포지션2로 전환된다. 여기서, 약 60(rps)은, 소정의 회전 속도 또는, 베어링 토크(T _sh )와 원심력 토크( T _c )의 대소 관계가 역전할 때의 회전 속도의 일례이다. 반대로, 도 4에 굵은 파선으로 나타낸 그래프로부터 알 수 있는 바와 같이, 회전 속도가 고속의 상태로부터 약 45(rps)보다도 저속으로 되면, 원심력 토크( T _c )가 베어링 토크(T _sh )보다 작아져, 부시의 위치는 포지션2로부터 포지션1로 전환된다. 또한, 이 경우의

의 상한값 및 하한값이나, 포지션1과 포지션2가 전환될 때의 회전수는, 설계 항목이며, 설계의 의도대로 변경해도 좋다.FIG. 4 is a graph showing changes in bearing torque ( T _sh ) and centrifugal force torque ( T _c ) when the rotation speed of the rotating shaft 23 changes. The thin line represents the change in bearing torque ( T _sh ), and the thick line represents the change in centrifugal torque ( T _c ) . Here, in Figure 2

In this case, the center of gravity (G) rotates around E while keeping G _r constant, so r and ϕ are

It becomes a value dependent on . On the right side of equation (1),

Since there is neither r nor ϕ, the bearing torque ( T _sh ) is

It becomes constant without depending on , but on the right side of equation (2)

Since there is neither r nor ϕ, the centrifugal torque ( T _c ) is

differs by Therefore, in Figure 4, the change in centrifugal torque ( T _c ) is,

The lower limit of -45° and

It is shown for 45°, which is the upper limit of . solid line,

= Centrifugal torque ( T _c ) at -45°, and the dashed line is,

= Centrifugal torque ( T _c ) at 45°. As can be seen from the graph shown by the thick solid line in FIG. 4, when the rotation speed becomes faster than about 60 (rps), the centrifugal force torque ( T _c ) becomes greater than the bearing torque ( T _sh ), and the bush becomes eccentric shaft 232. ), the position changes from position 1 to position 2. Here, about 60 (rps) is an example of a predetermined rotation speed or a rotation speed when the magnitude relationship between the bearing torque ( T _sh ) and the centrifugal force torque ( T _c ) is reversed. Conversely, as can be seen from the graph shown by the thick dashed line in FIG. 4, when the rotation speed decreases from a high speed to a speed lower than about 45 (rps), the centrifugal force torque ( T _c ) becomes smaller than the bearing torque ( T _sh ). , the position of the bush is switched from position 2 to position 1. Also, in this case

The upper and lower limits of and the rotation speed when position 1 and position 2 are switched are design items and may be changed according to design intent.

Next, a modified example of the slide bush mechanism 40 according to the present embodiment will be described.

From equation (2), it can be seen that the centrifugal torque ( T _c ) depends on the length (G r ) from the center (E) of the eccentric axis 232 to the center of gravity ( _G ) of the bush. Therefore, by adjusting the position of the center of gravity (G) of the bush, the magnitude of the centrifugal force torque (T _c ) can be adjusted.

Fig. 5 is a top view of a first modified example of the slide bush mechanism 40. FIG. 5 shows the state of the inside of the casing 30 when viewed from above after the compression unit 10 is removed from the scroll compressor 1 of FIG. 1.

The first modification of the slide bush mechanism 40 includes a slide bush 41 and an inner bush 42, and also includes a switching weight 423 connected to the inner bush 42. In this first modification, the position of the center of gravity G of the bush is adjusted by installing the switching weight 423. In addition, the switching weight 423 is connected to the inner bush 42 as described above, but a through hole is formed in a portion close to the upper surface of the main shaft 231 below the slide bush 41, and this through hole is formed. It can be arranged by stretching it on the outside of the slide bush 41. This through hole may be shaped so as not to interfere with the slide along the second slide surface 421 of the slide bush 41. Additionally, the height of the cylindrical portion 123 of the orbiting scroll 12 may be shortened by the height of the switching weight 423 so that the rotation of the orbiting scroll 12 is not hindered by the switching weight 423. . Alternatively, the switching weight 423 may be connected to the slide bush 41. In this sense, the switching weight 423 can be said to be an example of a convex part for adjusting the center of gravity that is connected to at least one of the slide bush 41 and the inner bush 42.

Fig. 6 is a top view of a second modified example of the slide bush mechanism 40. FIG. 6 shows the state of the inside of the casing 30 when viewed from above after the compression unit 10 is removed from the scroll compressor 1 of FIG. 1.

The second modification of the slide bush mechanism 40 includes a slide bush 41 and an inner bush 42, and a switching hole 413 is provided in the slide bush 41. In this second modification, the position of the center of gravity G of the bush is adjusted by providing the switching hole 413. Alternatively, the switching hole 413 may be provided in the inner bush 42. In this sense, the switching hole 413 can be said to be an example of a recess for adjusting the center of gravity provided in at least one of the slide bush 41 and the inner bush 42.

In this way, in this embodiment, when the rotation speed of the rotation shaft 23 becomes high, the slide surfaces 411 and 421 between the slide bush 41 and the inner bush 42 are applied to the orbiting scroll 12. The amount of eccentricity from the main axis 231 of the orbiting scroll 12 was suppressed by orienting the slide bush 41 in a predetermined slideable direction to reduce the amount of eccentricity. As a result, when the rotation speed of the rotation shaft 23 becomes high, it is possible to suppress the generation of excessive pressing force of the orbiting scroll 12 against the fixed scroll 11.

Additionally, in this embodiment, when the rotation speed of the rotation shaft 23 becomes high, the amount of eccentricity from the main shaft 231 of the orbiting scroll 12 is suppressed. However, this can be viewed more broadly as suppressing the pressing force of the orbiting scroll 12 against the fixed scroll 11 when the rotation speed of the rotation shaft 23 becomes high. Furthermore, it may be understood as changing the pressing force of the orbiting scroll 12 against the fixed scroll 11 according to the rotation speed of the rotation shaft 23.

Here, suppressing the amount of eccentricity from the main shaft 231 of the orbiting scroll 12 when the rotation speed of the rotation shaft 23 becomes high requires that the rotation speed of the rotation shaft 23 be low, as explained in this embodiment. In this case, the amount of eccentricity from the main axis 231 of the orbiting scroll 12 is increased, and when the rotation speed of the rotating shaft 23 is high, the amount of eccentricity from the main shaft 231 of the orbiting scroll 12 is fixed. It is assumed to be included. In addition, in order to suppress the pressing force of the orbiting scroll 12 against the fixed scroll 11 when the rotation speed of the rotation shaft 23 becomes high, the rotation speed of the rotation shaft 23 as described in this embodiment is low. In one case, the orbiting scroll 12 is pressed by the fixed scroll 11, and when the rotation speed of the rotation shaft 23 is high, the orbiting scroll 12 is not pressed against the fixed scroll 11. Let's do it.

1: Scroll compressor
11: Fixed scroll
12: Orbiting scroll
23: rotation axis
231: main axis
232: Eccentric axis
232a: first stopper
232b: Second stopper
40: Slide bush mechanism
41: Slide bush
411: First slide surface
421: Second slide surface
413: Transition Hall
42: Inner bush
422: protrusion
423: Transition weight

Claims (20)

A fixed scroll fixed within the housing;
an orbiting scroll rotating in engagement with the fixed scroll;
a rotation shaft that supports and rotates the orbiting scroll on an eccentric shaft eccentric from the main shaft; and
It is installed between the bearing of the orbiting scroll and the eccentric shaft, and changes the amount of eccentricity by the gas load applied to the orbiting scroll according to the rotation speed of the rotation shaft, thereby changing the pressing force of the orbiting scroll on the fixed scroll. Slide bush mechanism;
Including,
The slide bush mechanism includes a slide bush that is fitted into the bearing of the orbiting scroll, and an inner bush that is installed between the slide bush and the eccentric shaft and is fitted with the eccentric shaft,
A scroll compressor wherein the center of gravity of the slide bush and the inner bush is at a position delayed in the rotation direction of the rotation shaft from a straight line connecting the center of the main shaft and the center of the eccentric shaft. According to paragraph 1,
The slide bush mechanism suppresses the pressing force of the orbiting scroll against the fixed scroll when the rotation speed of the rotation shaft becomes high, and when the rotation speed of the rotation shaft becomes low, the orbiting scroll presses the fixed scroll. compressor. According to paragraph 2,
A scroll compressor wherein the slide bush mechanism suppresses the pressing force of the orbiting scroll against the fixed scroll by suppressing the amount of eccentricity on the main axis of the orbiting scroll. delete delete According to paragraph 1,
The slide bush and the inner bush each have a first slide surface and a second slide surface, and the first slide surface and the second slide surface are in contact with each other so that the slide bush rotates according to the rotation of the inner bush. compressor. According to clause 6,
The eccentric shaft includes a stopper that limits rotation of the inner bush, and the inner bush includes a protrusion that contacts the stopper to limit rotation of the inner bush. In clause 7,
A gap is formed between the slide bush and the inner bush, and the first slide surface of the slide bush slides along the second slide surface with respect to the inner bush by the gap. According to clause 8,
A scroll compressor in which a first torque generated by rotation of the bearing of the orbiting scroll and a second torque generated by centrifugal force on the slide bush and the inner bush act on the slide bush and the inner bush. According to clause 9,
The stopper is a scroll compressor including a first stopper that limits counterclockwise rotation of the inner bush and a second stopper that limits clockwise rotation of the inner bush. According to clause 10,
When the rotation speed of the rotation shaft is low, the first torque is greater than the second torque, so the inner bush is a horizontal line where a straight line connecting the center of the eccentric shaft and the centers of the slide bush and the inner bush passes through the center of the eccentric shaft. A scroll compressor in which rotation is restricted by the protrusion contacting the first stopper in a state in which the protrusion is rotated counterclockwise by 45 degrees. According to clause 11,
When the inner bush is rotated counterclockwise by 45 degrees, the slide bush moves in a direction in which the eccentricity of the first slide surface increases along the second slide surface by the gap due to the load of gas on the orbiting scroll. A scroll compressor that is moved by a slide. According to clause 12,
When the rotation speed of the rotation shaft is high, the first torque is smaller than the second torque, so that the inner bush is a horizontal line where a straight line connecting the center of the eccentric shaft and the centers of the slide bush and the inner bush passes through the center of the eccentric shaft. A scroll compressor in which rotation is limited by contacting the second stopper with the protrusion while being rotated clockwise by 45 degrees. According to clause 13,
In a state in which the inner bush is rotated clockwise by 45 degrees, the slide bush moves in a direction in which the eccentricity of the first slide surface decreases along the second slide surface by the gap due to the load of gas on the orbiting scroll. A scroll compressor that slides. According to clause 9,
The first torque changes as a linear function of the rotation speed of the rotation shaft, and the second torque changes as a quadratic function of the rotation speed of the rotation shaft. A fixed scroll fixed within the housing;
an orbiting scroll that rotates in engagement with the fixed scroll;
a rotation shaft that supports and rotates the orbiting scroll on an eccentric shaft eccentric from the main shaft; and
It includes a slide bush mechanism installed between the bearing of the orbiting scroll and the eccentric shaft, and changing the pressing force of the orbiting scroll against the fixed scroll,
The slide bush mechanism is,
a slide bush fitted into the bearing of the orbiting scroll and having a first slide surface;
an inner bush installed between the slide bush and the eccentric shaft, fitted with the eccentric shaft, and having a second slide surface in contact with the first slide surface so that the slide bush rotates together;
Including,
A scroll compressor in which the first slide surface of the slide bush slides along the second slide surface of the inner bush by a gas load applied to the orbiting scroll according to the rotation speed of the rotation shaft, thereby changing the amount of eccentricity. According to clause 16,
The slide bush mechanism suppresses the pressing force of the orbiting scroll against the fixed scroll when the rotation speed of the rotation shaft becomes high, and when the rotation speed of the rotation shaft becomes low, the orbiting scroll presses the fixed scroll. compressor. According to clause 17,
A scroll compressor wherein the slide bush mechanism suppresses the pressing force of the orbiting scroll against the fixed scroll by suppressing the amount of eccentricity on the main axis of the orbiting scroll. According to clause 16,
A scroll compressor wherein at least one of the slide bush and the inner bush includes a switching weight for adjusting the center of gravity of the slide bush and the inner bush. According to clause 16,
A scroll compressor wherein at least one of the slide bush and the inner bush includes a transition hole for adjusting the center of gravity of the slide bush and the inner bush.

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