JP6701453B1 - Scroll compressor - Google Patents

Abstract

The scroll compressor includes a fixed scroll in which a fixed scroll is erected on a fixed base plate and a swing scroll in which a swing scroll is set up on a swing base plate. The refrigerant is compressed in a compression chamber formed by meshing with and. One of the outer curve and the inner curve of each of the fixed spiral body and the oscillating spiral body is a curve that is an expansion line of the basic circle, and the expansion angle θ and the basic circle radius a in the x, y coordinate system. Is used as the curve defined by the equations (1) and (2). A function that increases the extension arm length w(θ) in the equations (1) and (2) while changing into a sine wave or cosine wave with π [rad] as one cycle with respect to the extension angle θ. did. x=a·cos θ+w(θ)·sin θ (1) y=a·sin θ−w(θ)·cos θ (2)

Description

  The present invention relates to a scroll compressor used for an air conditioner, a refrigerator, and the like.

  A scroll compressor used for an air conditioner, a refrigerator, and the like includes a compression mechanism section that compresses a refrigerant in a compression chamber formed by combining a fixed scroll and an orbiting scroll, and a container that houses the compression mechanism section. It has a different configuration. Each of the fixed scroll and the orbiting scroll has a structure in which a spiral body is erected on a base plate, and the spiral bodies are meshed with each other to form a compression chamber. By swinging the swing scroll, the compression chamber moves while reducing its volume, and the refrigerant is sucked and compressed in the compression chamber. In this type of scroll compressor, in order to reduce the size and cost, the technology aims to increase the suction capacity of the compression chamber as much as possible to increase the compression function while keeping the container diameter the same. Development is important. In order to increase the suction volume of the compression chamber while keeping the diameter of the container the same, it is necessary to devise the spiral shape of the spiral body.

  As a spiral shape of a scroll compressor, there is a technique in which an involute curve having a true circle with a predetermined radius as a basic circle is used and the outline of the spiral body is circular. On the other hand, in recent years, there is a technique in which the entire spiral body has a flat shape instead of a circular shape, and the spiral shape of the spiral body is also flat (for example, see Patent Document 1).

  An Oldham ring having a function of preventing the orbiting scroll from rotating is disposed near the compression mechanism of the scroll compressor. Considering that the key portion of the Oldham ring is released, it is preferable that the base plate of the orbiting scroll has a flat shape rather than a circular shape in order to improve the packing density of the compressor parts. When the base plate has a flat outer shape, the spiral shape of the spiral body also has a flat shape, so that the limited space on the base plate can be effectively utilized to secure a large suction volume of the compression chamber. It is possible. Therefore, as in Patent Document 1, making the spiral shape of the spiral body a flat shape is effective in increasing the suction volume of the compression chamber.

JP, 10-54380, A

  Although Patent Document 1 describes that the contour of the spiral body and the spiral shape are made flat, a specific definition of the spiral shape is not described. As for the spiral shape of the spiral body, there is a technology defined by an involute curve with a perfect circle having a predetermined radius as a basic circle as described above. It is necessary to specifically define the spiral shape.

  The present invention has been made in view of the above points, and an object thereof is to provide a scroll compressor capable of defining a spiral shape of a spiral body having a flat contour by an expression.

A scroll compressor according to the present invention includes a fixed scroll in which a fixed scroll is erected on a fixed base plate, and a swing scroll in which a swing scroll is set up on a swing base plate. In a scroll compressor that compresses refrigerant in a compression chamber formed by meshing with an oscillating scroll, one of the outer curve and the inner curve of each of the fixed scroll and the oscillating scroll is set to extend the basic circle. A curve which is an open line and is defined by the formula (1) and the formula (2) using the expansion angle θ and the basic circle radius a in the x and y coordinate systems, and the formula (1) and the formula ( Equation (1) and equation (2) are defined as a function in which the extension arm length w(θ) in 2) is changed while changing in a sine wave shape or a cosine wave shape with π [rad] as one cycle with respect to the extension angle θ. When the curve defined in (2) is an outer curve, the inner curve of each of the fixed spiral body and the swinging spiral body is on the curve obtained by rotating the outer curve by π [rad] with the center of the base circle as a reference. When the curve is an outer envelope of a group of circles having a center and a radius equal to the oscillating radius of the oscillating scroll, and the curves defined by the formulas (1) and (2) are the inner curves, the fixed spiral body and the wobble Each outer curve of the dynamic scroll has its center on a curve obtained by rotating the inner curve by π [rad] with respect to the center of the basic circle, and the inner envelope of a group of circles whose radius is equal to the swing radius of the orbiting scroll. By forming the line, the outer shape of the entire swing volute is made flatter than the outer shape of the swirl body using the involute curve, and the wall thickness of the fixed scroll and the swing volute is the extension arm length w. The value of (θ) periodically changes so as to increase at the expansion angle θ at which the value periodically increases .
x=a·cos θ+w(θ)·sin θ (1)
y=a·sin θ−w(θ)·cos θ (2)

According to the present invention, the spiral shape of the spiral body is defined by the expressions (1) and (2) using the expansion angle θ and the basic circle radius a in the x and y coordinate systems, and also the expressions (1) and The extension arm length w(θ) in the equation (2) is a function that increases while changing in a sine wave shape or a cosine wave shape with π [rad] as one cycle with respect to the extension angle θ. Thereby, the spiral shape of the spiral body having a flat contour can be defined by an equation.
x=a·cos θ+w(θ)·sin θ (1)
y=a·sin θ−w(θ)·cos θ (2)

It is a schematic longitudinal cross-sectional view of the entire configuration of the scroll compressor according to Embodiment 1 of the present invention. It is a cross-sectional view of a compression mechanism portion of the scroll compressor according to Embodiment 1 of the present invention. FIG. 3 is a plan view showing a fixed scroll and a swing scroll of the compression mechanism section of the scroll compressor according to the first embodiment of the present invention. FIG. 4 is a compression process diagram showing an operation during one rotation of the orbiting scroll in the scroll compressor according to Embodiment 1 of the present invention. It is explanatory drawing of the spiral drafting method which comprises the compression mechanism part of the scroll compressor which concerns on Embodiment 1 of this invention. It is a figure which shows an example of the characteristic of the extension arm length w ((theta)) used for drawing the spiral shape of the spiral body in the scroll compressor which concerns on Embodiment 1 of this invention. It is a figure which shows the change of the oblateness of the outer side curve of the scroll in the scroll compressor which concerns on Embodiment 2 of this invention. It is a figure which shows the outer side curve of the spiral body in the scroll compressor which concerns on Embodiment 3 of this invention. It is a figure which shows the spiral shape of the spiral body in the scroll compressor which concerns on Embodiment 4 of this invention. It is a figure which shows the characteristic of the extension arm length w ((theta)) which specifies the spiral shape of the spiral body in the scroll compressor which concerns on Embodiment 4 of this invention.

  Hereinafter, a scroll compressor according to an embodiment of the present invention will be described with reference to the drawings and the like. Here, in the following drawings, including FIG. 1, those denoted by the same reference numerals are the same or equivalent, and are common to all text of the embodiments described below. Further, the forms of the constituent elements shown in the entire specification are merely examples, and the forms are not limited to the forms described in the specification.

Embodiment 1.
1 is a schematic vertical cross-sectional view of the overall configuration of a scroll compressor according to Embodiment 1 of the present invention.
The scroll compressor according to the first embodiment includes a compression mechanism unit 8, an electric mechanism unit 110 that drives the compression mechanism unit 8 via the rotary shaft 6, and other components, which form an outer shell. It has a configuration of being housed inside an airtight container 100.

  A frame 7 and a sub-frame 9 are further housed in the closed container 100 so as to face each other with the electric mechanism unit 110 interposed therebetween. The frame 7 is arranged on the upper side of the electric mechanism unit 110 and is located between the electric mechanism unit 110 and the compression mechanism unit 8. The sub-frame 9 is located below the electric mechanism unit 110. The frame 7 is fixed to the inner peripheral surface of the closed container 100 by shrink fitting or welding. The sub-frame 9 is fixed to the inner peripheral surface of the closed container 100 by shrink fitting or welding via the sub-frame holder 9a.

  Below the sub-frame 9, a pump element 112 including a positive displacement pump is attached. The pump element 112 supplies the refrigerating machine oil stored in the oil sump 100a at the bottom of the closed container 100 to sliding parts such as a main bearing 7a of the compression mechanism 8 described later. The pump element 112 axially supports the rotary shaft 6 at its upper end surface.

  The closed container 100 is provided with a suction pipe 101 for sucking the refrigerant and a discharge pipe 102 for discharging the refrigerant.

  The compression mechanism portion 8 has a function of compressing the refrigerant sucked from the suction pipe 101 and discharging the compressed refrigerant to a high pressure portion formed in the upper portion of the closed container 100. The compression mechanism section 8 includes a fixed scroll 1 and an orbiting scroll 2.

  The fixed scroll 1 is fixed to the closed container 100 via a frame 7. The orbiting scroll 2 is disposed below the fixed scroll 1 and is rotatably supported by an eccentric shaft portion 6a of the rotary shaft 6 described later.

  The fixed scroll 1 includes a fixed base plate 1a and a fixed spiral body 1b that is a spiral protrusion provided upright on one surface of the fixed base plate 1a. The oscillating scroll 2 includes an oscillating base plate 2a and an oscillating scroll body 2b which is a spiral protrusion erected on one surface of the oscillating base plate 2a. The fixed scroll 1 and the orbiting scroll 2 are arranged in the hermetic container 100 in a symmetrical spiral shape in which the fixed scroll 1b and the orbiting scroll 2b are meshed in opposite phases. A compression chamber 71 is formed between the fixed spiral body 1b and the oscillating spiral body 2b, the volume of which decreases as the rotary shaft 6 rotates from the outer side toward the inner side in the radial direction.

  A baffle 4 is fixed to a surface of the fixed base plate 1 a of the fixed scroll 1 opposite to the orbiting scroll 2. The baffle 4 is formed with a through hole 4a communicating with the discharge port 1c of the fixed scroll 1, and the discharge valve 11 is provided in the through hole 4a. Then, a discharge muffler 12 is attached to the baffle 4 so as to cover the through hole 4a.

  The frame 7 has a fixed scroll 1 and a thrust surface that axially supports the thrust force acting on the orbiting scroll 2. Further, the frame 7 is formed with an opening 7 c penetrating the refrigerant sucked from the suction pipe 101 into the compression mechanism portion 8.

  An Oldham ring 14 is arranged on the frame 7 to prevent rotation of the orbiting scroll 2 during the orbiting motion. The key portion 14 a of the Oldham ring 14 is arranged on the outer peripheral side of the swing base plate 2 a of the swing scroll 2.

  The electric mechanism unit 110 supplies a rotational driving force to the rotating shaft 6, and includes an electric motor stator 110a and an electric motor rotor 110b. The electric motor stator 110a is connected to a glass terminal (not shown) existing between the frame 7 and the electric motor stator 110a by a lead wire (not shown) in order to obtain electric power from the outside. The electric motor stator 110a is fixed to the rotary shaft 6 by shrink fitting or the like. A first balance weight 60 is fixed to the rotating shaft 6 and a second balance weight 61 is fixed to the electric motor stator 110a in order to balance the entire rotation system of the scroll compressor.

  The rotary shaft 6 is composed of an eccentric shaft portion 6 a above the rotary shaft 6, a main shaft portion 6 b, and a sub shaft portion 6 c below the rotary shaft 6. The eccentric shaft portion 6a is fitted to the orbiting scroll 2 via a slider 5 with a balance weight and an orbiting bearing 2c, and the orbiting scroll 2 is caused to orbit by the rotation of the rotating shaft 6. The main shaft portion 6b is fitted via a sleeve 13 to a main bearing 7a arranged on the inner circumference of a cylindrical boss portion 7b provided on the frame 7, and slides on the main bearing 7a via an oil film of refrigerating machine oil. To do. The main bearing 7a is fixed in the boss portion 7b by press-fitting a bearing material such as a copper-lead alloy used for a slide bearing.

  A sub-bearing 10 made up of a ball bearing is provided on the upper portion of the sub-frame 9, and the rotating shaft 6 is axially supported by the lower portion of the electric mechanism portion 110. The sub bearing 10 may be pivotally supported by a bearing structure other than the ball bearing. The sub shaft portion 6c is fitted with the sub bearing 10 and slides on the sub bearing 10 through an oil film of refrigerating machine oil. The shaft centers of the main shaft portion 6b and the sub shaft portion 6c coincide with the shaft center of the rotary shaft 6.

  Here, the space inside the closed container 100 is defined as follows. Of the internal space of the closed container 100, the space on the electric motor rotor 110b side of the frame 7 is referred to as a first space 72. A space formed by the inner wall of the frame 7 and the fixed base plate 1a is referred to as a second space 73. Further, the space on the discharge pipe 102 side of the fixed base plate 1a is referred to as a third space 74.

Next, the component arrangement of the compression mechanism portion 8 inside the closed container 100 will be described.
FIG. 2 is a cross-sectional view of the compression mechanism portion of the scroll compressor according to the first embodiment of the present invention. FIG. 3 is a plan view showing a fixed spiral body and an oscillating spiral body of the compression mechanism portion of the scroll compressor according to Embodiment 1 of the present invention. 2 and 3, in order to facilitate the distinction between the fixed scroll 1b of the fixed scroll 1 and the swing scroll 2b of the swing scroll 2, the swing scroll 2b of the swing scroll 2 is hatched. It has been given. The same applies to the figures described below.

  The closed container 100 has a perfect circular shape in plan view, and is fixed inside the closed container 100 with the outer peripheral surface of the frame 7 being in contact with the inner peripheral surface of the closed container 100. Therefore, the outer peripheral surface of the frame 7 also has a perfect circular shape. In the second space 73 inside the frame 7, the fixed scroll 1b of the fixed scroll 1 and the orbiting scroll 2 are arranged. The key portion 14 a of the Oldham ring 14 is arranged in the second space 73. In such a specification, since the swing base plate 2a needs to be arranged so as to avoid the movable range of the key portion 14a, the outer shape of the swing base plate 2a is a flat shape. Note that the flat shape includes an elliptical shape and an elliptical shape, and in short, refers to any shape that is flatter than a circle.

  Since the outer shape of the rocking base plate 2a is flat as described above, the rocking spiral body 2b which is erected on the rocking base plate 2a also has a flat shape, so that the rocking base plate 2a is mounted on the rocking base plate 2a. The space can be effectively used and the space efficiency can be improved. The same applies to the fixed base plate 1a, and the fixed base plate 1a and the fixed spiral body 1b have a flat shape. By increasing the space efficiency in this way, the volume of the compression chamber 71 can be expanded while the size of the closed container 100 remains the same, and the compression function can be improved. On the contrary, in order to secure the same compressive force, the closed container 100 can be downsized. In the following, the fixed spiral body 1b and the swinging spiral body 2b are not distinguished from each other, and both are collectively referred to as a "spiral body". The same applies to the base plate, and when the fixed base plate 1a and the swing base plate 2a are not distinguished and both are referred to, they are collectively referred to as "base plate".

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

  FIG. 4 is a compression process diagram showing an operation during one rotation of the orbiting scroll in the scroll compressor according to Embodiment 1 of the present invention. FIG. 4A shows the position of the spiral body when the rotation phase is 0 [rad] (2π [rad]). FIG. 4B shows the position of the spiral body when the rotation phase is π/2 [rad]. FIG. 4C shows the position of the spiral body when the rotation phase is π [rad]. FIG. 4D shows the position of the spiral body when the rotation phase is 3π/2 [rad].

  When the electric motor stator 110a of the electric mechanism unit 110 is energized, the electric motor rotor 110b receives a rotational force and rotates. Accordingly, the rotary shaft 6 fixed to the electric motor rotor 110b is rotationally driven. The rotary motion of the rotary shaft 6 is transmitted to the orbiting scroll 2 via the eccentric shaft portion 6a. The oscillating scroll 2b of the oscillating scroll 2 oscillates with an oscillating radius while its rotation is restricted by the Oldham ring 14. The swing radius means the amount of eccentricity of the eccentric shaft 6a with respect to the main shaft 6b.

  With the driving of the electric mechanism unit 110, the refrigerant flows from the external refrigeration cycle into the first space 72 in the closed container 100 via the suction pipe 101. The low-pressure refrigerant flowing into the first space 72 flows into the second space 73 through the two openings 7c installed in the frame 7. The low-pressure refrigerant that has flowed into the second space 73 is sucked into the compression chamber 71 as the rocking spiral body 2b and the fixed spiral body 1b of the compression mechanism portion 8 relatively rock. The refrigerant sucked into the compression chamber 71 is increased in pressure from low pressure to high pressure due to the geometrical volume change of the compression chamber 71 due to the relative movement of the oscillating scroll 2b and the fixed scroll 1b as shown in FIG. To be done. Then, the high-pressure refrigerant passes through the discharge port 1c of the fixed scroll 1 and the through hole 4a of the baffle 4, pushes the discharge valve 11 open, and is discharged into the discharge muffler 12. The refrigerant discharged into the discharge muffler 12 is discharged into the third space 74, and is discharged from the discharge pipe 102 as a high-pressure refrigerant to the outside of the compressor.

  In the first embodiment, the contours of the oscillating spiral body 2b and the fixed spiral body 1b are flat as described above, and the spiral shape is also flat. As described above, in the compression mechanism portion 8 in which the spiral shape of the spiral body is a flat shape, even when the swing spiral body 2b is operated with a constant swing radius as shown in FIG. The outward surface and the inward surface of are operated while contacting the inward surface and the outward surface of the fixed spiral body 1b facing each other.

  The first embodiment is characterized in that the spiral shape of the spiral body having a flat contour is defined by an equation. The spiral shape is determined by an outer curve that specifies the outward surface of the spiral body and an inner curve that specifies the inward surface of the spiral body. In defining the spiral shape of the spiral body by an expression, specifically, one of the outer curve and the inner curve of the spiral body is a curve that is an extension line of the basic circle, and in the x, y coordinate system. A curve defined by equations (1) and (2) is obtained using the expansion angle θ.

  A in the formulas (1) and (2) is the radius of the basic circle. The extension arm length w(θ) in the equations (1) and (2) is the point on the curve at the extension angle θ of the extension line from the point on the circumference at the extension angle θ of the base circle. Is a length of a straight line connecting the lines, and is given by a function that changes in a sine wave shape or a cosine wave shape with π [rad] as one cycle. Accordingly, the spiral shape of the spiral body having a flat contour can be defined by an equation. In addition, the extension arm length w(θ) changes in a sine wave shape or a cosine wave shape as described above, but in the first embodiment, as an example, it changes in a sine wave shape as in Expression (3). Let it be done. Note that α and β in the equation (3) are coefficients. N is a natural number of 1 or more.

  In Expression (3), α holds true even if it is a positive value or a negative value. β is a positive value. The flatness of the contour is changed by changing α. Further, by changing β, the reduction ratio of the wall thickness of the spiral body changes. Specific changes in the spiral body when α and β are changed will be described in the second and third embodiments.

  Next, a method for drawing the spiral shape of each of the fixed spiral body 1b and the swinging spiral body 2b will be described. Since the fixed spiral body 1b and the swinging spiral body 2b have the same method of drawing, the swinging spiral body 2b will be described below as a representative. The spiral shape is determined by the outer curve that specifies the outward surface of the spiral body and the inner curve that specifies the inward surface of the spiral body as described above. Here, a method of drawing a spiral shape in the case where the outer curve is a curve defined by the equations (1) and (2) will be described with reference to FIG.

  FIG. 5: is explanatory drawing of the drawing method of the spiral shape which comprises the compression mechanism part of the scroll compressor which concerns on Embodiment 1 of this invention. In FIG. 5, the steps (a), (b), (c), and (d) are drawn. In drawing, first, as shown in FIG. 5( a ), an incision line 30 of the basic circle is drawn. Here, the extension arm length w(θ) increases in a sine wave shape with π [rad] as one cycle in accordance with the extension angle θ as described above. The incision line 30 drawn here is the outer curve.

  Next, an inner curve is drawn by the procedure of FIG.5(b)-FIG.5(d). That is, first, as shown in FIG. 5(b), a curve 31 obtained by rotating the incision line 30 drawn in step (a) by π [rad] with respect to the center O of the base circle is drawn. Since the inside curve is created here, the curved portion of the curve 31 located outside the curve 30 (the dotted line portion in FIG. 5B) is not used in the subsequent drawing procedure.

  Next, as shown in FIG. 5C, a plurality of circles 32 each having a center equal to the swing radius of the swing scroll 2 and having the center on the curve 31 drawn in the step (b) are drawn. Next, as shown in FIG. 5D, the outer envelope 33 of the circle group drawn in step (c) is drawn. The curve 33 drawn in this procedure (d) becomes the inner curve.

  As a result, the curve 30 drawn in step (a) becomes the outer curve of the oscillating spiral body 2b, the curve 33 drawn in step (d) becomes the inner curve of the oscillating spiral body 2b, and the hatched area in step (d) is obtained. Is the cross section of the oscillating spiral body 2b. In addition, in FIG. 5, the extension arm length w(θ) is a swinging swirl in the case where the value of α is 0.5, the value of β is 0.015, and the value of N is 1 in Expression (3). The shape of the body 2b is described.

  With respect to the fixed spiral body 1b, the same procedure as the above-described swing spiral body 2b is performed, and in the specification having the same thickness as the swing spiral body 2b, the shape of the swing spiral body 2b is rotated by π [rad]. It becomes a shape.

  Here, the spiral-shaped drawing method in which the outer curve is defined by the equations (1) and (2) has been described, but the inner curve is defined by the equations (1) and (2). The spiral-shaped drawing method in the case of the curved line is basically the same. When the inner curve is defined by the equations (1) and (2), the outer curve may be drawn as follows. First, the procedure of FIG. 5(a) is performed, and then the curve portion of the curve 30 located outside the curve 31 in FIG. 5(b) is not used in the subsequent drawing procedure. Then, a plurality of circles 32 each having a center on the curve 31 and a radius equal to the swing radius of the swing scroll 2 are drawn. The inner envelope of this group of circles is the outer curve.

  FIG. 6 is a diagram showing an example of characteristics of the extension arm length w(θ) used for drawing the spiral shape of the spiral body in the scroll compressor according to Embodiment 1 of the present invention. The vertical axis of FIG. 6 represents the ratio of w(θ) to the product of the basic circle radius a and the expansion angle θ. The horizontal axis of FIG. 6 indicates the extension angle θ [rad].

  Similar to FIG. 5, FIG. 6 shows the extension arm length with respect to the extension angle θ when the value of α in Expression (3) is 0.5, the value of β is 0.015, and the value of N is 1. It shows a periodic change in the height w(θ). In the waveform of the extended arm length w(θ) shown in FIG. 6, it is shown that the larger the value of w(θ)/a·θ, the thicker the spiral body becomes. Therefore, the thickness of the spiral body becomes thicker at π/2, 3π/2, 5π/2, and 7π/2. Further, in the waveform of the extension arm length w(θ), the spiral body has a shape extended in the direction of the extension angle having a peak exceeding 1.0. Therefore, in the example of FIG. 6, when the expansion angle is π/2, 3π/2, 5π/2, and 7π/2, the peak that exceeds 1.0 is present, so that as shown in FIG. It becomes a stretched shape.

  When β is 0, the peak period of the extended arm length w(θ) is π [rad]. Here, since β is 0.015, which is 0 or more, the cycle of the peak of the extended arm length w(θ) is slightly shorter than π[rad]. When β is 0 or less, the peak period of the extended arm length w(θ) becomes slightly longer than π[rad]. As described above, the period of the extension arm length w(θ) may deviate from π [rad] depending on the value of β, but the deviation is slight. Therefore, the expression “the length of the extended arm w(θ) changes sinusoidally with π[rad] as one cycle with respect to the extended angle θ” indicates that the cycle matches π[rad]. It is not limited to this, but includes cases where there is some deviation.

  As described above, in the first embodiment, the spiral shape of the spiral body is defined by the above equations (1) and (2) using the expansion angle θ. Then, the extension arm length w(θ) in the equations (1) and (2) is a function that changes into a sine wave or a cosine wave with π [rad] as one cycle with respect to the extension angle θ. .. Thereby, the spiral shape of the spiral body having a flat contour can be defined by an equation.

  Further, since the spiral body according to the first embodiment has a flat shape along with the base plate, the mounting density of the spiral body on the base plate can be improved. Conventionally, there is also a technology in which the contours of the base plate and the spiral body are both made into a perfect circle shape, but the mounting density of the spiral body can be improved compared to this conventional technology, and the total length of the spiral of the spiral body is set to be long. It becomes possible to do. Since the total length of the spiral of the spiral body can be increased, the area of the entire tip end surface in the axial direction of the spiral body can be set large. Some scroll compressors have a compliant mechanism that brings the fixed scroll 1 and the orbiting scroll 2 into contact with each other in the axial direction. Even in this type of scroll compressor, the surface pressure generated at the tip end surface of the scroll is reduced. It can be reduced. Therefore, abrasion and seizure due to sliding can be suppressed, and reliability can be improved.

  Further, in the spiral shape of the spiral body according to the first embodiment, the rotation phases of 0 and π slide on the side surface of the spiral body as compared with the rotation phases of π/2 and 3π/2 in FIG. The speed can be set small. Therefore, the PV value on the side surface of the spiral body is set by setting the sliding speed to a low value in the rotation phase in which the horizontal gas load increases and setting the sliding speed to a large value in the rotation phase in which the horizontal gas load decreases. Can be reduced. The PV value is the product of the load and the sliding speed. Since the PV value can be reduced in this way, abrasion and seizure due to sliding can be suppressed, and reliability can be improved.

Embodiment 2.
In the second embodiment, a change in flatness of the contour of the spiral body according to the value of α in the above formula (3) will be described. Hereinafter, the second embodiment will be described focusing on the configuration different from that of the first embodiment, and the configuration not described in the second embodiment is the same as that of the first embodiment.

  In the above formula (3), the shape of the spiral body when the value of α is changed is shown in FIG. 7 below.

  FIG. 7: is a figure which shows the change of the oblateness of the outer side curve of the scroll in the scroll compressor which concerns on Embodiment 2 of this invention. In FIG. 7, (a) shows the case of α=0, (b) shows the case of α=0.1, and (c) shows the case of α=0.2. Further, in FIG. 7, the value of β is fixed to 0.005 and the value of N is fixed to 1.

  By changing the value of α as shown in FIG. 7, it becomes possible to arbitrarily set the flatness of the contour of the spiral body. The oblateness is the ratio D1/D2 of the major axis D1 and the minor axis D2 as shown in FIG. 7(a). Therefore, as shown in FIG. 7, the oblateness increases as the value of α increases.

  According to the second embodiment, the same effect as that of the first embodiment can be obtained, and the flatness of the contour of the spiral body can be set arbitrarily by changing the value of α. Therefore, by changing α according to the shape of the base plate and setting the flatness of the contour of the spiral body, the contour of the spiral body is optimized and the packing density of the spiral body on the base plate is improved. be able to.

Embodiment 3.
In the third embodiment, a change in the reduction ratio of the wall thickness of the spiral body according to the value of β in the above formula (3) will be described. Hereinafter, the third embodiment will be described focusing on the configuration different from that of the first embodiment, and the configuration not described in the third embodiment is the same as that of the first embodiment.

  In the above equation (3), the shape of the spiral body when the value of β is changed is shown in FIG. 8 below.

  FIG. 8: is a figure which shows the outer side curve of the scroll in the scroll compressor which concerns on Embodiment 3 of this invention. In FIG. 8, (a) shows the case where β=0, (b) shows the case where β=0.005, and (c) shows the case where β=0.010. Further, in FIG. 8, the value of α is fixed to 0.2 and the value of N is fixed to 1.

  By changing the value of β as shown in FIG. 8, it becomes possible to arbitrarily set the reduction rate of the interval from the winding start portion to the winding end portion of the spiral body. The interval reduction rate is the ratio P1/P2 between the winding start interval P1 and the winding end interval P2, as shown in FIG. 8A. Therefore, from FIG. 8, as β is increased to 0 or more, the reduction rate of the interval increases. The reduction ratio of the wall thickness of the spiral body also increases as β increases to 0 or more like the reduction ratio of the interval. The reduction ratio of the wall thickness is the ratio of the wall thickness at the winding start portion to the wall thickness at the winding end portion of the spiral body.

  In the above equation (3), β takes a value of 0 or more. When β is increased, the value of (1-βθ) in equation (3) decreases as the extension angle θ increases. Therefore, as is apparent from FIG. 6, the value of w(θ)/a·θ decreases every π/2 from the expansion angle θ. Specifically, w(θ)/a·θ is about 1.46 when the expansion angle θ is π/2, but w(θ)/a·θ when the expansion angle θ is 3π/2. Is about 1.39, which is small. Then, as described above, when w(θ)/a·θ is large, it means that the thickness of the spiral body is large. Therefore, when the extension arm length w(θ) changes as shown in FIG. The thickness of the spiral body is reduced at each expansion angle π from the beginning to the end of winding. The effects obtained by this configuration will be described below.

  The pressure difference between the compression chambers 71 formed in the compression mechanism portion 8 becomes larger in the central portion where the pressure is increased by compressing the refrigerant, that is, in the central portion of the spiral body. That is, the pressure difference between the compression chambers 71 is larger at the winding start portion of the spiral body than at the winding end portion. Therefore, when designing the wall thickness of the spiral body, it is necessary to design the wall thickness to withstand the pressure difference generated at the center of the spiral body. Here, if the wall thickness of the spiral body is constant from the start of winding to the end of winding so as to withstand the pressure difference generated at the center of the spiral body, the end of winding with a small pressure difference between the compression chambers 71 In the vicinity of the part, the strength is excessively designed. That is, since the thickness of the spiral body is formed to be thicker than necessary, the volume of the compression chamber 71 at the time of completion of suction, that is, the suction volume is unnecessarily reduced.

  On the other hand, in the third embodiment, by appropriately setting β, it is possible to arbitrarily set the reduction ratio of the wall thickness from the winding start portion to the winding end portion. Therefore, by setting β according to the specifications and operating conditions of the compressor, the wall thickness of the strength required at the beginning of winding can be reduced while the wall thickness at the end of winding is thin, so that the space is limited. Thus, it is possible to obtain a spiral body capable of ensuring a large suction volume. Specifically, as β increases with a value of 0 or more, the reduction ratio of the wall thickness increases. Therefore, when the pressure difference between the compression chambers 71 at the center of the spiral body is large, the value of β is increased. However, if the pressure difference between the compression chambers 71 at the center of the spiral body is small, the value of β may be reduced.

  As described above, according to the third embodiment, the same effect as that of the first embodiment can be obtained, and by changing the value of β, the reduction ratio of the wall thickness of the spiral body can be arbitrarily set. It becomes possible.

  Further, by combining the third embodiment with the second embodiment, it is possible to define a specific mathematical expression capable of arbitrarily setting the flatness ratio of the contour of the spiral body and the reduction ratio of the wall thickness, and to define the spiral body on the base plate. The degree of freedom in designing the spiral shape can be improved. Then, the flatness of the contour of the spiral body is set according to the shape of the base plate, and β is set according to the specifications and operating conditions of the compressor, thereby optimizing the contour of the spiral body. It is possible to increase the suction volume while improving the packaging density. This makes it possible to improve the compression function without increasing the size of the compressor. Alternatively, it is possible to reduce the size of the compressor with the same compression function.

Fourth Embodiment
In the fourth embodiment, a change in the spiral shape according to the characteristic of the extension arm length w(θ) will be described. Hereinafter, the configuration in which the fourth embodiment is different from the first embodiment will be mainly described, and configurations that are not described in the fourth embodiment are the same as those in the first embodiment.

  FIG. 9: is a figure which shows the spiral shape of the spiral body in the scroll compressor which concerns on Embodiment 4 of this invention. 9A to 9D are, in order, the functional formula of the extended arm length w(θ), the formula (3) shown in the first embodiment, and the following formulas (4) to. The shapes of the fixed spiral body 1b and the swinging spiral body 2b in the case of (6) are described. FIG. 10: is a figure which shows the characteristic of the extension arm length w ((theta)) which specifies the spiral shape of the spiral body in the scroll compressor which concerns on Embodiment 4 of this invention. FIGS. 10A to 10D correspond to FIGS. 9A to 9D, and sequentially show the extended arm length w(θ) in the first embodiment. Formula (3) and the following formulas (4) to (6). The vertical axis of FIG. 10 represents the ratio of w(θ) to the product of the basic circle radius a and the expansion angle θ. The horizontal axis of FIG. 10 indicates the extension angle θ [rad]. Further, in FIGS. 9 and 10, the value of α is 0.1, the value of β is 0, and the value of N is 1.

  As shown in FIG. 9, the contours of the fixed spiral body 1b and the swing spiral body 2b can be arbitrarily set by changing the functional expression of the extension arm length w(θ).

  In Embodiments 1 to 4, the low-pressure shell type scroll compressor in which the inside of the closed container 100 is filled with the low-pressure refrigerant has been described, but the high-pressure shell type scroll compressor in which the inside of the closed container 100 is filled with the high-pressure refrigerant. Even in the case, the same effect can be obtained.

  1 fixed scroll, 1a fixed base plate, 1b fixed scroll body, 1c discharge port, 2 swing scroll plate, 2a swing base plate, 2b swing scroll body, 2c swing bearing, 4 baffle, 4a through hole, 5 balance weight Slider, 6 rotating shaft, 6a eccentric shaft part, 6b main shaft part, 6c sub-shaft part, 7 frame, 7a main bearing, 7b boss part, 7c opening part, 8 compression mechanism part, 9 subframe, 9a subframe holder, 10 secondary bearing, 11 discharge valve, 12 discharge muffler, 13 sleeve, 14 Oldham ring, 14a key part, 21 overcompression relief port, 22 overcompression relief port, 30 extension line, 32 circle, 33 outer envelope, 60th 1 balance weight, 61 2nd balance weight, 71 compression chamber, 72 1st space, 73 2nd space, 74 3rd space, 100 airtight container, 100a oil sump part, 101 suction pipe, 102 discharge pipe, 110 electric mechanism part , 110a electric motor stator, 110b electric motor rotor, 112 pump element.

Claims (7)

A fixed scroll in which a fixed scroll is erected on a fixed base plate and a swing scroll in which a swing scroll is set up on a swing base plate are provided, and the fixed scroll and the swing scroll are meshed with each other. In the scroll compressor that compresses the refrigerant in the compression chamber formed by that,
One of the outer curve and the inner curve of each of the fixed spiral body and the oscillating spiral body is a curve that is an expansion line of a basic circle, and an expansion angle θ and a basic circle in an x, y coordinate system. The curves are defined by the formulas (1) and (2) using the radius a, and the extension arm length w(θ) in the formulas (1) and (2) is expressed with respect to the extension angle θ. As a function that increases while changing in a sine wave shape or a cosine wave shape with π [rad] as one cycle,
When the curves defined by the formula (1) and the formula (2) are the outer curves, the inner curves of the fixed spiral body and the oscillating spiral body respectively correspond to the outer curve of the base circle. An outer envelope of a group of circles having a radius equal to the swing radius of the orbiting scroll and having a center on a curve rotated by π [rad] with the center as a reference,
When the curves defined by the formula (1) and the formula (2) are the inner curves, the outer curves of the fixed spiral body and the oscillating spiral body respectively correspond to the inner curve of the basic circle. By making an inner envelope of a group of circles having a radius equal to the swing radius of the orbiting scroll, the center of which is on a curve rotated by π [rad] with the center as a reference,
The outer shape of the entire oscillating spiral body is a flatter shape than the outer shape of the spiral body using an involute curve,
The wall thicknesses of the fixed spiral body and the oscillating spiral body periodically change so as to increase at the extension angle θ where the value of the extension arm length w(θ) increases periodically. Compressor.

An Oldham ring for preventing the orbiting scroll from rotating,
The outer shape of the swing base plate is a flat shape,
The scroll compressor according to claim 1, wherein the key portion of the Oldham ring is arranged outside the flat rocking base plate in the lateral direction. The scroll compressor according to claim 1, wherein the extension arm length w(θ) is given by Expression (3).
Here, α and β are coefficients, and N is a natural number of 1 or more.

The scroll compressor according to claim 1, wherein the extension arm length w(θ) is given by Expression (4).
Here, α and β are coefficients, and N is a natural number of 1 or more.

The scroll compressor according to claim 1, wherein the extension arm length w(θ) is given by Expression (5).
Here, α and β are coefficients, and N is a natural number of 1 or more.

The scroll compressor according to claim 1, wherein the extension arm length w(θ) is given by Expression (6).
Here, α and β are coefficients, and N is a natural number of 1 or more.

The scroll compressor according to claim 3, wherein the coefficient β is 0 or more .

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