WO2020208803A1

WO2020208803A1 - Scroll compressor

Info

Publication number: WO2020208803A1
Application number: PCT/JP2019/015943
Authority: WO
Inventors: 雷人河村; 関屋　慎
Original assignee: 三菱電機株式会社
Priority date: 2019-04-12
Filing date: 2019-04-12
Publication date: 2020-10-15
Also published as: JP6625297B1; CN113677892A; CN113677892B; JPWO2020208803A1

Abstract

Either one of an outside curve and an inside curve of a fixed spiral body and an orbiting spiral body respectively is a curve that is an involute of a base circle, and that is defined by formula (1) and formula (2) using an involute angle θ in an x, y coordinate system. A radius a(θ) of the base circle in formula (1) and formula (2) is a term obtained as the product of "a coefficient which varies in the shape of a sine wave or a cosine wave, with π [rad] as one cycle, with respect to the involute angle θ", and "a coefficient represented as a step function, with π [rad] as one cycle".　(1) x=a(θ)(cosθ+θ∙sinθ) (2) y=a(θ)(sinθ-θ∙cosθ)

Description

Scroll compressor

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

A scroll compressor used in an air conditioner, a refrigerator, or the like includes a compression mechanism unit that compresses a refrigerant in a compression chamber formed by combining a fixed scroll and a swing scroll, and a container that houses the compression mechanism unit. Has a structure. Each of the fixed scroll and the swing scroll has a structure in which spiral bodies are erected on a base plate, and the spiral bodies are meshed with each other to form a compression chamber. Then, by swinging the swing scroll, the compression chamber moves while reducing the 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 compression function by increasing the suction volume of the compression chamber as much as possible while keeping the diameter of the container 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.

Conventionally, there is a technique in which the spiral shape of the scroll compressor is an involute curve based on a perfect circle with a predetermined radius, and the outline of the entire spiral body is circular. On the other hand, in recent years, there is a technique in which the outline of the entire spiral body is not circular but flat, and the spiral shape of the spiral body is also flat (see, for example, Patent Document 1).

JP-A-10-54380

Although Patent Document 1 describes that the outline and the spiral shape of the spiral body are flat, the specific definition of the spiral shape is not described. As described above, the spiral shape of the spiral body is defined by an involute curve based on a perfect circle with a predetermined radius. However, even when the spiral shape is a flat shape, the spiral body can be manufactured. It is necessary to specifically define the spiral shape in.

By the way, in the vicinity of the compression mechanism of the scroll compressor, an introduction flow path for introducing the refrigerant into the suction space through which the refrigerant before being compressed in the compression chamber flows is installed. It is desirable that the introduction flow path is not blocked by the spirals and base plate of the fixed scroll and the swing scroll, regardless of the rotation phase.

In a structure in which the contour and spiral shape of the spiral body are flat with a major axis and a minor axis as in Patent Document 1, a pair of sides facing each other in the minor axis direction and an inner peripheral surface of the container are separated from each other. Two empty spaces facing each other by 180 ° are formed. In the structure in which two empty spaces are formed in this way, in order to secure the flow path area of the introduction flow path as much as possible, the introduction flow path is installed in each empty space. That is, there are a plurality of introduction flow paths. However, if there are a plurality of introduction channels, the number of processing steps at the time of manufacturing increases, so that the manufacturing cost increases.

In order to avoid such an increase in manufacturing cost, it is effective to consolidate the empty space for providing the introduction flow path in one place and to install the introduction flow path with a secured flow path area in the empty space. .. In order to consolidate the empty space for providing the introduction flow path in one place while making the spiral shape of the spiral body flat, it is conceivable to make the spiral shape a combination of multiple flat shapes with different flatness. Be done. That is, it is conceivable to secure an empty space by making the flat shape on the side where the empty space is provided more crushed than the flat shape on the side where the empty space is not provided. However, there is no prior art that can define such a shape by an equation.

The present invention has been made in view of these points, and provides a scroll compressor capable of defining a spiral shape of a spiral body having a contour combining a plurality of flat shapes having different flatnesses by an equation. The purpose.

The scroll compressor according to the present invention includes a fixed scroll in which a fixed spiral body is erected on a fixed base plate and a swing scroll in which a swing spiral body is erected on a rocking base plate. In a scroll compressor that compresses a refrigerant in a compression chamber formed by meshing with a swinging spiral, one of the outer curve and the inner curve of the fixed spiral and the swinging spiral is an involute of the base circle. A curve that is an open line and is defined by equations (1) and (2) using the involute angle θ in the x and y coordinate systems, and is the basic circle in equations (1) and (2). The radius a (θ) of is expressed by "a function that changes in a spiral or cosine wave shape with π [rad] as one cycle with respect to the involute angle θ" and "a step function with π [rad] as one cycle". It has a term of product with "coefficient to be".
x = a (θ) (csθ + θ ・ sinθ) ・・・ (1)
y = a (θ) (sinθ−θ ・ cоsθ) ・・・ (2)

According to the present invention, the spiral shape of the spiral body is defined by the equations (1) and (2) using the extension angle θ in the x and y coordinate systems, and the equations (1) and (2) are also defined. The fundamental pi a (θ) in is "a function that changes into a sinusoidal or cosine wave shape with π [rad] as one cycle with respect to the extension angle θ" and "a step function with π [rad] as one cycle". It is assumed that it has a term of product with "coefficient represented by". Thereby, the spiral shape of the spiral body having a contour combining a plurality of flat shapes having different flatness can be defined by the equation.
x = a (θ) (cоsθ + θsinθ) ... (1)
y = a (θ) (sinθ-θcоsθ) ... (2)

FIG. 5 is a schematic vertical sectional view of the overall configuration of the scroll compressor according to the first embodiment. It is sectional drawing of the compression mechanism part of the scroll compressor which concerns on Embodiment 1. FIG. It is a top view which showed the fixed spiral body and the rocking spiral body of the compression mechanism part of the scroll compressor which concerns on Embodiment 1. FIG. It is a compression process diagram which shows the operation during one rotation of the swing scroll in the scroll compressor which concerns on Embodiment 1. FIG. It is explanatory drawing of the drawing method of the spiral shape which constitutes the compression mechanism part of the scroll compressor which concerns on Embodiment 1. FIG. It is a figure which shows an example of the characteristic about the base circular radius a (θ) used for drawing the spiral shape of the spiral body in the scroll compressor which concerns on Embodiment 1. FIG. It is a figure which shows the change of the flatness of the outer curve of the spiral body in the scroll compressor which concerns on Embodiment 2. FIG. It is a figure which shows the spiral body in the scroll compressor which concerns on Embodiment 3. It is a compression process diagram which shows the operation during one rotation of the swing scroll in the scroll compressor which concerns on FIG. 8B. It is a figure which shows the characteristic about the base circular radius a (θ) of the spiral body in the scroll compressor which concerns on Embodiment 4. FIG.

Hereinafter, the scroll compressor according to the embodiment will be described with reference to drawings and the like. Here, in the following drawings including FIG. 1, those having the same reference numerals are the same or equivalent thereto, and are common to the whole texts of the embodiments described below. The form of the component represented in the full text of the specification is merely an example, and is not limited to the form described in the specification.

Embodiment 1.
FIG. 1 is a schematic vertical sectional view of the overall configuration of the scroll compressor according to the first embodiment.
The scroll compressor of the first embodiment includes a compression mechanism unit 8, an electric mechanism unit 110 that drives the compression mechanism unit 8 via a rotating shaft 6, and other components, which form an outer shell. It has a structure housed inside the closed container 100. In the closed container 100, the compression mechanism portion 8 is arranged above, and the electric mechanism portion 110 is arranged below the compression mechanism portion 8.

Further, the frame 7 and the subframe 9 are housed in the closed container 100 so as to face each other with the electric mechanism portion 110 interposed therebetween. The frame 7 is arranged above the electric mechanism portion 110 and is located between the electric mechanism portion 110 and the compression mechanism portion 8, and the subframe 9 is located below the electric mechanism portion 110. The frame 7 is fixed to the inner peripheral surface of the closed container 100 by shrink fitting, welding, or the like. Further, the subframe 9 is fixed to the inner peripheral surface of the closed container 100 by shrink fitting or welding via the subframe holder 9a.

A pump element 112 including a positive displacement pump is attached below the subframe 9. The pump element 112 supplies the refrigerating machine oil stored in the oil reservoir 100a at the bottom of the closed container 100 to a sliding portion such as a main bearing 7a described later of the compression mechanism 8. The pump element 112 supports the rotating shaft 6 in the axial direction on the 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 unit 8 has a function of compressing the refrigerant sucked from the suction pipe 101 and discharging the compressed refrigerant to the high-pressure part formed above the closed container 100. The compression mechanism unit 8 includes a fixed scroll 1 and a swing scroll 2.

The fixed scroll 1 is fixed to the closed container 100 via the frame 7. The swing scroll 2 is arranged below the fixed scroll 1 and is swingably supported by an eccentric shaft portion 6a described later of the rotation shaft 6.

The fixed scroll 1 includes a fixed base plate 1a and a fixed spiral body 1b which is a spiral protrusion erected on one surface of the fixed base plate 1a. The oscillating scroll 2 includes a oscillating base plate 2a and a oscillating spiral body 2b which is a spiral projection erected on one surface of the oscillating base plate 2a. The fixed scroll 1 and the swing scroll 2 are arranged in the closed container 100 in a symmetrical spiral shape in which the fixed spiral body 1b and the swing spiral body 2b are meshed with each other in opposite phases. A compression chamber 71 is formed between the fixed spiral body 1b and the rocking spiral body 2b whose volume decreases from the outer side to the inner side in the radial direction as the rotation shaft 6 rotates.

The baffle 4 is fixed to the surface of the fixed base plate 1a of the fixed scroll 1 opposite to the swing 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 through hole 4a is provided with a discharge valve 11. Further, a discharge muffler 12 is attached to the baffle 4 so as to cover the discharge port 1c.

The frame 7 has a fixed scroll 1 arranged in a fixed manner and has a thrust surface that supports the thrust force acting on the swing scroll 2 in the axial direction. Further, the frame 7 is formed through an introduction flow path 7c that guides the refrigerant sucked from the suction pipe 101 into the compression mechanism portion 8.

Further, on the frame 7, an old dam ring 14 is arranged to prevent the swing scroll 2 from rotating during the turning motion. The key portion 14a of the old dam ring 14 is arranged below the rocking base plate 2a of the rocking 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. Further, the motor stator 110a is fixed to the rotating shaft 6 by shrink fitting or the like. Further, in order to balance the entire rotating system of the scroll compressor, the first balance weight 60 is fixed to the rotating shaft 6, and the second balance weight 61 is fixed to the motor stator 110a.

The rotating shaft 6 is composed of an upper eccentric shaft portion 6a, an intermediate main shaft portion 6b, and a lower sub-shaft portion 6c. The eccentric shaft portion 6a is eccentric with respect to the axial center of the rotating shaft 6. The eccentric shaft portion 6a is fitted to the swing scroll 2 via a slider 5 with a balance weight and a swing bearing 2c, and the swing scroll 2 swings due to the rotation of the rotation shaft 6. There is. The spindle portion 6b is fitted to the main bearing 7a arranged on the inner circumference of the cylindrical boss portion 7b provided on the frame 7 via the sleeve 13, and is fitted to the main bearing 7a via an oil film of refrigerating machine oil. Sliding. The main bearing 7a is fixed in the boss portion 7b by press-fitting a bearing material used for a slide bearing such as a copper-lead alloy.

An auxiliary bearing 10 made of a ball bearing is provided on the upper part of the subframe 9, and the auxiliary bearing 10 pivotally supports the rotating shaft 6 in the radial direction at the lower part of the electric mechanism portion 110. The auxiliary bearing 10 may be pivotally supported by a bearing configuration other than the ball bearing. The auxiliary shaft portion 6c is fitted with the auxiliary bearing 10 and slides with the auxiliary bearing 10 via an oil film formed by refrigerating machine oil. The axes of the spindle 6b and the sub-axis 6c coincide with the axes of the rotating 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 motor rotor 110b side of the frame 7 is designated as the first space 72. Further, the space surrounded by the inner wall of the frame 7 and the fixed base plate 1a is referred to as the second space 73. Further, the space on the discharge pipe 102 side of the fixed base plate 1a is designated as the third space 74. Of the second space 73, the outside of the structure portion in which the fixed spiral body 1b and the rocking spiral body 2b are combined is referred to as a suction space 73a. The refrigerant before being compressed in the compression chamber 71 is introduced into the suction space 73a from the introduction flow path 7c.

Next, the arrangement of the parts 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. FIG. 3 is a plan view showing a fixed spiral body and a swinging spiral body of the compression mechanism portion of the scroll compressor according to the first embodiment. In addition, in FIGS. 2 and 3, in order to facilitate the distinction between the fixed spiral body 1b of the fixed scroll 1 and the rocking spiral body 2b of the rocking scroll 2, dots are added to the rocking spiral body 2b of the rocking scroll 2. It has been given. The same applies to the figures described later.

The closed container 100 has a perfect circular shape when viewed in a plane, and is fixed to the inside of the closed container 100 in a state where the outer peripheral surface of the frame 7 is 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.

Then, in the first embodiment, the outer shape of the rocking base plate 2a is a flat shape. Therefore, by making the spiral shape of the swinging spiral body 2b erected on the rocking base plate 2a also a flat shape, the space on the rocking base plate 2a can be effectively used and the space efficiency can be improved. it can. The same applies to the fixed base plate 1a, and the outer shape of the fixed base plate 1a and the spiral shape of the fixed spiral body 1b are made flat. By increasing the space efficiency in this way, it is possible to increase the volume of the compression chamber 71 while keeping the size of the closed container 100 the same, and it is possible to improve the compression function force. On the contrary, in order to secure the same compression function force, the size of the closed container 100 can be reduced. In the following, when the fixed spiral body 1b and the rocking spiral body 2b are not distinguished and both are referred to, they are collectively referred to as "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".

Further, the first embodiment is characterized in that the spiral shape of the spiral body has a shape obtained by combining two flat shapes having different flatnesses. Specifically, as shown in FIG. 3, the spiral shape of the first embodiment has a flat shape having a different flatness between the region A and the region B. As described above, in the first embodiment, by changing the flattening ratio between the region A and the region B, the flat shape of one region side, that is, the region side B in this example, is the flattening of the region A. It has a crushed shape compared to the shape. With such a shape, an empty space can be formed between the flat shape on the region side of B and the inner peripheral surface of the closed container 100, and the introduction flow path 7c is installed in this empty space. The flat shape also includes an oval shape and an elliptical shape, and in short, refers to all shapes that are flatter than a perfect circle. The details of the spiral shape configured as described above will be described again.

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

FIG. 4 is a compression process diagram showing the operation of the swing scroll during one rotation in the scroll compressor according to the first embodiment. 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 rotational force and rotates. Along with this, the rotating shaft 6 fixed to the electric motor rotor 110b is rotationally driven. The rotational motion of the rotating shaft 6 is transmitted to the swing scroll 2 via the eccentric shaft portion 6a. The oscillating spiral body 2b of the oscillating scroll 2 oscillates with an oscillating radius while its rotation is regulated by the old dam ring 14. The swing radius means the amount of eccentricity of the eccentric shaft portion 6a with respect to the spindle portion 6b.

As the electric mechanism unit 110 is driven, 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 that has flowed into the first space 72 flows into the suction space 73a through the introduction flow path 7c installed in the frame 7. The low-pressure refrigerant that has flowed into the suction space 73a is sucked into the compression chamber 71 along with the relative swinging motion of the swinging spiral body 2b and the fixed spiral body 1b of the compression mechanism unit 8. As shown in FIG. 4, the refrigerant sucked into the compression chamber 71 is boosted from low pressure to high pressure due to the geometric volume change of the compression chamber 71 accompanying the relative operation of the swinging spiral body 2b and the fixed spiral body 1b. Will 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 to the outside of the compressor as a high-pressure refrigerant. The arrow in FIG. 1 indicates the flow of this refrigerant.

In the first embodiment, as described above, the contours of the swinging spiral body 2b and the fixed spiral body 1b are flat, and the spiral shape is also flat. As described above, in the compression mechanism unit 8 in which the spiral shape of the spiral body is flat, even when the swing spiral body 2b is operated with a constant swing radius as shown in FIG. 4, the swing spiral body 2b Operates while contacting the inward and outward surfaces of the fixed spiral body 1b whose outward and inward surfaces face each other.

Then, the first embodiment is characterized in that the spiral shape of the spiral body having a contour combining a plurality of flat shapes having different flatness is defined by an equation. The shape of the spiral is determined by an outer curve that identifies the outward surface of the spiral and an inner curve that identifies the inward surface of the spiral. In defining the spiral shape of the spiral body by the equation, specifically, either the outer curve or the inner curve of the spiral body is a curve that is an involute of the base circle, and is in the x, y coordinate system. The curve defined by the following equations (1) and (2) is obtained by using the involute angle θ.

A (θ) in equations (1) and (2) is the radius of the base circle. As shown in the following equation (3), a (θ) is a “function that changes in a sinusoidal or cosine wave shape with π [rad] as one cycle with respect to the extension angle θ” and “π [rad]. Is given by a functional expression having a term of product with a coefficient α "represented by a step function α (θ) with one cycle. The coefficient α is a coefficient indicating the degree of flatness. Thereby, the spiral shape of the spiral body having a contour combining a plurality of flat shapes having different flatness can be defined by the equation. In the first embodiment, the basic circular radius a (θ) is changed as shown in the equation (3) as an example.

In the formula (3), a ₀ is serving as a reference base radius (hereinafter, criterion of radius) is. Further, in the equation (3), the step function α (θ) with π [rad] as one cycle is a real function in which the graph becomes stepped with respect to the extension angle θ, and π [rad]. There is an indicator function with 1 cycle, and it is a function represented by their linear connection. Specifically, the step function α (θ) is a function in which the value changes alternately every π / 2 with π [rad] as one cycle. Here, α (θ) alternates between α1 and α2 every π / 2. That is, α (θ) = α1 when the involute angle θ is from 0 to π / 2, and α (θ) = α2 when the involute angle θ is from π / 2 to π. Similarly, in the next one cycle, α (θ) = α1 from π to 3π / 2, and α (θ) = α2 from the involute angle θ from 3π / 2 to 2π.

Also, in equation (3), N is a natural number of 1 or more. ξ is a constant [rad], and the flat shape when α (θ) in equation (3) is α1 (hereinafter referred to as the flat shape by α1) and α (θ) in equation (3) are α2. It is an involute angle that combines the flat shape in a certain case (hereinafter referred to as the flat shape by α2).

In equation (3), by changing the coefficient α, the flatness of the contour of the spiral body can be set arbitrarily. Specifically, as the value of α increases, the flatness of the contour of the spiral body increases and the shape becomes flat. The spiral shape of the spiral body of the first embodiment is a combination of a flat shape formed by α1 and a flat shape formed by α2. In FIG. 3, the flat shape of the region A shows the case where α1 is 0.3. The flat shape of the region B shows the case where α2 is −0.2. Further, in FIG. 3, the value of N is 1 and the value of ξ is 0. The change in the shape of the spiral body when ξ is changed will be described in the third embodiment described later.

Next, a method for drawing the spiral shapes of the fixed spiral body 1b and the swinging spiral body 2b will be described. Since the drawing method of the fixed spiral body 1b and the swinging spiral body 2b is the same, the swinging spiral body 2b will be described below as a representative. Further, the spiral shape of the swinging spiral body 2b is a shape in which two flat shapes having different flatnesses are combined as described above, but the drawing method itself of each flat shape is the same.

The shape of the spiral 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 when the outer curve is a curve defined by the equations (1) and (2) will be described with reference to FIG.

FIG. 5 is an explanatory diagram of a spiral-shaped drawing method constituting the compression mechanism portion of the scroll compressor according to the first embodiment. In FIG. 5, drawings are drawn according to the procedures (a), (b), (c), and (d).

First, as shown in FIG. 5A, draw an involute 30 of the base circle. Here, a (θ) increases in a sinusoidal shape with π [rad] as one cycle according to the involute angle θ as described above. The involute 30 drawn here is the outer curve. Let a (θ) be α1.

Next, draw an inner curve according to the procedure shown in FIGS. 5 (b) to 5 (d). That is, first, as shown in FIG. 5 (b), a curve 31 is drawn by rotating the involute 30 drawn in the procedure (a) by π [rad] with respect to the center of the base circle O. Here, since the inner curve is created, the curved portion (dotted line portion in FIG. 5B) located outside the curve 30 of the curve 31 is not used in the subsequent drafting procedure.

Next, as shown in FIG. 5 (c), a plurality of circles 32 having a center on the curve 31 drawn in the procedure (b) and having a radius equal to the swing radius of the swing scroll 2 are drawn.

Next, as shown in FIG. 5 (d), the outer envelope 33 of the circle group drawn in the procedure (c) is drawn. The curve 33 drawn in this procedure (d) becomes the inner curve.

From the above, the curve 30 drawn in the procedure (a) becomes the outer curve of the swinging spiral body 2b, and the curve 33 drawn in the procedure (d) becomes the inner curve of the swinging spiral body 2b. Then, one region divided to the left and right about the center of the basic circle O of the dot region in the procedure (d) becomes one cross section of the two spiral shapes constituting the swinging spiral body 2b.

Similarly, the spiral shape when a (θ) is α2 is drawn by the procedure of FIGS. 5 (a) to 5 (d), centering on the base circle center O of the dot region of the procedure (d). The other region divided into left and right is the other cross section of the two spiral shapes constituting the swinging spiral body 2b. From the above, the spiral shape of the swinging spiral body 2b can be drawn.

Regarding the fixed spiral body 1b, the same procedure as that of the swinging spiral body 2b described above was adopted, and the shape of the rocking spiral body 2b was rotated by π [rad] in the specification having the same wall thickness as the rocking spiral body 2b. It becomes a shape.

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

FIG. 6 is a diagram showing an example of characteristics related to the basic circular radius a (θ) used for drawing the spiral shape of the spiral body in the scroll compressor according to the first embodiment. The vertical axis of FIG. 6 shows the ratio of base circle with respect to a reference radius a ₀ radius a (theta). The horizontal axis of FIG. 6 indicates the extension angle θ [rad].

FIG. 6 shows the case where the value of α (θ) in the equation (3) is α1 = 0.3 and α2 = −0.2, the value of N is 1, and the value of ξ is 0, as in FIG. The periodic change of the base circle radius a (θ) with respect to the involute angle θ is shown. In the waveform of the basic circular radius a (θ) shown in FIG. 6, it is shown that the larger the value of a (θ) / a ₀ , the thicker the wall thickness of the spiral body. Therefore, the wall thickness of the spiral body becomes thicker at π / 4, 5π / 4, and 9π / 4. Further, in the waveform of the basic circular radius a (θ), the spiral body is stretched in the direction of the involute angle where the peak exceeding 1.0 is present. Therefore, in the example of FIG. 6, when the involute angles are π / 4, 5π / 4, and 9π / 4, the peak exceeding 1.0 comes, so that the involute is stretched in the lateral direction as shown in FIG. Shape.

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 extension angle θ. Then, the fundamental pi a (θ) in the equations (1) and (2) is changed to "a function that changes in a sinusoidal shape or a cosine wave shape with π [rad] as one cycle with respect to the extension angle θ" and ". It is assumed that it has a term of product with the coefficient α "represented by the step function α (θ) with π [rad] as one cycle. Thereby, the spiral shape of the spiral body having a contour combining a plurality of flat shapes having different flatness can be defined by the equation.

In the first embodiment, the contours of the fixed spiral body 1b and the swinging spiral body 2b can be arbitrarily set by setting the basic circular radius a (θ) to the equation (3).

In the first embodiment, α (θ) is a function in which the value changes alternately every π / 2, with the change period as π [rad]. By taking two values of α in this way, the spiral shape of the spiral body that can consolidate the empty space in one place can be defined by the equation. Specifically, by setting the value of one α to a value smaller than the value of the other α, an empty space can be formed on the flat shape side using one α. The introduction flow path 7c can be formed in this empty space, and when the introduction flow path 7c is unified, the flow path area of the introduction flow path 7c can be set large.

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

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

FIG. 7 is a diagram showing a change in the flatness of the outer curve of the spiral body in the scroll compressor according to the second embodiment. In FIG. 7, (a) is when α1 = 0 and α2 = 0, (b) is when α1 = 0.3 and α2 = 0, and (c) is when α1 = 0.3 and α2 = −0.2. Shows the case.

As shown in FIG. 7, by changing the value of α, it is possible to arbitrarily set the flatness of the contour of the spiral body. The flatness is the ratio (D11 + D12) / D2 of the major axis D11 + D12 to the minor axis D2 as shown in FIG. 7A. Of these, the flattening ratio of the region A in the figure, that is, the region forming the spiral at α1, is (D11 × 2) / D2. Further, the flatness of the region B in the figure, that is, the region forming the spiral with α2 is (D12 × 2) / D2.

Specifically, the flattening rate increases as the value of α increases. In FIG. 7, as is clear by comparing the flat shapes of the regions A in (a) and (b), the flattening ratio of (b) having a large value of α1 is larger than that of (a). .. In FIGS. 7 (b) and 7 (c), as is clear by comparing the flat shapes of the region B, the flattening ratio of (b) having a large α2 value is larger than that of (c). ..

Further, as is clear from FIG. 7, the flatness of each of the flat shapes of the region A and the region B in FIG. 7 can be set independently by the values of α1 and α2.

According to the second embodiment, the same effect as that of the first embodiment can be obtained, and the flattening ratio of each flat shape can be arbitrarily set by the values of α1 and α2. Therefore, by setting α1 and α2 according to the installation space of the introduction flow path 7c, the flow path area of the introduction flow path 7c can be set large even when the introduction flow path 7c is unified.

Embodiment 3.
In the third embodiment, the case where the extension angle ξ is changed will be described. Hereinafter, the configuration in which the third embodiment is different from the first embodiment will be mainly described, and the configurations not described in the third embodiment are the same as those in the first embodiment.

FIG. 8 is a diagram showing a spiral body in the scroll compressor according to the third embodiment. In FIG. 8, when (a) is α1 = 0.3, α2 = −0.2, ξ = 0 [rad], (b) is α1 = 0.3, α2 = −0.2, ξ = π / The case of 4 [rad] is shown. ξ is an involute angle that combines the flat shape of α1 and the flat shape of α2 as described above. In both the spirals of FIGS. 8 (a) and 8 (b), the region A in FIG. 8 shows a flat shape due to α1, and the region B shows a flat shape due to α2. As is clear from FIG. 8, changing the value of ξ changes the direction of the spiral shape as a whole.

FIG. 9 is a compression process diagram showing the operation of the swing scroll in one rotation in the scroll compressor according to FIG. 8 (b). FIG. 9A shows the position of the spiral body when the rotation phase is 0 [rad] (2π [rad]). FIG. 9B shows the position of the spiral body when the rotation phase is π / 2 [rad]. FIG. 9C shows the position of the spiral body when the rotation phase is π [rad]. FIG. 9D shows the position of the spiral body when the rotation phase is 3π / 2 [rad]. As shown in FIG. 9, even when the value of ξ is set to a phase other than 0 [rad], the compression operation can be realized in the same manner as in the case of FIG. 4 of the first embodiment.

According to the third embodiment, the same effect as that of the first embodiment and the second embodiment can be obtained, and by changing the value of ξ, the spiral shape as a whole is adjusted to the position where the introduction flow path 7c is arranged. You can change the orientation of.

Embodiment 4.
In the fourth embodiment, another functional expression of the basic circular radius a (θ) will be described. Hereinafter, the configuration in which the fourth embodiment is different from the first embodiment will be mainly described, and the configurations not described in the fourth embodiment are the same as those in the first embodiment.

FIG. 10 is a diagram showing the characteristics of the basic circular radius a (θ) of the spiral body in the scroll compressor according to the fourth embodiment. 10 (a) to 10 (d) show, in order, the functional equations of the basic circular radius a (θ), the equation (3) shown in the first embodiment, and the following equations (4) to (2). It corresponds to the case of 6). The vertical axis of FIG. 10 shows the ratio of base circle with respect to a reference radius a ₀ radius a (theta). The horizontal axis of FIG. 10 indicates the extension angle θ [rad]. Further, in all of FIGS. 10A to 10D, α1 = 0.3, α2 = −0.2, N = 1, and ξ = 0.

For the basic circular radius a (θ), equations (4) to (6) can be used in addition to the equation (3) shown in the first embodiment. By changing the basic circular radius a (θ) as in equations (3) to (6), the contours of the fixed spiral body 1b and the swinging spiral body 2b can be arbitrarily set.

In the first to fourth embodiments, the low-pressure shell type scroll compressor in which the inside of the closed container 100 is filled with the low-pressure refrigerant is shown, but the inside of the closed container 100 is filled with the high-pressure refrigerant. The same effect can be obtained even when a scroll compressor is used.

1 fixed scroll, 1a fixed base plate, 1b fixed spiral body, 1c discharge port, 2 rocking scroll, 2a rocking base plate, 2b rocking spiral body, 2c rocking bearing, 4 baffle, 4a through hole, 5 balance weight Attached slider, 6 rotary shaft, 6a eccentric shaft part, 6b main shaft part, 6c sub-shaft part, 7 frame, 7a main bearing, 7b boss part, 7c introduction flow path, 8 compression mechanism part, 9 subframe, 9a subframe holder 10, Auxiliary bearing, 11 Discharge valve, 12 Discharge muffler, 13 Sleeve, 14 Oldam ring, 14a Key part, 30 Extension wire, 32 yen, 33 Outer wrapping wire, 60 1st balance weight, 61 2nd balance weight, 71 Compression chamber, 72 1st space, 73 2nd space, 73a suction space, 74 3rd space, 100 closed container, 100a oil reservoir, 101 suction pipe, 102 discharge pipe, 110 electric mechanism part, 110a electric motor stator, 110b Motor rotor, 112 pump element.

Claims

A fixed scroll in which a fixed spiral body is erected on a fixed base plate and a swing scroll in which a swing spiral body is erected on a swing base plate are provided, and the fixed spiral body and the swing spiral body mesh with each other. In a scroll compressor that compresses the refrigerant in the compression chamber formed by
One of the outer curve and the inner curve of the fixed spiral body and the rocking spiral body is a curve that is an involute of the base circle, and the extension angle θ is used in the x and y coordinate systems. The curve is defined by the equations (1) and (2), and the radius a (θ) of the base circle in the equations (1) and (2) is “π [rad” with respect to the involute angle θ. ] Is a function that changes in a sinusoidal or cosine wave shape with one cycle ”and“ a coefficient represented by a step function with π [rad] as one cycle ”is a scroll compressor having a term.
The scroll compressor according to claim 1, wherein the basic circular radius a (θ) is given by any of the equations (3) to (6).
Here, a 0 is a reference basic circular radius, α (θ) is the step function, N is a natural number of 1 or more, and ξ is a constant [rad].
The scroll compressor according to claim 2, wherein α (θ) is a function in which the value changes alternately every π / 2, with the change period as π [rad].
When the curves defined by the equation (1) and the equation (2) are the outer curves, the inner curves of the fixed spiral body and the swinging spiral body each have the outer curve of the base circle. An outer wrapping line of a group of circles having a center on a curve rotated by π [rad] with respect to the center and having a radius equal to the swing radius of the swing scroll.
When the curves defined by the equations (1) and (2) are the inner curves, the outer curves of the fixed spiral body and the swinging spiral body each have the inner curve of the base circle. Any one of claims 1 to 3, wherein the inner wrapping line of a circle group having a center on a curve rotated by π [rad] with respect to the center and having a radius equal to the swing radius of the swing scroll. The scroll compressor described in the section.
The scroll compressor according to any one of claims 1 to 4, wherein the rocking base plate has a flat outer shape.