阅读说明：本技术 涡旋压缩机 (Scroll compressor having a plurality of scroll members ) 是由 河村雷人 关屋慎 于 2019-04-12 设计创作，主要内容包括：将固定涡旋体和摆动涡旋体各自的外侧曲线及内侧曲线中的任一方设为作为基圆的渐开线的曲线,且该曲线在x、y坐标系中使用渐开角θ由式(1)及式(2)定义。式(1)及式(2)中的基圆的半径a(θ)具有“相对于渐开角θ呈以π[rad]为1个周期的正弦波状或余弦波状地变化的函数”与“由以π[rad]为1个周期的阶梯函数表示的系数”之积的项,x＝a(θ)(cosθ+θ·sinθ)...(1),y＝a(θ)(sinθ-θ·cosθ)...(2)。(Either one of the outer curve and the inner curve of each of the fixed scroll and the oscillating scroll is defined as a curve which is an involute curve to a base circle, and the curve is defined by equations (1) and (2) using an involute angle θ in an x-y coordinate system. The radius a (θ) of the base circle in the formulas (1) and (2) has a term of a product of a "function varying in a sine-wave or cosine-wave shape with 1 cycle of pi [ rad ] with respect to the involute angle θ" and a "coefficient represented by a step function with 1 cycle of pi [ rad ]", where x is a (θ) (cos θ + θ · sin θ). (1) and y is a (θ) (sin θ - θ · cos θ) · (2).)

1. A scroll compressor comprising a fixed scroll having a fixed scroll standing on a fixed platen and a swing scroll having a swing scroll standing on a swing platen, wherein a refrigerant is compressed in a compression chamber formed by meshing the fixed scroll with the swing scroll,

one of an outer curve and an inner curve of each of the fixed scroll and the oscillating scroll is defined as a curve of an involute curve as a base circle, and the curve is defined by expressions (1) and (2) using an involute angle theta in an x-y coordinate system, a radius a (theta) of the base circle in the expressions (1) and (2) has a term of a product of a function of changing in a sine wave or cosine wave shape with 1 cycle of pi [ rad ] with respect to the involute angle theta and a coefficient of a step function with 1 cycle of pi [ rad ],

[ numerical formula 1]

x＝a(θ)(cosθ+θ·sinθ)…(1)

[ numerical formula 2]

y＝a(θ)(sinθ-θ·cosθ)…(2)。

2. The scroll compressor of claim 1,

the base radius a (theta) is given by any one of the formulas (3) to (6),

herein, a₀Is a base radius serving as a reference, alpha (theta) is the step function, N is a natural number of 1 or more, and xi is a constant [ rad ]]，

[ numerical formula 3]

a(θ)＝a₀·θ(1+α(θ)·(sin(θ-ξ))^2N)…(3)

[ numerical formula 4]

a(θ)＝a₀·θ(1+α(θ)·(cos(θ-ξ))^2N)…(4)

[ numerical formula 5]

a(θ)＝a₀·θ(1+α(θ)·(1+sin2(θ-ξ)))…(5)

[ numerical formula 6]

a(θ)＝a₀·θ(1+α(θ)·(1+cos2(θ-ξ)))…(6)。

3. The scroll compressor of claim 2, wherein,

the alpha (0) is a function which sets the change period as pi [ rad ] and changes alternately every pi/2.

4. A scroll compressor as claimed in any one of claims 1 to 3,

when the curves defined by the expressions (1) and (2) are the outer curves, the inner curves of the fixed scroll and the oscillating scroll are outer envelope curves of a circle group having a center on a curve obtained by rotating the outer curve by pi [ rad ] with respect to the center of the base circle and having a radius equal to the oscillation radius of the oscillating scroll,

when the curves defined by the expressions (1) and (2) are the inner curves, the outer curves of the fixed scroll and the oscillating scroll are inner envelope curves of a circle group having a center on a curve obtained by rotating the inner curve by pi [ rad ] with respect to the center of the base circle and having a radius equal to the oscillation radius of the oscillating scroll.

5. The scroll compressor according to any one of claims 1 to 4,

the shape of the swing bedplate is a flat shape.

Technical Field

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

Background

The scroll compressor used for an air conditioner, a refrigerator, and the like has the following structure: the compressor includes a compression mechanism for compressing a refrigerant in a compression chamber formed by combining a fixed scroll and a swing scroll, and a container for housing the compression mechanism. The fixed scroll and the oscillating scroll have a structure in which a scroll is vertically provided on a platen, and the scrolls mesh with each other to form a compression chamber. Then, by oscillating the oscillating scroll, the compression chamber moves while reducing the volume, and the refrigerant is sucked into and compressed in the compression chamber. In such a scroll compressor, in order to achieve a reduction in size and cost, it is important to develop a technique for increasing the compressor capacity by increasing the suction capacity of the compression chamber as much as possible while keeping the diameter of the container the same. In order to increase the suction volume of the compression chamber while keeping the diameter of the container the same, it is necessary to design the scroll shape of the scroll.

Conventionally, there are techniques as follows: the scroll shape of the scroll compressor is an involute curve having a perfect circle of a predetermined radius as a base circle, and the contour of the entire scroll is a circle. In contrast, in recent years, there are techniques as follows: the outline of the entire scroll is formed into a flat shape instead of a circular shape, and the scroll shape of the scroll is also formed into a flat shape (for example, see patent document 1).

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 10-54380

Disclosure of Invention

Problems to be solved by the invention

Patent document 1 describes that the contour and the scroll shape of the scroll are flat, but does not describe a specific definition of the scroll shape. As described above, there is a technique for defining the spiral shape of a scroll by an involute curve having a perfect circle with a predetermined radius as a base circle.

In addition, an introduction flow passage for introducing the refrigerant into a suction space through which the refrigerant flows before being compressed in the compression chamber is provided in the vicinity of the compression mechanism section of the scroll compressor. It is desirable that the introduction flow path is not blocked by the scroll and the platen of each of the fixed scroll and the oscillating scroll regardless of the rotational phase.

In a structure in which the contour and the scroll shape of the scroll are flat having a major axis and a minor axis as in patent document 1, 2 void spaces facing each other at 180 ° are formed between a pair of opposing sides in the minor axis direction and the inner peripheral surface of the container. In the structure in which the void spaces 2 are formed in this way, an introduction flow path is provided in each void space in order to secure the flow path area of the introduction flow path as much as possible. That is, the introduction flow path is plural. However, if there are a plurality of introduction flow paths, the number of processing steps during production increases, and therefore the production cost increases.

In order to avoid such an increase in manufacturing cost, it is effective to concentrate the void space for providing the introduction flow path in 1 place and provide the introduction flow path having a secured flow path area in the void space. In order to make the scroll shape of the scroll flat and concentrate the void space for providing the introduction flow path at 1 position, it is conceivable to make the scroll shape a combination of a plurality of flat shapes having different flattening ratios. That is, it is conceivable to secure the void space by, for example, making the flat shape on the side where the void space is provided flat compared with the flat shape on the side where the void space is not provided. However, no prior art that can define such a shape by a mathematical expression has been found.

The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a scroll compressor capable of mathematically defining a scroll shape of a scroll body having a contour in which a plurality of flat shapes having different flat ratios are combined.

Means for solving the problems

A scroll compressor of the present invention includes a fixed scroll having a fixed scroll standing on a fixed platen and a swing scroll having a swing scroll standing on a swing platen, and compresses a refrigerant in a compression chamber formed by meshing the fixed scroll and the swing scroll, wherein either one of an outer curve and an inner curve of each of the fixed scroll and the swing scroll is a curve which is an involute curve of a base circle, and the curve is defined by expressions (1) and (2) using an involute angle theta in an x-y coordinate system, a radius a (theta) of a base circle in expressions (1) and (2) has a term of a product of a function which changes in a sine wave or cosine wave form with [ rad ] being 1 pi cycle with respect to the involute angle theta and a coefficient which is expressed by a step function with pi [ rad ] being 1 cycle,

x＝a(θ)(cоsθ+θ·sinθ)...(1)

y＝a(θ)(sinθ-θ·cоsθ)...(2)。

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the scroll shape of the scroll is defined by the expressions (1) and (2) using the involute angle θ in the x-y coordinate system, and the base radius a (θ) in the expressions (1) and (2) is set to have a term having a product of "a function that varies in a sine wave or cosine wave shape with 1 period of π [ rad ] with respect to the involute angle θ" and "a coefficient represented by a step function with 1 period of π [ rad ]. Thus, the scroll shape of the scroll body having the contour in which a plurality of flat shapes having different flattening ratios are combined can be defined by the mathematical expression.

x＝a(θ)(cоsθ+θsinθ)...(1)

y＝a(θ)(sinθ-θcоsθ)...(2)

Drawings

Fig. 1 is a schematic longitudinal sectional view of the overall structure of a scroll compressor according to embodiment 1.

Fig. 2 is a cross-sectional view of a compression mechanism of the scroll compressor according to embodiment 1.

Fig. 3 is a plan view showing a fixed scroll and a swinging scroll of a compression mechanism section of the scroll compressor according to embodiment 1.

Fig. 4 is a compression process diagram showing an operation in the course of 1 rotation of the orbiting scroll in the scroll compressor according to embodiment 1.

Fig. 5 is an explanatory diagram of a drawing method of the scroll shape of the compression mechanism portion constituting the scroll compressor according to embodiment 1.

Fig. 6 is a diagram showing an example of characteristics relating to the base radius a (θ) used for drawing the scroll shape of the scroll in the scroll compressor according to embodiment 1.

Fig. 7 is a diagram showing a change in the flattening ratio of the outer curve of the scroll in the scroll compressor according to embodiment 2.

Fig. 8 is a view showing a scroll in the scroll compressor according to embodiment 3.

Fig. 9 is a compression process diagram showing an operation in the course of 1 rotation of the orbiting scroll in the scroll compressor of fig. 8 (b).

Fig. 10 is a diagram showing characteristics relating to the base radius a (θ) of the scroll in the scroll compressor according to embodiment 4.

Detailed Description

Hereinafter, a scroll compressor according to an embodiment will be described with reference to the drawings and the like. In the drawings, including fig. 1, the same or corresponding portions are denoted by the same reference numerals and are common throughout the embodiments described below. The embodiments of the constituent elements shown throughout the specification are merely examples, and are not limited to the embodiments described in the specification.

Embodiment mode 1

Fig. 1 is a schematic longitudinal sectional view of the overall structure of a scroll compressor according to embodiment 1.

The scroll compressor according to embodiment 1 includes a compression mechanism portion 8, an electric mechanism portion 110 for driving the compression mechanism portion 8 via a rotary shaft 6, and other components, and is configured to be housed in a hermetic container 100 constituting an outer shell. In the closed casing 100, the compression mechanism 8 is disposed at an upper position, and the electric mechanism 110 is disposed at a lower position than the compression mechanism 8.

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

Below the subframe 9 is mounted a pump element 112 comprising a displacement pump. The pump element 112 supplies the refrigerating machine oil stored in the oil reservoir 100a at the bottom of the hermetic 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 rotary shaft 6 in the axial direction with an upper end surface.

The sealed 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 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 above the inside of the closed casing 100. The compression mechanism 8 includes the fixed scroll 1 and the oscillating scroll 2.

The fixed scroll 1 is fixed to the hermetic container 100 via a frame 7. The oscillating scroll 2 is disposed below the fixed scroll 1, and is supported to be freely oscillated by an eccentric shaft portion 6a, described later, of the rotary shaft 6.

The fixed scroll 1 includes a fixed platen 1a and a fixed scroll 1b as a spiral protrusion standing on one surface of the fixed platen 1 a. The oscillating scroll 2 includes an oscillating platen 2a and an oscillating scroll 2b as a spiral protrusion vertically provided on one surface of the oscillating platen 2 a. The fixed scroll 1 and the oscillating scroll 2 are disposed in the sealed container 100 in a symmetrical scroll shape in which the fixed scroll 1b and the oscillating scroll 2b are meshed with each other in opposite phases. A compression chamber 71, the volume of which decreases from the radially outer side to the radially inner side as the rotating shaft 6 rotates, is formed between the fixed scroll 1b and the orbiting scroll 2 b.

A baffle 4 is fixed to a surface of the fixed platen 1a of the fixed scroll 1 opposite to the oscillating 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 4 a. Further, a discharge muffler 12 is attached to the baffle 4 so as to cover the discharge port 1 c.

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

Further, a oldham ring 14 for preventing rotation in the orbiting motion of the orbiting scroll 2 is disposed on the frame 7. The key portion 14a of the oldham ring 14 is disposed below the swing platen 2a of the swing scroll 2.

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

The rotary shaft 6 includes an upper eccentric shaft portion 6a, a middle main shaft portion 6b, and a lower sub shaft portion 6 c. The eccentric shaft portion 6a is eccentric with respect to the axis of the rotating shaft 6. The eccentric shaft portion 6a is fitted to the swing scroll 2 via the slider 5 with a balance weight and the swing bearing 2c, and the swing scroll 2 is swung by the rotation of the rotary shaft 6. The main shaft portion 6b is fitted to a main bearing 7a via a sleeve 13, and slides on the main bearing 7a via an oil film formed of refrigerating machine oil, and the main bearing 7a is disposed on the inner periphery of a cylindrical boss portion 7b provided in the frame 7. The main bearing 7a is fixed in the boss portion 7b by press-fitting a bearing material or the like used for a sliding bearing such as a copper-lead alloy.

A sub-bearing 10 formed of a ball bearing is provided on the upper portion of the sub-frame 9, and the sub-bearing 10 axially supports the rotary shaft 6 in the radial direction on the lower portion of the electric mechanism 110. The sub-bearing 10 may be supported by a bearing structure other than a ball bearing. The sub-shaft 6c is fitted to the sub-bearing 10 and slides on the sub-bearing 10 via an oil film formed of refrigerating machine oil. The axial centers of the main shaft portion 6b and the auxiliary shaft portion 6c coincide with the axial center of the rotary shaft 6.

Here, the space in the closed casing 100 is defined as follows. A space on the motor rotor 110b side of the frame 7 in the internal space of the sealed container 100 is defined as a first space 72. A space surrounded by the inner wall of the frame 7 and the fixed platen 1a is defined as a second space 73. A space on the discharge pipe 102 side of the fixed platen 1a is defined as a third space 74. The outside of the structural portion in which the fixed scroll 1b and the orbiting scroll 2b in the second space 73 are combined is referred to as a suction space 73 a. The refrigerant before being compressed in the compression chamber 71 is introduced into the suction space 73a through the introduction flow path 7 c.

Next, the arrangement of the components of the compression mechanism 8 in the closed casing 100 will be described.

Fig. 2 is a cross-sectional view of a compression mechanism of the scroll compressor according to embodiment 1. Fig. 3 is a plan view showing a fixed scroll and a swinging scroll of a compression mechanism section of the scroll compressor according to embodiment 1. In fig. 2 and 3, the oscillating scroll 2b of the oscillating scroll 2 is dotted to easily distinguish the fixed scroll 1b of the fixed scroll 1 from the oscillating scroll 2b of the oscillating scroll 2. The same applies to the later-described drawings.

The sealed container 100 has a perfect circular shape in plan view, and is fixed inside the sealed container 100 in a state where the outer peripheral surface of the frame 7 is in contact with the inner peripheral surface of the sealed container 100. Therefore, the outer peripheral surface of the frame 7 is also in a perfect circle shape.

In embodiment 1, the swing platen 2a has a flat outer shape. Therefore, by making the spiral shape of the oscillating scroll 2b erected on the oscillating platen 2a also flat, the space on the oscillating platen 2a can be effectively used, and space efficiency can be improved. Similarly, the fixed platen 1a is formed in a flat shape by forming the outer shape of the fixed platen 1a and the spiral shape of the fixed scroll 1 b. By improving the space efficiency in this way, the capacity of the compression chamber 71 can be increased while keeping the size of the hermetic container 100 the same, and the compressor capacity can be improved. Conversely, the hermetic container 100 can be downsized while securing the same compressor capacity. Hereinafter, when the fixed scroll 1b and the orbiting scroll 2b are referred to as "scrolls" without distinction therebetween, they are collectively referred to as "scrolls". Similarly, the platen is also collectively referred to as a "platen" when the fixed platen 1a and the swing platen 2a are not distinguished from each other but referred to as both.

Further, embodiment 1 is characterized in that the scroll shape of the scroll has a shape in which 2 flat shapes having different flattening ratios are combined. Specifically, as shown in fig. 3, the scroll shape of embodiment 1 has a flat shape having different flattening ratios in the a region and the B region. As described above, in embodiment 1, by changing the flattening ratio between the a region and the B region, the flattened shape on one region side, in this example, the B region side, becomes a flattened shape compared to the flattened shape of the a region. By forming such a shape, a void space can be formed between the flat shape on the B region side and the inner peripheral surface of the sealed container 100, and the introduction flow path 7c can be provided in this void space. The flat shape includes an oblong shape and an elliptical shape, and in short, refers to a shape that is flat compared to a perfect circle. The details of the scroll shape configured as described above will be described further.

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

Fig. 4 is a compression process diagram showing an operation in the course of 1 rotation of the orbiting scroll in the scroll compressor according to embodiment 1. FIG. 4(a) shows the position of the scroll in the case where the rotational phase is 0[ rad ] (2 π [ rad ]). FIG. 4(b) shows the position of the scroll in the case where the rotational phase is π/2[ rad ]. FIG. 4(c) shows the position of the scroll in the case where the rotational phase is π [ rad ]. FIG. 4(d) shows the position of the scroll in the case where the rotational phase is 3 π/2[ rad ].

When the motor stator 110a of the electric mechanism 110 is energized, the motor rotor 110b is rotated by a rotational force. In response, the rotary shaft 6 fixed to the motor rotor 110b is driven to rotate. The rotational motion of the rotary shaft 6 is transmitted to the swing scroll 2 via the eccentric shaft portion 6 a. The oscillating scroll 2b of the oscillating scroll 2 oscillates with an oscillation radius while being restricted in rotation by the oldham ring 14. The swing radius is an eccentric amount of the eccentric shaft portion 6a with respect to the main shaft portion 6 b.

As the electric mechanism 110 is driven, the refrigerant flows from the external refrigeration cycle into the first space 72 in the closed casing 100 through the suction pipe 101. The low-pressure refrigerant flowing into the first space 72 flows into the suction space 73a through the introduction flow path 7c provided in the frame 7. The low-pressure refrigerant flowing into the suction space 73a is sucked into the compression chamber 71 in accordance with the relative oscillating motion of the oscillating scroll 2b and the fixed scroll 1b of the compression mechanism portion 8. As shown in fig. 4, the refrigerant sucked into the compression chamber 71 is increased in pressure from a low pressure to a high pressure by a change in the geometric volume of the compression chamber 71 accompanying the relative movement of the orbiting scroll 2b and the fixed scroll 1 b. 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 open the discharge valve 11, 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 as a high-pressure refrigerant from the discharge pipe 102 to the outside of the compressor. The arrows in fig. 1 indicate the flow of the refrigerant.

In embodiment 1, as described above, the outlines of the oscillating scroll 2b and the fixed scroll 1b are formed in a flat shape, and the scroll shape is also formed in a flat shape. In the compression mechanism 8 having a flat scroll shape, as shown in fig. 4, even when the orbiting scroll 2b is operated at a constant orbiting radius, the outward surface and the inward surface of the orbiting scroll 2b are operated while being in contact with the inward surface and the outward surface of the fixed scroll 1b facing each other.

In addition, the present embodiment 1 is characterized in that the scroll shape of a scroll body having a contour in which a plurality of flat shapes having different flattening ratios are combined is defined by a mathematical expression. The wrap shape is determined by an outer curve defining the outer facing surface of the wrap and an inner curve defining the inner facing surface of the wrap. In the case of defining the scroll shape of a scroll by a mathematical expression, specifically, either one of an outer curve and an inner curve of the scroll is defined as a curve which is an involute of a base circle, and the curve is defined by the following expressions (1) and (2) using an involute angle θ in an x-y coordinate system.

A (θ) in the formulae (1) and (2) is the radius of the base circle. a (θ) is given by a functional expression having a term of a product of a "function varying in a sine-wave or cosine-wave manner with 1 cycle of pi [ rad ] with respect to the involute angle θ" and a "coefficient α represented by a step function α (θ) with 1 cycle of pi [ rad ], as shown by the following expression (3). The coefficient α is a coefficient indicating the degree of flattening. Thus, the scroll shape of the scroll body having the contour in which a plurality of flat shapes having different flattening ratios are combined can be defined by the mathematical expression. In embodiment 1, the base radius a (θ) is changed as shown in formula (3), for example.

[ numerical formula 1]

x＝a(θ)(cosθ+θ·sinθ) …(1)

[ numerical formula 2]

y＝a(θ)(sinθ-θ·cosθ) …(2)

[ numerical formula 3]

a(θ)＝a₀·θ(1+a(θ)·(sin(θ-ξ))^2N) …(3)

In the formula (3), a₀Is a base radius (hereinafter referred to as a reference radius) serving as a reference. In addition, in the formula (3), the formula is represented by π [ rad ]]The step function α (θ) of 1 cycle is a real function having a stepwise profile with respect to the involute angle θ, and is represented by π [ rad ]]The step function α (θ) is a function represented by a linear combination thereof, which is an index function of 1 cycle. Specifically, the step function α (θ) is π [ rad ]]Is a function of 1 cycle alternating every pi/2 value. Here, α (θ) changes alternately to α 1 and α 02 every π/2. That is, the involute angle θ is α (θ) ═ α 1 from 0 to pi/2, and the involute angle θ is α (θ) ═ α 2 from pi/2 to pi. In the next 1 cycle, similarly, α (θ) ═ α 1 is set from pi to 3 pi/2, and α (θ) ═ α 2 is set from 3 pi/2 to 2 pi.

In formula (3), N is a natural number of 1 or more. ξ is a constant [ rad ], and is an involute angle combining a flat shape when α (θ) of expression (3) is α 1 (hereinafter referred to as a flat shape based on α 1) and a flat shape when α (θ) of expression (3) is α 2 (hereinafter referred to as a flat shape based on α 2).

In the equation (3), the flattening ratio of the contour of the scroll can be arbitrarily set by changing the coefficient α. Specifically, as the value of α increases, the flattening ratio of the contour of the scroll increases, and the scroll has a flattened shape. The scroll shape of the scroll according to embodiment 1 is a combination of 2 shapes, i.e., a flat shape based on α 1 and a flat shape based on α 2. In fig. 3, the flat shape of the a region shows a case where α 1 is set to 0.3. The flat shape of the B region shows the case where α 2 is set to-0.2. In fig. 3, the value of N is 1, and the value of ξ is 0. The change in the shape of the scroll when ξ is changed is explained in embodiment 3 described later.

Next, a method of drawing the scroll shapes of the fixed scroll 1b and the oscillating scroll 2b will be described. Since the fixed scroll 1b and the oscillating scroll 2b are drawn in the same manner, the oscillating scroll 2b will be described below as a representative. The scroll shape of the oscillating scroll 2b is a combination of 2 flat shapes having different flattening ratios as described above, but the drawing method itself of each flat shape is the same.

As described above, the scroll shape is determined by the outer curve defining the outward facing surface of the scroll and the inner curve defining the inward facing surface of the scroll. Here, a method of plotting the scroll shape when the outer curve is defined by the equations (1) and (2) will be described with reference to fig. 5.

Fig. 5 is an explanatory diagram of a drawing method of the scroll shape of the compression mechanism portion constituting the scroll compressor according to embodiment 1. In FIG. 5, the drawing is performed according to the steps (a), (b), (c), and (d).

First, as shown in fig. 5(a), an involute 30 of a base circle is drawn. Here, a (θ) increases in a sine wave shape with 1 cycle of pi [ rad ] according to the involute angle θ as described above. The involute curve 30 described here is an outer curve. a (θ) is α 1.

Next, the inner curve is plotted according to the steps of fig. 5(b) to 5 (d). That is, first, as shown in fig. 5(b), a curve 31 is drawn by rotating the involute curve 30 drawn in step (a) by pi [ rad ] with respect to the base circle center O. Since the inner curve is created, the curve portion (the dotted line portion in fig. 5 (b)) of the curve 31 located on the outer side of the curve 30 is not used in the subsequent drawing step.

Next, as shown in fig. 5(c), a plurality of circles 32 are drawn, and the circles 32 have centers on the curve 31 drawn in step (b) and have radii equal to the swing radius of the swing scroll 2.

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

Through the above steps, the curve 30 drawn in step (a) becomes the outer curve of the oscillating scroll 2b, and the curve 33 drawn in step (d) becomes the inner curve of the oscillating scroll 2 b. One of the regions of the dotted region in step (d) divided left and right about the base circle center O is one of the cross sections of the 2 spiral shapes constituting the orbiting scroll 2 b.

Similarly, the scroll shape when a (θ) is α 2 is plotted according to the steps of fig. 5(a) to 5(d), and the other region of the dotted region in step (d) divided left and right around the base circle center O is the other cross section of the 2 scroll shapes constituting the orbiting scroll 2 b. This enables the formation of a scroll shape of the orbiting scroll 2 b.

The fixed scroll 1b is formed into a shape obtained by rotating the shape of the oscillating scroll 2b by pi [ rad ] in a specification equal in thickness to the oscillating scroll 2b in the same procedure as the oscillating scroll 2b described above.

Note that, although the description has been given of the method of plotting the scroll shape when the outer curve is defined by the equations (1) and (2), the method of plotting the scroll shape when the inner curve is defined by the equations (1) and (2) is basically the same. When the inner curve is defined as a curve defined by the expressions (1) and (2), the outer curve may be drawn as follows. First, the step of fig. 5(a) is performed, and then, in the subsequent drawing step, the curve portion of the curve 30 located on the outer side of the curve 31 in fig. 5(b) is not used. Then, a plurality of circles 32 having centers on the curved lines 31 and having a radius equal to the swing radius of the swing scroll 2 are drawn. The inner envelope of the circle group becomes the outer curve.

Fig. 6 is a diagram showing an example of characteristics relating to the base radius a (θ) used for drawing the scroll shape of the scroll in the scroll compressor according to embodiment 1. The vertical axis of fig. 6 shows the base radius a (θ) relative to the reference radius a₀The ratio of (a) to (b). The horizontal axis of FIG. 6 showsInvolute angle theta rad]。

Fig. 6 shows a periodic change in the base circle radius a (θ) with respect to the involute angle θ, when the value α (θ) of equation (3) is set to α 1 ═ 0.3 and α 2 ═ 0.2, the value N is set to 1, and the value ξ is set to 0, as in fig. 3. In the waveform of the base radius a (θ) shown in fig. 6, a (θ)/a₀The larger the value of (A) is, the thicker the thickness of the scroll is. Therefore, the thickness of the vortex becomes thicker at π/4, 5 π/4, and 9 π/4. In the waveform of the base radius a (θ), the scroll is elongated in a direction having an involute angle of one peak exceeding 1.0. Therefore, in the example of fig. 6, at the involute angles of pi/4, 5 pi/4, and 9 pi/4, one peak exceeding 1.0 appears, and thus, as shown in fig. 3, the shape is elongated in the lateral direction.

As described above, in embodiment 1, the scroll shape of the scroll is defined by the above-described expressions (1) and (2) using the involute angle θ. The base radius a (θ) in the expressions (1) and (2) is a term having a product of a "function that varies in a sine wave or cosine wave form with 1 cycle of pi [ rad ] with respect to the involute angle θ" and a "coefficient α represented by a step function α (θ) with 1 cycle of pi [ rad"). Thus, the scroll shape of the scroll body having the contour in which a plurality of flat shapes having different flattening ratios are combined can be defined by the mathematical expression.

In embodiment 1, the contours of the fixed scroll 1b and the oscillating scroll 2b can be arbitrarily set by setting the base radius a (θ) to equation (3).

In embodiment 1, α (θ) is a function in which the change period is pi [ rad ] and the change period alternates every pi/2. By setting α to 2 values in this way, the scroll shape of a scroll in which the void space can be concentrated in 1 part can be defined by a mathematical expression. Specifically, by setting the value of α to be smaller than the value of α on the other side, a void space can be formed on the flat side using α on the one side. The introduction flow path 7c can be formed in this void space, and when the number of the introduction flow paths 7c is 1, the flow path area of the introduction flow path 7c can be set large.

Embodiment mode 2

In embodiment 2, a change in flattening ratio of the contour of the scroll corresponding to the value of α in the above expression (3) will be described. Hereinafter, the configuration of embodiment 2 different from that of embodiment 1 will be mainly described, and the configuration not described in embodiment 2 is the same as that of embodiment 1.

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

Fig. 7 is a diagram showing a change in the flattening ratio of the outer curve of the scroll in the scroll compressor according to embodiment 2. In fig. 7, (a) shows the case where α 1 is 0 and α 2 is 0, (b) shows the case where α 1 is 0.3 and α 2 is 0, and (c) shows the case where α 1 is 0.3 and α 2 is-0.2.

As shown in fig. 7, by changing the value of α, the flattening ratio of the contour of the scroll can be arbitrarily set. As shown in fig. 7(a), the flattening ratio is a ratio of the long diameter D11+ D12 to the short diameter D2 (D11+ D12)/D2. In the drawing, the flattening ratio of the region a, i.e., the region where the vortex is formed at α 1 is (D11 × 2)/D2. The flattening ratio of the region B in the figure, i.e., the region where the vortex is formed at α 2, is (D12 × 2)/D2.

Specifically, as the value of α is increased, the flattening ratio becomes larger. In fig. 7, comparing the flat shapes of the a regions in (a) and (b), it is seen that the flat rate of (b) having a large value of α 1 is larger than that of (a). As can be seen from comparison of the flat shapes of the B regions in fig. 7 (B) and (c), the flat rate of (B) having a large value of α 2 is larger than that of (c).

As is clear from fig. 7, the flattening ratios of the flat shapes in the region a and the region B in fig. 7 can be set independently from each other by the values of α 1 and α 2.

According to embodiment 2, the same effects as those of embodiment 1 can be obtained, and the flattening ratios of the respective flattened shapes can be arbitrarily set by the values of α 1 and α 2. Therefore, by setting α 1 and α 2 in accordance with 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 number of the introduction flow paths 7c is 1.

Embodiment 3

In embodiment 3, a case where the involute angle ξ is changed will be described. Hereinafter, the configuration of embodiment 3 different from that of embodiment 1 will be mainly described, and the configuration not described in embodiment 3 is the same as that of embodiment 1.

Fig. 8 is a view showing a scroll in the scroll compressor according to embodiment 3. In fig. 8, (a) shows the case where α 1 ═ 0.3, α 2 ═ 0.2, and ξ ═ 0[ rad ], (b) shows the case where α 1 ═ 0.3, α 2 ═ 0.2, and ξ ═ pi/4 [ rad ]. ξ is the involute angle combining the flat shape based on α 1 and the flat shape based on α 2 as described above. In each of the scrolls of fig. 8(a) and 8(B), each of regions a and B in fig. 8 shows a flat shape based on α 1 and a flat shape based on α 2. As is clear from fig. 8, by changing the value ξ, the direction of the entire scroll shape changes.

Fig. 9 is a compression process diagram showing an operation in the course of 1 rotation of the orbiting scroll in the scroll compressor of fig. 8 (b). FIG. 9(a) shows the position of the scroll in the case where the rotational phase is 0[ rad ] (2 π [ rad ]). FIG. 9(b) shows the position of the scroll in the case where the rotational phase is π/2[ rad ]. FIG. 9(c) shows the position of the scroll in the case where the rotational phase is π [ rad ]. FIG. 9(d) shows the position of the scroll in the case where the rotational phase is 3 π/2[ rad ]. As shown in fig. 9, even when 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 embodiment 1.

According to embodiment 3, the same effects as those of embodiments 1 and 2 can be obtained, and by changing the value of ξ, the direction of the entire scroll shape can be changed in accordance with the position where the introduction flow path 7c is arranged.

Embodiment 4

In embodiment 4, another functional expression of the base radius a (θ) will be described. Hereinafter, the configuration of embodiment 4 different from embodiment 1 will be mainly described, and the configuration not described in embodiment 4 is the same as embodiment 1.

FIG. 10 shows a base radius a (θ) of a scroll in the scroll compressor according to embodiment 4) A graph of the associated characteristics. Fig. 10(a) to 10(d) correspond to the case where the functional formula of the base radius a (θ) is expressed by the formula (3) shown in the above embodiment 1 and the following formulas (4) to (6) in this order. The vertical axis of fig. 10 shows the base radius a (θ) relative to the reference radius a₀The ratio of (a) to (b). The horizontal axis of FIG. 10 shows the involute angle θ [ rad ]]. In fig. 10, (a) to (d) are each α 1 ═ 0.3, α 2 ═ -0.2, N ═ 1, and ξ ═ 0.

[ numerical formula 4]

a(θ)＝a₀·θ(1+α(θ)·(cos(θ-ξ))^2N)…(4)

[ numerical formula 5]

a(θ)＝a₀·θ(1+α(θ)·(1+sin2(θ-ξ))) …(5)

[ numerical formula 6]

a(θ)＝a₀·θ(1+α(θ)·(1+cos2(θ-ξ))) …(6)

The base radius a (θ) can be expressed by expressions (4) to (6) in addition to expression (3) shown in embodiment 1. By changing the base radius a (θ) as in expressions (3) to (6), the contours of the fixed scroll 1b and the oscillating scroll 2b can be arbitrarily set.

Although embodiments 1 to 4 show the low-pressure shell type scroll compressor in which the inside of the sealed container 100 is filled with the low-pressure refrigerant, similar effects can be obtained also in the case of a high-pressure shell type scroll compressor in which the inside of the sealed container 100 is filled with the high-pressure refrigerant.

Description of the reference numerals

1 fixed scroll, 1a fixed platen, 1b fixed scroll, 1c discharge port, 2 oscillating scroll, 2a oscillating platen, 2b oscillating scroll, 2c oscillating bearing, 4 baffle, 4a through hole, 5 slider with balance weight, 6 rotating shaft, 6a eccentric shaft, 6b main shaft, 6c sub shaft, 7 frame, 7a main bearing, 7b boss, 7c introduction flow path, 8 compression mechanism, 9 sub frame, 9a sub frame holder, 10 sub bearing, 11 discharge valve, 12 discharge muffler, 13 sleeve, 14 cross slide ring, 14a key, 30 involute, 32 circle, 33 outer envelope, 60 first balance weight, 61 second balance weight, 71 compression chamber, 72 first space, 73 second space, 73a suction space, 74 third space, 100 sealed container, 100a oil reservoir, 101 suction pipe, 102 discharge pipe, etc, 110 electric mechanism portion, 110a motor stator, 110b motor rotor, 112 pump element.