CN116806291A - Scroll compressor having a rotor with a rotor shaft having a rotor shaft with a - Google Patents

Abstract

A scroll compressor is provided with: a fixed scroll formed with a fixed scroll body at a fixed platen; and a swinging scroll in which a swinging scroll is formed on a swinging platen, a compression chamber for compressing a refrigerant is formed by meshing a fixed scroll with the swinging scroll, and any one of an outer curve of the fixed scroll, an inner curve of the fixed scroll, an outer curve of the swinging scroll, and an inner curve of the swinging scroll is set as a curve of an involute curve of a base circle, the curve is defined by expression (1) and expression (2) in x and y coordinate systems using an involute angle [ rad ], a base circle radius a (θ) in expression (1) and expression (2) is represented by a product of a function having a sine wave or cosine wave change in pi [ rad ] for 1 cycle with respect to the involute angle [ theta ] and a function having a product of a coefficient "which is represented by a step function of a value switched in accordance with the involute angle [ rad ], a step angle represented by the function is formed as a product of a function of a value which is reduced as the involute angle [ rad ] is larger, and a step angle represented by the function is formed as a step angle of a function of a value which is defined by a step angle of a arbitrary involute angle [ rad ] and a value which is smaller than an involute [ angle [ phi ] s (35 c-1 ] and a value is formed by a section of a +1-c (35 c) and a value which is smaller than an interval of [ angle [ phi ] s (1-s(s).

Description

Scroll compressor having a rotor with a rotor shaft having a rotor shaft with a

Technical Field

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

Background

A scroll compressor used in an air conditioner, a refrigerator, or the like has a structure including a compression mechanism unit that compresses a refrigerant in a compression chamber formed by combining a fixed scroll and a orbiting scroll, and a container that accommodates the compression mechanism unit. The fixed scroll and the orbiting scroll each have a structure in which a scroll body is formed on a platen, and the scroll bodies are engaged with each other to form a compression chamber. In addition, the scroll compressor causes the orbiting scroll to perform an orbiting motion, whereby the compression chamber moves while reducing the volume, and refrigerant is sucked and compressed in the compression chamber. In such a scroll compressor, in order to achieve downsizing and cost reduction, development of a technique for increasing the capacity of the compressor by making the diameter of a container the same and increasing the suction volume of a compression chamber as much as possible is important. In order to set the diameters of the containers to be the same and to increase the suction volume of the compression chamber, it is necessary to study the scroll shape of the scroll.

Conventionally, there is a technique in which a scroll shape of a scroll compressor is an involute curve of a base circle that is a perfect circle of a predetermined radius, and an outline of the entire scroll is a circle. In contrast, in recent years, there is a technique in which the entire contour of the scroll body is formed in a flat shape instead of a circular shape, and further, the scroll body is formed in a flat shape (for example, refer to patent document 1).

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open 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 for specifying the scroll shape. As for the scroll shape of the scroll, there is a technique of defining an involute curve of a base circle which is a perfect circle of a predetermined radius as described above, but in the case where the scroll shape is a flat shape, it is necessary to specifically define the scroll shape in terms of manufacturing the scroll.

In addition, in the scroll compressor, when the number of windings of the scroll is set to be small, the swing radius can be set to be large, and thus a larger suction volume can be ensured with respect to a limited installation space. However, in this configuration, the ratio of the compression chamber volume to the suction volume immediately before the scroll compressor communicates with the innermost chamber, that is, the assembly volume ratio becomes small. Therefore, the scroll compressor has the following problems: when the ratio of the high pressure to the low pressure in the operating condition, that is, the operating compression ratio is large, the pressure in the compression chamber is communicated with the innermost chamber before reaching the high pressure, and the high pressure in the innermost chamber is reversed and expanded again, thereby increasing the loss. In general, in a compression chamber formed of a scroll body having an involute curve, since the volume change of the compression chamber from immediately after the start of compression to immediately before the start of communication with the innermost chamber changes substantially linearly, it is difficult to ensure the suction volume and the assembly volume ratio, and elimination of the dilemma is a problem.

The present disclosure has been made in view of the above problems, and an object thereof is to provide a scroll compressor capable of securing both suction volume and assembly volume ratio.

Means for solving the problems

The scroll compressor of the present invention comprises: a fixed scroll formed with a fixed scroll body at a fixed platen; and a swinging vortex piece, wherein a swinging vortex body is formed on a swinging platen, a compression chamber for compressing refrigerant is formed by meshing a fixed vortex body and a swinging vortex body, any one of an outer curve of the fixed vortex body, an inner curve of the fixed vortex body, an outer curve of the swinging vortex body and an inner curve of the swinging vortex body is set as a curve of an involute of a basic circle, the curve is defined by an involute angle [ rad ] in an x and y coordinate system by a formula (1) and a formula (2), a basic circle radius a (theta) in the formula (1) and the formula (2) is represented by a function of sine wave or cosine wave changing with pi [ rad ] as 1 period relative to the involute angle [ rad ], a function of a product of a coefficient' represented by a step function of a value switched according to the involute angle [ rad ] and a product of a function of which the value is reduced as the involute angle [ rad ] becomes larger, a step angle represented by the function is formed as a value of the involute angle [ rad ], the step angle represented by the coefficient of the function is formed by the curve, and the involute angle [ rad ] is smaller than the involute angle [ rad ] in an arbitrary section of the section of which is formed by a smaller than the involute angle [ phi ] and smaller than the involute angle in an interval,

x＝a(θ)(cоsθ+θsinθ)…(1)

y＝a(θ)(sinθ-θcоsθ)…(2)。

Effects of the invention

According to the present disclosure, the degree of flattening of the scroll body is reduced in a section smaller than Φrad with respect to an arbitrarily determined involute angle Φ, as compared with a section greater than Φrad and less than an end point angle. Thus, the scroll shape of the scroll having a profile in which a plurality of flat shapes having different flatness ratios are combined can be defined by the formula, and the tooth thickness near the scroll center of the scroll can be thickened. Therefore, the scroll compressor has a scroll shape with a large flattening ratio on the outer peripheral side of the scroll body, and the scroll compressor has a scroll shape with a large flattening ratio immediately after the start of compression, thereby securing a suction volume. The scroll compressor has a scroll shape with a small flattening ratio on the inner peripheral side of the scroll body, and the scroll shape with a small flattening ratio immediately before the communication with the innermost chamber is formed, thereby reducing the compression chamber volume immediately before the communication. By changing the volume change characteristic of the compression process in a nonlinear manner in this way, the scroll compressor can secure the assembly volume ratio and expand the suction volume.

Drawings

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

Fig. 2 is a plan view showing a fixed scroll and a orbiting scroll of a compression mechanism of the scroll compressor of embodiment 1.

Fig. 3 is a compression process diagram showing an operation in 1 week of rotation of the orbiting scroll in the scroll compressor of embodiment 1.

Fig. 4 is an explanatory diagram of a drawing method of a scroll shape of a compression mechanism portion constituting the scroll compressor of embodiment 1.

Fig. 5 is a diagram showing an example of characteristics related to the flattening ratio used in the drawing of the scroll shape of the scroll in the scroll compressor of embodiment 1.

Fig. 6 is a diagram showing a base circle radius a (θ) of a scroll in the scroll compressor of embodiment 1.

Fig. 7 is a diagram showing an example of characteristics related to the tooth thickness of the scroll in the scroll compressor according to embodiment 1.

Fig. 8 is a schematic view showing a change in the volume of a compression chamber with respect to the crank angle in the scroll compressor according to embodiment 1.

Fig. 9 is a plan view showing a fixed scroll and a orbiting scroll of a compression mechanism of the scroll compressor of embodiment 2.

Fig. 10 is a diagram showing an example of characteristics related to the flattening ratio used in the drawing of the scroll shape of the scroll in the scroll compressor of embodiment 2.

Fig. 11 is a diagram showing an example of characteristics related to the tooth thickness of the scroll in the scroll compressor according to embodiment 2.

Fig. 12 is a plan view showing a fixed scroll and a orbiting scroll of a compression mechanism of the scroll compressor of embodiment 3.

Fig. 13 is a diagram showing an example of characteristics related to the tooth thickness of the scroll in the scroll compressor according to embodiment 3.

Detailed Description

Hereinafter, a scroll compressor according to an embodiment of the present invention will be described with reference to the drawings. In the following drawings including fig. 1, the same reference numerals are used to designate the same or corresponding parts, and are common throughout the following embodiments. The form of the constituent elements shown throughout 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 cross-sectional view of the overall structure of the scroll compressor 150 according to embodiment 1. The scroll compressor 150 of embodiment 1 includes the compression mechanism 8, the motor mechanism 110 for driving the compression mechanism 8 via the rotation shaft 6, and other components, and has a structure in which the components are housed in the sealed container 100 that forms the outer contour. In the sealed container 100, the compression mechanism 8 is disposed above, and the electric mechanism 110 is disposed below the compression mechanism 8.

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

A pump element 111 comprising a positive displacement pump is mounted below the subframe 9. The pump element 111 supplies the refrigerating machine oil stored in the oil reservoir 100a at the bottom of the closed casing 100 to a sliding portion such as a main bearing 7a of the compression mechanism 8, which will be described later. The pump element 111 supports the rotary shaft 6 in the axial direction at the upper end face.

A suction pipe 101 for sucking in a refrigerant and a discharge pipe 102 for discharging the refrigerant are provided in the closed casing 100.

The compression mechanism 8 compresses the refrigerant sucked from the suction pipe 101 and discharges 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 orbiting scroll 2. The high-pressure portion is a third space 74 described later.

The fixed scroll 1 is fixed to the hermetic container 100 via the frame 7. The orbiting scroll 2 is disposed below the fixed scroll 1 and is swingably supported by an eccentric shaft portion 6a of the rotating shaft 6, which will be described later.

The fixed scroll 1 includes a fixed platen 1a and a fixed scroll 1b as a scroll-like protrusion formed on one surface of the fixed platen 1 a. The orbiting scroll 2 includes an orbiting platen 2a and an orbiting scroll 2b as a scroll-like protrusion formed on one surface of the orbiting platen 2 a. The fixed scroll 1 and the orbiting scroll 2 are disposed in the sealed container 100 in a state of symmetrical scroll shapes in which the fixed scroll 1b and the orbiting scroll 2b are engaged with each other in opposite phases. A compression chamber 71 whose volume decreases from the outside toward the inside in the radial direction as the rotation shaft 6 rotates is formed between the fixed scroll 1b and the orbiting scroll 2b.

A baffle 4 is fixed to a surface of the fixed platen 1a of the fixed scroll 1 opposite to the orbiting scroll 2. The baffle plate 4 has 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 is fixedly provided with the fixed scroll 1 and has a thrust surface for supporting thrust acting on the orbiting scroll 2 in the axial direction. Further, an introduction passage 7c for guiding the refrigerant sucked from the suction pipe 101 into the compression mechanism 8 is formed through the frame 7.

In addition, an cross ring 14 for preventing rotation during the orbiting motion of the orbiting scroll 2 is disposed on the frame 7. The key portion 14a of the cross ring 14 is disposed below the oscillating platen 2a of the oscillating scroll 2.

The electric mechanism 110 supplies a rotational driving force to the rotary shaft 6, and includes a motor stator 110a and a motor rotor 110b. To obtain electric power from the outside, the motor stator 110a is connected to a glass terminal (not shown) existing between the frame 7 and the motor stator 110a via a lead (not shown). The motor rotor 110b is fixed to the rotary shaft 6 by press-fitting or the like. In order to balance the entire rotation system of the scroll compressor 150, the first counterweight 60 is fixed to the rotation shaft 6, and the second counterweight 61 is fixed to the motor rotor 110b.

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 axial center of the rotary shaft 6. The eccentric shaft portion 6a is fitted to the orbiting scroll 2 via the slider 5 with a counterweight and the orbiting bearing 2c, and the orbiting scroll 2 is made to perform an orbiting motion by the rotation of the rotating shaft 6. The main shaft portion 6b is fitted to the main bearing 7a via the sleeve 13, and slides with the main bearing 7a via an oil film based on refrigerating machine oil, and the main bearing 7a is disposed on the inner periphery of a cylindrical boss portion 7b provided on the frame 7. The main bearing 7a is fixed in the boss portion 7b by pressing a bearing material or the like used for a slide bearing such as copper-lead alloy.

A sub-bearing 10 composed of a ball bearing is provided on the upper portion of the sub-frame 9, and the sub-bearing 10 supports the rotary shaft 6 in a 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 portion 6c is fitted to the sub-bearing 10, and slides on the sub-bearing 10 via an oil film formed by refrigerating machine oil. The axes of the main shaft portion 6b and the auxiliary shaft portion 6c coincide with the axis of the rotary shaft 6.

The space in the closed casing 100 is defined as follows. The 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. The space surrounded by the inner wall of the frame 7 and the fixed platen 1a is set as a second space 73. The space closer to the discharge pipe 102 than the fixed platen 1a is set as the third space 74. The outer side of the structure portion of the second space 73, in which the fixed scroll 1b and the orbiting scroll 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 7 c.

Fig. 2 is a plan view showing the fixed scroll 1b and the orbiting scroll 2b of the compression mechanism 8 of the scroll compressor 150 according to embodiment 1. Next, the component arrangement of the compression mechanism 8 in the sealed container 100 will be described with reference to fig. 2. In the following description, the fixed scroll 1b and the orbiting scroll 2b are collectively referred to as "scrolls" when they are not distinguished from each other. The same applies to the platen, and the platen is collectively referred to as "platen" when both the fixed platen 1a and the swing platen 2a are not distinguished.

In the scroll compressor 150 of embodiment 1, the outer shape of the swing platen 2a is a flat shape. By forming the scroll shape of the swing scroll 2b formed to stand on the swing platen 2a also in a flat shape, the scroll compressor 150 can effectively use the space on the swing platen 2a, and the space efficiency can be improved. The flat shape also includes an oblong shape and an elliptical shape, and in short, refers to all shapes that are flatter than a perfect circle.

The same applies to the fixed platen 1a, and the outer shape of the fixed platen 1a and the scroll shape of the fixed scroll 1b are formed in a flat shape. In this way, the scroll compressor 150 can increase the capacity of the compression chamber 71 with the size of the closed casing 100 being the same, thereby improving the space efficiency. Conversely, the scroll compressor 150 can achieve downsizing of the hermetic container 100 while ensuring the same compressor capacity.

The scroll compressor 150 according to embodiment 1 is characterized in that the scroll shape of the scroll body is formed by combining a plurality of flat shapes having different flatness ratios. Specifically, the scroll shape of the scroll compressor 150 of embodiment 1 has a flat shape with a flattening ratio different according to the angle of gradual opening. The flattening ratio is the ratio D1/D2 of the transverse diameter D1 to the longitudinal diameter D2.

The outward surface 1ba and the inward surface 1bb of the fixed scroll 1b are each formed of a scroll shape having two flat ratios from the end of the scroll shape to the start of the scroll shape. As shown in fig. 2, the outward surface 1ba of the fixed scroll 1b in the fixed scroll 1 has a larger flattening ratio in the region from the point Fo1 to the point Fo2 and a smaller flattening ratio in the region from the point Fo2 to the point Fo 3. The inward surface 1bb of the fixed scroll 1b of the fixed scroll 1 has a large flattening ratio in the region from the point Fi1 to the point Fi2 and a small flattening ratio in the region from the point Fi2 to the point Fi 3.

In the fixed scroll 1b, a point Fo1 of the outward surface 1ba and a point Fi1 of the inward surface 1bb are positions forming end point angles. The end point angle is an angle that becomes a position of the end point of the angle of the taper. In the fixed scroll 1b, the point Fo2 of the outward surface 1ba and the point Fi2 of the inward surface 1bb are the forming positions of the involute angles determined by the designer. In the fixed scroll 1b, a point Fo3 on the outward surface 1ba and a point Fi3 on the inward surface 1bb are positions forming a start angle. The start point angle is an angle that becomes a position of the start point of the taper angle.

The partitions of the points Fo1 to Fo2 of the outward surface 1ba are located on the outer peripheral side of the fixed scroll 1b with respect to the partitions of the points Fo2 to Fo 3. The outward surface 1ba of the fixed scroll 1b is formed to wrap the scroll from the outer peripheral side toward the center side of the fixed scroll 1b with going from the point Fo1 toward the point Fo2 and from the point Fo2 toward the point Fo 3.

Similarly, the partitions from the point Fi1 to the point Fi2 of the inward surface 1bb are located on the outer peripheral side of the fixed scroll 1b with respect to the partitions from the point Fi2 to the point Fi 3. The inward surface 1bb of the fixed scroll 1b is formed so as to wrap the scroll from the outer peripheral side of the fixed scroll 1b toward the center side in accordance with the position from the point Fi1 toward the point Fi2 and the position from the point Fi2 toward the point Fi 3.

The scroll structure is similar to that of the orbiting scroll 2, and the outward surface 2ba and the inward surface 2bb are each formed of a scroll shape having two flat ratios from the end of winding to the start of winding, as described below. The outward surface 2ba of the orbiting scroll 2b in the orbiting scroll 2 has a larger flattening ratio in the region from the point Oo1 to the point Oo2 and a smaller flattening ratio in the region from the point Oo2 to the point Oo 3. The inward surface 2bb of the orbiting scroll 2b of the orbiting scroll 2 has a large flattening ratio in the region from the point Oi1 to the point Oi2 and a small flattening ratio in the region from the point Oi2 to the point Oi 3.

In the orbiting scroll 2b, a point Oo1 of the outward surface 2ba and a point Oi1 of the inward surface 2bb are positions forming an end point angle. In addition, in the orbiting scroll 2b, a point Oo2 of the outward facing surface 2ba and a point Oi2 of the inward facing surface 2bb are forming positions of involute angles determined by a designer. In addition, in the orbiting scroll 2b, a point Oo3 of the outward surface 2ba and a point Oi3 of the inward surface 2bb are positions forming a start angle.

The partitions of the points Oo1 to Oo2 of the outward surface 2ba are located on the outer peripheral side of the orbiting scroll 2b with respect to the partitions of the points Oo2 to Oo 3. The outward surface 2ba of the orbiting scroll 2b is formed to wrap the scroll from the outer peripheral side toward the center side of the orbiting scroll 2b as going from the point Oo1 toward the point Oo2 and from the point Oo2 toward the point Oo 3.

Similarly, the partitions of the points Oi1 to Oi2 of the inward surface 2bb are located on the outer peripheral side of the orbiting scroll 2b with respect to the partitions of the points Oi2 to Oi 3. The inward surface 2bb of the orbiting scroll 2b is formed to wrap the scroll from the outer peripheral side toward the center side of the orbiting scroll 2b as going from the point Oi1 toward the point Oi2 and from the point Oi2 toward the point Oi 3.

In addition, at the points where the flatness ratios of the outward surface 1ba and the inward surface 1bb of the fixed scroll 1 are switched, that is, at the positions of the point Fo2 and the point Fi2, the phase difference between the point Fo2 and the point Fi2 becomes pi [ rad ]. This relationship is also true for the orbiting scroll 2, and the phase difference between the point Oo2 and the point Oi2 becomes pi [ rad ] at the point where the flatness ratio of the outward surface 2ba and the inward surface 2bb of the orbiting scroll 2 is switched, that is, at the position of the point Oo2 and the point Oi 2. In either the fixed scroll 1 or the orbiting scroll 2, the involute angles for the flattening ratio switching in the outward surface and the inward surface are shifted by pi rad. The details of the scroll shape configured as described above will be described again.

Next, the operation of the scroll compressor 150 will be described.

Fig. 3 is a compression process diagram showing an operation in the rotation 1 of the orbiting scroll 2 in the scroll compressor 150 according to embodiment 1. Fig. 3 (a) shows the position of the scroll body in the case where the rotational phase of the orbiting scroll 2 is 0[ rad ] (2pi [ rad ]). Fig. 3 (b) shows the position of the scroll body in the case where the rotational phase of the orbiting scroll 2 is pi/2 rad. Fig. 3 (c) shows the position of the scroll body in the case where the rotational phase of the orbiting scroll 2 is pi rad. Fig. 3 (d) shows the position of the scroll body in the case where the rotational phase of the orbiting scroll 2 is 3 pi/2 rad.

When the motor stator 110a of the electric mechanism 110 is energized, the motor rotor 110b is rotated by the rotational force. With this, the rotary shaft 6 fixed to the motor rotor 110b is driven to rotate. The rotational movement of the rotation shaft 6 is transmitted to the orbiting scroll 2 via the eccentric shaft portion 6 a. The orbiting scroll 2b of the orbiting scroll 2 performs an orbiting motion with an orbiting radius while restricting its rotation by the cross ring 14. The swing radius refers to the eccentric amount of the eccentric shaft portion 6a with respect to the main shaft portion 6 b.

With the driving of the electric mechanism 110, 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 formed in the frame 7. The low-pressure refrigerant flowing into the suction space 73a is sucked into the compression chamber 71 by the relative swinging motion of the orbiting scroll 2b and the fixed scroll 1b of the compression mechanism 8.

The refrigerant sucked into the compression chamber 71 is boosted from low pressure to high pressure by the change in geometric volume of the compression chamber 71 due to the relative movement of the orbiting scroll 2b and the fixed scroll 1b as shown in fig. 3. The high-pressure refrigerant passes through the discharge port 1c of the fixed scroll 1 and the through hole 4a of the baffle plate 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 high-pressure refrigerant from the discharge pipe 102 to the outside of the scroll compressor 150. The thick arrows in fig. 1 indicate the flow of this refrigerant.

In embodiment 1, as described above, the outlines of the orbiting 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 this way, in the compression mechanism 8 in which the scroll shape of the scroll is flat, even when the orbiting scroll 2b is operated with a constant swing radius as shown in fig. 3, the orbiting scroll 2b and the fixed scroll 1b are operated while bringing the facing surfaces facing each other into contact with each other. That is, in the compression mechanism 8, the outward surface 2ba of the orbiting scroll 2b is in contact with the inward surface 1bb of the fixed scroll 1b, and the inward surface 2bb of the orbiting scroll 2b is in contact with the outward surface 1ba of the fixed scroll 1b, and operates.

In embodiment 1, a scroll shape of a scroll having a profile in which a plurality of flat shapes having different flatness ratios are combined is defined by a formula. The scroll shape is determined by an outer curve defining an outward facing surface of the scroll body and an inner curve defining an inward facing surface of the scroll body. Specifically, when defining the scroll shape of the scroll by the formula, one of the outer curve and the inner curve of the scroll is defined by the following formulas (1) and (2) using the involute angle θrad in the x and y coordinate systems, and the curve is an involute curve to the base circle. That is, any one of the outer curve of the fixed scroll 1b, the inner curve of the fixed scroll 1b, the outer curve of the orbiting scroll 2b, and the inner curve of the orbiting scroll 2b is set as a curve of an involute curve of a base circle, and the curve is defined by the following formulas (1) and (2) using an involute angle θrad in x and y coordinate systems.

A (θ) in the formulas (1) and (2) is the radius of the base circle. As shown in the following equation (3), the base circle radius a (θ) is calculated by having a "angle θ [ rad ] with respect to the involute angle ]]In pi [ rad ]]The function AND of sine or cosine wave variation for 1 period consists of the AND involute angle θrad ]The function of the term of the product of the coefficients α "represented by the step function α (θ) of the corresponding switching value is given. Specifically, the functional formula is represented by (1+α (θ) Sin in the formula (3) ^2N (θ -. Zeta.)) representation. And, "relative to the angle of the gradual change [ theta ] [ rad ]]In pi [ rad ]]The function "of the sine wave or cosine wave variation for 1 cycle is represented by (Sin ^2N (θ -. Zeta.)) representation. The coefficient α is a coefficient indicating the degree of flattening (hereinafter referred to as flattening ratio α (θ)). Thus, the scroll shape of the scroll body having a contour formed by combining a plurality of flat shapes having different flatness ratios can be defined by a formula. Further, as shown in the formula (3) and the formulas (4) to (6) described later, a (θ) is represented by the angle of the gradient angle θ [ rad ] as a function and a value of the term having the product]The product of the functions, specifically (1-. Beta.θ), that become larger and smaller is expressed. In embodiment 1, the base circle radius a (θ) is changed as shown in the formula (3), for example.

x＝a(θ)(cоsθ+θsinθ)…(1)

y＝a(θ)(sinθ-θcоsθ)…(2)

a(θ)＝a ₀ (1+α(θ)sin ^2N (θ-ξ))(1-βθ)…(3)

In formula (3), a ₀ The base circle radius (hereinafter referred to as the base radius) is a reference. In addition, atIn the formula (3), pi [ rad ]]The step function α (θ) of 1 cycle is a real function in which the curve is stepped with respect to the involute angle θ, and is a function in which an indication function whose value varies at an arbitrary involute angle θ exists and which is represented by a linear combination of these indication functions. Here, the arbitrarily determined involute angle θ is defined as an involute angle Φ. In embodiment 1, the flatness ratio α (θ) of the outward surface is 2pi [ rad ] at the involute angle φ ]The flattening ratio alpha 1 is set to be less than 2 pi rad at the involute angle phi]And becomes the flattening ratio α2.

In formula (3), N is a natural number of 1 or more. The angle ζ is a constant [ rad ], and is an evolutionary angle obtained by combining a flat shape in the case where the flattening ratio α (θ) of the formula (3) is the flattening ratio α1 (hereinafter referred to as a flat shape based on the flattening ratio α1) and a flat shape in the case where the flattening ratio α (θ) of the formula (3) is the flattening ratio α2 (hereinafter referred to as a flat shape based on the flattening ratio α2). The coefficient β is a variable that determines the degree of tapering from the start of winding to the end of winding of the scroll.

In the expression (3), the flattening ratio α (θ) is changed, whereby the flattening ratio of the contour of the scroll can be arbitrarily set. Specifically, as the value of the flattening ratio α (θ) increases, the flattening ratio of the contour of the scroll increases, and the scroll becomes flat. The scroll of embodiment 1 has a shape in which two flat shapes, i.e., a flat shape based on the flattening ratio α1 and a flat shape based on the flattening ratio α2, are combined.

In fig. 2, the flat shape of the region of the points Fo1 to Fo2, fi1 to Fi2, oo1 to Oo2, and Oi1 to Oi2 indicates a shape in which the flattening ratio α1 is 0.2. The flat shapes of the areas of the points Fo2 to Fo3, the points Fi2 to Fi3, the points Oo2 to Oo3, and the points Oi2 to Oi3 represent the shapes in the case where the flattening ratio α2 is set to 0.

That is, the scroll shape of the scroll compressor 150 is formed such that the coefficient value (flattening ratio α (θ)) is the flattening ratio α2 and the flattening ratio α2 is 0 in the involute angle range smaller than the involute angle Φrad, which is an arbitrary involute angle determined by the designer. The scroll compressor 150 is formed such that the value of the coefficient (flattening ratio α (θ)) represented by the step function is the flattening ratio α1 in the section constituting the angle of not less than the involute angle Φrad and not more than the end point angle, and the flattening ratio α1 is 0.2. Therefore, in the scroll compressor 150, the value of the coefficient (flattening ratio α (θ)) represented by the step function is set to be smaller than a section constituting an angle equal to or larger than the involute angle Φrad and equal to or smaller than the end point angle in a section constituting an angle smaller than the involute angle Φrad with respect to the arbitrarily determined involute angle Φrad.

In the expression (3), the coefficient β is set to 0, the value of N is set to 1, and the value of the angle ζ is set to 0. In fig. 3, the scroll is flattened in the 0 ° direction because the angle ζ is 0. The angle ζ is an angle determining the flat direction of the scroll, and can change the scroll direction to- ζ °. The change in the shape of the scroll body when the coefficient β is changed will be described in embodiment 3 described later.

Next, a drawing method of the scroll shapes of the fixed scroll 1b and the orbiting scroll 2b will be described. Since the drawing method of the fixed scroll 1b is the same as the drawing method of the orbiting scroll 2b, the drawing method of the orbiting scroll 2b will be described as a representative. The scroll shape of the orbiting scroll 2b is a shape obtained by combining two flat shapes having different flatness 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 an outer side curve defining an outward facing surface of the scroll body and an inner side curve defining an inward facing surface of the scroll body. Here, a drawing method of the spiral shape in the case where the outer curve is the curve defined by the formulas (1) and (2) will be described with reference to fig. 4.

Fig. 4 is an explanatory diagram of a drawing method of the scroll shape of the compression mechanism 8 constituting the scroll compressor 150 of embodiment 1. The scroll shape producer constituting the compression mechanism 8 is plotted in the order of steps (a), (b), (c), and (d) in fig. 4.

First, as shown in step (a) of fig. 4, an involute 30 of a base circle is drawn. Here, as described above, a (θ) increases in a sine wave shape with pi [ rad ] as 1 cycle according to the taper angle θ. The involute 30 is drawn here as a curve, and becomes the outer curve described above.

Next, the inner curves are plotted in the order of steps (b) to (d) in fig. 4. That is, first, as shown in step (b) of fig. 4, a curve 31 is drawn in which the involute 30 drawn in step (a) is rotated by pi [ rad ] with respect to the base circle center O. Here, in order to create the inside curve, a curve portion (a broken line portion in step (b) of fig. 4) of the curve 31 located outside the involute 30 is not used in the subsequent drawing step.

Next, as shown in step (c) of fig. 4, a plurality of circles 32 having a center and a radius equal to the swing radius of the swing scroll 2 are drawn on the curve 31 drawn in step (b).

Next, as shown in step (d) of fig. 4, an outer envelope 33 is depicted as an envelope located outside the circle group constituted by the circles 32 depicted in step (c). The outer envelope 33 drawn in the step (d) is a curve, and becomes the inner curve described above.

As described above, the involute curve 30, which is the curve drawn in step (a) of fig. 4, is the outer curve of the orbiting scroll 2b, and the outer envelope curve 33, which is the curve drawn in step (d) of fig. 4, is the inner curve of the orbiting scroll 2 b.

The procedure of steps (a) to (d) in fig. 4 is performed, in which the flattening ratio α (θ) is defined as the flattening ratio α1 on the outer side with the involute angle phi of the outward surface as a boundary, the flattening ratio α (θ) is defined as the flattening ratio α2 on the inner side with the involute angle phi as a boundary, and curves of different flattening ratios are connected. The other region divided left and right about the base circle center O of the point region in step (d) is the other cross section of the two scroll shapes constituting the orbiting scroll 2 b. With the above, the scroll shape of the orbiting scroll 2b can be plotted.

The fixed scroll 1b is formed into a shape by which the shape of the orbiting scroll 2b is rotated by pi rad in a specification having a wall thickness equal to that of the orbiting scroll 2b by the same procedure as that of the above-described orbiting scroll 2 b.

Here, although the scroll shape drawing method has been described in the case where the outer curve is the curve defined by the formula (1) and the formula (2), the scroll shape drawing method in the case where the inner curve is the curve defined by the formula (1) and the formula (2) is also basically the same. When the inner curve is defined by the formulas (1) and (2), the outer curve may be drawn as follows.

First, step (a) of fig. 4 is performed, and then, in step (b) of fig. 4, a curve portion of the involute 30 located outside the curve 31 is not used in the subsequent drawing step. 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, which is the envelope inside the circle set consisting of the plurality of circles 32, becomes the outer curve of the scroll.

Fig. 5 is a diagram showing an example of characteristics related to the flattening ratio used in the drawing of the scroll shape of the scroll in the scroll compressor 150 according to embodiment 1. The vertical axis of fig. 5 represents the flattening ratio α (θ), which is a coefficient indicating the degree of flattening, and the horizontal axis of fig. 5 represents the involute angle θ [ rad ]. As shown in fig. 5, the scroll shape of the scroll in the scroll compressor 150 is formed in the shape of the flattening α2 from the start point angle to the involute angle Φ, and in the shape of the flattening α1 from the involute angle Φ to the end point angle.

Fig. 6 is a diagram showing a base circle radius a (θ) of a scroll in the scroll compressor 150 of embodiment 1. The lower graph (a) of fig. 6 is a graph showing the base circle radius a (θ) of embodiment 1, and the upper graph (b) of fig. 6 is a graph showing the base circle radius a (θ) in the case where each of the flattening ratio α1 and the flattening ratio α2 used in embodiment 1 is applied. The vertical axis of fig. 6 represents the base circle radius a (θ), and the horizontal axis of fig. 6 represents the involute angle θ [ rad ].

As shown in fig. 6, when the flattening ratio α (θ) is any value, the values at which the base circle radius a (θ) is minimum are equal, and when the flattening ratio α (θ) is switched at the point where the base circle radius a (θ) is minimum, the scroll shape of the flattening ratio α1 and the scroll shape of the flattening ratio α2 can be connected in a smooth curve at the switching portion. That is, the base circle radius a (θ) is preferably switched to the flattening ratio α (θ) at the involute angle θ that becomes the flattening direction angle ζ+npi (where n is an integer) and the base circle radius a (θ) becomes the smallest.

That is, it is preferable that the value of the involute angle Φrad is an involute angle when the value of "a function of a sine wave or cosine wave variation having pi rad as 1 cycle with respect to the involute angle θrad" becomes a minimum value. The value of the involute angle Φrad may be an involute angle in which the value of "a function of a sine wave or cosine wave change having pi rad as 1 cycle with respect to the involute angle θrad" is the minimum value. The minimum value is 0 because it is a trigonometric function.

Fig. 7 is a diagram showing an example of characteristics related to tooth thickness of a scroll in the scroll compressor 150 according to embodiment 1. The vertical axis of fig. 7 represents the tooth thickness of the scroll body, and the horizontal axis of fig. 7 represents the involute angle θ [ rad ]. Fig. 8 is a schematic diagram showing a change in the volume of the compression chamber 71 with respect to the crank angle in the scroll compressor 150 according to embodiment 1. The vertical axis of fig. 8 represents the volume of the compression chamber 71, and the horizontal axis of fig. 8 represents the crank angle. Fig. 8 (1) shows a compression chamber volume immediately before communication with the innermost chamber in the conventional scroll compressor, and fig. 8 (2) shows a suction volume of the conventional scroll compressor. Fig. 8 (3) is a compression chamber volume immediately before communication with the innermost chamber in the scroll compressor 150 of the present embodiment, and fig. 8 (4) is a suction volume of the scroll compressor of the present embodiment.

As shown by the solid line in fig. 8, since the volume change rate (the slope of the straight line) of the conventional scroll compressor is constant, there is a problem that the assembly volume ratio is reduced when the suction volume is increased by directly biasing the solid line upward. The compression mechanism 8 of the present embodiment has a smaller internal flatness ratio α (θ) than external flatness ratio α (θ) on the center side of the scroll, and thus the tooth thickness of the scroll increases at the center portion. Therefore, as shown in fig. 8, the compression mechanism 8 can increase the rate of change of the volume of the compression chamber 71 by the scroll from the middle of the crank angle. As a result, the scroll compressor 150 can increase the swing radius of the scroll body, and the suction volume of the scroll compressor 150 can be obtained to be larger than that of the scroll body formed with a constant flatness ratio while maintaining the assembly volume ratio. Here, the tooth thickness is defined as the thickness of the scroll body at a portion where the distance between any point on the outward surface and any point on the inward surface of the scroll body is smallest.

In the scroll compressor 150 according to embodiment 1, the degree of flattening of the scroll body is reduced in a section smaller than Φrad with respect to an arbitrarily determined involute angle Φ, as compared with a section equal to or larger than Φrad and equal to or smaller than the end point angle. Thus, the scroll shape of the scroll having an outline formed by combining a plurality of flat shapes having different flatness ratios can be defined by a formula, and the tooth thickness near the scroll center of the scroll can be thickened. Therefore, the scroll compressor 150 has a scroll shape with a large flattening ratio on the outer peripheral side of the scroll body, and the suction volume is ensured by having a scroll shape with a large flattening ratio immediately after the start of compression. The scroll compressor 150 has a scroll shape with a small flattening ratio on the inner peripheral side of the scroll body, and the scroll shape with a small flattening ratio immediately before the communication with the innermost chamber is formed, thereby reducing the volume of the compression chamber 71 immediately before the communication. By thus nonlinearly changing the volume change characteristic of the compression process, the scroll compressor 150 can secure the assembly volume ratio and expand the suction volume.

As described above, in embodiment 1, the expansion of the suction volume of the scroll compressor 150 can be achieved by increasing the flattening α (θ) of the outer side of the scroll in accordance with the shape of the swing platen 2a and decreasing the flattening α (θ) to increase the tooth thickness of the inner side of the scroll. As a result, the capacity of the scroll compressor 150 can be increased.

In addition to the formula (3) shown in embodiment 1, the following formulas (4) to (6) can be used for the base radius a (θ). The scroll compressor 150 can arbitrarily set the outlines of the fixed scroll 1b and the orbiting scroll 2b by changing the base radius a (θ) as in the formulas (3) to (6).

a(θ)＝a ₀ (1+α(θ)cos ^2N (θ-ξ))(1-βθ)…(4)

a(θ)＝a ₀ (1+α(θ)(1+sin2(θ-ξ)))(1-βθ)…(5)

a(θ)＝a ₀ (1+α(θ)(1+cos2(θ-ξ)))(1-βθ)…(6)

Embodiment 2

In embodiment 2, the setting of the flattening ratio α (θ) in the above formula (3) is different from that in embodiment 1. Hereinafter, a description will be given mainly of a configuration different from embodiment 2 and embodiment 1, and a configuration not described in embodiment 2 is the same as embodiment 1.

In embodiment 1, the flattening ratio α (θ) is defined as the flattening ratio α1 at the outer side of the scroll body with the involute angle Φ being defined, and the flattening ratio α (θ) is defined as the flattening ratio α2 at the inner side with the involute angle Φ being defined. In contrast, in embodiment 2, the taper angle Φ is 2ρ [ rad ]. The flattening ratio α (θ) is defined as a flattening ratio α1 in a section forming an angle equal to or greater than the involute angle phi and equal to or less than the ending angle phi, a flattening ratio α2 in a section forming an angle equal to or greater than the involute angle phi and less than the involute angle phi, and a flattening ratio α3 in a section forming an angle equal to or greater than the starting angle and less than the involute angle phi. The flattening ratios α1, α2, and α3 decrease in the order of the flattening ratio α1, α2, and α3, and the flattening ratio α1 > α2 > α3. Wherein the involute angle (phi-pi) is larger than the starting point angle.

Fig. 9 is a plan view showing the fixed scroll 1b and the orbiting scroll 2b of the compression mechanism 8 of the scroll compressor 150 according to embodiment 2. In fig. 9, the shape of the scroll in the case of setting the flattening ratio α (θ) based on the above formula (3) is described. In fig. 9, the flat shape of the region of the points Fo1 to Fo2, fi1 to Fi2, oo1 to Oo2, and Oi1 to Oi2 indicates a shape in which the flattening ratio α1 is 0.2.

The flat shape of the areas of the points Fo2 to Fo3, fi2 to Fi3, oo2 to Oo3, and Oi2 to Oi3 represents a shape in which the flattening ratio α2 is set to 0. The flat shape of the areas of the points Fo3 to Fo4, fi3 to Fi4, oo3 to Oo4, and Oi3 to Oi4 represents a shape in which the flattening ratio α3 is-0.2. The diagonally hatched area HA in fig. 9 shows the difference between embodiment 1 and embodiment 2.

Here, in the fixed scroll 1b of embodiment 2, the point Fo1 of the outward surface 1ba and the point Fi1 of the inward surface 1bb are positions forming the end point angle. In the fixed scroll 1b, the point Fo2 of the outward surface 1ba and the point Fi2 of the inward surface 1bb are the forming positions of the involute angle Φ determined by the designer, and are the flat positions of the switching scroll. In the fixed scroll 1b, the point Fo3 of the outward surface 1ba and the point Fi3 of the inward surface 1bb are the formation positions of the involute angles (Φ -pi), and are the flat positions of the switching scroll. In the fixed scroll 1b, a point Fo4 on the outward surface 1ba and a point Fi4 on the inward surface 1bb are positions forming a start angle.

Similarly, in the orbiting scroll 2b of embodiment 2, the point Oo1 of the outward surface 2ba and the point Oi1 of the inward surface 2bb are positions forming the end point angle. In addition, in the orbiting scroll 2b, a point Oo2 of the outward facing surface 2ba and a point Oi2 of the inward facing surface 2bb are forming positions of the involute angle Φ determined by a designer. In addition, in the orbiting scroll 2b, a point Oo3 of the outward facing surface 2ba and a point Oi3 of the inward facing surface 2bb are forming positions of the involute angle (Φ -pi). In addition, in the orbiting scroll 2b, a point Oo4 of the outward surface 2ba and a point Oi4 of the inward surface 2bb are positions forming a start point angle.

That is, the section having the flatness ratio α1 of 0.2 is a region of points Fo1 to Fo2, points Fi1 to Fi2, points Oo1 to Oo2, and points Oi1 to Oi2, and the region is a section constituting an angle of not less than the angle of gradual opening Φ and not more than the end point angle. The section having the flattening ratio α2 of 0 is a region of points Fo2 to Fo3, points Fi2 to Fi3, points Oo2 to Oo3, and points Oi2 to Oi3, and forms an angle equal to or larger than the involute angle (Φ -pi) and smaller than the involute angle Φ. The section having the flattening ratio α3 of-0.2 is a region constituting an angle equal to or larger than the starting point angle and smaller than the involute angle (Φ -pi), and the section is a region of points Fo3 to Fo4, fi3 to Fi4, oo3 to Oo4, and Oi3 to Oi 4.

Fig. 10 is a diagram showing an example of characteristics related to the flattening ratio α (θ) used in the drawing of the scroll shape of the scroll in the scroll compressor 150 according to embodiment 2. The vertical axis of fig. 10 represents the flattening ratio α (θ), which is a coefficient indicating the degree of flattening, and the horizontal axis of fig. 10 represents the involute angle θ [ rad ]. As shown in fig. 10, the scroll shape of the scroll in the scroll compressor 150 is formed in the shape of the flattening ratio α3 from the start point angle to the involute angle (Φ -pi). In the scroll compressor 150, the scroll shape of the scroll is formed in the shape of the flattening α2 from the involute angle (Φ -pi) to the involute angle Φ, and in the shape of the flattening α1 from the involute angle Φ to the terminal angle.

That is, the scroll compressor 150 is formed such that the flattening ratio α3 is-0.2 in a section constituting an angle equal to or larger than the starting point angle and smaller than the involute angle (Φ -pi) [ rad ]. The scroll compressor 150 is formed such that the flattening ratio α2 is 0 in a section constituting an angle equal to or larger than the involute angle (Φ -pi) [ rad ] and equal to or smaller than the involute angle Φrad. Therefore, in the scroll compressor 150, the value of the coefficient (flattening ratio α (θ)) represented by the step function is set smaller in the section constituting the angle equal to or larger than the start angle and smaller than the involute angle (Φ -pi) [ rad ], than in the section constituting the angle equal to or larger than the involute angle (Φ -pi) [ rad ] and smaller than the involute angle Φ [ rad ].

Fig. 11 is a diagram showing an example of characteristics related to tooth thickness of a scroll in the scroll compressor 150 according to embodiment 2. The vertical axis of fig. 11 represents the tooth thickness of the scroll body, and the horizontal axis of fig. 11 represents the involute angle θ [ rad ].

In the scroll compressor 150 according to embodiment 2, in order to further increase the tooth thickness on the inner side of the central portion which becomes the scroll body as compared with embodiment 1, a portion constituting the flattening ratio α3 is additionally provided in the scroll body according to embodiment 1. The scroll compressor 150 according to embodiment 2 has a portion constituting the flattening ratio α3, whereby the assembly volume ratio can be increased, and the swing radius can be increased, and as a result, the suction volume of the scroll compressor 150 can be obtained to be large.

The scroll compressor 150 according to embodiment 2 has the scroll body having the flatness ratio α (θ) shown in embodiment 2, and thus the tooth thickness of the center portion of the scroll body is increased, and the assembly volume ratio can be increased as compared with the scroll compressor 150 according to embodiment 1. As a result, the scroll compressor 150 according to embodiment 2 can increase the swing radius of the scroll body and increase the suction volume, and thus can improve the capacity of the compressor. In addition, in the scroll compressor 150 according to embodiment 2, the tooth thickness of the center portion of the scroll increases, and the strength of the scroll increases, whereby the reliability of the compressor can be improved.

Embodiment 3

Embodiment 3 is different from embodiment 1 in that the value of the coefficient β in the above formula (3) is a value other than 0. Hereinafter, a description will be given mainly of a configuration different from embodiment 3 and embodiment 1, and a configuration not described in embodiment 3 is the same as embodiment 1.

Fig. 12 is a plan view showing the fixed scroll 1b and the orbiting scroll 2b of the compression mechanism 8 of the scroll compressor 150 according to embodiment 3. In the formula (3), the coefficient β is a variable that determines the degree of tapering from the start of winding to the end of winding of the scroll, and the larger the value of the coefficient β is, the larger the difference in tooth thickness between the start of winding and the end of winding is.

Here, as an example, the scroll compressor 150 is the same as the scroll compressor 150 of embodiment 1, except that the coefficient β is set to 0.02. That is, the scroll of the scroll compressor 150 according to embodiment 3 has a shape in which two flat shapes, i.e., a flat shape based on the flattening ratio α1 and a flat shape based on the flattening ratio α2, are combined.

In fig. 12, the flat shape of the region of the points Fo1 to Fo2, fi1 to Fi2, oo1 to Oo2, and Oi1 to Oi2 indicates a shape in which the flattening ratio α1 is 0.2. The flat shapes of the areas of the points Fo2 to Fo3, the points Fi2 to Fi3, the points Oo2 to Oo3, and the points Oi2 to Oi3 represent the shapes in the case where the flattening ratio α2 is set to 0.

Fig. 13 is a diagram showing an example of characteristics related to tooth thickness of a scroll in the scroll compressor 150 according to embodiment 3. The vertical axis of fig. 13 shows the tooth thickness of the scroll body, and the horizontal axis of fig. 13 shows the involute angle θ [ rad ]. Since the scroll compressor 150 of embodiment 3 has a value of the coefficient β as compared with the scroll compressor 150 of embodiment 1, the scroll of the scroll body has a tapered shape, and the tooth thickness decreases from the inside to the outside, which is the center side of the scroll body.

In the scroll compressor 150 according to embodiment 3, the tooth thickness of the scroll body becomes smaller as the scroll body is rotated in a tapered shape from the inside to the outside, so that the tooth thickness can be increased at the inside of the scroll body having a high pressure and reduced at the outside of the scroll body having a low pressure. Therefore, the scroll compressor 150 of embodiment 3 can obtain a larger suction volume of the compressor than the scroll compressor 150 of embodiment 1.

The scroll compressor 150 according to embodiment 3 can optimize the tooth thickness of the center portion of the scroll body by setting the coefficient β of expression (3) to a value other than 0, and can increase the suction volume as compared with the scroll compressor 150 according to embodiment 1, thereby improving the capacity of the compressor.

The structures described in embodiments 1 to 3 above represent examples of the present disclosure, and may be combined with other known techniques, and a part of the structures may be omitted or modified within a range not departing from the gist of the present disclosure. For example, in embodiments 1 to 3, the low-pressure shell type scroll compressor 150 in which the inside of the closed casing 100 is filled with low-pressure refrigerant is shown, but even in the case of the high-pressure shell type scroll compressor 150 in which the inside of the closed casing 100 is filled with high-pressure refrigerant, the same effect can be obtained.

Description of the reference numerals

A fixed scroll, a fixed platen, a fixed scroll 1b, an outward facing surface 1ba, an inward facing surface 1bb, a discharge port 1c, a swinging scroll 2, a swinging platen 2b, a swinging scroll 2ba outward facing surface, an inward facing surface 2bb, a swinging bearing 2c, a baffle 4, a through hole 4a, a slider with counterweight 5, a rotating shaft 6, an eccentric shaft 6a, a main shaft 6b, an auxiliary shaft 6c, a frame 7, a main bearing 7b, a boss 7c inlet flow path, a compression mechanism 8, a frame 9, an auxiliary frame holder 9a, an auxiliary bearing 10, a discharge valve 11, a discharge muffler 12, a sleeve 13, a cross ring 14, a key portion 30 involute, a 32 circle, an envelope 33 outside, a first counterweight 60, a second counterweight 61, a compression chamber 71, a first space 72, a second space 73, a suction space 73a third space 74, a sealed container 100, an oil reservoir 100a suction pipe 101, 102, an electric motor 110a motor 110b, a stator element 150, a motor rotor element 111, and a compressor element 150.

Claims (6)

1. A scroll compressor, wherein the scroll compressor comprises:

a fixed scroll formed with a fixed scroll body at a fixed platen; and

a swing scroll member having a swing scroll body formed on a swing platen,

a compression chamber for compressing a refrigerant is formed by engaging the fixed scroll with the orbiting scroll,

any one of an outer curve of the fixed scroll, an inner curve of the fixed scroll, an outer curve of the orbiting scroll, and an inner curve of the orbiting scroll is set as a curve of an involute of a base circle, the curve is defined by the formulas (1) and (2) using an involute angle θrad in x and y coordinate systems,

the radius a (θ) of the base circle in the expression (1) and the expression (2) is represented by a product of a function having a product of "a sine wave or a cosine wave varying with pi [ rad ] as 1 cycle with respect to the involute angle [ rad ]" and "a coefficient represented by a step function whose value is switched in accordance with the involute angle [ rad ]," and a function whose value decreases as the involute angle [ rad ] becomes larger,

the value of the coefficient represented by the step function is set so that, with respect to an arbitrarily determined involute angle [ phi ] rad, the value of the coefficient is smaller in a section constituting an angle smaller than the involute angle [ phi ] rad than in a section constituting an angle equal to or larger than the involute angle [ phi ] rad and equal to or smaller than an end point angle,

x＝a(θ)(cоsθ+θsinθ)…(1)

y＝a(θ)(sinθ-θcоsθ)…(2)。

2. The scroll compressor of claim 1, wherein,

when the involute angle (phi-pi) rad is larger than the starting point angle, the value of the coefficient expressed by the step function is set smaller in the section constituting the angle of the starting point angle or more and smaller than the involute angle (phi-pi) rad than in the section constituting the angle of the involute angle or more and smaller than the involute angle phi rad.

3. The scroll compressor of claim 1 or 2, wherein,

the value of the involute angle phi rad is an involute angle when the value of the "function of a sine wave or cosine wave variation having pi rad as 1 cycle with respect to the involute angle thetad" becomes a minimum value.

4. The scroll compressor of claim 1, wherein,

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

here, a ₀ Is a basic radius to be a reference, alpha (θ) is a value of a coefficient expressed by the step function, beta is an arbitrary coefficient, N is a natural number of 1 or more, and ζ is a constant [ rad ]]，

a(θ)＝a ₀ (1+α(θ)sin ^2N (θ-ξ))(1-βθ)…(3)

a(θ)＝a ₀ (1+α(θ)cos ^2N (θ-ξ))(1-βθ)…(4)

a(θ)＝a ₀ (1+α(θ)(1+sin2(θ-ξ)))(1-βθ)…(5)

a(θ)＝a ₀ (1+α(θ)(1+cos2(θ-ξ)))(1-βθ)…(6)。

5. The scroll compressor of claim 1, wherein,

the value of the coefficient represented by the step function is set smaller in the interval constituting the angle of the starting point angle (phi-pi) to less than the involute angle (phi-pi) rad than in the interval constituting the angle of the involute angle (phi-pi) to less than the involute angle (phi rad).

6. The scroll compressor of claim 4 or 5, wherein,

the involute angle phi rad has a value of xi+npi, wherein n is an integer.