JP5951456B2 - Scroll compressor - Google Patents

Description

  The present invention relates to a scroll compressor that constitutes, for example, an indoor air conditioner.

A scroll compressor used in a refrigeration cycle such as an air conditioner or a refrigeration apparatus includes a fixed scroll and a turning scroll. The fixed scroll and the orbiting scroll are each formed by integrally forming a spiral wrap wall on one surface side of a disk-shaped end plate. Such a fixed scroll and the orbiting scroll are made to face each other with the lap wall meshed, and the orbiting scroll is caused to revolve with an electric motor or the like with respect to the fixed scroll. Then, the refrigerant gas in the compression chamber is compressed by reducing the volume while moving the compression chamber formed between both wrap walls from the outer peripheral side to the inner peripheral side.
The refrigerant gas compressed in the compression chamber passes through the discharge port formed in the end plate of the fixed scroll, flows into the high-pressure chamber between the discharge cover and the housing, and further flows into the refrigerant from the discharge pipe provided in the housing. It is discharged toward the circuit.

Since the discharge port formed in the fixed scroll affects the performance of the scroll compressor or noise, various proposals have been made.
For example, Patent Document 1 proposes forming a diffuser in the discharge port in order to reduce pressure loss and improve mechanical efficiency. Patent Document 2 proposes a muffler chamber that opens to the upper surface of the end plate of the fixed scroll and communicates with the discharge port of the fixed scroll in order to stably reduce the noise of the compressor over a long period of time. ing.

JP-A-6-66271 JP 2012-122376 A

In order to suppress environmental load, mixed refrigerants such as R410C (pseudo azeotropic refrigerant mixture) or R407C (non-azeotropic refrigerant mixture) have been used. When using the mixed refrigerant, it was confirmed that components in the 1 k to 2 kHz region of the discharge pulsation at the discharge port of the fixed scroll are generated as noise. According to the study by the present inventors, Patent Literature 1 and Patent Literature 2 do not give a solution for this noise.
The present invention has been made based on such a technical problem, and an object of the present invention is to provide a scroll compressor that can reduce noise in a specific frequency range generated when a mixed refrigerant is used.

The inventors of the present invention have studied to achieve the above object, and have concluded that the relationship between the sound speed of the mixed refrigerant and the distance of the refrigerant flow path including the discharge port is involved in noise generation.
In the formula (1) relating to the speed of sound, considering boundary conditions, λ = 4L (L: L1 (fixed scroll end plate thickness) + L1 (scroll tooth height)).
c = f × λ (1)
c: speed of sound (mm / s) f: frequency (kHz) λ: wavelength (4L)
The speed of sound at the discharge port of the mixed refrigerant such as R410A and 407C is about 160 to 180 m / s. The fixed scroll end plate thickness L1 is 10 to 20 mm, and the scroll tooth height L2 is 10 to 20 mm. Here, L1 corresponds to the length of the discharge port formed in the fixed scroll end plate, and L2 corresponds to the length of the compression chamber formed by the fixed scroll and the orbiting scroll. The refrigerant flow distance across. When the sound speed (160 m / s) of the mixed refrigerant and the distance L of the refrigerant passage are substituted into the formula (1), the acoustic eigenvalue (f) becomes 1 to 2 kHz. When the discharge pulsation resonates in this frequency range, it easily resonates with other structural members of the scroll compressor and the surrounding structure of the scroll compressor (hereinafter referred to as “structure”), and noise from the compressor is generated. It will be amplified.

Therefore, the present inventor has focused on adjusting the acoustic eigenvalue so as to avoid resonance with the structure, and has completed the present invention.
That is, the scroll type compressor of the present invention forms a turning scroll that is rotatably connected to the eccentric shaft portion of the main shaft, a compression chamber that compresses the refrigerant by facing the turning scroll, and the compressed refrigerant is high-pressure. A fixed scroll having an end plate on which a discharge port for discharging toward the chamber is formed . The discharge port is connected to the compression chamber, and is connected to the upstream port portion having an opening area A1 and the upstream port portion. the opening area A1 is greater than the downstream port of A2 is upstream port section consists city, a boundary of the upstream port unit and the downstream port unit, antinodes of vibration mode Ji live, the opening area A2 of the downstream port unit, upstream port It is set so that an antinode of vibration mode is generated in relation to the opening area A1 of the part .
The scroll compressor according to the present invention generates an antinode of vibration mode at the boundary between the upstream port portion and the downstream port portion by making the opening areas of the upstream port portion and the downstream port portion different from each other . Only the upstream port part is applicable to the part. This shortens the distance L of the refrigerant passage described above, and the acoustic eigenvalue obtained by the formula (1) can be adjusted high so as to avoid resonance with the structure.

The discharge port in the present invention includes several forms.
About the downstream port part, opening area A2 can be made constant by the direction through which a refrigerant | coolant flows , and can also be expanded in steps or continuously. It is preferable to use a circular port with the same diameter in terms of workability.

According to the present invention, by Rukoto with different opening area of the upstream port unit and the downstream port unit causes belly boundaries vibration mode of the upstream port unit and the downstream port unit, to shorten the distance L of the refrigerant passages Thus, the acoustic eigenvalue can be adjusted to be low and resonance with the structure can be avoided. Therefore, the scroll compressor according to the present invention can reduce noise in a specific frequency range that is generated when the mixed refrigerant is used.

It is a longitudinal section showing a scroll type compressor in this embodiment. (A) is the elements on larger scale of FIG. 1, (b) is the IIa-IIa arrow directional cross-sectional view of (a). It is a figure for demonstrating the effect | action and effect by the discharge port of the fixed end plate of this embodiment, (a) shows typically the discharge flow path of the refrigerant | coolant containing the discharge port of this embodiment, (b) 1 schematically shows a conventional refrigerant discharge passage. It is a figure which shows the modification of the discharge port of this embodiment, (a) shows the example which expanded the downstream port part in steps, (b) has shown the example which expanded the downstream port part continuously . . Sound can be reduced.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.
As shown in FIG. 1, the scroll compressor 1 of this embodiment includes an electric motor 12 and a scroll compression mechanism 2 driven by the electric motor 12 in a housing 10. The scroll compressor 1 compresses refrigerant such as R410C and R407C and supplies the compressed refrigerant to a refrigerant circuit such as an air conditioner or a refrigerator.

The housing 10 includes a bottomed cylindrical housing main body 101 having an open upper end, and a housing top 102 that covers an opening at the upper end of the housing main body 101.
A suction pipe 13 for introducing a refrigerant into the housing body 101 from an accumulator (not shown) is provided on a side surface of the housing body 101.
The housing top 102 is provided with a discharge pipe 14 that discharges the refrigerant compressed by the scroll compression mechanism 2. The interior of the housing 10 is partitioned into a low pressure chamber 10A and a high pressure chamber 10B by a discharge cover 25.

The electric motor 12 includes a stator 15 and a rotor 16.
The stator 15 is provided with a winding that generates a magnetic field when electric power is supplied through a power supply unit (not shown) attached to the side surface of the housing body 101. The rotor 16 includes a permanent magnet and a yoke as main elements, and a main shaft 17 is integrally coupled around the center.

An upper bearing 18 and a lower bearing 19 that rotatably support the main shaft 17 are provided on both ends of the main shaft 17 with the electric motor 12 interposed therebetween.
In the accommodation space 190 formed in the upper bearing 18, an eccentric pin 17A provided at the upper end of the main shaft 17 protrudes and is accommodated.

The scroll compression mechanism 2 includes a fixed scroll 20 and a turning scroll 30 that revolves with respect to the fixed scroll 20.
The fixed scroll 20 includes a fixed end plate 21 and a spiral wrap 22 erected from one surface of the fixed end plate 21. The fixed scroll 20 is also provided with a discharge port 23 in the fixed end plate 21. The discharge port 23 passes through the front and back of the fixed end plate 21, and one end (downward in the figure) opens toward the compression chamber PR formed between the fixed scroll 20 and the orbiting scroll 30, and the other end (see FIG. (Center, upper) opens toward the discharge port 27 of the discharge cover 25 covering the upper side of the fixed scroll 20.

In the present embodiment, the discharge port 23 has an upstream port portion 23A located on the upstream side and a downstream port located on the downstream side of the upstream port portion 23A with reference to the refrigerant flow direction F (FIG. 2A). It consists of part 23B. The upstream port portion 23A is continuous with the compression chamber PR, and the downstream port portion 23B is continuous with the upstream port portion 23A. As shown in FIG. 2B, the upstream port portion 23A has a circular opening shape, and the opening area is A1. Further, the downstream port portion 23B has a fan-shaped opening shape, and its opening area is A2. In the present embodiment, the opening area A2 of the downstream port portion 23B is larger than the opening area A1 of the upstream port portion 23A. Moreover, based on the difference in opening area, the upstream port portion 23A and the downstream port portion 23B have antinodes in the vibration mode at the boundary portion. Thus, the operation and effect of the discharge port 23 including the upstream port portion 23A and the downstream port portion 23B will be described later.

The orbiting scroll 30 is also provided with a disc-shaped orbiting end plate 31 and a spiral wrap 32 erected from one surface of the orbiting end plate 31.
A boss 34 is provided on the rear surface of the orbiting end plate 31 of the orbiting scroll 30, and a drive bush 36 is assembled to the boss 34 via a bearing. An eccentric pin 17A is fitted inside the drive bush 36. As a result, the orbiting scroll 30 is eccentrically coupled to the axis of the main shaft 17. Therefore, when the main shaft 17 rotates, the orbiting scroll 30 rotates (revolves) with the eccentric distance from the axis of the main shaft 17 as the orbiting radius.
An Oldham ring (not shown) that restrains rotation is provided between the orbiting scroll 30 and the main shaft 17 so that the orbiting scroll 30 does not rotate while revolving.

  The wraps 22 and 32 that are eccentric with each other by a predetermined amount and are engaged with each other by shifting the phase by 180 degrees contact each other at a plurality of locations according to the rotation angle of the orbiting scroll 30. Then, the compression chamber PR is formed point-symmetrically with respect to the spiral center portions (innermost peripheral portions) of the wraps 22 and 32, and the compression chamber reduces its volume as the orbiting scroll 30 turns. Gradually moved to the inner circumference. The refrigerant is compressed to the maximum at the center of the spiral. The compression chamber PR in FIG. 1 shows this portion.

  In this scroll type compression mechanism 2, the volume of the compression chamber PR formed between both scrolls 20 and 30 is also reduced in the height direction of the wrap in the middle of the spiral. Therefore, in both the fixed scroll 20 and the orbiting scroll 30, the height of the wrap is made lower on the inner peripheral side than on the outer peripheral side, and the other end plate facing the stepped wrap is placed on the inner side from the outer peripheral side. On the circumferential side, it protrudes toward the inner surface of the end plate.

In order to start the scroll compressor 1 having the above configuration, the electric motor 12 is excited and a refrigerant is introduced into the housing 10 through the suction pipe 13.
When the electric motor 12 is energized, the main shaft 17 rotates, and the orbiting scroll 30 revolves with respect to the fixed scroll 20 accordingly. Then, the refrigerant is compressed in the compression chamber PR between the orbiting scroll 30 and the fixed scroll 20, and the refrigerant introduced into the low pressure chamber 10 </ b> A in the housing 10 from the suction pipe 13 is exchanged between the orbiting scroll 30 and the fixed scroll 20. Inhaled in between. Then, the refrigerant compressed in the compression chamber PR sequentially passes through the discharge port 23 of the fixed end plate 21 and the discharge port 27 of the discharge cover 25 and is discharged to the high pressure chamber 10B, and further discharged from the discharge pipe 14 to the outside. Is done. In this way, refrigerant suction, compression, and discharge are continuously performed.

In the present embodiment, the discharge port 23 of the fixed scroll 20 includes the upstream port portion 23A and the downstream port portion 23B described above, and the opening area A2 of the downstream port portion 23B is larger than the opening area A1 of the upstream port portion 23A. The upstream port portion 23A and the downstream port portion 23B have vibration mode antinodes at their boundaries. The action and effect by doing so will be described with reference to FIG.

First, a conventional discharge port 123 having a constant opening area shown in FIG. This opening area is set to A1 which is the same as the upstream port portion 23A of the present embodiment. That is, the discharge port 123 is the same as that in which the upstream port portion 23A of the present embodiment is connected to the downstream end.
In FIG. 3B, the wavelength λ in the following equation (1) is specified by the total value of L1 ′, L2 ′, and L3 ′ defined below. When the conventional discharge port 123 is applied, the vibration mode is continuous between the flow path C1 ′ and the flow path C2 ′, but the flow path C3 ′ is the same as the flow path C1 and the flow path C2 on the upstream side. An antinode of vibration mode occurs at the boundary. Then, the total length L ′ (L1 ′ + L2 ′) of the channel C1 ′ and the channel C2 ′ is λ = 4L ′ in consideration of boundary conditions. As described above, the speed of sound in the refrigerant flow path of the mixed refrigerant such as R410A and 407C is about 160 to 180 m / s, the thickness (L2 ′) of the fixed end plate is 10 to 20 mm, the scroll tooth height (L1 ′). ) Is 10 to 20 mm, the acoustic eigenvalue (f) is 1 to 2 kHz (when c = 160 m / s). However, this can cause resonance with the structure.

c = f × λ (1)
c: speed of sound (mm / s) f: frequency (kHz) λ: wavelength (4L)

λ = L1 ′ + L2 ′ + L3 ′
L1 ′: Length of refrigerant flow path C1 ′ in compression chamber PR L2 ′: Length of refrigerant flow path C2 ′ in fixed end plate 21 L3 ′: Length of refrigerant flow path C3 ′ after fixed end plate 21 The

Therefore, as shown in FIG. 3A of the present embodiment, the opening of the discharge port 23 is greatly expanded from the middle, and an antinode of vibration mode is generated between the upstream port portion 23A and the downstream port portion 23B. . Then, since L corresponding to conventional L ′ is shortened, the acoustic eigenvalue (f) can be increased, and resonance with the structure can be avoided. For example, if the downstream port portion 23B is formed from a position that is ¼ of the thickness of the fixed end plate 21, the acoustic eigenvalue (f) is 1.6 to 3.2 kHz.

By the way, it can be easily estimated that the fixed end plate 21 may be thinned to shorten L. However, the fixed end plate 21 may not be thinned in order to ensure the strength required for the fixed scroll 20. In particular, the scroll compressor 1 is required to be rotated at a high speed and further reduced in weight, so that the fixed end plate 21 of the fixed scroll 20 is thinned within an allowable range even at present, and it is difficult to further reduce the thickness. It is in. Therefore, the configuration of the discharge port 23 of the present embodiment is an effective means that can avoid resonance with the structure without reducing the thickness of the fixed end plate 21.
Moreover, since the pressure loss of the refrigerant | coolant in the said part can be reduced by enlarging the opening area of the downstream port part 23B like the discharge port 23, it can also contribute to the performance improvement of the scroll compressor 1. FIG.

In the present embodiment, the opening area A2 of the downstream port portion 23B is set so as to cause vibration mode antinodes in relation to the opening area A1 of the upstream port portion 23A. The length L2 of the upper flow ports 23 A, considering the vibration of the surrounding structure, the acoustic eigenvalue can avoid resonance with structure (f) is set so as to obtain. Both can be obtained by performing a vibration test by simulation.

In the above embodiment, an example in which the opening area of the downstream port portion 23B is constant in the direction in which the refrigerant flows is shown, but the present invention is not limited to this. For example, as long as the effect of the present invention is obtained, the downstream port portion 23B may be enlarged stepwise as shown in FIG. 4 (a), or the downstream port portion 23B may be continuously connected as shown in FIG. 4 (b). May be enlarged. Further, although the illustration of the upstream port portion 23A is omitted, the opening area may be changed stepwise or continuously.
Moreover, although the downstream port portion 23B has a fan-shaped opening shape, the present invention is not limited to this, and may have another opening shape, for example, a circular shape.
Furthermore, the present invention has been described based on the fact that the components in the 1 to 2 kHz region of the discharge pulsation are generated as noise. However, this is merely an example, and the present invention is applied to reduce the noise of components outside this range. Needless to say, you can.
Furthermore, the opening shape of the downstream port portion 23B is arbitrary and is not limited to the fan shape.
In addition to this, as long as it does not depart from the gist of the present invention, the configuration described in the above embodiment can be selected or changed to another configuration as appropriate.

DESCRIPTION OF SYMBOLS 1 Scroll type compressor 2 Scroll type compression mechanism 10 Housing 10A Low pressure chamber 10B High pressure chamber 12 Electric motor 13 Suction pipe 14 Discharge pipe 15 Stator 16 Rotor 17 Main shaft 17A Eccentric pin 18 Lower bearing 19 Upper bearing 20 Fixed scroll 22, 32 Lap 23 Discharge port 23A Upstream port portion 23B Downstream port portion 25 Discharge cover 27 Discharge port 30 Orbiting scroll 34 Boss 36 Drive bush 101 Housing body 102 Housing top 21 Fixed end plate 31 Orbiting end plate

Claims (5)

An orbiting scroll rotatably connected to the eccentric shaft portion of the main shaft,
A fixed scroll having an end plate that forms a compression chamber that compresses the refrigerant by facing the orbiting scroll and that has a discharge port that discharges the compressed refrigerant toward the high-pressure chamber;
The discharge port is
An upstream port portion connected to the compression chamber and having an opening area A1,
Continuous with the upstream port portion, the opening area A1 is greater than the downstream port of the opening area A2 is the upstream port section consists city, a boundary of the said downstream ports and the upstream port unit, antinodes of vibration mode raw Flip,
The opening area A2 of the downstream port portion is set so that the antinode of the vibration mode occurs in relation to the opening area A1 of the upstream port portion.
A scroll compressor characterized by that. The downstream port portion is
The opening area A2 is constant in the direction in which the refrigerant flows .
The scroll compressor according to claim 1.   The downstream port portion is
  The opening area A2 expands stepwise or continuously,
The scroll compressor according to claim 1.   The downstream port portion is
  The opening shape is circular or fan-shaped,
The scroll type compressor according to any one of claims 1 to 3.   The downstream port portion is
  The opening shape is circular,
The scroll type compressor according to any one of claims 1 to 4.

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