Rotary compressor

Abstract

A rotary compressor is provided with: a blade that is in contact with the outer peripheral surface of a piston rotor and partitions the space of a compression chamber; and a pressing spring for pressing the base end of the wiper blade, the cylinder (60) being provided with: a wiper blade groove (66) for slidably holding the base end of the wiper blade; a bridge section (70) that is provided on the rear end side of the blade groove (66) and forms the outer peripheral section of the cylinder (60); and a spring groove (72) which is formed in the bridge portion (70) and which accommodates the pressing spring, the spring groove (72) being formed in a horizontal direction orthogonal to the axial direction of the cylinder (60), and the spring groove (72) being formed in a longitudinal cross-sectional view of the cylinder (60) in a cross-section including a spring groove center axis (CL2) of the spring groove (72), the blade groove (66), and the bridge portion (70). If the horizontal dimension of the remaining portion (70a) of the bridge portion (70) located on both sides of the spring groove (72) in the axial direction is v and the axial dimension is h, v < h.

Description

Technical Field

[0001] The invention relates to a rotary compressor. Background Art

[0002] As one of the compressors used in refrigeration apparatuses, air conditioners, and the like, a rotary compressor is known (see Patent Document 1).

[0003] Previous technical literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-76817 Summary of the invention

[0006] Technical issues to be solved by the invention

[0007] Since the compressor assembly can be designed with spatial freedom, the larger the core diameter of the rotary compressor, the more preferred it is. However, if the core diameter of the rotary compressor is large, the amount of material increases, which leads to problems of increased weight and material cost.

[0008] Therefore, the rotary compressor is required to be miniaturized. However, if the rotary compressor is miniaturized, the core diameter becomes smaller and the refrigerant charge amount of the compression part may be reduced. In particular, when a low-pressure refrigerant (for example, a refrigerant with a combustion level set to slightly flammable (A2L) or highly flammable (A3)) is used as the refrigerant, a charge amount of about twice that of R32 is required. Therefore, it is expected that the rotary compressor can be miniaturized while ensuring the charge amount.

[0009] The present invention has been made in view of such circumstances, and an object of the present invention is to provide a rotary compressor capable of achieving miniaturization while ensuring the refrigerant charge amount of the compression section.

[0010] Means for solving technical problems

[0011] The rotary compressor according to one embodiment of the present invention comprises: a cylinder body 60, which is formed with a compression chamber 60A having a cylindrical shape inside; a piston rotor 63, which compresses the refrigerant by eccentrically rotating inside the compression chamber; a scraper 64, which abuts against the outer peripheral surface of the piston rotor and divides the space of the compression chamber; and a pressing spring, which presses the base end of the scraper in the direction in which the front end of the scraper abuts against the outer peripheral surface of the piston rotor, and the cylinder body comprises: a scraper groove 66 for slidably holding the base end 64b of the scraper; a bridge portion 70, The blade groove is arranged at the rear end side of the scraper groove and forms the outer periphery of the cylinder body; and a spring groove 72 is formed in the bridge portion for accommodating the pressing spring, the spring groove is formed at the central position of the axial direction of the cylinder body toward the horizontal direction orthogonal to the axial direction, and when the cylinder body is longitudinally sectioned in a cross section including the central axis of the spring groove, the scraper groove and the bridge portion, the horizontal dimension of the remaining portion 70a of the bridge portion located on both sides of the axial direction of the spring groove is set to v, and the dimension in the axial direction is set to h, then v <h。

[0012] Effects of the Invention

[0013] The refrigerant charge amount of the compression part of the rotary compressor can be ensured while achieving miniaturization. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a longitudinal cross-sectional view showing a rotary compressor according to one embodiment of the present invention.

[0015] Figure 2 Yes means Figure 1 A side view of a rotary compressor installed on a mounting surface.

[0016] Figure 3 yes Figure 1 The plan view of the cylinder body.

[0017] Figure 4 is along Figure 3 A cross-sectional view taken along the line indicated by arrow IV. DETAILED DESCRIPTION

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0019] like Figure 1 As shown, the rotary compressor (hereinafter referred to as "compressor") 1 involved in this embodiment is a closed electric rotary compressor used in, for example, an air conditioner or a refrigeration device. The compressor 1 includes a compressor body 10 and a liquid accumulator 12. The liquid accumulator 12 is connected to the compressor body 10 via a suction pipe 11.

[0020] The compressor body 10 includes a substantially cylindrical housing 2, a rotating shaft body 3, an electric motor 5, and a rotary compression unit 6. The rotating shaft body 3 has a rotation axis CL that coincides with the central axis of the housing 2. The rotating shaft body 3 is arranged to extend in the vertical direction and rotates in the housing 2 around the rotation axis CL.

[0021] The housing 2 is a closed type and extends in the vertical direction. The housing 2 includes a main body 21 in a cylindrical shape, and an upper cover 22 and a lower cover 23 that close the upper and lower openings of the main body 21 .

[0022] A plurality of legs 7 are fixed below the main body 21. The legs 7 are arranged at predetermined angles in the circumferential direction of the main body 21. Figure 2 As shown, each leg portion 7 is fixed to the installation surface FI via a vibration-proof rubber 8 .

[0023] The housing 2 has an opening 24 formed at a position in the lower portion of the side wall facing the outer peripheral surface of the cylinder 60. The cylinder 60 has a suction port 25 formed at a position facing the opening 24 and communicating with a predetermined position in the cylinder.

[0024] An oil reservoir for storing lubricating oil is formed at the bottom of the housing 2. The liquid level of the oil reservoir when the oil is initially sealed is located above the rotary compressor 6. Thus, the rotary compressor 6 is driven in the oil reservoir.

[0025] The upper cover 22 is provided with a discharge pipe 13 and a terminal block 30. The discharge pipe 13 penetrates the upper cover 22 in the thickness direction, with the lower portion arranged inside the housing 2 and the upper portion arranged outside the housing 2. The discharge pipe 13 discharges the compressed refrigerant to the outside of the housing 2. The terminal block 30 is provided with three power supply terminals 31 for supplying power to the electric motor 5. Three-phase power is supplied to the power supply terminals 31 from an inverter device (not shown).

[0026] The accumulator 12 is used to separate the refrigerant into gas and liquid before supplying it to the compressor body 10. The accumulator 12 is set to be roughly cylindrical in shape and is fixed to the outer peripheral surface of the shell 2 via a bracket 14. An inlet pipe 15 for introducing refrigerant guided from an evaporator not shown in the figure is provided at the upper part of the accumulator 12. A suction pipe 11 for sucking the internal refrigerant into the compressor body 10 is connected to the accumulator 12. The suction pipe 11 is connected to the suction port 25 through the opening 24 of the shell 2. The accumulator 12 supplies the gas phase refrigerant to the rotary compression part 6 via the suction pipe 11.

[0027] As the refrigerant, a low-pressure refrigerant is used, for example, a slightly flammable refrigerant (A2L) or a highly flammable refrigerant (A3) such as propane. In addition, R410A, R32, R1234yf, and a natural refrigerant (R290, isobutane, etc.) can be used.

[0028] The electric motor 5 is accommodated in the central part of the housing 2 in the vertical direction. The electric motor 5 includes a rotor 51 and a stator 52. The rotor 51 is fixed to the outer peripheral surface of the rotating shaft body 3 and is arranged above the rotary compression unit 6. The stator 52 is arranged to surround the outer peripheral surface of the rotor 51 and is fixed to the inner surface 21a of the main body 21 of the housing 2.

[0029] Electric power is supplied from each power supply terminal 31 to the stator 52 via the wiring 32. The electric motor 5 rotates the rotating shaft body 3 by the electric power supplied from the power supply terminal 31.

[0030] The rotary compression unit 6 is disposed in a state of being sandwiched from above and below by the upper bearing 4A and the lower bearing 4B. The upper bearing 4A and the lower bearing 4B are each formed of a metal material and are fixed to a cylinder 60 constituting the rotary compression unit 6 by bolts 61.

[0031] The rotating shaft body 3 is supported by an upper bearing 4A and a lower bearing 4B so as to be rotatable around the rotation axis CL.

[0032] The rotary compression section 6 is disposed at the bottom of the housing 2 below the electric motor 5. The rotary compression section 6 includes a cylinder 60, an eccentric shaft 62, and a piston rotor 63.

[0033] The cylinder 60 is formed with a compression chamber 60A, a suction port 60B, and a discharge port (not shown). The compression chamber 60A is formed inside the cylinder 60. A piston rotor 63 is accommodated in the compression chamber 60A.

[0034] The rotary compression section 6 is fixed to the inner surface 21a of the main body 21 of the housing 2. Specifically, the upper bearing 4A of the clamping cylinder 60 is fixed to the inner surface 21a of the main body 21 of the housing 2. The upper bearing 4A is fixed by plug welding at multiple locations in the circumferential direction of the housing 2. In addition, heat press fitting, shrink fitting, etc. can also be used instead of plug welding.

[0035] The eccentric shaft portion 62 is provided at the lower end portion of the rotating shaft body 3 , and is provided inside the piston rotor 63 in a state of being offset in a direction orthogonal to the central axis of the rotating shaft body 3 .

[0036] The piston rotor 63 is arranged inside the cylinder 60 in a cylindrical shape with an outer diameter smaller than the inner diameter of the cylinder 60 and is fixed to the outer periphery of the eccentric shaft portion 62. The piston rotor 63 rotates eccentrically with respect to the rotation axis CL as the rotating shaft body 3 rotates.

[0037] The suction hole 60B is a hole for introducing the refrigerant into the interior of the cylinder 60 , and is formed in a direction orthogonal to the rotation axis CL.

[0038] The high-pressure refrigerant discharged from a discharge hole (not shown) formed in the cylinder 60 is guided into a space formed between the discharge cover 65 and the upper bearing 4A, and then guided into the internal space of the casing 2 .

[0039] exist Figure 3 , a plan view of the cylinder 60 is shown in FIG. 6 . The cylinder 60 is provided with a scraper 64 that divides the compression chamber 60A into two. The cylinder 60 is formed with a scraper groove 66 that extends in the radial direction. The scraper 64 is slidably guided on the inner surface 66a of the scraper groove 66, and is held so as to be able to move forward and backward freely in the direction of approaching and separating relative to the piston rotor 63. Moreover, in the scraper 64, the base end portion 64b on the radially outer side is elastically pressed by a pressing spring (compression spring) not shown in the figure, and the front end portion 64a is in a state of being always pressed by the outer peripheral surface 63a of the piston rotor 63.

[0040] The eccentric shaft portion 62 has an outer diameter slightly smaller than the inner diameter of the piston rotor 63. Therefore, when the rotating shaft body 3 rotates, the eccentric shaft portion 62 rotates around the rotating shaft body 3, and the piston rotor 63 rotates eccentrically in the cylinder body 60. At this time, the scraper 64 is pressed by a pressing spring (not shown), so the front end portion 64a moves forward and backward following the movement of the piston rotor 63 and is always pressed by the piston rotor 63.

[0041] The outer diameter D1 of the cylinder 60 is set to be greater than or equal to 90 mm and less than or equal to 105 mm.

[0042] The inner diameter D2 of the compression chamber 60A is set to be greater than or equal to 37 mm and less than or equal to 50 mm.

[0043] A through hole 66b is formed at the rear end or outer peripheral side of the scraper groove 66 and penetrates along the axial direction of the cylinder 60 (ie, the rotation axis CL direction). The through hole 66b is cylindrical. A bridge portion 70 is provided at the rear end or outer peripheral side of the through hole 66b.

[0044] The bridge portion 70 is formed on the outer periphery of the cylinder body 60. Figure 3 It can also be seen that the bridge portion 70 is weak at the position where the wall thickness is the thinnest in the cylinder body 60. In addition, a spring groove 72 for accommodating a pressing spring is formed in the bridge portion 70 (see Figure 4 ), so the strength is further weakened.

[0045] Figure 4 Indicates along Figure 3 The cross section is cut by arrow IV, and is a longitudinal cross-sectional view of the cylinder body 60 on a cross section including the central axis of the spring groove 72 , the scraper groove 66 and the bridge portion 70 .

[0046] like Figure 4As shown, the spring groove 72 is formed in the central position in the axial direction of the cylinder block 60 (i.e., the direction of the rotation axis CL) toward the horizontal direction orthogonal to the axial direction. That is, the central axis CL2 of the spring groove is horizontally arranged. The central axis CL2 of the spring groove is preferably arranged to intersect the rotation axis CL. The diameter of the spring groove 72 is, for example, set to be 6 or more and 10 or less.

[0047] On both sides in the axial direction of the spring groove 72, the remaining parts 70a of the bridging portion 70 are respectively provided. The strength of the bridging portion 70 is ensured in these remaining parts 70a. When the horizontal dimension of the remaining part 70a is set to v and the axial dimension is set to h, it is set to v < h. That is, the axial dimension h is made larger than the horizontal dimension v of the remaining part 70a. As Figure 4 viewed in this way, it is a vertically long rectangle.

[0048] It is more preferably set to the following range as the value of h / v.

[0049] 1.4 ≤ h / v ≤ 3.5

[0050] The horizontal dimension v is, for example, set to be 2.0 mm or more and 7.5 mm or less.

[0051] The axial dimension h is, for example, set to be 2.5 mm or more and 8.5 mm or less.

[0052] The above-described compressor 1 operates as follows.

[0053] The refrigerant guided from an evaporator (not shown) is taken into the accumulator 12 via the inlet pipe 15. The refrigerant is gas-liquid separated in the accumulator 12, and its gas phase is guided to the rotary compression section 6 via the suction pipe 11. In the rotary compression section 6, the refrigerant is guided to the compression chamber 60A via the suction hole 60B. Then, by the eccentric rotation of the piston rotor 63, the volume of the compression chamber 60A gradually decreases and the refrigerant is compressed. The compressed refrigerant is guided to the internal space of the housing 2 after passing through the space in the discharge cover 65 via the discharge hole. The refrigerant discharged into the internal space of the housing 2 is guided to a condenser (not shown) via the discharge pipe 13 provided at the upper part of the housing 2.

[0054] The functions and effects of the present embodiment described above are as follows.

[0055] The bridging portion 70 provided on the rear end side of the vane groove 66 and forming the outer peripheral portion of the cylinder block 60 is weak in strength at the position where the wall thickness of the cylinder block 60 is the thinnest. And since the spring groove 72 for accommodating the pressing spring is formed in the bridging portion 70, the strength is further weakened.

[0056] When miniaturizing the compressor main body 10, it is necessary to reduce the outer diameter of the cylinder block 60. However, in order to ensure the refrigerant charge amount, it is desirable to avoid reducing the inner diameter D2 of the compression chamber 60A. Thus, it is necessary to make the wall thickness of the bridging portion 70 thinner.

[0057] The inventors have found the shape of the bridging portion 70 that ensures the strength of the bridging portion 70 under such constraints. That is, when the cylinder block 60 is longitudinally sectioned in a cross section including the spring groove center axis CL2 of the spring groove 72, the wiper groove 66, and the bridging portion 70 (refer to Figure 4 ), when the horizontal dimension of the remaining portion 70a of the bridging portion 70 located on both sides in the axial direction of the spring groove 72 is set to v and the axial dimension is set to h, then v < h. Make h larger than v, that is, make the axial dimension h larger than the horizontal dimension v of the remaining portion 70a.

[0058] In the case where miniaturization is not required and there is no constraint on the outer diameter D1 of the cylinder block 60, the horizontal dimension v can be increased to ensure the area of the remaining portion 70a and obtain the desired strength of the bridging portion 70. However, in the case where miniaturization is required, the outer diameter D1 of the cylinder block 60 becomes smaller, and the horizontal dimension v cannot be increased in order to obtain the refrigerant charge amount. Therefore, in the present embodiment, the desired strength of the bridging portion 70 is obtained by ensuring the area of the remaining portion 70a by making the axial dimension h larger than the horizontal dimension v.

[0059] Even for low-pressure refrigerants such as slightly flammable refrigerants (A2L) or highly flammable refrigerants (A3) such as propane, the desired refrigerant charge amount can be obtained, and thus a compressor having a specified performance can be provided.

[0060] The rotary compressor described in the embodiment described above is grasped as follows, for example.

[0061] The rotary compressor 1 involved in the first embodiment of the present invention comprises: a cylinder body 60, which forms a compression chamber 60A with a cylindrical shape inside; a piston rotor 63, which compresses the refrigerant by eccentrically rotating inside the compression chamber; a scraper 64, which abuts against the outer peripheral surface of the piston rotor and divides the space of the compression chamber; and a pressing spring, which presses the base end of the scraper in the direction in which the front end of the scraper abuts against the outer peripheral surface of the piston rotor, and the cylinder body comprises: a scraper groove 66 for slidably holding the base end 64b of the scraper; a bridge portion 70, The blade groove is arranged at the rear end side of the scraper groove and forms the outer periphery of the cylinder body; and a spring groove 72 is formed in the bridge portion for accommodating the pressing spring, the spring groove is formed at the central position of the axial direction of the cylinder body toward the horizontal direction orthogonal to the axial direction, and when the cylinder body is longitudinally sectioned in a cross section including the central axis of the spring groove, the scraper groove and the bridge portion, the horizontal dimension of the remaining portion 70a of the bridge portion located on both sides of the axial direction of the spring groove is set to v, and the dimension in the axial direction is set to h, then v <h。

[0062] The bridge portion, which is arranged at the rear end side of the scraper groove and forms the outer periphery of the cylinder body, is weak at the position where the wall thickness is the thinnest in the cylinder body. In addition, a spring groove for accommodating a pressing spring is formed in the bridge portion, so the strength is further weakened.

[0063] In order to achieve miniaturization of the rotary compressor, the outer diameter of the cylinder needs to be reduced, but in order to ensure the refrigerant charge amount, it is desired to avoid reducing the inner diameter of the compression chamber. In this case, the wall thickness of the bridge portion must be reduced.

[0064] The inventors have found a shape of the bridge portion that ensures the strength of the bridge portion under such constraints. That is, when the cylinder body is longitudinally cut in a cross section including the central axis of the spring groove, the scraper groove, and the bridge portion, the horizontal dimension of the remaining portion of the bridge portion located on both sides of the axial direction of the spring groove is set to v, and the axial dimension is set to h, then v<h. h is made larger than v, that is, the axial dimension h is made larger than the horizontal dimension v of the remaining portion.

[0065] When miniaturization is not required and there is no restriction on the outer diameter of the cylinder, the horizontal dimension v can be increased to ensure the area of ​​the remaining part and obtain the desired strength of the bridge portion. However, when miniaturization is required, the outer diameter of the cylinder becomes smaller, and the horizontal dimension v cannot be increased in order to obtain the refrigerant charge amount. Therefore, in the present invention, the axial dimension h is made larger than the horizontal dimension v to ensure the area of ​​the remaining part and obtain the desired strength of the bridge portion.

[0066] In the rotary compressor according to the second aspect of the present invention, in the first aspect, v and h satisfy the following relational expression:

[0067] 1.4≤h / v≤3.5.

[0068] By setting the range of 1.4≤h / v≤3.5, it is possible to ensure the remaining area of ​​the bridge portion and obtain desired strength.

[0069] A rotary compressor according to a third aspect of the present invention uses a slightly flammable refrigerant or a highly flammable refrigerant as the refrigerant in the first aspect or the second aspect.

[0070] Even with a low-pressure refrigerant such as a slightly flammable refrigerant (A2L) or a highly flammable refrigerant (A3) such as propane, a desired refrigerant charge amount can be obtained, thereby providing a compressor having predetermined performance.

[0071] Explanation of symbols

[0072] 1- compressor (rotary compressor), 2- housing, 3- rotating shaft, 4A- upper bearing, 4B- lower bearing, 5- electric motor, 6- rotary compression part, 7- foot part, 8- vibration-proof rubber, 10- compressor body, 11- suction pipe, 12- reservoir, 13- discharge pipe, 14- bracket, 15- inlet pipe, 21- main body, 21a- inner surface, 22- upper cover part, 23- lower cover part, 24- opening part, 25- suction port, 30- terminal block, 31- power supply terminal, 32-wiring, 51-rotor, 52-stator, 60-cylinder body, 60A-compression chamber, 60B-intake hole, 61-bolt, 62-eccentric shaft, 63-piston rotor, 64-scraper, 64a-front end, 64b-base end, 65-discharge cover, 66-scraper groove, 66a-inner surface, 66b-through hole, 70-bridging portion, 72-spring groove, CL-rotation axis, CL2-spring groove center axis, FI-setting surface, v-horizontal dimension, h-axial dimension.

Claims

1. A rotary compressor comprising: A cylinder body having a compression chamber formed in a cylindrical shape inside; A piston rotor compresses the refrigerant by eccentrically rotating inside the compression chamber; a scraper blade abutting against the outer peripheral surface of the piston rotor and partitioning the space of the compression chamber; and The pressing spring presses the base end of the scraper blade in a direction in which the front end of the scraper blade abuts against the outer peripheral surface of the piston rotor. The cylinder body comprises: a blade groove for slidably holding the base end of the blade; a bridge portion provided at the rear end side of the blade groove and forming the outer periphery of the cylinder body; and a spring groove formed in the bridge portion for accommodating the pressing spring. The spring groove is formed at a central position in the axial direction of the cylinder body toward a horizontal direction orthogonal to the axial direction. When the cylinder body is longitudinally cut in a cross section including the central axis of the spring groove, the scraper groove and the bridge portion, the horizontal dimension of the remaining portion of the bridge portion located on both sides of the axial direction of the spring groove is set as v, and the axial dimension is set as h, then v <h。 2. The rotary compressor according to claim 1, wherein: The v and the h satisfy the following relationship: 1.4≤h / v≤3.

5.

3. The rotary compressor according to claim 1 or 2, wherein: As the refrigerant, a slightly flammable refrigerant or a highly flammable refrigerant is used.

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