Compressor mounting structure and compressor

Abstract

To prevent vibration of a compression mechanism due to vibration of a vehicle.SOLUTION: A compressor installation structure is to install a compressor 10 on a vehicle. The compressor 10 comprises: a rotating body 19 provided with a rotary shaft 12 and a compression mechanism 13 which is arranged at a first edge 12a in an axial direction X of the rotary shaft 12 and compresses fluid by being rotated with the rotary shaft 12; a radial bearing 15 which rotatably supports the rotary shaft 12 in a radial direction; a thrust bearing 16 which rotatably supports the rotary shaft 12 in a thrust direction; and a housing 11 which stores the rotating body 19, the radial bearing 15, and the thrust bearing 16. The radial bearing 15 and the thrust bearing 16 are gas bearings and provided with installation legs made of an elastic member fixed to the housing 11 and installation surfaces. Resonant frequency of the installation legs is smaller than resonant frequency of the radial bearing 15 and the thrust bearing 16.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a compressor mounting structure and a compressor. [Background technology]

[0002] Patent Document 1 describes a compressor mounting structure for mounting a compressor to a mounting surface of a vehicle. The compressor includes, for example, a rotating body, a bearing, and a housing. The rotating body includes, for example, a rotating shaft and a compression mechanism provided at at least one axial end of the rotating shaft and rotating together with the rotating shaft to compress a fluid. The bearing includes, for example, a radial bearing that rotatably supports the rotating shaft in the radial direction, and a thrust bearing that rotatably supports the rotating shaft in the thrust direction. The housing accommodates, for example, the rotating body, the radial bearing, and the thrust bearing. The mounting structure described in Patent Document 1 includes mounting feet. The mounting feet are fixed, for example, to the compressor housing and the mounting surface of the vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-44313 Summary of the Invention [Problem to be solved by the invention]

[0004] Vibrations from the vehicle may be transmitted to the compressor, causing the compressor to vibrate. If the compression mechanism vibrates too much, it may cause a collision within the compression mechanism, which is undesirable. Therefore, it has been desired to suppress the vibration of the compression mechanism that occurs due to vehicle vibration. [Means for solving the problem]

[0005] A compressor mounting structure that solves the above problem is a compressor mounting structure for mounting a compressor, which includes a rotating body including a rotating shaft and a compression mechanism that is provided at at least one axial end of the rotating shaft and rotates together with the rotating shaft to compress a fluid, a radial bearing that rotatably supports the rotating shaft in a radial direction, and a thrust bearing that rotatably supports the rotating shaft in a thrust direction, to a mounting surface of a vehicle, wherein the radial bearing and the thrust bearing are gas bearings, and the compressor includes mounting feet made of elastic members that are fixed to the housing and the mounting surface, and the resonant frequency of the mounting feet is lower than the resonant frequency of the radial bearing and is also lower than the resonant frequency of the thrust bearing.

[0006] According to the above configuration, the amount of vibration of the rotor can be reduced when the radial bearing resonates, which is the timing when the rotor vibrates most significantly, and therefore vibration of the compression mechanism caused by vibration of the vehicle can be suppressed.

[0007] In the compressor mounting structure, the compression mechanism may be provided at one end in the axial direction of the rotary shaft, but not at the other end. With the above configuration, the amount of vibration of the rotating body is likely to be greater than when the compression mechanisms are provided at both axial ends of the rotating shaft. Even in such cases where vibration of the rotating body is a greater concern, the adoption of the compressor mounting structure makes it possible to suppress vibration of the compression mechanism caused by vibration of the vehicle.

[0008] In the compressor mounting structure, the compression mechanism may include an impeller. According to the above configuration, the tip clearance formed between the shroud surface of the housing and the impeller is small. Therefore, when the compression mechanism vibrates significantly, the impeller is likely to collide with the housing. However, by suppressing the vibration of the compression mechanism caused by the vibration of the vehicle, the impeller can be prevented from colliding with the housing.

[0009] The compressor that solves the above problem is characterized in that it is attached to the attachment surface of the vehicle by the above attachment structure, and the fluid is a refrigerant. According to the above configuration, since refrigerant has a higher load density than air, the rotating shaft is less likely to collide with the radial bearing and thrust bearing when vibration is applied to the housing, compared to when air is used as the fluid compressed by the compression mechanism. On the other hand, vibration of the compression mechanism, which is a concern when the rotating shaft does not collide with the radial bearing and thrust bearing when vibration is applied to the housing, can be suppressed by adopting a compressor mounting structure. [Effects of the Invention]

[0010] According to the present invention, vibrations of the compression mechanism caused by vibrations of the vehicle can be suppressed. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a schematic diagram showing a compressor and a mounting structure for the compressor. [Figure 2] FIG. 2 is a schematic diagram showing a compressor. [Figure 3] FIG. 2 is a cross-sectional view showing a part of the compressor. [Figure 4] 10 is a graph showing the vibration frequency and the amount of vibration of a rotating body. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, a compressor mounting structure and a compressor according to an embodiment will be described with reference to the drawings. The compressor according to the present embodiment is an electric compressor. The compressor according to the present embodiment is used in, for example, a vehicle air conditioning system.

[0013] <Compressor> As shown in FIG. 1, the compressor 10 includes a housing 11. The housing 11 is, for example, cylindrical. The housing 11 is made of metal. The housing 11 is, for example, made of aluminum. The direction in which the axis m of the housing 11 extends is defined as the axial direction X. The housing 11 may be formed of multiple housing components that can be separated in the axial direction X.

[0014] As shown in Fig. 2, the compressor 10 includes a rotating body 19 and a bearing 18. The rotating body 19 includes a rotating shaft 12 and a compression mechanism 13. The compression mechanism 13 includes a compression section 13a. The bearing 18 includes a radial bearing 15 and a thrust bearing 16. That is, the compressor 10 includes the radial bearing 15 and the thrust bearing 16. The housing 11 accommodates the rotating body 19, the radial bearing 15, and the thrust bearing 16.

[0015] 3, the housing 11 has a shroud surface 11b. The shroud surface 11b has a truncated cone shape. The compression section 13a is located in a space surrounded by the shroud surface 11b. That is, the housing 11 accommodates the compression section 13a.

[0016] As shown in FIG. 2, the rotating shaft 12 extends in the same direction as the axis m of the housing 11. That is, the axial direction X corresponds to the axial direction of the rotating shaft 12. A rotational axis L, which is the axis of the rotating shaft 12, extends in the axial direction X. The rotating shaft 12 has, for example, a cylindrical shape extending in the axial direction X. In the axial direction X, one end of the rotating shaft 12 is referred to as a first end 12a, and the other end of the rotating shaft 12 is referred to as a second end 12b. The second end 12b is the end of the rotating shaft 12 opposite to the first end 12a. In the axial direction X, the direction from the center of gravity C1 of the compressor 10 toward the first end 12a is referred to as a first direction X1, and the direction from the center of gravity C1 of the compressor 10 toward the second end 12b is referred to as a second direction X2. In this embodiment, the center of gravity C1 of the compressor 10 is located on the rotating shaft 12.

[0017] As shown in Figures 2 and 3, the compression mechanism 13 is provided at at least one end, or a first end 12a, of the rotating shaft 12 in the axial direction X. In this embodiment, the compression mechanism 13 is provided at the first end 12a, or one end, of the rotating shaft 12 in the axial direction X, and is not provided at the other end, or a second end 12b. In this embodiment, the compression section 13a is an impeller. That is, the compression mechanism 13 includes an impeller. The compression section 13a has a truncated cone shape. The compression section 13a is covered by a shroud surface 11b of the housing 11. The compression section 13a is spaced apart from the shroud surface 11b. This forms a tip clearance 11c between the compression section 13a and the shroud surface 11b. When the rotating shaft 12 rotates, the compression section 13a rotates integrally with the rotating shaft 12.

[0018] As shown in Fig. 2, the compressor 10 includes an electric motor 14. The electric motor 14 is attached to a rotating shaft 12. The electric motor 14 is driven by power supplied from an inverter (not shown). As the electric motor 14 is driven, the rotating shaft 12 rotates.

[0019] The radial bearing 15 supports the rotating shaft 12 rotatably in the radial direction. The radial direction is the diameter direction of the rotating shaft 12. In this embodiment, the bearing 18 includes two radial bearings 15. One of the two radial bearings 15 is also referred to as a first radial bearing 15a, and the other is also referred to as a second radial bearing 15b. The first radial bearing 15a supports the rotating shaft 12 between the first end 12a and a portion where the electric motor 14 is provided. The second radial bearing 15b supports the rotating shaft 12 between the portion where the electric motor 14 is provided and the second end 12b. In this embodiment, the center of gravity C1 of the compressor 10 is located between the two radial bearings 15 in the axial direction X. The two radial bearings 15 are fixed to the housing 11. The two radial bearings 15 support the rotating shaft 12 rotatably with respect to the housing 11.

[0020] The rotating body 19 includes a support portion 19a. The support portion 19a protrudes in an annular shape from the outer circumferential surface of the rotating shaft 12. The support portion 19a is disk-shaped. The support portion 19a rotates integrally with the rotating shaft 12.

[0021] In this embodiment, the bearing 18 includes one thrust bearing 16. The thrust bearings 16 are arranged in pairs in the axial direction X, sandwiching the support portion 19a. The thrust bearing 16 supports the support portion 19a rotatably in the thrust direction. As a result, the thrust bearing 16 supports the rotating shaft 12 rotatably in the thrust direction. The thrust direction is the axial direction X of the rotating shaft 12. The thrust bearing 16 supports the rotating shaft 12 rotatably with respect to the housing 11.

[0022] Radial bearing 15 and thrust bearing 16 are gas bearings. When bearing 18 serves as a gas bearing, rotating shaft 12 contacts bearing 18 until the rotation speed of rotating shaft 12 reaches a predetermined rotation speed. When the rotation speed of rotating shaft 12 reaches the predetermined rotation speed, an air film is formed between rotating shaft 12 and bearing 18 due to air drawn in by the rotation of rotating shaft 12. Rotating shaft 12 is lifted by the dynamic pressure of the air film formed between rotating shaft 12 and bearing 18. Therefore, when the rotation speed of rotating shaft 12 reaches the predetermined rotation speed, bearing 18 supports rotating shaft 12 by the air film without contacting rotating shaft 12. By using a gas bearing as bearing 18, contact between rotating shaft 12 and housing 11 can be suppressed.

[0023] In the compressor 10, the compression mechanism 13 rotates together with the rotary shaft 12 to compress a fluid. In this embodiment, the fluid is a refrigerant. The compression mechanism 13 compresses the refrigerant drawn into the housing 11 as the electric motor 14 is driven.

[0024] As shown in FIG. 1, the compressor 10 has a plurality of protrusions 11d. The protrusions 11d protrude from the outer surface 11a of the housing 11. The protrusions 11d are integrated with the housing 11. Therefore, the protrusions 11d are made of the same metal as the housing 11. The plurality of protrusions 11d extend in the same direction from the outer surface 11a of the housing 11. The plurality of protrusions 11d are, for example, cylindrical and extend from the outer surface 11a of the housing 11 toward the mounting surface 100a. The compressor 10 in this embodiment has two protrusions 11d. The two protrusions 11d are spaced apart from each other in the axial direction X.

[0025] 2, one of the two protrusions 11d is provided on a portion of the housing 11 that covers the rotating shaft 12 on the first direction X1 side of the first radial bearing 15a. The other of the two protrusions 11d is located on the second direction X2 side of the portion of the housing 11 that surrounds the electric motor 14. Both of the two protrusions 11d may be located on the second direction X2 side of the portion of the housing 11 that surrounds the compression portion 13a.

[0026] An imaginary line VL extends from the center of gravity C1 of the compressor 10 in one direction perpendicular to the axial direction X of the rotating shaft 12. An imaginary plane VP includes the center of gravity C1 of the compressor 10 and is perpendicular to the axial direction X of the rotating shaft 12. The imaginary line VL extends on the imaginary plane VP.

[0027] The direction perpendicular to the axial direction X is also referred to as the first orthogonal direction Y. The direction perpendicular to the axial direction X and the first orthogonal direction Y is also referred to as the second orthogonal direction Z. The second orthogonal direction Z is the direction in which the imaginary line VL extends. The first orthogonal direction Y is the direction in which an imaginary straight line perpendicular to the rotation axis L of the rotation shaft 12 and the imaginary line VL extends.

[0028] The imaginary plane VP is located between the two protrusions 11d in the axial direction X. Of the multiple protrusions 11d, at least one protrusion 11d is located further in the first direction X1 than the imaginary plane VP, and at least one protrusion 11d is located further in the second direction X2 than the imaginary plane VP. In this embodiment, one protrusion 11d is located further in the first direction X1 than the imaginary plane VP, and one protrusion 11d is located further in the second direction X2 than the imaginary plane VP.

[0029] <Compressor mounting structure> 1, the compressor 10 is mounted to a mounting surface 100a of the vehicle 100 by a mounting structure 30. In other words, the mounting structure 30 for the compressor 10 is for mounting the compressor 10 to the mounting surface 100a of the vehicle 100. The mounting surface 100a is, for example, a part of a frame 101 that constitutes the vehicle 100.

[0030] The mounting structure 30 includes a plurality of mounting feet 20. The mounting feet 20 are fixed to each of the plurality of protrusions 11d. That is, the mounting feet 20 are fixed to the housing 11. The mounting structure 30 in this embodiment includes two mounting feet 20. The two mounting feet 20 are spaced apart from each other in the axial direction X.

[0031] The mounting feet 20 are made of an elastic material. The elastic material is formed, for example, from a rubber material or a urethane material, which is an elastically deformable resin material. The mounting feet 20 are attached, for example, to the end of the protrusion 11d opposite the outer surface 11a of the housing 11. The mounting feet 20 are, for example, cylindrical and extend from the end of the protrusion 11d opposite the outer surface 11a of the housing 11 toward the mounting surface 100a. The mounting feet 20 are attached to the mounting surface 100a by bolting or the like. In this embodiment, the mounting surface 100a to which the multiple mounting feet 20 are attached is the same plane.

[0032] 1 and 2, one of the two mounting feet 20 is fixed to one of the two protrusions 11d, and the other of the two mounting feet 20 is fixed to the other of the two protrusions 11d. Therefore, one of the two mounting feet 20 is connected to a portion of the housing 11 that covers the rotating shaft 12 and is closer to the first direction X1 than the first radial bearing 15a. The other of the two mounting feet 20 is connected to a portion of the housing 11 that is closer to the second direction X2 than the portion that surrounds the electric motor 14. An imaginary plane VP is located between the two mounting feet 20 in the axial direction X. One of the two mounting feet 20 is located closer to the first direction X1 than the imaginary plane VP, and the other is located closer to the second direction X2 than the imaginary plane VP.

[0033] <Resonant frequency magnitude relationship> The resonant frequency of the mounting feet 20 is defined as the mounting foot resonant frequency F1. The resonant frequency of the radial bearing 15 is defined as the radial bearing resonant frequency F2. The resonant frequency of the thrust bearing 16 is defined as the thrust bearing resonant frequency F3. In this embodiment, the resonant frequencies of all the mounting feet 20 provided in the mounting structure 30 of the compressor 10 are defined as the mounting foot resonant frequency F1. The mounting foot resonant frequencies F1 of two mounting feet 20 provided in the mounting structure 30 of the compressor 10 may be the same value or may be different values.

[0034] The mounting foot resonant frequency F1 has a translational component and a rotational component. The translational component of the mounting foot resonant frequency F1 has three components: a translational component along a virtual axis extending in the axial direction X, a translational component along a virtual axis extending in the first orthogonal direction Y, and a translational component along a virtual axis extending in the second orthogonal direction Z. The rotational component of the mounting foot resonant frequency F1 has three components: a rotational component about a virtual axis extending in the axial direction X, a rotational component about a virtual axis extending in the first orthogonal direction Y, and a rotational component about a virtual axis extending in the second orthogonal direction Z. Of these six types of mounting foot resonant frequencies F1, the mounting foot resonant frequency F1 as a translational component along a virtual axis extending in the first orthogonal direction Y is illustrated below.

[0035] In the compressor 10, the radial bearing resonance frequencies F2 are set to the same number as the radial bearings 15 provided in the compressor 10. Therefore, in the compressor 10 of this embodiment, two resonance frequencies are set as the radial bearing resonance frequencies F2.

[0036] In the compressor 10, the number of thrust bearing resonance frequencies F3 is set to the same as the number of thrust bearings 16 provided in the compressor 10. Therefore, in the compressor 10 of this embodiment, one resonance frequency is set as the thrust bearing resonance frequency F3.

[0037] The weight of the housing 11 is defined as the housing weight M1. The weight of the rotating body 19 is defined as the rotating body weight M2. The sum of the rigidities of the multiple mounting feet 20 is defined as the mounting foot rigidity K1. The sum of the rigidities of the radial bearings 15 is defined as the radial bearing rigidity K2. The sum of the rigidities of the thrust bearings 16 is defined as the thrust bearing rigidity K3. The mounting foot rigidity K1, the radial bearing rigidity K2, and the thrust bearing rigidity K3 are values ​​expressed in units of N / m. The mounting foot rigidity K1, the radial bearing rigidity K2, and the thrust bearing rigidity K3 are components in the extension direction of the virtual line VL. The component in the extension direction of the virtual line VL is the vibration direction acting on the compressor 10 from the vehicle 100 via the mounting feet 20.

[0038] The rigidity of the mounting feet 20 is a value that is set uniquely for each mounting foot 20 depending on the shape, material, etc. of the mounting foot 20. The rigidity of the two mounting feet 20 provided in the mounting structure 30 of the compressor 10 may be the same value or different values. Of the total rigidity of the multiple mounting feet 20, the total rigidity in the radial direction and the total rigidity in the thrust direction have the same value, mounting foot rigidity K1.

[0039] The rigidity of the radial bearing 15 is a value that is set specifically for the radial bearing 15 based on the shape, material, etc. of the radial bearing 15. The rigidity of the two radial bearings 15 provided in the compressor 10 may be the same value or different values. The rigidity of the thrust bearing 16 is a value that is set specifically for the thrust bearing 16 based on the shape, material, etc. of the thrust bearing 16.

[0040] The mounting leg resonance frequency F1 can be expressed by the following equation (1).

[0041]

number

[0042] The radial bearing resonance frequency F2 can be expressed by the following equation (2).

[0043]

number

[0044] The thrust bearing resonance frequency F3 can be expressed by the following equation (3).

[0045]

number

[0046] The mounting foot resonance frequency F1 is lower than the radial bearing resonance frequency F2 and lower than the thrust bearing resonance frequency F3. Therefore, from the above equations (1), (2), and (3), the following equation (4) and equation (5) are established.

[0047]

number

[0048]

number

[0049] The mounting foot resonance frequency F1 at which the above equations (4) and (5) hold is the mounting foot resonance frequency F1 as a component in the translation direction along an imaginary axis extending in the first orthogonal direction Y. In this embodiment, this mounting foot resonance frequency F1 and at least one of the multiple other mounting foot resonance frequencies F1 are lower than the radial bearing resonance frequency F2 and lower than the thrust bearing resonance frequency F3. The above-mentioned "other mounting foot resonance frequencies F1" include the mounting foot resonance frequency F1 as a component in the translation direction along an imaginary axis extending in the axial direction X, and the mounting foot resonance frequency F1 as a component in the translation direction along an imaginary axis extending in the second orthogonal direction Z. Furthermore, the above-mentioned "another mounting foot resonance frequency F1" includes the mounting foot resonance frequency F1 as a component in the rotational direction about an imaginary axis extending in the axial direction X, and the mounting foot resonance frequency F1 as a component in the rotational direction about an imaginary axis extending in the first orthogonal direction Y. Furthermore, the above-mentioned "another mounting foot resonance frequency F1" includes the mounting foot resonance frequency F1 as a component in the rotational direction about an imaginary axis extending in the second orthogonal direction Z.

[0050] <Data comparison> Next, the relationship between the excitation frequency and the amount of runout of the rotor 19 was obtained by experiment for the mounting structure 30 for the compressor 10 of the first embodiment and the mounting structure 30 for the compressor 10 of the first comparative example. The results are shown in FIG. 4. In FIG. 4, the horizontal axis represents the excitation frequency, and the vertical axis represents the amount of runout of the rotor 19. The excitation frequency is the frequency of vibration applied to the compressor 10 from outside the compressor 10. The amount of runout of the rotor 19 is the amount of runout of the compression section 13a. The amount of runout of the compression section 13a is, for example, the amount of displacement of the compression section 13a in the radial direction of the rotating shaft 12. In FIG. 4, the trajectory of the numerical values ​​for the first embodiment is shown by a solid line. In FIG. 4, the trajectory of the numerical values ​​for the first comparative example is shown by a dashed line.

[0051] The mounting structure 30 of the compressor 10 in the first example is such that the mounting foot resonance frequency F1 is smaller than the radial bearing resonance frequency F2, as in the embodiment. The mounting structure 30 of the compressor 10 in the first comparative example is such that the mounting foot resonance frequency F1 is larger than the radial bearing resonance frequency F2, as opposed to the embodiment.

[0052] 4, the vibration frequency at which the runout of rotor 19 in Example 1 peaks is lower than the vibration frequency at which the runout of rotor 19 in Comparative Example 1 peaks. The peak of runout of rotor 19 in Comparative Example 1 occurred when the vibration frequency was near radial bearing resonance frequency F2, whereas the peak of runout of rotor 19 in Example 1 occurred when the vibration frequency was lower than radial bearing resonance frequency F2. Therefore, when the vibration frequency was radial bearing resonance frequency F2, the runout of rotor 19 in Example 1 was smaller than the runout of rotor 19 in Comparative Example 1.

[0053] When the excitation frequency is the radial bearing resonance frequency F2, the radial bearing 15 resonates in response to the vibrations applied to the compressor 10, causing the rotor 19 to vibrate most significantly. Therefore, in order to suppress vibration of the compression section 13a, it is desirable to reduce the amount of runout of the rotor 19 when the excitation frequency is the radial bearing resonance frequency F2. Figure 4 shows that vibration of the compression section 13a can be suppressed if the mounting foot resonance frequency F1 is lower than the radial bearing resonance frequency F2, as in the mounting structure 30 of the compressor 10 in the first embodiment.

[0054] The same can be said for the thrust bearing resonance frequency F3 as for the radial bearing resonance frequency F2. That is, the mounting structure 30 for the compressor 10 in the second embodiment is one in which the mounting foot resonance frequency F1 is smaller than the thrust bearing resonance frequency F3. The mounting structure 30 for the compressor 10 in the second comparative example is one in which the mounting foot resonance frequency F1 is larger than the thrust bearing resonance frequency F3. In this case, the peak of the runout of the rotor 19 in the second comparative example occurs when the excitation frequency is near the thrust bearing resonance frequency F3, whereas the peak of the runout of the rotor 19 in the second embodiment occurs when the excitation frequency is lower than the thrust bearing resonance frequency F3. Therefore, when the excitation frequency is the thrust bearing resonance frequency F3, the runout of the rotor 19 in the second embodiment is smaller than the runout of the rotor 19 in the second comparative example.

[0055] When the excitation frequency is the thrust bearing resonance frequency F3, the thrust bearing 16 resonates in response to the vibrations applied to the compressor 10, causing the rotor 19 to vibrate significantly. Therefore, in order to suppress vibration of the compression section 13a, it is desirable to reduce the amount of runout of the rotor 19 when the excitation frequency is the thrust bearing resonance frequency F3. Therefore, as in the mounting structure 30 of the compressor 10 in the second embodiment, if the mounting foot resonance frequency F1 is lower than the thrust bearing resonance frequency F3, vibration of the compression section 13a can be suppressed.

[0056] [Actions and Effects of the Embodiments] The operation and effects of the embodiment will be described. (1) The mounting foot resonance frequency F1 is lower than the radial bearing resonance frequency F2 and lower than the thrust bearing resonance frequency F3. Therefore, the amount of runout of the rotor 19 can be reduced when the radial bearing 15 resonates, which is the timing when the rotor 19 vibrates most significantly. This makes it possible to suppress vibration of the compression mechanism 13 that occurs due to vibration of the vehicle 100.

[0057] (2) The compression mechanism 13 is provided at the first end 12a, which is one end in the axial direction X of the rotating shaft 12, but not at the second end 12b, which is the other end. Therefore, compared to when the compression mechanisms 13 are provided at both ends in the axial direction X of the rotating shaft 12, the amount of vibration of the rotating body 19 is likely to increase due to a deviation in the center of gravity of the rotating body 19. Even when vibration of the rotating body 19 is of greater concern, the use of the mounting structure 30 for the compressor 10 can suppress vibration of the compression mechanism 13 that occurs due to vibration of the vehicle 100.

[0058] (3) The compression mechanism 13 includes a compression portion 13a serving as an impeller. In this case, because the compression portion 13a is not in contact with the housing 11, the amount of vibration of the compression portion 13a becomes an issue. Furthermore, because the dimension of the tip clearance 11c formed between the shroud surface 11b of the housing 11 and the compression portion 13a is small, the compression portion 13a is likely to collide with the housing 11 when the compression mechanism 13 vibrates significantly. Even in such a case, by suppressing the vibration of the compression mechanism 13 that occurs in association with the vibration of the vehicle 100, it is possible to prevent the compression portion 13a from colliding with the housing 11.

[0059] (4) The compressor 10 is mounted on the mounting surface 100a of the vehicle 100 by the mounting structure 30. The fluid compressed by the compression mechanism 13 is a refrigerant. Because the refrigerant has a higher load density than air, the rotating shaft 12 is less likely to collide with the radial bearing 15 and the thrust bearing 16 when vibration is applied to the housing 11, compared to when air is used as the fluid compressed by the compression mechanism 13. On the other hand, the mounting structure 30 for the compressor 10 can suppress vibration of the compression mechanism 13, which is a concern when vibration is applied to the housing 11 because the rotating shaft 12 does not collide with the radial bearing 15 and the thrust bearing 16.

[0060] (5) The radial bearing 15 and the thrust bearing 16 are gas bearings. Gas bearings tend to have lower rigidity than rolling bearings. Therefore, when gas bearings are used for the radial bearing 15 and the thrust bearing 16, the radial bearing resonance frequency F2 and the thrust bearing resonance frequency F3 are smaller than when rolling bearings are used for the radial bearing 15 and the thrust bearing 16. Thus, even when the radial bearing resonance frequency F2 and the thrust bearing resonance frequency F3 tend to be close to the mounting foot resonance frequency F1, the mounting structure 30 for the compressor 10 can suppress vibration of the compression mechanism 13 caused by vibration of the vehicle 100. Furthermore, because the radial bearing 15 and the thrust bearing 16 are gas bearings and do not contact the rotating shaft 12, the amount of runout of the compression mechanism 13 becomes an issue. The mounting structure 30 for the compressor 10 can suppress such vibration of the compression mechanism 13.

[0061] (6) The mounting feet 20 are made of an elastic material. Therefore, the damping effect of the mounting feet 20 is greater than when the mounting feet 20 are made of a metal material, and vibration of the compressor 10 when the vehicle 100 vibrates can be suppressed. This further suppresses vibration of the compression mechanism 13 that occurs due to vibration of the vehicle 100. Furthermore, by using mounting feet 20 made of an elastic material, the mounting rigidity of the mounting feet 20 relative to the housing 11 and the mounting surface 100a can be reduced compared to mounting feet 20 made of a metal material, for example. Therefore, the mounting foot rigidity K1 can be reduced, and the mounting foot resonance frequency F1 can be made lower than the radial bearing resonance frequency F2 and lower than the thrust bearing resonance frequency F3.

[0062] (7) The compressor 10 is mounted on the vehicle 100. Therefore, vibrations from the vehicle 100 are transmitted to the compressor 10, and therefore the compressor 10 is subjected to greater vibrations from outside the compressor 10 than when the compressor 10 is mounted in a location other than the vehicle 10. By adopting the mounting structure 30 for the compressor 10 for the compressor 10, which is subjected to greater vibrations from outside, the vibrations of the compression mechanism 13 can be suppressed.

[0063] [Example of change] The embodiment can be modified as follows: The embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0064] The number of mounting feet 20 included in the mounting structure 30 for the compressor 10 may be one, or may be three or more. The number of protrusions 11d provided on the housing 11 may be changed depending on the number of mounting feet 20.

[0065] The mounting feet 20 may be fixed directly to the outer surface 11a of the housing 11 without using the protrusions 11d. In this case, the protrusions 11d may be omitted from the compressor 10. When the mounting structure 30 for the compressor 10 includes multiple mounting feet 20, the mounting surfaces 100a to which the multiple mounting feet 20 are fixed do not have to be the same plane. Furthermore, the directions in which the mounting surfaces 100a to which at least one of the multiple mounting feet 20 is fixed may be different from the directions in which the mounting surfaces 100a to which at least one other mounting foot 20 is fixed may be different. In this case, the axial directions of the mounting feet 20 extending from the housing 11 toward the mounting surface 100a may be different for each mounting foot 20.

[0066] When the mounting structure 30 for the compressor 10 includes multiple mounting feet 20, two or more of the mounting feet 20 may be positioned in the first direction X1 relative to the imaginary plane VP, and two or more of the mounting feet 20 may be positioned in the second direction X2 relative to the imaginary plane VP. All of the mounting feet 20 included in the mounting structure 30 for the compressor 10 may be positioned in the first direction X1 relative to the imaginary plane VP, or may be positioned in the second direction X2 relative to the imaginary plane VP.

[0067] The compressor 10 may include one radial bearing 15 or three or more radial bearings 15. The compressor 10 may include two or more thrust bearings 16. The compression mechanisms 13 may be provided at both ends of the rotary shaft 12 in the axial direction X.

[0068] The compression mechanism 13 does not necessarily include an impeller as the compression section 13a. For example, the compressor 10 may be a piston type or a scroll type. Although the compressor 10 has been described as being used in a vehicle air conditioner, the use of the compressor 10 is not limited thereto. The compressor 10 may be used in any manner as long as it compresses a refrigerant, and the use of the compressor 10 may be changed as appropriate.

[0069] The compression mechanism 13 may compress a fluid other than a refrigerant. For example, the compression mechanism 13 may compress air as a fluid. The technical ideas that can be understood from the above-described embodiment and modified examples will be described.

[0070] [Aspect 1] a compressor mounting structure for mounting a compressor, the compressor comprising: a rotating body including a rotating shaft; a compression mechanism provided at at least one axial end of the rotating shaft and rotating together with the rotating shaft to compress a fluid; a radial bearing that rotatably supports the rotating shaft in a radial direction; and a thrust bearing that rotatably supports the rotating shaft in a thrust direction; and a housing that accommodates the rotating body, the radial bearing, and the thrust bearing, to a mounting surface of a vehicle, wherein the radial bearing and the thrust bearing are gas bearings, and the compressor mounting structure comprises mounting feet made of elastic members that are fixed to the housing and the mounting surface, and the resonant frequency of the mounting feet is lower than the resonant frequency of the radial bearing and is also lower than the resonant frequency of the thrust bearing.

[0071] [Aspect 2] The compressor mounting structure according to [Aspect 1], wherein the compression mechanism is provided at one end of the rotating shaft in the axial direction, but not at the other end.

[0072] [Aspect 3] The compressor mounting structure according to [Aspect 1] or [Aspect 2], wherein the compression mechanism includes an impeller. [Aspect 4] A compressor mounted on the mounting surface of the vehicle by the mounting structure according to any one of [Aspect 1] to [Aspect 3], wherein the fluid is a refrigerant. [Explanation of symbols]

[0073] X...axial direction, F1...mounting foot resonance frequency, F2...radial bearing resonance frequency, F3...thrust bearing resonance frequency, 10...compressor, 11...housing, 12...rotating shaft, 12a...first end as one end, 12b...second end as the other end, 13...compression mechanism, 15...radial bearing, 16...thrust bearing, 19...rotating body, 20...mounting foot, 30...mounting structure, 100...vehicle, 100a...mounting surface.

Claims

1. a rotating body including a rotating shaft and a compression mechanism provided at at least one end of the rotating shaft in an axial direction and rotating together with the rotating shaft to compress a fluid; a radial bearing that supports the rotating shaft rotatably in a radial direction, and a thrust bearing that supports the rotating shaft rotatably in a thrust direction; a housing that accommodates the rotating body, the radial bearing, and the thrust bearing, to a mounting surface of a vehicle, the radial bearing and the thrust bearing are gas bearings, mounting feet made of elastic members fixed to the housing and the mounting surface; A compressor mounting structure, characterized in that the resonance frequency of the mounting feet is lower than the resonance frequency of the radial bearing and lower than the resonance frequency of the thrust bearing.

2. 2. The compressor mounting structure according to claim 1, wherein the compression mechanism is provided at one axial end of the rotary shaft, and not at the other axial end.

3. 3. The compressor mounting structure according to claim 1, wherein the compression mechanism includes an impeller.

4. 3. A compressor mounted to the mounting surface of the vehicle by the mounting structure according to claim 1, wherein the fluid is a refrigerant.

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