Air Compressor

Abstract

To provide an air compression apparatus which can cool air compressed by a compressor efficiently while inhibiting enlargement in view of issues regarding cooling of the compressed air.SOLUTION: An air compression apparatus 100 includes: a compressor 10 which generates compressed air; a motor 12 which drives the compressor 10; a multi-blade fan 16 which is driven by the motor 12 and generates airflow; and a first cooler 18 which cools compressed air and a second cooler 20 which cools the compressed air cooled by the first cooler 18 with airflow. The first cooler 18 cools compressed air with the airflow that has cooled the second cooler 20.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an air compression device. [Background technology]

[0002] An air compression device that generates compressed air is known. For example, Patent Document 1 describes a packaged compressor having a compressor body driven by an electric motor. This compressor includes a compressor body that compresses air, a motor that drives the compressor body, an inverter that controls the rotation speed of the motor, and a cooling fan that cools the compressor body. An aftercooler that cools the air compressed by the scroll compressor body is disposed on the rear of this compressor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-075159 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present inventors have come to the following realization regarding air compression devices. The air compressed in the compressor body is at a high temperature of 200°C or more, and it is desirable to cool it to about room temperature when it is used. In the air compressor described in Patent Document 1, the aftercooler is cooled by the cooling air of the cooling fan after cooling the scroll compressor body. In other words, the cooling air of the cooling fan is used both to cool the compressor body and the aftercooler. If the compressor body is sufficiently cooled, the temperature of the cooling air after cooling becomes high, and the cooling of the aftercooler becomes insufficient. Conversely, if an attempt is made to sufficiently cool the aftercooler, the cooling of the compressor body becomes insufficient.

[0005] It is possible to enlarge the cooling fan in order to sufficiently cool the compressor body and the aftercooler. However, this goes against the demand for miniaturization of the air compression device in which the cooling fan is installed. In other words, there is a trade-off between sufficiently cooling the aftercooler and miniaturization of the device. From these findings, the inventors recognized that there is room for improvement in air compression devices in terms of efficiently cooling compressed air.

[0006] The present invention has been made in consideration of these problems, and one of its objects is to provide an air compression device that can efficiently cool air compressed by a compressor while preventing the device from becoming too large. [Means for solving the problem]

[0007] In order to solve the above problems, an air compression device according to one embodiment of the present invention includes a compressor that generates compressed air, a motor that drives the compressor, a fan that is driven by the motor to generate an air flow, a first cooler that cools the compressed air, and a second cooler that cools the compressed air cooled by the first cooler with the air flow. The first cooler cools the compressed air with the air flow that has cooled the second cooler.

[0008] In addition, any combination of the above, or mutual substitution of the components or expressions of the present invention among methods, devices, programs, temporary or non-temporary storage media recording programs, systems, etc., are also valid aspects of the present invention. Effect of the Invention

[0009] According to the present invention, it is possible to provide an air compression device that can efficiently cool air compressed by a compressor while suppressing an increase in size. [Brief description of the drawings]

[0010] [Figure 1] 1 is a system diagram showing a schematic configuration of an air compression device according to a first embodiment of the present invention. [Diagram 2]FIG. 2 is a schematic diagram showing a state in which the air compression device of FIG. 1 is installed in a railway vehicle. [Diagram 3] 2 is a side cross-sectional view that shows a schematic view of the periphery of a compressor drive unit and a multi-blade fan of the air compression device of FIG. 1. [Figure 4] FIG. 2 is a perspective view showing a schematic diagram of a cooler for the air compression device of FIG. [Diagram 5] FIG. 5 is a schematic diagram illustrating the air flow in the cooler of FIG. [Figure 6] 4 is an enlarged cross-sectional side view of the periphery of a labyrinth portion of the compressor drive portion of FIG. 3. [Figure 7] FIG. 2 is a perspective view showing the periphery of a multi-blade fan of the air compression device of FIG. [Figure 8] 4 is a front view showing the periphery of a balance weight of the compressor driving section shown in FIG. 3. [Figure 9] 4 is a rear view showing the periphery of a balance weight of the compressor driving unit of FIG. 3. [Figure 10] FIG. 2 is a front view showing a schematic diagram of a compressor and a blower fan of the air compression device shown in FIG. [Figure 11] 2 is another front view showing the compressor and the blower fan of the air compression device of FIG. 1. [Figure 12] 11 is a diagram illustrating a schematic view of an air flow from the blower fan of FIG. 10. FIG. [Figure 13] FIG. 4 is a front view showing a schematic view of the periphery of a compressor of an air compression device according to a first modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will be described below based on a preferred embodiment with reference to the drawings. In the embodiment and the modified examples, the same or equivalent components and members are given the same reference numerals, and duplicated descriptions are omitted as appropriate. The dimensions of the members in each drawing are enlarged or reduced as appropriate for ease of understanding. Some of the members that are not important for explaining the embodiment are omitted in each drawing. In addition, terms including ordinal numbers such as first, second, etc. are used to describe various components, but these terms are used only for the purpose of distinguishing one component from another component, and the components are not limited by these terms.

[0012] [First embodiment] The configuration of an air compression device 100 according to a first embodiment of the present invention will be described with reference to the drawings. As an example, the air compression device 100 is provided under the floor of a railway vehicle and can be used as an air compression device for a railway vehicle that supplies compressed air to the vehicle. FIG. 1 is a system diagram showing a schematic configuration of the air compression device 100. FIG. 2 is a schematic diagram showing a state in which the air compression device 100 is installed in a railway vehicle 90. In this figure, for ease of understanding, a portion of the bearing holder 38 and the multi-blade fan 16 are broken away, and the blower fan 28 is depicted smaller than its actual proportions.

[0013] The air compression device 100 of this embodiment includes a compressor 10, a compressor drive unit 14, a multi-blade fan 16, a cooler 22, a dehumidifier 24, an air introduction unit 26, a blower fan 28, an air suction unit 32, a compressed air delivery unit 34, an inverter control device 40, and a housing case 36. The air compression device 100 compresses air sucked through the air suction unit 32 by the compressor 10, cools it by the cooler 22, dehumidifies it by the dehumidifier 24, delivers it from the compressed air delivery unit 34, and supplies it to the vehicle 90.

[0014] The compressor 10 generates compressed air. The compressor drive unit 14 includes a motor 12 that drives the compressor 10. The inverter control device 40 drives the motor 12 of the compressor drive unit 14. The multi-blade fan 16 is driven by the motor 12 and generates an airflow used for cooling in the cooler 22. The multi-blade fan 16 is sometimes called a sirocco fan. The air introduction unit 26 introduces the compressed air to the motor 12. The blower fan 28 generates an airflow that cools the compressor 10.

[0015] Hereinafter, the direction along the central axis La of the rotating shaft 10a of the compressor 10 will be referred to as the "axial direction", and the circumferential direction and radial direction of a circle centered on the central axis La will be referred to as the "circumferential direction" and the "radial direction", respectively. For convenience, one side in the axial direction (the right side in the figure) will be referred to as the input side, and the other side (the left side in the figure) will be referred to as the anti-input side. In this example, the motor 12 is provided on the input side of the compressor 10, and the compressor 10 is provided on the anti-input side of the motor 12.

[0016] The air suction section 32 is installed in the housing case 36, and functions as a mechanism for sucking in air (outside air) to be compressed by the compressor 10. The air suction section 32 is formed so as to communicate with the compressor 10 through an intake pipe 32b. The air suction section 32 is provided with an intake filter 32a that suppresses the passage of dust such as sand and dust when the intake air passes through. The intake filter 32a may be a filter using a mesh.

[0017] The compressed air delivery unit 34 functions as a mechanism for delivering compressed air Ar10d that has been cooled by a cooler 22 described below and dehumidified by a dehumidifier 24. The compressed air delivery unit 34 supplies the generated compressed air Ar10d to a compressed air reservoir 92 that is installed outside the accommodation case 36. The compressed air delivery unit 34 may include a valve mechanism 34d provided in a path that communicates between the dehumidifier 24 and the compressed air reservoir 92. The valve mechanism 34d may be a check valve that allows the compressed air Ar10d to pass to the compressed air reservoir 92 side and prevents backflow from the compressed air reservoir 92 when the dehumidifier 24 side is at or above a predetermined pressure.

[0018] The cooler 22 will be described with reference to Figs. 2 to 5. Fig. 3 is a side cross-sectional view that generally shows the periphery of the compressor driving unit 14 and the multi-blade fan 16. Fig. 4 is a perspective view that generally shows the cooler 22. Fig. 5 is a schematic diagram that describes the air flow in the cooler 22. The cooler 22 cools the high-temperature (e.g., 200°C to 250°C) compressed air supplied from the compressor 10 to a temperature slightly higher than room temperature (e.g., 40°C to 50°C) and supplies the air to the dehumidifier 24.

[0019] The cooler 22 of this embodiment includes a first cooler 18 and a second cooler 20 that sequentially cool the compressed air generated by the compressor 10. The first cooler 18 is a pre-stage cooler provided in front of the second cooler 20, and the second cooler 20 is a post-stage cooler provided in the rear of the first cooler 18. The second cooler 20 may be called an aftercooler, and the first cooler 18 may be called a precooler. The second cooler 20 secondarily cools the compressed air cooled by the first cooler 18 by the air flow Ar16a generated by the multi-blade fan 16. The first cooler 18 primarily cools the compressed air from the compressor 10 by the air flow Ar16b used for cooling in the second cooler 20.

[0020] The first cooler 18 and the second cooler 20 may be disposed anywhere as long as the desired cooling effect can be obtained. In this embodiment, the first cooler 18 and the second cooler 20 are disposed above the center in the vertical direction of the air compression device 100. The first cooler 18 and the second cooler 20 may be disposed in a direction perpendicular to the rotation axis of the multi-blade fan 16. In particular, the first cooler 18 and the second cooler 20 are disposed above the multi-blade fan 16 and between the multi-blade fan 16 and the floor of the railway vehicle 90. The path of the air flow Ar16a sent out from the multi-blade fan 16 is shortened, and unnecessary piping space can be saved. In addition, the front-to-rear length of the air compression device 100 can be shortened compared to the case where they are disposed in the front-to-rear direction of the multi-blade fan 16.

[0021] The first cooler 18 and the second cooler 20 may be disposed apart from each other, but in this embodiment, the first cooler 18 may be disposed on the opposite side of the second cooler 20 from the multi-blade fan 16. In this example, the first cooler 18 is stacked above the second cooler 20 and disposed integrally. By disposing them integrally, the heat-resistant connecting hose between them can be shortened or omitted. The airflow may flow around the first and second coolers 18, 20 in a direction perpendicular to the rotation axis of the multi-blade fan 16. In this example, the airflow from the multi-blade fan 16 flows from bottom to top through the first and second coolers 18, 20 disposed integrally.

[0022] The detailed configuration of the first cooler 18 and the second cooler 20 will be described. The first cooler 18 and the second cooler 20 have bent pipes 18p and 20p and pipe housings 18c and 20c that house the pipes, respectively. The bent pipes 18p and 20p meander and have multiple bends, and allow compressed air to flow from one end of the pipe to the other. The pipe housings 18c and 20c have thin, rectangular cylindrical outer walls on the top and bottom, and function as wind tunnels that allow cooling air to flow up and down.

[0023] Wire mesh parts 18m, 20m that support the bent pipes 18p, 20p are fixed to the lower parts of the pipe accommodating parts 18c, 20c. The upper surface of the pipe accommodating part 20c is open, and a wire mesh part 20n is fixed to the upper surface of the pipe accommodating part 18c. In this way, the pipe accommodating parts 18c, 20c have a configuration that allows air to easily pass up and down.

[0024] The first introduction portion 18b provided at one end of the bent pipe 18p protrudes to the outside from the side wall of the pipe accommodating portion 18c of the first cooler 18. The first introduction portion 18b communicates with the discharge port 10e of the compressor 10. The first outlet portion 18e provided at the other end of the bent pipe 18p protrudes to the outside from the side wall of the pipe accommodating portion 18c of the first cooler 18. The first outlet portion 18e communicates with the second introduction portion 20b.

[0025] The second inlet 20b provided at one end of the bent pipe 20p protrudes from the bottom of the pipe housing 20c of the second cooler 20 to the outside. The second inlet 20b communicates with the first outlet 18e via a heat-resistant connecting hose. The second outlet 20e provided at the other end of the bent pipe 20p protrudes from the side wall of the pipe housing 20c of the second cooler 20 to the outside. The second outlet 20e communicates with the dehumidifier 24.

[0026] The pipe accommodating portion 18c is disposed above the pipe accommodating portion 20c. The airflow Ar16a sent out from the multi-blade fan 16 is supplied to the lower surface of the pipe accommodating portion 20c through the duct 16d. The airflow Ar16a flows through the gaps in the wire mesh portion 20m and the gaps in the bent pipe 20p, and is discharged from the upper surface of the pipe accommodating portion 20c. The compressed air in the bent pipe 20p is cooled as the airflow Ar16a passes through the outer circumferential surface of the bent pipe 20p.

[0027] The air flow Ar16b discharged from the pipe accommodating portion 20c is supplied to the lower surface of the pipe accommodating portion 18c. The air flow Ar16b flows through the gaps in the wire mesh portion 18m, the gaps in the bent pipe 18p, and the gaps in the wire mesh portion 20n, and is discharged from the upper surface of the pipe accommodating portion 18c. The compressed air Ar20c in the bent pipe 18p is cooled by the air flow Ar16b passing through the outer circumferential surface of the bent pipe 18p. The air discharged from the pipe accommodating portion 18c is diffused into the atmosphere.

[0028] In this way, the air flow Ar16a sent out from the multi-blade fan 16 is first supplied to the second cooler 20 and used for secondary cooling of the compressed air after primary cooling. The air flow Ar16b discharged from the second cooler 20 is supplied to the first cooler 18 and used for primary cooling of the compressed air. Compared to the case where the air flow Ar16a is first used for primary cooling, the temperature difference between the compressed air and the cooled air in secondary cooling becomes larger, and therefore the cooling efficiency can be improved.

[0029] The compressor driving unit 14 will be described with reference to Figures 2, 3, and 6. Figure 6 is an enlarged side cross-sectional view showing the periphery of the labyrinth portion 12f of the compressor driving unit 14. The compressor driving unit 14 mainly includes a motor 12 that rotates the compressor 10, and a balance weight 15.

[0030] The motor 12 will be described. The motor 12 includes an output shaft 12a, a rotor 12k, a stator 12s, a casing 12c, and a labyrinth portion 12f. In this embodiment, the output shaft 12a of the motor 12 is provided integrally with the rotating shaft 10a of the compressor 10. The rotor 12k has a magnet 12m having a plurality of magnetic poles in the circumferential direction, and is fixed to the outer periphery of the output shaft 12a. The rotor 12k is fixed to the input side of a rotor fixing portion 15d of a balance weight 15 described later by a fastener such as a bolt (not shown). An adhesive may be used in combination for these fixations.

[0031] The stator 12s has a stator core 12j that surrounds the rotor 12k via a magnetic gap, and a coil 12g that is wound around the stator core 12j. The outer periphery of the stator 12s is fixed to the inner periphery of the casing 12c. The casing 12c has a tube portion 12d and a bottom portion 12e, and functions as an outer shell that surrounds the rotor 12k and the stator 12s. In this example, the casing 12c has a bottomed cylindrical shape that is open on the opposite input side and has the bottom portion 12e on the input side. The bottom portion 12e is provided with an inlet 12h that takes in air from the air inlet portion 26.

[0032] The labyrinth portion 12f is provided to cover the non-input side of the cylindrical portion 12d, and is disk-shaped in this example. The labyrinth portion 12f includes a rotating body portion 12n fixed to the output shaft 12a and a stationary body portion 12p fixed to the cylindrical portion 12d. The stationary body portion 12p is a donut-shaped disk member having a stationary body side labyrinth forming portion 12q provided on the outer periphery of the non-input side end face. The stationary body side labyrinth forming portion 12q has a stationary body side recess 12t and a stationary body side protrusion 12u. The stationary body side recess 12t is inserted into a labyrinth protrusion 15h described later. The stationary body side protrusion 12u is inserted into a labyrinth recess 15g described later. The stationary body side protrusion 12u is an annular wall provided around the inner periphery of the stationary body side recess 12t. The rotating body portion 12n also serves as a balance weight 15, which will be described later. A labyrinth 12r is provided between the rotating body portion 12n and the stationary body portion 12p. In this example, the labyrinth 12r is a maze made up of a combination of bent gaps. The labyrinth portion 12f has the labyrinth 12r to reduce the intrusion of dust into the motor 12.

[0033] In addition, the compressed air Ar10e introduced from the inlet 12h flows from the labyrinth 12r to the outside, so that the dust in the labyrinth 12r is easily discharged to the outside by this air flow.

[0034] The motor 12 generates a field magnetic field in the magnetic air gap when a drive current is supplied from an inverter control device 40 (drive circuit) described later to the coil 12g of the stator 12s. The motor 12 generates a rotational driving force in the rotor 12k and the output shaft 12a due to the action of this field magnetic field and the magnet 12m of the rotor 12k. The rotational driving force of the output shaft 12a drives the multi-blade fan 16 and the compressor 10 through the rotating shaft 10a. A bearing that supports the rotating shaft 10a is provided in a bearing holder 38 outside the compressor driving unit 14, and is not provided inside the compressor driving unit 14.

[0035] The multi-blade fan 16 will be described with reference to Figures 3, 6, and 7. Figure 7 is a perspective view showing the periphery of the multi-blade fan 16. This figure shows the rotor 12k and the balance weight 15 integrated with the multi-blade fan 16. The multi-blade fan 16 is disposed between the compressor 10 and the motor 12 in the axial direction. The multi-blade fan 16 functions as a fan that rotates integrally with the rotor 12k of the motor 12. In particular, the multi-blade fan 16 functions as a blower that collects airflow generated from its center toward its outer periphery in a delivery duct 16d and delivers the airflow. The multi-blade fan 16 includes a disk portion 16b and a plurality of blades 16c.

[0036] The disk portion 16b is a doughnut-shaped disk member whose inner circumferential side is fixed to the rotating shaft 10a via the balance weight 15. In particular, the disk portion 16b is fixed to a fan fixing portion 15c provided on the end face of the balance weight 15 on the opposite input side by a fastener such as a bolt (not shown). An adhesive may be used for these fixations. The blades 16c extend from the disk portion 16b to the opposite input side near the outer periphery of the disk portion 16b. The blades 16c are arranged at predetermined angles in the circumferential direction. The blades 16c function as an air flow generating portion that generates an air flow toward the outer periphery by rotating. The casing 16e is a cylindrical member that surrounds the disk portion 16b and the blades 16c.

[0037] As shown in Fig. 6, the disk portion 16b is disposed on the end face of the non-input side of the motor 12 with an axial gap 16g therebetween. A width W16 of the axial gap 16g may be narrower than a thickness H16 of the disk portion 16b. As shown in Fig. 3, the blade 16c axially overlaps with the second bearing 13e in the axial direction.

[0038] Delivery duct 16d is a cylindrical member extending from casing 16e to cooler 22. Lower portion 16h of delivery duct 16d is a generally rectangular cylindrical portion extending upward from an upper portion of casing 16e. Upper portion 16j of delivery duct 16d is a portion that communicates from an upper portion of lower portion 16h to a lower portion of cooler 22. Upper portion 16j is generally a truncated quadrangular pyramid shape with a wider upper side.

[0039] The multi-blade fan 16 may axially overlap at least a portion of the bearing 38j that supports the rotating shaft 10a of the compressor 10. In this case, the axial length of the air compression device 100 can be made shorter than when the multi-blade fan 16 does not overlap the bearing 38j.

[0040] The balance weight 15 will be described with reference to Figs. 8 and 9. Fig. 8 is a front view showing the periphery of the balance weight 15. Fig. 9 is a rear view showing the periphery of the balance weight 15. The balance weight 15 also functions as an intermediate member disposed between the rotor 12k and the multi-blade fan 16. The balance weight 15 is a disk-shaped member made of a metal such as brass, and also serves as the rotor portion 12n of the labyrinth portion 12f as described above. The balance weight 15 has balance adjustment portions 15a and 15b, a fan fixing portion 15c, a rotor fixing portion 15d, a shaft fastening portion 15f, and a labyrinth forming portion 15e.

[0041] The fan fixing portion 15c is an annular portion on the end face opposite the input side to which the multi-blade fan 16 is fixed. The rotor fixing portion 15d is an annular portion on the end face on the input side to which the rotor 12k is fixed, and in this example, has a cylindrical outer shape protruding from the outer periphery to the input side. The shaft fastening portion 15f is a through hole through which the output shaft 12a is inserted and fixed.

[0042] The labyrinth forming portion 15e is a portion where the labyrinth recess 15g and the labyrinth protrusion 15h are provided on the outer periphery of the input side end face. The labyrinth recess 15g is a peripheral recess formed on the non-input side of the labyrinth forming portion 15e. The stationary body side protrusion 12u enters the labyrinth recess 15g through a gap. The labyrinth protrusion 15h is a portion that enters the stationary body side recess 12t through a gap. The labyrinth protrusion 15h in this example is an annular wall provided around the outer periphery of the labyrinth recess 15g.

[0043] The balance adjustment units 15a and 15b are sections that perform processing to reduce the total amount of unbalance among the balance weight 15, the rotor 12k, and the multi-blade fan 16. In other words, in a state in which the multi-blade fan 16 and the rotor 12k are fixed to the balance weight 15 and integrated, balance adjustments that reduce the total amount of unbalance are performed by the balance adjustment units 15a and 15b.

[0044] The balance adjustment parts 15a and 15b may be provided on only one end surface of the balance weight 15, but in this embodiment, they are provided on both end surfaces. The balance adjustment parts 15a and 15b include a fan side adjustment part 15a provided radially inward from the fan fixing part 15c and a rotor side adjustment part 15b provided radially outward from the rotor fixing part 15d. In particular, the balance adjustment part 15a may be provided radially inward from the air flow generating part of the multi-blade fan 16. In this example, the balance adjustment part 15a is provided radially inward from the multiple blades 16c. As shown in Figures 8 and 9, the balance adjustment parts 15a and 15b in this example are flat annular parts in the radial middle region of the balance weight 15.

[0045] The compressor 10 will be described with reference to Fig. 2 and Figs. 10 to 12. These figures show the compressor 10 and the blower fan 28 as viewed from the arrow F in Fig. 2. Fig. 10 is a front view showing the compressor 10 and the blower fan 28 in a schematic manner. Fig. 11 shows a state in which the fixed scroll portion 10j is removed. Fig. 12 shows the back space 10g in which the orbiting scroll portion 10h is removed. The compressor 10 of this embodiment is a scroll-type air compressor including a rotating shaft 10a, a body portion 10b, an intake port 10c, a discharge port 10e, air-cooling fins 10f, the orbiting scroll portion 10h, a fixed scroll portion 10j, and a back space 10g.

[0046] The compressor 10 has an intake port 10c that communicates with an air intake section 32, and compresses air Ar32 that is drawn from the air intake section 32 through an intake piping 32b into a pump space 10d. A valve mechanism 32d is provided between the air intake section 32 and the intake port 10c of the compressor 10. The valve mechanism 32d opens when the compressor 10 operates and the compressor 10 side becomes negative pressure. The discharge port 10e communicates with the cooler 22, and the compressed air is discharged from the discharge port 10e to the cooler 22.

[0047] The body portion 10b is a circumferential outer wall that defines the pump space 10d. The body portion 10b surrounds the fixed scroll 10m and the orbiting scroll 10n in the pump space 10d. The fixed scroll portion 10j includes a fixed disk portion 10k having a plurality of air-cooling fins 10f on the outside and a fixed scroll 10m fixed to the inside of the fixed disk portion 10k. A discharge port 10e is provided in the center of the fixed disk portion 10k. The orbiting scroll portion 10h includes an orbiting disk portion 10p and an orbiting scroll 10n fixed to the orbiting disk portion 10p. A rotating shaft 10a extending to the input side is fixed to the center of the orbiting disk portion 10p. A back space 10g is provided on the input side of the orbiting disk portion 10p, i.e., on the back side of the orbiting scroll portion 10h. Cooling air is introduced into the rear space 10g from a blower fan 28, forcibly cooling the rotating disk portion 10p and the rotating shaft 10a. The blower fan 28 will be described later.

[0048] The orbiting scroll 10n and the fixed scroll 10m are spiral bodies of the same shape. The compressor 10 compresses air by rotating the orbiting scroll 10n integrally with the rotating shaft 10a relative to the fixed scroll 10m, thereby changing the volume of the compression space. The compressor 10 draws air from the outer periphery and compresses it toward the center. The compressor 10 may be an oil-free type.

[0049] The blower fan 28 will be described with reference to Fig. 2 and Fig. 10 to Fig. 12. The blower fan 28 is a blowing mechanism that sends out cooling air (hereinafter, referred to as cooling air Ar28) to the compressor 10. The blower fan 28 supplies the cooling air Ar28 to the back space 10g on the back side of the orbiting scroll portion 10h, and mainly cools the orbiting scroll portion 10h.

[0050] The blower fan 28 of this embodiment is an electric axial flow blower having a propeller 28b. As shown in Fig. 12, the blower fan 28 is disposed on the side of the compressor 10 so that the rotation axis L28 of the propeller 28b is perpendicular to the rotation shaft 10a of the compressor 10. An outside air filter 28a made of a wire mesh or the like is provided upstream of the blower fan 28. A blower duct 28g that guides the cooling air Ar28 to the center of the orbiting scroll portion 10h is provided downstream of the blower fan 28.

[0051] The blower duct 28g has a generally rectangular pyramid shape with a cross-sectional area that decreases toward the compressor 10. The cooling air Ar28 is constricted along the inner surface of the blower duct 28g, and primarily cools the center of the orbiting scroll section 10h. Since the center of the orbiting scroll section 10h is the hottest, the cooling effect can be enhanced by primarily cooling the center. An exhaust duct 28h is provided downstream of the back space 10g. In this example, the upstream side of the exhaust duct 28h faces the blower duct 28g, and the downstream side faces downward.

[0052] The dehumidifier 24 is provided in a path that communicates between the cooler 22 and the compressed air delivery section 34. The dehumidifier 24 is a hollow fiber membrane type dehumidifying device that dehumidifies the cooled compressed air Ar10c. The dehumidifier 24 may include a filter element containing a desiccant. In the dehumidifier 24, the compressed air Ar10d delivered from the compressed air delivery section 34 is finally dehumidified. The compressed air Ar10d is delivered to the compressed air reservoir 92 via the compressed air delivery section 34.

[0053] The air introduction section 26 introduces the compressed air Ar10d dehumidified by the dehumidifier 24 into the inside of the casing 12c of the motor 12. By introducing the compressed air Ar10d, the pressure inside the casing 12c can be made positive, higher than the outside air pressure, thereby reducing the intrusion of dust. The air introduction section 26 sends out the compressed air Ar10d to the introduction port 12h provided in the bottom 12e. The air introduction section 26 is provided with a valve mechanism 26d on a path that introduces the compressed air Ar10d from the dehumidifier 24 to the casing 12c. The valve mechanism 26d may be a check valve that allows the compressed air Ar10d to pass to the casing 12c side and blocks backflow from the casing 12c to the dehumidifier 24 when the pressure on the dehumidifier 24 side is equal to or higher than a predetermined pressure.

[0054] The bearing holder 38 will be described with reference to Figs. 2 and 3. The bearing holder 38 is provided on the input side of the compressor 10 and supports the bearings 38h and 38j that support the rotating shaft 10a. The bearing holder 38 has a hollow cylindrical portion 38a and a plurality of fins 38f that extend radially outward from the cylindrical portion 38a. The radial outer end of the fin 38f has a triangular shape that extends radially outward as it approaches the compressor 10 in the axial direction. In this example, four fins 38f are provided at 90° intervals in the circumferential direction on the outer periphery of the cylindrical portion 38a. The bearing holder 38 also has a function of dissipating heat generated in the compressor 10 to suppress excessive temperature rise of the bearings 38h and 38j.

[0055] The bearings 38h, 38j include a first bearing 38h disposed near the compressor 10 and a second bearing 38j disposed near the motor 12. The first and second bearings 38h, 38j rotatably support the rotating shaft 10a. The first and second bearings 38h, 38j are held in a hollow portion of the cylindrical portion 38a while being spaced apart in the axial direction.

[0056] A portion of the bearing holder 38 axially extends into the inner periphery of the multi-blade fan 16. Also, at least a portion of the bearing 38j supporting the rotating shaft 10a of the compressor 10 axially overlaps with the multi-blade fan 16. In this case, the axial space can be used more effectively than in the case where there is no overlap.

[0057] The inverter control device 40 will be described with reference to Fig. 1 and Fig. 2. The inverter control device 40 functions as an inverter power supply device for controlling the drive of the motor 12. The inverter control device 40 is protected from dust or rainwater by being stored in a storage box 42. The storage box 42 may be made of metal. The inverter control device 40 includes electronic components such as a switching power module that supplies a drive current to the coil 12g and a smoothing capacitor (neither of which are shown).

[0058] These electronic components generate heat by themselves during operation, and the temperature inside the storage box 42 rises. If the temperature inside the box becomes too high, the lifespan of these electronic components will be shortened and may cause failure. In this embodiment, the storage box 42 is provided on the path of the intake air Ar32 between the air intake section 32 and the intake port 10c of the compressor 10. In this example, the storage box 42 is provided between the air intake section 32 and the valve mechanism 32d. That is, a part or all of the intake air Ar32 passes through the storage box 42 and is sent to the compressor 10 side. By the intake air Ar32 passing through the storage box 42, the inside of the box is forcibly ventilated, and the electronic components of the inverter control device 40 are air-cooled. In this case, the temperature rise inside the storage box 42 is suppressed, and the lifespan of the electronic components is extended.

[0059] The housing case 36 houses the compressor 10, the compressor drive section 14, the multi-blade fan 16, the cooler 22, the dehumidifier 24, the air introduction section 26, the blower fan 28, the air suction section 32, the compressed air discharge section 34 and a storage box 42 for the inverter control device 40.

[0060] An overview of one embodiment of the present invention is as follows: An air compression device 100 according to one embodiment of the present invention includes a compressor 10 that generates compressed air, a motor 12 that drives the compressor 10, a multi-blade fan 16 that is driven by the motor 12 to generate an airflow, a first cooler 18 that cools the compressed air, and a second cooler 20 that cools the compressed air cooled by the first cooler 18 with the airflow, and the first cooler 18 cools the compressed air with the airflow that has cooled the second cooler 20.

[0061] According to this embodiment, by providing the first cooler 18, it is possible to reduce the size and weight of the second cooler 20. Furthermore, by providing the first cooler 18, the input air temperature of the second cooler 20 is lowered, so that the thermal stress of the second cooler 20 is alleviated.

[0062] Moreover, the first cooler 18 can effectively utilize the exhaust air after cooling of the second cooler 20. Also, since the temperature difference between the air to be cooled and the cooling air in the first cooler 18 is small, the thermal stress of the second cooler 20 is alleviated. Also, since the temperature difference between the air to be cooled and the cooling air in the second cooler 20 is large, the efficiency of heat exchange can be increased.

[0063] The multi-blade fan 16 may be disposed between the motor 12 and the compressor 10. In this case, if the multi-blade fan 16 is provided on the opposite side of the compressor 10, it would be necessary to provide protrusions on both the front and rear sides of the motor 12 shaft, but with this arrangement, one of the protrusions can be omitted. As the number of protrusions is reduced, the infiltration of dust into the motor 12 through gaps in the protrusions can be reduced.

[0064] The first and second coolers 18, 20 may be disposed in a direction perpendicular to the rotation axis of the multi-blade fan 16. In this case, the airflow path from the multi-blade fan 16 to the first and second coolers 18, 20 is shortened, improving the efficiency of the multi-blade fan 16. The airflow path can be simplified.

[0065] The first cooler 18 may be disposed integrally with the second cooler 20 on the side opposite to the multi-blade fan 16. In this case, by disposing the first cooler 18 and the second cooler 20 integrally, the heat-resistant connecting hose connecting the two can be shortened or omitted.

[0066] The above-mentioned airflow may be made to flow around the integrally arranged first and second coolers 18, 20 in a direction perpendicular to the rotation axis of the fan. In this case, the airflow path is shortened, the flow resistance is reduced, and the efficiency of the multi-blade fan 16 is improved. The airflow path can be simplified.

[0067] The air compression device 100 is an air compression device for a railway vehicle that is mounted under the floor of the railway vehicle 90, and the multi-blade fan 16 may send out an air flow in a direction perpendicular to the traveling direction of the railway vehicle 90. In this case, the compressed air can be used in the vehicle 90. In addition, since the air flow is sent out in the perpendicular direction, it is possible to reduce the flow rate fluctuation of the air flow caused by the acceleration and deceleration of the vehicle 90. In addition, it is possible to reduce the amount of dust that comes from the traveling direction and enters the first and second coolers 18, 20 when the vehicle 90 travels. The above is a description of the first embodiment.

[0068] [Second embodiment] The second embodiment of the present invention is also an air compression device. This air compression device 100 includes a pre-cooler and a post-cooler which sequentially cool the compressed air generated by a compressor 10, and the pre-cooler is provided with a cooler which cools the compressed air by an airflow which has cooled the post-cooler. For example, the pre-cooler may be a first cooler 18, and the post-cooler may be a second cooler 20. The compressed air to be cooled may be cooled by an airflow generated by a multi-blade fan 16.

[0069] According to the second embodiment, the same actions and effects as those of the first embodiment are achieved.

[0070] Above, examples of the embodiments of the present invention have been described in detail. The above-mentioned embodiments merely show specific examples of implementing the present invention. The contents of the embodiments do not limit the technical scope of the present invention, and many design changes such as changing, adding, and deleting components are possible within the scope of the invention as defined in the claims. In the above-mentioned embodiments, the contents for which such design changes are possible are described with the notation "of the embodiment" or "in the embodiment", but this does not mean that design changes are not permitted for contents without such notation.

[0071] [Variations] The following describes the modified examples. In the drawings and description of the modified examples, the same or equivalent components and members as those in the embodiment are denoted by the same reference numerals. Explanations that overlap with the embodiment will be omitted as appropriate, and the description will focus on the configurations that differ from the first embodiment.

[0072] [First Modification] An air compression device 200 according to a first modified example will be described with reference to Fig. 13. This modified example differs from the embodiment in that a supercharger 210 is provided at the suction port of the compressor 10, and other configurations are the same, so the description will focus on the supercharger 210. Fig. 13 is a front view showing the periphery of the compressor 10, and corresponds to Fig. 10.

[0073] In a scroll compressor, the outer periphery becomes negative pressure, and the pressure difference between the outside and the inside makes it easy to suck in dust. To reduce the intrusion of dust, the compressor 10 is provided with a face seal (not shown) that seals the outer periphery. However, the face seal has a gap called a joint, and dust can intrude through this gap. For this reason, in this modification, a supercharger 210 is provided at the suction port 10c of the compressor 10.

[0074] The supercharger 210 is not particularly limited as long as it can increase the internal pressure of the compressor 10. The supercharger 210 of this modified example has an impeller 210b rotated by a motor 210m. The supercharger 210 pressurizes upstream air and increases downstream air pressure to atmospheric pressure or higher, and supplies the air to the intake port 10c of the compressor 10. The supercharger 210 is provided in a path between the valve mechanism 32d and the intake port 10c. By providing the supercharger 210, the internal pressure in the vicinity of the intake port 10c of the compressor 10, i.e., the outer periphery of the compressor 10, can be increased, and the intrusion of dust due to negative pressure can be suppressed.

[0075] [Other variations] In the description of the embodiment, the coolers 18 and 20 are heat exchangers that bring cooling air into contact with a pipe through which the air to be cooled flows, but the coolers are not limited to this. The coolers may be based on a different principle. For example, the coolers may be configured to bring cooling air into contact with cooling fins provided on a pipe, or may be configured to bring cooling air into contact with two metal plates that sandwich the air to be cooled, or may be configured to use a double pipe.

[0076] In the description of the embodiment, an example has been shown in which the output shaft 12a of the motor 12 is integral with the rotating shaft 10a of the compressor 10, but this is not limited thereto. For example, the output shaft of the motor may be separate from the rotating shaft of the compressor and connected to it by a coupling or the like.

[0077] In the description of the embodiment, the motor 12 does not include bearings, and the stator and rotor are each built into the compressor, but this is not limiting. For example, the motor may have a non-built-in structure in which the bearings, rotor, and stator are integrated into the motor case.

[0078] In the description of the embodiment, the motor 12 is a surface magnet type DC brushless motor, but the present invention is not limited to this. The motor may be any type of motor that can drive the compressor, such as an embedded magnet type motor, an AC motor, a brushed motor, a geared motor, or the like.

[0079] In the description of the embodiment, an example in which the compressor 10 is a scroll type has been shown, but the present invention is not limited to this. The compressor may be any type that can generate compressed air, and may be, for example, another type of air compressor such as a screw type or a reciprocating type.

[0080] In the embodiment, the rotor 12n of the labyrinth portion 12f also serves as the balance weight 15, but this is not limiting. The rotor of the labyrinth portion may be provided separately from the balance weight.

[0081] In the description of the embodiment, the valve mechanism 26d is a check valve, but is not limited to this. For example, the valve mechanism 26d may be a secondary pressure regulating valve (pressure reducing valve) capable of adjusting the pressure on the secondary side.

[0082] The above-described modified example provides the same functions and effects as the first embodiment.

[0083] Any combination of the above-described embodiments and modifications is also useful as an embodiment of the present invention. A new embodiment resulting from the combination has the combined effects of the respective embodiments and modifications. [Explanation of symbols]

[0084] 10 compressor, 12 motor, 12c casing, 12n rotating body portion, 12p stationary body portion, 12r labyrinth, 14 compressor drive portion, 15 balance weight, 15b balance adjustment portion, 16 multi-blade fan, 18 first cooler, 20 second cooler, 22 cooler, 24 dehumidifier, 26 air introduction portion, 26d valve mechanism, 28 blower fan, 32 air suction portion, 34 compressed air discharge portion, 38 bearing holder, 40 inverter control device, 42 storage box, 90 railway vehicle, 100 air compression device.

Claims

1. A compressor for generating compressed air; A motor that drives the compressor; a fan driven by the motor to generate an air flow; a first cooler that cools the compressed air and a second cooler that cools the compressed air cooled by the first cooler by the air flow, The first cooler cools the compressed air by the airflow that has cooled the second cooler, the first cooler and the second cooler are disposed in a direction perpendicular to a rotation axis of the fan, the first cooler and the second cooler are disposed above the fan and between the fan and a floor of a railcar, the first cooler is disposed on an opposite side of the second cooler from a side on which the fan is located, The air flow flows around the first cooler and the second cooler in a direction perpendicular to the rotation axis of the fan. Air compression equipment.

2. 2. The air compression apparatus of claim 1, wherein the fan is disposed between the motor and the compressor.

3. The air compressing device according to claim 1 or 2, wherein the first cooler is disposed integrally with the second cooler.

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