Testing device for cooling device and sealing device for hub unit bearing

Abstract

To achieve a structure capable of cooling a solution while preventing separation of a solute and a solvent.SOLUTION: A cooling device 1 includes the steps of: cooling a secondary refrigerant 4 stored in a secondary refrigerant tank 2 by a heat exchanger 5 for the secondary refrigerant cooling; cooling a solution S stored in a storage tank 3 immersed in a secondary refrigerant 4, having a temperature slightly lower than a desired set temperature as a target, using the secondary refrigerant 4; and heating the solution S by a heat exchanger 6 for heating the solution and adjusting the temperature of the solution S to the desired set temperature by finely adjusting the temperature of the solution S.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cooling device used for performing durability testing of a seal device, for example, in a low-temperature and muddy saltwater environment, and also to a testing device for a seal device incorporated in a hub unit bearing. [Background technology]

[0002] The wheels and braking rotors of an automobile are rotatably supported by a suspension system by a hub unit bearing. Fig. 4 shows a hub unit bearing 100 described in JP 2011-89558 A (Patent Document 1). The hub unit bearing 100 includes an outer ring 101, a hub 102, a plurality of rolling elements 103, and two seal devices 104a, 104b.

[0003] The outer ring 101 has a double-row outer ring raceway 105 on its inner circumferential surface, and a stationary flange 106 protruding radially outward at an axially intermediate portion. The stationary flange 106 has support holes 107 penetrating in the axial direction at multiple locations in the circumferential direction. The outer ring 101 is supported and fixed to the suspension by support bolts (not shown) that pass through the support holes 107 of the stationary flange 106, and does not rotate even when the wheel rotates.

[0004] The hub 102 is disposed radially inward of the outer ring 101 and coaxially therewith, and includes a double-row inner ring raceway 108 and a rotating flange 109. The double-row inner ring raceway 108 is provided over the entire circumference of the outer circumferential surface of the hub 102 in a portion that faces the double-row outer ring raceway 105. The rotating flange 109 is provided on the hub 102 in a portion that is axially outward of the axially outer end of the outer ring 101 so as to protrude radially outward, and has mounting holes 110 that penetrate in the axial direction at multiple locations in the circumferential direction of a radially intermediate portion.

[0005] With respect to the hub unit bearing 100, the axial outer side refers to the outer side in the width direction of the vehicle when assembled to the automobile (left side in FIG. 4), and the axial inner side refers to the central side in the width direction of the vehicle when assembled to the automobile (right side in FIG. 4).

[0006] The rolling elements 103 are arranged between a double row outer ring raceway 105 and a double row inner ring raceway 108 so as to be able to roll freely, with a plurality of rolling elements for each row.

[0007] The braking rotor, such as a disk or drum (not shown), and the wheels that constitute the wheel are supported and fixed to the rotating flange 109 of the hub 102 by using a plurality of studs 111. Each of the studs 111 has a serration portion 113 provided on a base end (the end on the inner side in the axial direction) of a shaft portion 112, which is press-fitted into a mounting hole 110 of the rotating flange 109 from the inside in the axial direction. The braking rotor and the wheel are supported and fixed to the rotating flange 109 by inserting the axial intermediate portions of each of the studs 111 through through holes formed at a plurality of locations in the circumferential direction of each of the studs 111 and screwing wheel nuts (not shown) into male thread portions 114 provided on the tip portions of each of the studs 111.

[0008] The seal devices 104 a, 104 b close openings on both axial sides of a cylindrical internal space 115 that exists between the inner peripheral surface of the outer ring 101 and the outer peripheral surface of the hub 102, respectively.

[0009] The axially outer seal device 104a is composed of a seal ring having a core metal 116 and a seal material 117. The core metal 116 is formed by bending a metal plate such as a soft steel plate into an L-shaped cross section and an annular shape as a whole, and includes a cylindrical fitting tube portion 118 fitted into the inner peripheral surface of the axially outer end of the outer ring 101, and a support portion 119 bent radially inward from the axially outer end of the fitting tube portion 118. The seal material 117 is composed of an elastic material such as an elastomer such as rubber, and a base end of the seal material 117 is supported and fixed to the support portion 119 by vulcanization adhesion. The seal material 117 also has three contact-type seal lips 120. The tip end of each seal lip 120 is in sliding contact with the axially inner surface of the rotating flange 109 or the axially middle outer peripheral surface of the hub 102 over the entire circumference.

[0010] The axially inner seal device 104 b is composed of a combination seal ring having a slinger 121 and a seal ring 122 .

[0011] The slinger 121 is formed by bending a corrosion-resistant metal plate such as a stainless steel plate into an L-shaped cross section and an overall circular ring shape, and comprises a cylindrical portion 123 fitted onto the axially inner end of the hub 102, and a circular plate portion 124 bent radially outward from the axially inner end of the cylindrical portion 123.

[0012] The seal ring 122 includes a metal core 125 and a seal member 126 made of an elastic material. The core 125 is formed by bending a metal plate such as a soft steel plate into an L-shaped cross section and an annular shape, and includes a fitting tubular portion 127 fitted into the axially inner end of the outer ring 101, and a support portion 128 bent radially inward from the axially outer end of the fitting tubular portion 127. The seal member 126 is made of an elastic material such as an elastomer such as rubber, and the base end is supported and fixed to the support portion 128 by vulcanization adhesion. The seal member 126 also has three contact-type seal lips 129. The tip end of each seal lip 129 is in sliding contact with the outer circumferential surface of the cylindrical portion 123 of the slinger 121 or the axially outer surface of the annular plate portion 124 over the entire circumference. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] JP 2011-89558 A [Patent Document 2] Japanese Patent Application Publication No. 7-27464 Summary of the Invention [Problem to be solved by the invention]

[0014] With the recent spread of automobiles, there is an increasing need to conduct durability tests of hub unit bearings in low-temperature environments such as cold regions where the temperature drops below freezing. In snowy environments in particular, the sealing device of the hub unit bearing may be splashed with low-temperature (below freezing) muddy water (muddy salt water) containing salt used as a snow-melting agent, or the sealing device may be immersed in the muddy salt water. The elasticity of rubber is obtained by the Brownian motion of polymers, and when the Brownian motion decreases with a drop in temperature, the elasticity of rubber also decreases. Therefore, in order to conduct durability tests assuming a low-temperature environment where the Brownian motion of polymers decreases, a cooling device is required to cool the muddy salt water to a low temperature.

[0015] Japanese Patent Laid-Open Publication No. 7-27464 (Patent Document 2) describes a cooling device that lowers the water temperature to a set temperature by circulating water in a circuit having an ice thermal storage type heat exchanger. As the heat exchanger, a cooling coil that circulates a refrigerant inside a tube and cools the fluid flowing outside the tube can generally be used. As the refrigerant, for example, an alternative fluorocarbon (HFC) such as R-404A (boiling point: -46.8°C) can be used.

[0016] As is clear from FIG. 5, which is a phase equilibrium diagram of salt water, salt water separates into ice and salt when it is cooled to -21.3°C or lower, regardless of the salt concentration. For this reason, when the cooling device described in JP-A-7-27464 is used to cool muddy salt water, when the muddy salt water is cooled to 21.3°C or lower around the cooling coil, only the water in that area freezes, and it may be separated into ice that does not contain salt and muddy salt water with a high salt concentration. Furthermore, if the salt-free ice adheres to and accumulates on the surface of the cooling coil and the ice becomes thick, it may not be possible to sufficiently exchange heat between the cooling coil and the muddy salt water, and it may not be possible to sufficiently cool the muddy salt water. As a result, it may not be possible to properly perform tests in low-temperature environments such as those in cold regions.

[0017] In consideration of the above-mentioned circumstances, the present invention aims to realize a cooling device that can sufficiently cool a solution while preventing separation of the solute and the solvent, and a structure of a testing device for a sealing device for a hub unit bearing that is equipped with the cooling device. [Means for solving the problem]

[0018] A cooling device according to one aspect of the present invention comprises: A secondary refrigerant tank; a storage tank disposed inside the secondary refrigerant tank for storing a solution; A secondary refrigerant stored in the secondary refrigerant tank; a secondary refrigerant cooling heat exchanger disposed inside the secondary refrigerant tank for cooling the secondary refrigerant; a solution heating heat exchanger disposed inside the storage tank for heating the solution; Equipped with The secondary refrigerant cooling heat exchanger cools the secondary refrigerant at a temperature higher than the freezing point (melting point) of the solution.

[0019] A cooling device according to one embodiment of the present invention can be provided with a level adjustment means for adjusting the liquid level (height of the liquid surface) of the solution in the storage tank, and the liquid level adjustment means has a level adjustment tank arranged inside the secondary refrigerant tank and a connecting pipe connecting the storage tank and the liquid level adjustment tank, and can adjust the liquid level of the solution in the storage tank by adjusting the pressure in the internal space of the level adjustment tank. Alternatively, the liquid level adjustment means can adjust the liquid level of the solution in the storage tank by raising and lowering the liquid level adjustment tank relative to the storage tank.

[0020] The cooling device according to one aspect of the present invention may include a solution stirring blade disposed inside the storage tank for stirring the solution.

[0021] A testing device for a seal device for a hub unit bearing according to one aspect of the present invention includes a cooling device according to one aspect of the present invention. Effect of the Invention

[0022] According to the cooling device of the present invention, it is possible to cool a solution to a desired temperature while preventing separation of the solute and the solvent. Specifically, for example, it is possible to cool a muddy salt solution to near the freezing point of saturated salt water (-21.3°C). Therefore, it is possible to stably perform tests in a low-temperature environment. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a cooling device according to a first embodiment of the present invention. [Diagram 2] FIG. 2(A) is a schematic cross-sectional view showing a cooling device according to a second embodiment of the present invention in a state where the liquid level of the solution in the storage tank is raised, and FIG. 2(B) is a schematic cross-sectional view showing the cooling device in a state where the liquid level of the solution in the storage tank is lowered. [Diagram 3]FIG. 3(A) is a schematic cross-sectional view showing a cooling device according to a third embodiment of the present invention in a state where the liquid level of the solution in the storage tank is raised, and FIG. 3(B) is a schematic cross-sectional view showing the cooling device in a state where the liquid level of the solution in the storage tank is lowered. [Figure 4] FIG. 4 is a cross-sectional view showing an example of a conventional structure of a hub unit bearing. [Diagram 5] FIG. 5 is a phase equilibrium diagram for salt water. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] [First Example of Implementation] A first embodiment of the present invention will be described with reference to Fig. 1. This embodiment is an example in which the cooling device of the present invention is applied to a testing device for sealing devices for hub unit bearings, which tests sealing devices attached to hub unit bearings in a low-temperature (below freezing) muddy / salty water environment, for cooling the muddy / salty water.

[0025] The cooling device 1 of this example includes a secondary refrigerant tank 2, a storage tank 3, a secondary refrigerant 4, a heat exchanger 5 for cooling the secondary refrigerant, a heat exchanger 6 for heating the solution, a secondary refrigerant agitator 7, and a solution agitator 8.

[0026] The secondary refrigerant tank 2 has a box shape. In this example, the secondary refrigerant tank 2 has a rectangular box (rectangular parallelepiped) shape. That is, the secondary refrigerant tank 2 has a rectangular cylindrical shape, and includes a side wall portion 9 formed by combining four flat plates, a bottom plate portion 10 that closes the lower end of the side wall portion 9, and an upper plate portion 11 that closes the upper end of the side wall portion 9. The side wall portion 9, the bottom plate portion 10, and the upper plate portion 11 are made of a material that has high thermal insulation performance between the external space and the internal space, and / or have a structure with high thermal insulation performance.

[0027] The storage tank 3 is disposed inside the secondary refrigerant tank 2 and stores the solution S to be cooled. The storage tank 3 has a vertical dimension smaller than the vertical dimension of the secondary refrigerant tank 2 and an outer diameter dimension smaller than the inner diameter dimension of the secondary refrigerant tank 2. The storage tank 3 is disposed in a floating state inside the secondary refrigerant tank 2. That is, there are gaps between the inner peripheral surface of the side wall portion 9 of the secondary refrigerant tank 2 and the outer peripheral surface of the side plate portion 12 of the storage tank 3, between the upper surface of the bottom plate portion 10 of the secondary refrigerant tank 2 and the lower surface of the bottom plate portion 13 of the storage tank 3, and between the lower surface of the upper plate portion 11 of the secondary refrigerant tank 2 and the upper surface of the upper plate portion 14 of the storage tank 3. For this reason, for example, the storage tank 3 can be supported inside the secondary refrigerant tank 2 by placing the storage tank 3 on a support portion protruding upward from the bottom plate portion 10 of the secondary refrigerant tank 2. Additionally or alternatively, the storage tank 3 can be supported inside the secondary refrigerant tank 2 by suspending the storage tank 3 from a support portion that hangs down from the upper plate portion 11 of the secondary refrigerant tank 2 and / or that protrudes inward from the side wall portion 9. The storage tank 3 is made of a material that has high thermal conductivity between the external space and the internal space.

[0028] In this example, the solution S is composed of mud salt water, which is a mixture of mud, salt (sodium chloride) and / or calcium chloride, each of which is a solute, and water, which is a solvent. The amount of the solution S and the concentration of the solute are appropriately selected according to the experimental conditions, etc.

[0029] The secondary refrigerant 4 is stored in the secondary refrigerant tank 2. In this example, the amount of the secondary refrigerant 4 stored is adjusted so that the entire tank 3 is immersed in the secondary refrigerant 4. That is, the liquid level of the secondary refrigerant 4 is located above the upper surface of the upper plate portion 14 of the tank 3. However, the amount of the secondary refrigerant 4 stored in the tank 3 can be any amount as long as the temperature of the solution S stored in the tank 3 can be set to the desired set temperature. From the viewpoint of uniformly cooling the solution S, it is preferable to position the liquid level of the secondary refrigerant 4 above the liquid level of the solution S.

[0030] The secondary refrigerant 4 can be made of any fluid as long as it can set the solution S to a desired temperature and ensure the safety of the operator. When using muddy saltwater as the solution S and testing the sealing device as in this example, the secondary refrigerant 4 can be a fluid such as an aqueous solution of calcium chloride or ethylene glycol, or ethyl alcohol, which can cool the muddy saltwater to a temperature (for example, about -20°C to -21°C) slightly higher than the freezing point (-21.3°C in the case of saturated salt water) and has a freezing point lower than the boiling point of the primary refrigerant used in the heat exchanger 5 for cooling the secondary refrigerant, which will be described later.

[0031] The secondary refrigerant cooling heat exchanger 5 is disposed inside the secondary refrigerant tank 2 and has a function of cooling the secondary refrigerant 4. In this example, the secondary refrigerant cooling heat exchanger 5 is disposed in a floating state between an upper surface of the bottom plate portion 10 of the secondary refrigerant tank 2 and a lower surface of the bottom plate portion 13 of the storage tank 3. For this reason, for example, the secondary refrigerant cooling heat exchanger 5 is placed on a support portion protruding upward from the bottom plate portion 10 of the secondary refrigerant tank 2 and / or the secondary refrigerant cooling heat exchanger 5 is supported on the inside of the secondary refrigerant tank 2 by supporting the secondary refrigerant cooling heat exchanger 5 on a support portion protruding inward from the side wall portion 9.

[0032] The heat exchanger 5 for cooling the secondary refrigerant may have any structure as long as it can sufficiently cool the secondary refrigerant 4. When using muddy salt water as the solution S and testing the sealing device as in this example, the heat exchanger 5 for cooling the secondary refrigerant may have any structure as long as it can cool the secondary refrigerant 4 to a temperature slightly higher than the freezing point of the muddy salt water. Specifically, for example, the heat exchanger 5 for cooling the secondary refrigerant is configured by a cooling coil that circulates a refrigerant (primary refrigerant) inside a spiral metal tube and cools the secondary refrigerant 4 flowing outside the tube. For example, an alternative fluorocarbon such as R-404A can be used as the primary refrigerant.

[0033] The solution heating heat exchanger 6 is disposed inside the storage tank 3 and has a function of heating the solution S to a temperature equal to or higher than the freezing point so as not to separate the solution S into a solvent and a solute. Specifically, the solution heating heat exchanger 6 heats the solution S cooled by the secondary refrigerant 4 and finely adjusts the temperature (liquid temperature) of the solution S to a desired set temperature equal to or higher than the freezing point of the solution S. In this example, the solution heating heat exchanger 6 is disposed near the bottom of the storage tank 3. For this purpose, the solution heating heat exchanger 6 can be supported and fixed inside the storage tank 3 by, for example, placing the solution heating heat exchanger 6 on a support part protruding upward from the bottom plate part 13 of the storage tank 3, or suspending the solution heating heat exchanger 6 from a support part hanging downward from the upper plate part 14 of the storage tank 3.

[0034] The solution-heating heat exchanger 6 may have any structure as long as it can heat the solution S and finely adjust the temperature of the solution S. Specifically, for example, the solution-heating heat exchanger 6 may be configured with a sheath heater in which a nichrome wire is covered with a metal sheath.

[0035] The secondary refrigerant agitating blades 7 are disposed inside the secondary refrigerant vessel 2 and have the function of agitating the secondary refrigerant 4. In this example, the secondary refrigerant agitating blades 7 are disposed near the bottom of the secondary refrigerant vessel 2 and at a plurality of locations in the circumferential direction around the secondary refrigerant cooling heat exchanger 5. The secondary refrigerant agitating blades 7 are inserted into the through holes 15a formed in the upper plate portion 11 of the secondary refrigerant vessel 2 and are configured by supporting a plurality of (for example, about 3 to 6) blades 17 at the lower end of the rotating shaft 16 disposed in the vertical direction. Specifically, for example, the secondary refrigerant agitating blades 7 are configured by propeller blades. However, as long as the secondary refrigerant agitating blades 7 can agitate the secondary refrigerant 4 stored inside the secondary refrigerant vessel 2 to make the temperature (liquid temperature) uniform, the shape and number of the blades, the installation position, the number, etc. are not particularly limited, and the secondary refrigerant agitating blades 7 can have any structure. For example, the secondary refrigerant agitating blades 7 can be configured by low-viscosity agitating blades such as disk turbine blades or inclined paddle blades.

[0036] The solution agitating blade 8 is disposed inside the storage tank 3, and has the function of agitating the solution S to prevent precipitation of solutes such as mud and salt, and to promote heat exchange with the secondary refrigerant 4. In this example, the solution agitating blade 8 is disposed inside the storage tank 3, and at one location above the solution heating heat exchanger 6. The solution agitating blade 8 is inserted through a through hole 15b formed in the upper plate portion 11 of the secondary refrigerant tank 2 and a through hole 18 formed in the upper plate portion 14 of the storage tank 3, and is configured by supporting a plurality of blades 20 (for example, about 3 to 6 blades) at the lower end of a rotating shaft 19 disposed in the vertical direction. Specifically, for example, the solution agitating blade 8 is configured by an anchor blade. However, the shape and number of blades, the installation position, the number, etc. of the solution agitating blade 8 are not particularly limited as long as the solution agitating blade 8 can agitate the solution S stored inside the storage tank 3, prevent precipitation of mud, and make the temperature uniform, and can have any structure. For example, the solution agitating blade 8 can be configured with a medium-viscosity agitating blade such as a gate blade or a paddle blade, or a high-viscosity agitating blade such as a helical ribbon blade or a screw blade. If the solution agitating blade 8 is configured with a medium-viscosity agitating blade or a high-viscosity agitating blade, it is possible to prevent mud foreign matter from accumulating on the solution agitating blade 8. As a result, it is possible to prevent a decrease in the efficiency of heat exchange between the secondary refrigerant 4 and the solution heating heat exchanger 6 and the solution S, which is caused by a decrease in agitation efficiency, and a decrease in the mud concentration in the mud salt water.

[0037] In order to cool the solution S stored in the storage tank 3 by the cooling device 1 of this embodiment, the secondary refrigerant 4 is stirred by the secondary refrigerant stirring blade 7, and the solution S is stirred by the solution stirring blade 8. In this state, the secondary refrigerant 4 is cooled by the heat exchanger 5 for cooling the secondary refrigerant. Specifically, the secondary refrigerant 4 is cooled to a temperature slightly lower than the desired set temperature of the solution S, for example, a temperature about 0.5°C to 2.0°C lower than the set temperature and a temperature equal to or higher than the freezing point of the solution S. Specifically, for example, when cooling mud salt water to -20°C, the secondary refrigerant 4 is cooled to a temperature slightly lower than -20°C (about -20.5°C to -21°C). Then, while cooling the solution S stored in the storage tank 3 by the secondary refrigerant 4, the solution S is heated by the heat exchanger 6 for heating the solution, and the temperature of the solution S is finely adjusted to adjust the temperature of the solution S to the set temperature.

[0038] The seal device W to be tested is supported inside the storage tank 3 with a part or whole of it immersed in the solution S, and the test is performed. Specifically, for example, a durability test is performed in which the seal ring and the slinger constituting the seal device W are rotated relative to each other to detect wear of the seal lip over time and test the durability, and a startup test is performed in which an increase in sliding torque due to hardening of the seal lip at low temperatures is confirmed.

[0039] In the cooling device 1 of this embodiment, the secondary refrigerant 4 stored in the secondary refrigerant tank 2 is cooled by the heat exchanger 5 for cooling the secondary refrigerant, and the solution S stored in the storage tank 3 immersed in the secondary refrigerant 4 is cooled by the secondary refrigerant 4. Therefore, the cooling device 1 of this embodiment can prevent the problem of separation into ice containing no salt and muddy salt water with a high salt concentration, which occurs when muddy salt water is directly cooled by a cooling coil, due to only water freezing around the cooling coil. That is, the cooling device 1 of this embodiment can prevent the solution S, which is muddy salt water, from separating into salt as a solute and water as a solvent. In addition, the problem of ice hindering the removal of heat from the solution S can be prevented, so that the solution S can be sufficiently cooled. In addition, since a cooling coil made of a complexly bent metal tube is not arranged in the storage tank 3, there is no problem of mud accumulating on the cooling coil and the mud concentration in the muddy salt water decreasing.

[0040] Moreover, according to the cooling device 1 of this embodiment, the temperature (liquid temperature) of the solution S can be accurately and quickly adjusted to a desired set temperature. The cooling device 1 of this embodiment cools the secondary refrigerant 4 stored in the secondary refrigerant tank 2 by the heat exchanger 5 for cooling the secondary refrigerant, and further cools the solution S stored in the storage tank 3 immersed in the secondary refrigerant 4 by the secondary refrigerant 4. In short, in the cooling device 1 of this embodiment, the heat exchanger 5 for cooling the secondary refrigerant cools the solution S with a small temperature difference through the secondary refrigerant 4 and the storage tank 3. Therefore, it takes time to cool the solution S, and it is difficult to finely adjust the temperature of the solution S by only controlling the heat exchanger 5 for cooling the secondary refrigerant, and the adjustment speed of the temperature of the solution S is also slow.

[0041] In contrast, the cooling device 1 of this embodiment is configured to cool the solution S to a temperature slightly lower than a desired set temperature by the secondary refrigerant cooling heat exchanger 5 via the secondary refrigerant 4 and the storage tank 3, and to adjust the temperature of the solution S to the set temperature by heating the solution S with the solution heating heat exchanger 6. Therefore, with the cooling device 1 of this embodiment, the temperature of the solution S can be accurately and quickly adjusted to the set temperature.

[0042] The cooling device 1 of this embodiment includes a secondary refrigerant stirring blade 7 for stirring the secondary refrigerant 4. This allows the temperature of the secondary refrigerant 4 to be uniform, and the solution S stored in the storage tank 3 can be uniformly cooled from the surroundings. Therefore, the cooling device 1 of this embodiment can prevent only a part of the solution S stored in the storage tank 3 from being excessively cooled and only the water in that part from freezing. From this perspective, it is possible to prevent the solution S, which is muddy salt water, from separating into salt as a solute and water as a solvent, and also to prevent the cooling of the solution S from being hindered by ice, and the solution S can be sufficiently cooled.

[0043] The cooling device 1 of this embodiment includes a solution stirring blade 8 for stirring the solution S. This makes it possible to prevent mud from settling, to make the temperature of the solution S uniform, and to smoothly exchange heat between the solution S and the solution heating heat exchanger 6 and the secondary refrigerant 4.

[0044] The cooling device of the present invention is not limited to a cooling device for cooling muddy salt water for testing a seal device of a hub bearing, but can be applied to various other purposes. Also, the cooling device of the present invention can cool various solutions, not limited to muddy salt water.

[0045] [Second Example of the Implementation Form] A second embodiment of the present invention will be described with reference to Fig. 2(A) and Fig. 2(B). The cooling device 1a of this embodiment includes a liquid level adjustment means 21 for adjusting the liquid level (height of the liquid surface) of the solution S stored in the storage tank 3. The liquid level adjustment means 21 includes a liquid level adjustment tank 22 arranged inside the secondary refrigerant tank 2, a connecting pipe 23 connecting the storage tank 3 and the liquid level adjustment tank 22, and a lifting device (not shown) for raising and lowering the liquid level adjustment tank 22 relative to the storage tank 3. Note that Fig. 2(A) and Fig. 2(B) are shown without the secondary refrigerant cooling heat exchanger 5, solution heating heat exchanger 6, secondary refrigerant agitator 7, and solution agitator 8.

[0046] The liquid level adjustment tank 22 is supported inside the secondary refrigerant tank 2 so as to be movable up and down (displaceable in the vertical direction).

[0047] The connecting pipe 23 has flexibility. Specifically, for example, the connecting pipe 23 is configured of a hose made of rubber, vinyl, synthetic resin, or metal. One end of the connecting pipe 23 is connected to an opening 24 provided in the bottom plate portion 13 of the storage tank 3, and the other end is connected to an opening 26 provided in the bottom plate portion 25 of the liquid-level adjustment tank 22. In other words, the solution S can move between the storage tank 3 and the liquid-level adjustment tank 22 through the connecting pipe 23.

[0048] The lifting device adjusts the liquid level of the solution S stored in the storage tank 3 by raising and lowering the liquid level adjustment tank 22 relative to the storage tank 3 .

[0049] 2(A)→2(B), when the lifting device lowers the level adjustment tank 22 relative to the storage tank 3, a part of the solution S in the storage tank 3 moves to the level adjustment tank 22 through the connecting pipe 23 so that the level of the solution S in the storage tank 3 matches the level of the solution in the level adjustment tank 22. As a result, the level of the solution S in the storage tank 3 drops.

[0050] 2(B)→2(A), when the lifting device raises the level adjustment tank 22 relative to the storage tank 3, a part of the solution S in the level adjustment tank 22 moves to the storage tank 3 through the connecting pipe 23 so that the level of the solution S in the storage tank 3 and the level of the solution in the level adjustment tank 22 match. As a result, the level of the solution S in the storage tank 3 rises.

[0051] According to the cooling device 1a of this embodiment, the liquid level of the solution S stored in the storage tank 3 can be adjusted by raising and lowering the liquid level adjustment tank 22 relative to the storage tank 3. Therefore, during testing of the sealing device W supported inside the storage tank 3, the sealing device W can be switched between a state in which it is immersed in the solution S and a state in which it is taken out of the solution S and dried. Therefore, for example, a dry-wet repeated durability test can be easily performed in which a cycle of (immersion + rotation) → (immersion + stop) → (drying + stop) → (drying + rotation) is repeated. Therefore, according to the cooling device 1a of this embodiment, a test under conditions close to the actual usage state of the sealing device W can be relatively easily performed.

[0052] A heat exchanger for heating the solution S in the level adjustment tank 22 may be provided inside the level adjustment tank 22. And / or, a stirring blade for stirring the solution S in the level adjustment tank 22 may be provided inside the level adjustment tank 22. The configuration and effects of other parts are similar to those of the first embodiment.

[0053] [Third Example of the Implementation Form] A third embodiment of the present invention will be described with reference to Fig. 3(A) and Fig. 3(B). In the cooling device 1b of this embodiment, the structure of the liquid level adjustment means 21a for adjusting the liquid level stored in the storage tank 3 is different from the liquid level adjustment means 21 of the second embodiment. The liquid level adjustment means 21a has a liquid level adjustment tank 22a arranged inside the secondary refrigerant tank 2, a connecting pipe 23a connecting the storage tank 3 and the liquid level adjustment tank 22a, and a compressor 29 constituting a pressure adjustment device for adjusting the pressure in the internal space of the liquid level adjustment tank 22a. Note that Fig. 3(A) and Fig. 3(B) are shown without the secondary refrigerant cooling heat exchanger 5, solution heating heat exchanger 6, secondary refrigerant agitator 7, and solution agitator 8.

[0054] The level adjustment tank 22a is supported and fixed inside the secondary refrigerant tank 2. The level adjustment tank 22a has a valve 28 on the upper part of the side plate portion 27. That is, in this example, through the valve 28, compressed air from a compressor 29 can be sent into the level adjustment tank 22a as shown in Fig. 3(A), or air in the level adjustment tank 22a can be discharged to the outside space as shown in Fig. 3(B).

[0055] The connecting pipe 23a is One end, The connecting pipe 23a is connected to an opening 24a provided in the lower part of the side plate 12 of the storage tank 3, and the other end is connected to an opening 26a provided in the lower part of the side plate 27 of the liquid-level adjustment tank 22a. That is, the solution S can move between the storage tank 3 and the liquid-level adjustment tank 22a through the connecting pipe 23a. In this example, the connecting pipe 23a can be made of a flexible hose like the connecting pipe 23 in the first example of the embodiment, or can be made of a non-flexible pipe.

[0056] In the cooling device 1b of this embodiment, the liquid level of the solution S stored in the storage tank 3 can be adjusted by adjusting the pressure in the liquid level adjustment tank 22a.

[0057] That is, as shown in Fig. 3(A), compressed air ejected from a compressor 29 is sent to the internal space of the level adjustment tank 22a through a valve 28, thereby increasing the pressure in the internal space. This presses the liquid level of the solution S in the level adjustment tank 22a downward, and part of the solution S in the level adjustment tank 22a moves to the storage tank 3 through the connecting pipe 23a. As a result, the liquid level of the solution S in the storage tank 3 rises. As shown in the figure, if the piping 30 from the valve 28 to the internal space of the level adjustment tank 22a is bypassed and the distance through the secondary refrigerant 4 is increased, the compressed air can be cooled in the piping 30, and a rise (change) in the temperature of the solution S caused by sending the compressed air to the internal space of the level adjustment tank 22a can be prevented.

[0058] 3(B), when the air in the level adjustment tank 22a is discharged to the outside space through the valve 28, the pressure in the internal space of the level adjustment tank 22a decreases. As a result, when the force pressing downward on the liquid surface of the solution S in the level adjustment tank 22a by the air in the level adjustment tank 22a decreases, part of the solution S in the storage tank 3 moves to the level adjustment tank 22a through the connecting pipe 23a. As a result, the liquid level of the solution S in the storage tank 3 drops.

[0059] The valve 28 for supplying compressed air from the compressor 29 into the liquid-level adjustment tank 22a and the valve 28 for discharging the air in the liquid-level adjustment tank 22a to the outside space can be the same valve 28, or different valves 28. When lowering the liquid level of the solution S in the storage tank 3, the pressure in the internal space of the liquid-level adjustment tank 22a can be reduced by sucking the air in the liquid-level adjustment tank 22a with a vacuum pump through the valve 28.

[0060] The liquid level adjustment means 21a of this example adjusts the pressure in the internal space of the liquid level adjustment tank 22a to adjust the liquid level of the solution S in the storage tank 3. That is, with the liquid level adjustment means 21a of this example, it is not necessary to raise and lower the liquid level adjustment tank 22 relative to the storage tank 3, as with the liquid level adjustment means 21 of the second example of the embodiment, in order to adjust the liquid level of the solution S in the storage tank 3. Therefore, according to the cooling device 1b of this example, it is possible to prevent the secondary refrigerant tank 2 from becoming large. The configurations and effects of the other parts are similar to those of the first and second examples of the embodiment. [Explanation of symbols]

[0061] 1, 1a, 1b Cooling device 2 Secondary refrigerant tank 3. Storage tank 4 Secondary refrigerant 5 Heat exchanger for secondary refrigerant cooling 6 Heat exchanger for heating solutions 7 Secondary refrigerant mixing blade 8 Solution mixing blade 9 Side wall 10 Bottom plate part 11 Upper plate 12 Side plate part 13 Bottom plate part 14 Upper plate 15a, 15b through hole 16 Rotation Axis 17 Feather 18 Through hole 19 Rotational Axis 20 Feather 21, 21a Liquid level adjustment means 22, 22a Liquid level adjustment tank 23, 23a connecting pipe 24, 24a opening 25 Bottom plate part 26, 26a opening 27 Side plate part 28 Valve 29 Compressor 100 Hub unit bearing 101 Outer ring 102 Hub 103 Rolling elements 104a, 104b Sealing device 105 Outer raceway 106 Stationary Flange 107 Support hole 108 Inner raceway 109 Rotating flange 110 Mounting hole 111 Stud 112 Shaft 113 Serration section 114 Male thread 115 Interior Space 116 Core wire 117 Sealing materials 118 Fitting cylinder part 119 Support part 120 Seal Lip 121 Slinger 122 Seal ring 123 Cylindrical part 124 Annular plate part 125 Core wire 126 Sealing material 127 Fitting cylinder part 128 Support part 129 Seal Lip

Claims

1. A secondary refrigerant tank; a storage tank disposed inside the secondary refrigerant tank for storing a solution; A secondary refrigerant stored in the secondary refrigerant tank; a secondary refrigerant cooling heat exchanger disposed inside the secondary refrigerant tank for cooling the secondary refrigerant; a solution heating heat exchanger disposed inside the storage tank for heating the solution; Equipped with The secondary refrigerant cooling heat exchanger cools the secondary refrigerant at a temperature higher than the freezing point of the solution.

2. a liquid level adjusting means for adjusting the liquid level of the solution in the storage tank; The liquid level adjustment means includes a liquid level adjustment tank arranged inside the secondary refrigerant tank, a connecting pipe connecting the storage tank and the liquid level adjustment tank, and a pressure adjustment device that adjusts the pressure in the internal space of the liquid level adjustment tank. The cooling device according to claim 1 .

3. a liquid level adjusting means for adjusting the liquid level of the solution in the storage tank; The liquid level adjustment means includes a liquid level adjustment tank arranged inside the secondary refrigerant tank, a connecting pipe connecting the storage tank and the liquid level adjustment tank, and a lifting device for lifting and lowering the liquid level adjustment tank relative to the storage tank. The cooling device according to claim 1 .

4. a solution stirring blade disposed inside the storage tank for stirring the solution; The cooling device according to any one of claims 1 to 3.

5. Equipped with a cooling device according to any one of claims 1 to 4, Test equipment for sealing devices for hub unit bearings.

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