Lubricating oil composition and circulation system using lubricating oil composition

Abstract

To provide a lubricating oil composition capable of controlling the temperatures of a secondary battery, an electric motor, and a reduction gear, and a circulation system using the lubricating oil composition.SOLUTION: A lubricating oil composition is circulated in a circulation circuit connected to at least a secondary battery, an electric motor, and a reduction gear, and is used for controlling the temperatures of at least the secondary battery, the electric motor, and the reduction gear. In the measurement of the surface temperature T12 (°C) of the silver rod 12 seconds after the silver rod with an initial surface temperature T0 of 200°C is placed in the lubricating oil composition of 80°C in accordance with "Cooling performance test method: Method A" specified in JIS K2242:2012, the change in temperature ΔT of the silver rod calculated from T0-T12 is 70°C or higher, the flash point is 100°C or higher as measured according to the Cleveland Open Method (C.O.C method) in accordance with JIS K2265-4:2007, and the volume resistivity is 1.0×107 Ω cm or more as measured in accordance with JIS C2101:1999.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a lubricating oil composition that circulates in a circulation circuit connected to an object, and a circulation system that uses this lubricating oil composition. [Background technology]

[0002] Conventionally, a battery cooling system is known that includes a circulation circuit that circulates oil common to a transaxle, a battery, and an oil cooler, and uses the oil that lubricates the transaxle to cool the battery. An electric motor is provided inside a case that houses the transaxle, and the oil is used to cool the electric motor (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2020-62964 Summary of the Invention [Problem to be solved by the invention]

[0004] Some electric motors contain semiconductors, which generate heat when the motor is in operation. Electricity also flows through the battery and transaxle, so the oil flowing through them is required to have heat resistance and insulation properties. [Means for solving the problem]

[0005] The present invention provides a lubricating oil composition and a circulation system using the lubricating oil composition. Specific aspects of the present invention are as follows [1] to

[16] . [1] A lubricating oil composition which is circulated in a circulation circuit connected to at least a secondary battery, an electric motor, and a reducer and is used to control temperatures of at least the secondary battery, the electric motor, and the reducer, In accordance with the "Cooling Performance Test Method: Method A" specified in JIS K2242:2012, a silver rod with an initial surface temperature T0 of 200°C was placed in a lubricating oil composition at 80°C and the surface temperature T 12 (℃), T0-T 12 The silver rod temperature change ΔT calculated from is 70°C or more, The flash point measured by the Cleveland Open Chamber (COC) method in accordance with JIS K2265-4:2007 is 100°C or higher. The volume resistivity measured in accordance with JIS C2101:1999 is 1.0×10 7 Ω·cm or more. [2] Kinematic viscosity at 30℃ is 5.0 to 40.0mm 2 The lubricating oil composition according to the above [1], [3] The lubricating oil composition according to the above-mentioned [1] or [2], which contains a base oil and one or more lubricating oil additives selected from antiwear agents, metal deactivators, metal detergents, dispersants, and antifoaming agents. [4] The lubricating oil composition according to any one of the above [1] to [3], which has a transmittance of 90% or more. [5] A circulation system comprising a circulation circuit connected to at least a secondary battery, an electric motor, and a reducer, the circulation circuit being capable of circulating the lubricating oil composition according to any one of the above [1 to 4], and controlling the temperature of at least the secondary battery, the electric motor, and / or the reducer. [6] The circulation system described in [5] above, wherein the circulation circuit further includes a first path connected to the secondary battery and a second path connected to the electric motor and the reducer. [7] The circulation system described in [6] above, wherein the first path and the second path are both connected to the same radiator. [8] The circulation system according to [6] or [7] above, wherein the first path and the second path are connected in parallel. [9] The circulation system according to [6] or [7] above, wherein at least a portion of the circulation circuit connects the secondary battery, the electric motor, and the reducer in series.

[10] The circulation system according to any one of the above [6] to [9], wherein the first path and / or the second path is provided with an oil pump.

[11] The circulation system according to any one of the above [6] to

[10] , wherein the first path and the second path are both connected to the same oil tank.

[12] The circulation system according to any one of the above [6] to

[11] , wherein the first path and the second path are both connected to the same oil pump.

[13] The circulation system according to any one of the above [6] to

[12] , further comprising a control valve provided at a connection between the first path and the second path.

[14] The circulation system according to any one of the above [6] to

[13] , further comprising a control valve for controlling a flow of the lubricating oil composition from an oil cooler to the first path and / or the second path.

[15] The circulation system according to

[13] or

[14] above, wherein the control valve opens and closes depending on the temperature of the secondary battery.

[16] The circulation system according to any one of the above

[13] to

[15] , wherein the control valve opens and closes depending on temperatures of the electric motor and the reducer. Effect of the Invention

[0006] According to a preferred embodiment of the present invention, a lubricating oil composition and a circulation system using this lubricating oil composition capable of controlling the temperatures of a secondary battery, an electric motor, and a reducer, and a circulation system using this lubricating oil composition can be obtained. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing an example of a circulation system according to the present invention. [Diagram 2] FIG. 1 is a schematic diagram showing an example of a circulation system according to the present invention. [Diagram 3] FIG. 1 is a schematic diagram showing an example of a circulation system according to the present invention. [Figure 4] FIG. 1 is a schematic diagram showing an example of a circulation system according to the present invention. [Diagram 5] FIG. 1 is a schematic diagram showing an example of a circulation system according to the present invention. [Figure 6] FIG. 1 is a schematic diagram showing an example of a circulation system according to the present invention. [Figure 7] FIG. 1 is a schematic diagram showing an example of a circulation system according to the present invention. [Figure 8] FIG. 1 is a schematic diagram showing an example of a circulation system according to the present invention. [Figure 9] FIG. 1 is a schematic diagram showing an example of a circulation system according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [Constitution of lubricating oil composition] First, a lubricating oil composition according to one embodiment of the present invention will be described. The lubricating oil composition of the present invention is a lubricating oil composition that is circulated in a circulation circuit connected to at least a secondary battery, an electric motor, and a reducer and is used to control the temperatures of at least the secondary battery, the electric motor, and the reducer, and satisfies the following requirements (I) to (III). Requirement (I): In accordance with the "Cooling Performance Test Method: Method A" specified in JIS K2242:2012, a silver rod with an initial surface temperature T0 of 200°C is placed in a lubricating oil composition at 80°C and the surface temperature T 12 (℃), T0-T 12 The silver rod temperature change ΔT calculated from is 70°C or more. Requirement (II): The flash point measured by the Cleveland Open Chamber (COC) method in accordance with JIS K2265-4:2007 is 100°C or higher. Requirement (III): The volume resistivity measured in accordance with JIS C2101:1999 is 1.0×10 7 Ω·cm or more.

[0009] The lubricating oil composition of the present invention is circulated in a circulation circuit connected to at least a secondary battery, an electric motor, and a reduction gear, and the properties required for each device are different. For example, a secondary battery is required to have high cooling performance and to maintain the temperature of the secondary battery constant. On the other hand, an electric motor and a reducer are required to have a relatively high allowable temperature and therefore do not require as high cooling performance as a secondary battery, but are required to have safety and lubrication performance. In addition, the lubricating composition circulating in the circulation circuit connected to the secondary battery, the electric motor, and the reducer is also required to have high insulation properties. As described above, the performance requirements for lubricating oil compositions for cooling and / or lubricating secondary batteries, electronic motors, and reducers differ, and thus, up until now, different lubricating oil compositions have been used for each device. However, the lubricating oil composition circulating through these devices needs to satisfy all of the performance requirements of these devices. For this reason, the lubricating oil composition of the present invention is adjusted so as to satisfy the above requirements (I) to (III).

[0010] Requirement (I) specifies the cooling performance of a lubricating oil composition. A lubricating oil composition that satisfies requirement (I) has high cooling performance and is particularly capable of maintaining a constant temperature of a secondary battery. From the above viewpoint, the silver rod temperature change rate ΔT specified in requirement (I) may be 72° C. or more, 74° C. or more, or 76° C. or more. The silver rod temperature change rate ΔT specified in requirement (I) can be increased by adjusting the kinetic viscosity of the lubricating oil composition to a low value. However, if the kinetic viscosity of the lubricating oil composition is set too low, it may become difficult to adjust it so as to satisfy requirement (II).

[0011] Requirement (II) specifies the safety of the lubricating oil composition. For example, an electric motor may temporarily reach a high temperature, and at that time, the lubricating oil composition may ignite. Requirement (II) is a requirement for the lubricating oil composition to ensure safety, particularly when used to lubricate an electric motor. From the above viewpoint, the flash point specified in requirement (II) may be 110°C or higher, 120°C or higher, 130°C or higher, 140°C or higher, 150°C or higher, 160°C or higher, or 170°C or higher. The flash point defined in requirement (II) can be increased by adjusting the kinetic viscosity of the lubricating oil composition to a high value. However, if the kinetic viscosity of the lubricating oil composition is set too high, it may become difficult to adjust it so as to satisfy requirement (I).

[0012] Requirement (III) specifies the insulating property of the lubricating oil composition. High insulating property is required for the lubricating oil composition circulating in the circulation circuit connected to the secondary battery, the electric motor, and the reduction gear. From the above viewpoint, the volume resistivity stipulated in requirement (III) is 5.0×10 7 Ω cm or more, 1.0×10 8 Ω cm or more, 5.0×10 8 Ω cm or more, or 1.0×10 9 It may be Ω·cm or more. The volume resistivity defined by requirement (III) can be adjusted by selecting a base oil having low polarity as the base oil used in the lubricating oil composition.

[0013] The lubricating oil composition of one embodiment of the present invention has a kinetic viscosity at 30° C. of 5.0 mm from the viewpoint of satisfying the above requirement (II) and adjusting the composition to have excellent lubricating performance. 2 / s or more, 6.0mm 2 / s or more, 7.0mm 2 / s or more, 8.0mm 2 / s or more, 9.0mm 2 / s or more, 10.0mm 2 / s or more, or 11.0 mm 2 / s or more, and from the viewpoint of adjusting to satisfy the above requirement (I),2 / s or less, 35.0mm 2 / s or less, 30.0mm 2 / s or less, 25.0mm 2 / s or less, 20.0mm 2 / s or less, or 15.0 mm 2 / s or less may be used. In particular, by adjusting the kinetic viscosity at 30°C to the above range, it is possible to exhibit high cooling performance for the secondary battery and keep the temperature of the secondary battery constant, while maintaining good cooling and lubricating performance for the electric motor and the reducer. Therefore, the lubricating oil composition can be circulated in a circulation circuit connected to at least the secondary battery, the electric motor, and the reducer, and is more suitable for applications in which the lubricating oil composition is used to control the temperatures of at least the secondary battery, the electric motor, and the reducer.

[0014] The kinematic viscosity at 40° C. of the lubricating oil composition of one embodiment of the present invention satisfies the above-mentioned requirement (II) and is set to 3.0 mm from the viewpoint of adjusting the composition to a lubricating oil composition having excellent lubricating performance. 2 / s or more, 4.0mm 2 / s or more, 5.0mm 2 / s or more, 6.0mm 2 / s or more, 7.0mm 2 / s or more, or 8.0 mm 2 / s or more, and from the viewpoint of adjusting to satisfy the above requirement (I), 2 / s or less, 25.0mm 2 / s or less, 20.0mm 2 / s or less, 15.0mm 2 / s or less, or 10.0 mm 2 / s or less may be used.

[0015] The lubricating oil composition of one embodiment of the present invention has a kinematic viscosity at 100° C. of 1.0 mm 2 / s or more, 1.2mm 2 / s or more, 1.5mm 2 / s or more, 1.7mm 2 / s or more, 2.0mm 2 / s or more, or 2.2 mm 2 / s or more, and from the viewpoint of adjusting to satisfy the above requirement (I), 2 / s or less, 4.5mm 2 / s or less, 4.0mm 2 / s or less, 3.5mm 2 / s or less, or 3.0 mm 2 / s or less may be used.

[0016] The viscosity index of the lubricating oil composition of one embodiment of the present invention may be 70 or greater, 80 or greater, 90 or greater, 100 or greater, 110 or greater, or 120 or greater. In this specification, the kinematic viscosity and viscosity index at each temperature refer to values ​​measured and calculated in accordance with JIS K2283:2000.

[0017] The lubricating oil composition of one embodiment of the present invention may have a transmittance of 90% or more, 93% or more, 95% or more, or 97% or more. In this specification, the transmittance of a lubricating oil composition means a value measured at a wavelength of 600 nm in accordance with JIS K0115.

[0018] The lubricating oil composition of one embodiment of the present invention contains a base oil and may further contain lubricating oil additives. The base oil and lubricating oil additives that may be contained in the lubricating oil composition of one embodiment of the present invention will be described below.

[0019] <Base oil> The base oil contained in the lubricating oil composition used in one embodiment of the present invention may be one or more oils selected from mineral oils and synthetic oils. Examples of mineral oils include atmospheric residual oils obtained by atmospheric distillation of crude oils such as paraffinic crude oil, intermediate base crude oil, and naphthenic crude oil; distillate oils obtained by vacuum distillation of these atmospheric residual oils; and refined oils obtained by subjecting the distillate oils to one or more refining treatments such as solvent deasphalting, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, and hydrorefining. Examples of synthetic oils include poly-α-olefins such as α-olefin homopolymers or α-olefin copolymers (e.g., α-olefin copolymers having 8 to 14 carbon atoms, such as ethylene-α-olefin copolymers); isoparaffins; polyalkylene glycols; ester-based oils such as polyol esters, dibasic acid esters, and phosphate esters; ether-based oils such as polyphenyl ether; alkylbenzenes; alkylnaphthalenes; and synthetic oils (GTL) obtained by isomerizing wax produced from natural gas by the Fischer-Tropsch process or the like (GTL wax (Gas To Liquids WAX)). Among these, the base oil used in one embodiment of the present invention is preferably a base oil with low polarity from the viewpoint of preparing a lubricating oil composition that satisfies the above requirement (III), and more preferably contains one or more selected from mineral oils and poly-α-olefins.

[0020] In the lubricating oil composition of one embodiment of the present invention, the content of the base oil may be, based on the total amount (100 mass%) of the lubricating oil composition, 50 mass% or more, 60 mass% or more, 70 mass% or more, 75 mass% or more, 80 mass% or more, 85 mass% or more, 90 mass% or more, or 93 mass% or more, or may be 100 mass% or less, 99 mass% or less, 98 mass% or less, or 97 mass% or less.

[0021] <Lubricant additives> The lubricating oil composition used in one embodiment of the present invention may contain lubricating oil additives together with the base oil depending on the application, as long as the effects of the present invention are not impaired. Examples of lubricating oil additives include pour point depressants, viscosity index improvers, extreme pressure agents, antioxidants, metal detergents, ashless dispersants, antiwear agents, demulsifiers, friction modifiers, rust inhibitors, metal deactivators, antistatic agents, and antifoaming agents. These lubricating oil additives may be used alone, or two or more of them may be used in combination. As a specific embodiment, the lubricating oil composition used in one embodiment of the present invention may be a lubricating oil composition containing a base oil and one or more lubricating oil additives selected from antiwear agents, metal deactivators, metal detergents, dispersants, and antifoaming agents.

[0022] The content of each of these lubricating oil additives can be appropriately adjusted within a range that does not impair the effects of the present invention, but is usually 0.001 to 15 mass%, preferably 0.005 to 10 mass%, and more preferably 0.01 to 5 mass%, for each additive independently, based on the total amount (100 mass%) of the lubricating oil composition.

[0023] [Circulation System] First, a first embodiment of the present invention will be described with reference to FIG. 1. FIG. 1 shows a first circulation system 100 attached to a vehicle 10. The vehicle 10 mainly includes a secondary battery (battery) 11, an electric motor 12, a reducer 13, and a PCU (Power Control Unit) 14. A battery cooling jacket 111 is provided around the secondary battery 11 so as to be in close contact with the secondary battery 11, a motor cooling jacket 112 is provided around the electric motor 12 and the reducer 13 so as to be in close contact with the electric motor 12 and the reducer 13 so as to be able to exchange heat, and a PCU cooling jacket 141 is provided around the PCU 14 so as to be in close contact with a component to be cooled in the PCU 14, for example, a semiconductor, so as to be able to exchange heat. The battery cooling jacket 111, the motor cooling jacket 112, and the PCU cooling jacket 141 are each configured to be liquid-tight while having jacket inlets 111a, 112a, and 141a and jacket outlets 111b, 112b, and 141b.

[0024] The first circulation system 100 mainly includes a battery cooling jacket 111, a motor cooling jacket 112, a PCU cooling jacket 141, a circulation circuit 120, an oil pump 130, an oil tank 140, and a radiator (oil cooler) 150.

[0025] The oil pump 130 is connected to an oil tank 140, which is connected to a radiator 150. The radiator 150 receives the lubricating oil composition and flows it through an internal flow path, and then blows air or liquid against a number of fins in contact with the outside of this internal flow path to exchange heat with the lubricating oil composition, for example, to cool it, and sends it to the oil tank 140. The oil tank 140 receives and stores the lubricating oil composition from the radiator 150. The oil pump 130 pressure-feeds the lubricating oil composition in the oil tank 140 to the outside.

[0026] The circulation circuit 120 includes a first path 121 connected to the secondary battery 11, and a second path 122 connected to the electric motor 12 and the reducer 13, and is capable of circulating the lubricating oil composition.

[0027] The first path 121 mainly comprises a first inlet pipe 121a connecting the outlet of the oil pump 130 and the jacket inlet 111a of the battery cooling jacket 111, and a first outlet pipe 121b connecting the jacket outlet 111b of the battery cooling jacket 111 and the jacket inlet 141a of the PCU cooling jacket 141.

[0028] The second path 122 mainly comprises a second inlet pipe 122a connecting the outlet of the oil pump 130 and the jacket inlet 112a of the motor cooling jacket 112, and a second outlet pipe 122b connecting the jacket outlet 112b of the motor cooling jacket 112 and the inlet of the radiator 150.

[0029] The outlet 121d of the first path 121 is connected to the jacket inlet 141a of the PCU cooling jacket 141, the jacket outlet 141b of the PCU cooling jacket 141 is connected to the inlet of the radiator 150, the outlet of the radiator 150 is connected to the inlet of the oil tank 140, and the outlet of the oil tank 140 is connected to the inlet of the oil pump 130.

[0030] An outlet 122d of the second path 122 is connected to an inlet of the radiator 150, an outlet of the radiator 150 is connected to an inlet of the oil tank 140, and an outlet of the oil tank 140 is connected to an inlet of the oil pump 130. That is, the first path 121 and the second path 122, or the secondary battery 11, the electric motor 12, and the reducer 13 are connected in parallel to the radiator 150, the oil tank 140, and the oil pump 130. The first path 121 and the second path 122 are connected together to the same or one radiator 150, together to the same or one oil tank 140, and together to the same or one oil pump 130.

[0031] Next, the flow of the lubricating oil composition in the first circulation system 100 will be described.

[0032] The lubricating oil composition stored in the oil tank 140 is pumped to the first path 121 and the second path 122 by the oil pump 130. The lubricating oil composition pumped to the second path 122 flows into the motor cooling jacket 112 through the second inlet pipe 122a, and cools the electric motor 12 and the reducer 13 to keep them at a constant temperature. This increases the temperature of the lubricating oil composition. Then, the lubricating oil composition is pumped to the radiator 150 through the second outlet pipe 122b. The radiator 150 cools the lubricating oil composition and sends it to the oil tank 140. The radiator 150 keeps the temperature of the lubricating oil composition constant. On the other hand, the lubricating oil composition pumped from the oil tank 140 to the first path 121 flows into the battery cooling jacket 111 through the first inlet pipe 121a, and keeps the secondary battery 11 warm, that is, keeps the temperature of the secondary battery 11 constant. As described above, the lubricating oil composition in the oil tank 140 is kept at a constant temperature by the radiator 150, so that when the temperature of the secondary battery 11 is lower than the desired temperature, the secondary battery 11 can be warmed, and when the temperature of the secondary battery 11 is higher than the desired temperature, the secondary battery 11 can be cooled. Then, the lubricating oil composition flows into the PCU cooling jacket 141 through the first outflow pipe 121b, and cools the PCU 14 to keep it at a constant temperature. This increases the temperature of the lubricating oil composition. Then, the lubricating oil composition is pumped from the PCU cooling jacket 141 to the radiator 150. The radiator 150 cools the lubricating oil composition and sends it to the oil tank 140. The temperature of the lubricating oil composition is kept constant by the radiator 150.

[0033] According to the first circulation system 100, the temperatures of the secondary battery 11, the electric motor 12, and the reducer 13 can be controlled, and more specifically, the temperature of the secondary battery 11 can be kept constant while cooling the electric motor 12 and the reducer 13.

[0034] A second embodiment of the present invention will be described with reference to Fig. 2. Fig. 2 shows a second circulation system 200 that is attached to a vehicle 10. Configurations similar to those of the first embodiment are given the same reference numerals and descriptions thereof will be omitted.

[0035] The second circulation system 200 mainly includes a battery cooling jacket 111, a motor cooling jacket 112, a PCU cooling jacket 141, a circulation circuit 220, a first oil pump 231, a second oil pump 232, an oil tank 140, and a radiator (oil cooler) 150.

[0036] The first oil pump 231 and the second oil pump 232 are connected to the oil tank 140 and pump the lubricating oil composition in the oil tank 140 to the outside. The oil tank 140 is connected to the radiator 150 and receives and stores the lubricating oil composition from the radiator 150. The radiator 150 receives the lubricating oil composition, cools it, and sends it to the oil tank 140.

[0037] The circulation circuit 220 includes a first path 221 connected to the secondary battery 11 and a second path 222 connected to the electric motor 12 and the reducer 13 . The first path 221 mainly comprises a first inlet upstream pipe 221e connecting the outlet of the oil tank 140 and the inlet of the first oil pump 231, a first inlet downstream pipe 221a connecting the outlet of the first oil pump 231 and the jacket inlet 111a of the battery cooling jacket 111, and a first outlet pipe 221b connecting the jacket outlet 111b of the battery cooling jacket 111 and the jacket inlet 141a of the PCU cooling jacket 141.

[0038] The second path 122 mainly comprises a second inlet upstream pipe 222e connecting the outlet of the oil tank 140 and the inlet of the second oil pump 232, a second inlet downstream pipe 222a connecting the outlet of the second oil pump 232 and the jacket inlet 112a of the motor cooling jacket 112, and a second outlet pipe 222b connecting the jacket outlet 112b of the motor cooling jacket 112 and the inlet of the radiator 150.

[0039] An outlet 221d of the first path 221 is connected to a jacket inlet 141a of the PCU cooling jacket 141, a jacket outlet 141b of the PCU cooling jacket 141 is connected to an inlet of the radiator 150, and an outlet of the radiator 150 is connected to an inlet of the oil tank 140.

[0040] An outlet 222d of the second path 222 is connected to an inlet of the radiator 150, and an outlet of the radiator 150 is connected to an inlet of the oil tank 140. That is, the first path 221 and the second path 222, or the secondary battery 11, the electric motor 12, and the reducer 13 are connected in parallel to the radiator 150 and the oil tank 140. The first path 221 and the second path 222 are both connected to the same or one radiator 150, and are also both connected to the same or one oil tank 140.

[0041] Next, the flow of the lubricating oil composition in the second circulation system 200 will be described.

[0042] The lubricating oil composition stored in the oil tank 140 is pumped to the first path 221 and the second path 222 by the first oil pump 231 and the second oil pump 232, respectively. The lubricating oil composition pumped to the second path 222 flows into the motor cooling jacket 112 through the second inlet leading pipe 222e, the second oil pump 232, and the second inlet trailing pipe 222a, and cools the electric motor 12 and the reducer 13 to keep them at a constant temperature. This increases the temperature of the lubricating oil composition. Then, the lubricating oil composition is pumped to the radiator 150 through the second outlet pipe 222b. The radiator 150 cools the lubricating oil composition and sends it to the oil tank 140. The radiator 150 keeps the temperature of the lubricating oil composition constant. On the other hand, the lubricating oil composition pumped from the oil tank 140 to the first path 121 flows into the battery cooling jacket 111 through the first inflow upstream pipe 221e, the first oil pump 231, and the first inflow downstream pipe 221a, and keeps the secondary battery 11 warm, that is, keeps the temperature of the secondary battery 11 constant. As described above, the lubricating oil composition in the oil tank 140 is kept at a constant temperature by the radiator 150, so that when the temperature of the secondary battery 11 is lower than the desired temperature, the secondary battery 11 can be warmed, and when the temperature of the secondary battery 11 is higher than the desired temperature, the secondary battery 11 can be cooled. Then, the lubricating oil composition flows into the PCU cooling jacket 141 through the first outflow pipe 221b, and cools the PCU 14 to keep it at a constant temperature. This causes the temperature of the lubricating oil composition to rise. Then, the lubricating oil composition is pumped from the PCU cooling jacket 141 to the radiator 150. The radiator 150 cools the lubricating oil composition and sends it to the oil tank 140. The radiator 150 keeps the temperature of the lubricating oil composition constant.

[0043] According to the second circulation system 200, the temperatures of the secondary battery 11, the electric motor 12, and the reducer 13 can be controlled, and more specifically, the temperature of the secondary battery 11 can be kept constant while cooling the electric motor 12 and the reducer 13.

[0044] 3, an oil cooler 251 may be used instead of the radiator 150. For example, long-life coolant (LLC) or an air conditioner refrigerant is circulated through such oil cooler 251 using a pump 233 to cool the lubricating oil composition or keep the temperature constant.

[0045] A third embodiment of the present invention will be described with reference to Fig. 4. Fig. 4 shows a third circulation system 300 that is attached to a vehicle 10. Configurations similar to those of the first and second embodiments are given the same reference numerals and descriptions thereof will be omitted.

[0046] The third circulation system 300 mainly includes a battery cooling jacket 111, a motor cooling jacket 112, a PCU cooling jacket 141, a circulation circuit 320, an oil pump 130, a control valve 160, an oil tank 140, and a radiator (oil cooler) 150.

[0047] The control valve 160 is connected to the oil pump 130 and can be opened and closed based on the temperatures of at least the lubricating oil composition, the secondary battery 11, the electric motor 12, the reducer 13, and / or the PCU 14, and pumps the lubricating oil composition to the first path 121 and the second path 122. The control valve 160 can be opened and closed based on only the temperature of the secondary battery 11, or only the temperatures of the electric motor 12 and the reducer 13. The oil pump 130 is connected to the oil tank 140, and the oil tank 140 is connected to the radiator 150. The radiator 150 receives the lubricating oil composition, cools it, and sends it to the oil tank 140. The oil tank 140 receives the lubricating oil composition from the radiator 150 and stores it. The oil pump 130 pumps the lubricating oil composition in the oil tank 140 to the outside.

[0048] The circulation circuit 120 includes a first path 321 connected to the secondary battery 11 and a second path 322 connected to the electric motor 12 and the reducer 13 .

[0049] The first path 321 mainly comprises a first inlet pipe 321a connecting the outlet of the control valve 160 and the jacket inlet 111a of the battery cooling jacket 111, and a first outlet pipe 321b connecting the jacket outlet 111b of the battery cooling jacket 111 and the jacket inlet 141a of the PCU cooling jacket 141.

[0050] The second path 322 mainly comprises a second inlet pipe 322a connecting the outlet of the control valve 160 and the jacket inlet 112a of the motor cooling jacket 112, and a second outlet pipe 322b connecting the jacket outlet 112b of the motor cooling jacket 112 and the inlet of the radiator 150. A control valve 160 is provided at the junction of the first path 321 and the second path 322 to control the flow of the lubricating oil composition from the radiator (oil cooler) 150 to the first path 321 and / or the second path 322.

[0051] The outlet 321d of the first path 321 is connected to the jacket inlet 141a of the PCU cooling jacket 141, the jacket outlet 141b of the PCU cooling jacket 141 is connected to the inlet of the radiator 150, the outlet of the radiator 150 is connected to the inlet of the oil tank 140, and the outlet of the oil tank 140 is connected to the inlet of the oil pump 130.

[0052] An outlet 322d of the second path 322 is connected to an inlet of the radiator 150, an outlet of the radiator 150 is connected to an inlet of the oil tank 140, and an outlet of the oil tank 140 is connected to an inlet of the oil pump 130. That is, the first path 321 and the second path 322, or the secondary battery 11, the electric motor 12, and the reducer 13 are connected in parallel to the oil pump 130, the oil tank 140, and the radiator 150. The first path 321 and the second path 322 are connected together to the same or one radiator 150, are connected together to the same or one oil tank 140, and are connected together to the same or one oil pump 130.

[0053] Next, the flow of the lubricating oil composition in the third circulation system 300 will be described.

[0054] The lubricating oil composition stored in the oil tank 140 is pumped to the control valve 160 by the oil pump 130. The control valve 160 opens and closes based on the temperatures of at least the lubricating oil composition, the secondary battery 11, the electric motor 12, the reducer 13, and / or the PCU 14, and pumps the lubricating oil composition to the first path 121 and the second path 122.

[0055] The control valve 160 is capable of pumping the lubricating oil composition to both or either the first path 121 and the second path 122. Also, the flow rate to the first path 121 and the second path 122 can be adjusted.

[0056] For example, when the temperatures of the secondary battery 11, the electric motor 12, the reducer 13, and the PCU 14 are higher than a desired temperature, the lubricating oil composition is sent to the first path 321 and the second path 322 to lower the temperatures of the secondary battery 11, the electric motor 12, the reducer 13, and the PCU 14 to the desired temperature. At this time, the flow rates to the first path 121 and the second path 122 are adjusted according to the temperatures of these components.

[0057] For example, when the temperature of the secondary battery 11 is lower than the desired temperature and the temperature of the lubricating oil composition is higher than the desired temperature, the lubricating oil composition is sent to the first path 321 to raise the temperature of the secondary battery 11 to the desired temperature.

[0058] As a result, when the temperature of the secondary battery 11 is lower than a desired temperature, the secondary battery 11 can be heated, and when the temperature of the secondary battery 11 is higher than a desired temperature, the secondary battery 11 can be cooled.

[0059] According to the third circulation system 300, the temperatures of the secondary battery 11, the electric motor 12, and the reducer 13 can be controlled, and more specifically, the temperature of the secondary battery 11 can be kept constant more precisely while cooling the electric motor 12 and the reducer 13.

[0060] As shown in Fig. 5, an oil cooler 351 may be used instead of the radiator 150. For example, long-life coolant (LLC) or an air conditioner refrigerant is caused to flow through such oil cooler 351 using a pump 333, and the lubricating oil composition is cooled or its temperature is kept constant via the oil cooler 351. In addition to this, as shown in Fig. 7, the long-life coolant (LLC) or the air conditioner refrigerant may be caused to flow through a PCU cooling jacket 141 using a pump 333, to cool the PCU 14 or keep its temperature constant.

[0061] A fourth embodiment of the present invention will be described with reference to Fig. 8. Fig. 8 shows a fourth circulation system 400 attached to a vehicle 10. The same components as those in the first to third embodiments are given the same reference numerals and the description thereof will be omitted.

[0062] The fourth circulation system 400 mainly includes a battery cooling jacket 111, a motor cooling jacket 112, a PCU cooling jacket 141, a circulation circuit 420, a first oil pump 431, a second oil pump 432, and a radiator (oil cooler) 150.

[0063] The first oil pump 231 and the second oil pump 232 are connected to the radiator 150, and pump the lubricating oil composition supplied from the radiator 150 to the outside. The radiator 150 receives and cools the lubricating oil composition.

[0064] The circulation circuit 420 includes a first path 421 connected to the secondary battery 11 and a second path 422 connected to the electric motor 12 and the reducer 13 .

[0065] The first path 421 mainly comprises a first inlet upstream pipe 421e connecting the outlet of the radiator 150 and the inlet of the first oil pump 431, a first inlet downstream pipe 421a connecting the outlet of the first oil pump 431 and the jacket inlet 111a of the battery cooling jacket 111, and a first outlet pipe 421b connecting the jacket outlet 111b of the battery cooling jacket 111 and the inlet a of the radiator 150.

[0066] The second path 422 mainly comprises a second inlet upstream pipe 422e connecting the outlet of the radiator 150 and the inlet of the second oil pump 432, a second inlet downstream pipe 422a connecting the outlet of the second oil pump 432 and the jacket inlet 112a of the motor cooling jacket 112, and a second outlet pipe 422b connecting the jacket outlet 112b of the motor cooling jacket 112 and the inlet of the radiator 150.

[0067] An outlet 421d of the first path 421 and an outlet 422d of the second path 222 are connected to an inlet of the radiator 150. That is, the first path 421 and the second path 422, or the secondary battery 11, the electric motor 12, and the reducer 13 are connected in parallel to the radiator 150. The first path 421 and the second path 422 are connected together to the same or one radiator 150.

[0068] A third path 435, which is a system separate from the first path 421 and the second path 422, is connected to the radiator (oil cooler) 150. A pump 433, a PCU cooling jacket 141, and the radiator 150 are connected to the third path, and, for example, a long-life coolant (LLC) or a refrigerant of an air conditioner is caused to flow using the pump 433, and the lubricating oil composition is cooled or the temperature is kept constant via the radiator (oil cooler) 150. In addition, the long-life coolant (LLC) or the refrigerant of an air conditioner is caused to flow through the PCU cooling jacket 141 using the pump 433, and the PCU 14 is cooled or the temperature is kept constant.

[0069] Next, the flow of the lubricating oil composition in the fourth circulation system 400 will be described.

[0070] The lubricating oil composition flowing out from the radiator 150 is pumped to the first path 421 and the second path 422 by the first oil pump 431 and the second oil pump 432, respectively. The lubricating oil composition pumped to the second path 422 flows into the motor cooling jacket 112 through the second inlet leading pipe 422e, the second oil pump 432, and the second inlet trailing pipe 422a, and cools the electric motor 12 and the reducer 13 to keep them at a constant temperature. This increases the temperature of the lubricating oil composition. Then, the lubricating oil composition is pumped to the radiator 150 through the second outlet pipe 422b. The radiator 150 cools and sends out the lubricating oil composition. The temperature of the lubricating oil composition is kept constant by the radiator 150. On the other hand, the lubricating oil composition pumped from the radiator 150 to the first path 421 flows into the battery cooling jacket 111 through the first inflow upstream pipe 421e, the first oil pump 431, and the first inflow downstream pipe 421a, and keeps the secondary battery 11 warm, that is, keeps the temperature of the secondary battery 11 constant. As described above, since the lubricating oil composition is kept at a constant temperature by the radiator 150, when the temperature of the secondary battery 11 is lower than the desired temperature, the secondary battery 11 can be warmed, and when the temperature of the secondary battery 11 is higher than the desired temperature, the secondary battery 11 can be cooled. Then, the lubricating oil composition flows into the radiator 150 through the first outflow pipe 421b. The radiator 150 cools and sends out the lubricating oil composition. The temperature of the lubricating oil composition is kept constant by the radiator 150.

[0071] According to the fourth circulation system 400, the temperatures of the secondary battery 11, the electric motor 12, and the reducer 13 can be controlled, and more specifically, the temperature of the secondary battery 11 can be kept constant while cooling the electric motor 12 and the reducer 13.

[0072] A fifth embodiment of the present invention will be described with reference to Fig. 9. Fig. 9 shows a fifth circulation system 500 attached to a vehicle 10. The same components as those in the first to fourth embodiments are given the same reference numerals and the description thereof will be omitted.

[0073] The fifth circulation system 500 mainly includes a battery cooling jacket 111, a motor cooling jacket 112, a PCU cooling jacket 141, a circulation circuit 520, an oil pump 130, an oil tank 140, a radiator (oil cooler) 150, and a control valve 560. The configurations and connection relationships of the oil pump 130, the oil tank 140, and the radiator 150 are similar to those of the first embodiment, and therefore will not be described.

[0074] The circulation circuit 520 includes a first path 521 connected to the secondary battery 11, and a second path 522 connected to the electric motor 12 and the reducer 13, and is capable of circulating the lubricating oil composition.

[0075] The first path 521 mainly includes a first inlet pipe 521a connecting the outlet of the oil pump 130 and the jacket inlet 111a of the battery cooling jacket 111, and a first outlet pipe 521b connecting the jacket outlet 111b of the battery cooling jacket 111 and the jacket inlet 141a of the PCU cooling jacket 141 via a control valve 560. The control valve 560 causes a portion of the lubricating oil composition flowing to the secondary battery 11 to flow to the second path 522. The outlet 521d of the first path 521 is connected to the jacket inlet 141a of the PCU cooling jacket 141, and the jacket outlet 141b of the PCU cooling jacket 141 is connected to the inlet of the radiator 150.

[0076] The second path 522 mainly includes a second inlet pipe 522a connecting the outlet of the control valve 560 and the jacket inlet 112a of the motor cooling jacket 112, and a second outlet pipe 522b connecting the jacket outlet 112b of the motor cooling jacket 112 and the inlet of the radiator 150. An outlet 522d of the second path 522 is connected to the inlet of the radiator 150. That is, the secondary battery 11, the electric motor 12, and the reducer 13 are connected in series to the radiator 150, the oil tank 140, and the oil pump 130. In addition, the second path 522 and the first outlet pipe 521b are connected in parallel to the PCU 14. The first path 521 and the second path 522 are both connected to the same or one radiator 150, are also both connected to the same or one oil tank 140, and are also both connected to the same or one oil pump 130.

[0077] Next, the flow of the lubricating oil composition in the fifth circulation system 500 will be described.

[0078] The lubricating oil composition flowing out from the oil tank 140 is pumped to the first path 521 by the oil pump 130. The lubricating oil composition pumped to the first path 521 flows into the battery cooling jacket 111 through the first inlet pipe 521a, and keeps the secondary battery 11 warm, that is, keeps the temperature of the secondary battery 11 constant. The lubricating oil composition flowing out from the battery cooling jacket 111 flows into the control valve 560. The control valve 560 causes a part of the lubricating oil composition flowing out from the battery cooling jacket 111 to flow into the second path 522. The lubricating oil composition pumped to the second path 522 flows into the motor cooling jacket 112 through the second inlet pipe 522a, and cools the electric motor 12 and the reducer 13 to keep them at a constant temperature. This increases the temperature of the lubricating oil composition. Then, the lubricating oil composition is pumped to the radiator 150 through the second outlet pipe 522b. The radiator 150 cools and sends out the lubricating oil composition. The temperature of the lubricating oil composition is kept constant by the radiator 150. The lubricating oil composition is then pressure-fed by the oil pump 130 to the battery cooling jacket 111 via the first path 521. As described above, since the lubricating oil composition is kept at a constant temperature by the radiator 150, the secondary battery 11 can be warmed when the temperature of the secondary battery 11 is lower than a desired temperature, and the secondary battery 11 can be cooled when the temperature of the secondary battery 11 is higher than a desired temperature.

[0079] According to the fifth circulation system 500, the temperatures of the secondary battery 11, the electric motor 12, and the reducer 13 can be controlled, and more specifically, the temperature of the secondary battery 11 can be kept constant while cooling the electric motor 12 and the reducer 13.

[0080] The fifth circulation system 500 may include an oil pump in the second inlet pipe 522a.

[0081] The first to fifth circulation systems 100 to 500 may each include a secondary cell (battery) 11, an electric motor 12, a reducer 13, and a PCU (Power Control Unit) .

[0082] In the first to third and fifth circulation systems 100 to 300, 500, the PCU 14 is cooled by the lubricating oil composition, but the PCU 14 may not be provided with a PCU cooling jacket 141 and may be air-cooled instead of being cooled by the lubricating oil composition (see FIG. 6 for an example of a modified example of the third circulation system). In this case, the outlets 121d, 221d, 321d, 521d of the first paths 121, 221, 321, 521 are connected to the inlets of the radiator 150.

[0083] In any embodiment, it is preferable to install a filter capable of removing deposits from the lubricating oil composition after motor cooling jacket 112 with respect to the flow direction of the lubricating oil composition.

[0084] In any of the embodiments, an oil cooler may be used instead of a radiator. Such an oil cooler receives the lubricating oil composition and flows it through an internal flow path, and a large number of fins in contact with the outside of the internal flow path are pumped with, for example, long-life coolant (LLC) or a refrigerant for an air conditioner, to exchange heat with the lubricating oil composition, for example, to cool it or to keep the temperature constant.

[0085] In this specification and claims, the circulation circuit being connected to a secondary battery, an electric motor, and / or a reducer includes being connected to a battery cooling jacket and / or a motor cooling jacket, respectively.

[0086] According to a preferred embodiment of the lubricating oil composition of the present invention and a circulation system using this lubricating oil composition, it is possible to obtain a lubricating oil composition capable of controlling the temperatures of a secondary battery, an electric motor, and a reduction gear, and a circulation system using this lubricating oil composition. EXAMPLES

[0087] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. The methods for measuring and evaluating various physical properties are as follows. (1)Kinematic viscosity, viscosity index Measurements and calculations were made in accordance with JIS K2283:2000. (2) Silver bar temperature change ΔT In accordance with the "Cooling Performance Test Method: Method A" specified in JIS K2242:2012, the silver rod is heated so that the initial surface temperature T0 of the silver rod is 200°C, and the heated silver rod is placed in sample oil heated to 80°C. The temperature T of the silver rod surface 12 seconds after the silver rod is placed in the sample oil is 12 (℃) was measured. And, T0-T 12 was calculated as the silver rod temperature change ΔT. (3) Flash point Measurements were performed using the Cleveland Open Chamber (COC) method in accordance with JIS K2265-4:2007. (4) Volume resistivity Measurements were performed at a temperature of 80°C and 250V in accordance with JIS C2101:1999. (5) Shell abrasion test In accordance with ASTM D2783, a shell abrasion test was conducted using a four-ball tester at a rotation speed of 1800 rpm, a load of 392 N, an oil temperature of 80°C, and a test time of 30 minutes, and the average wear scar diameter of three 1 / 2 inch balls was calculated. The smaller the wear scar diameter, the better the abrasion resistance. (6) Visual Observation of Lubricating Oil Composition The lubricating oil composition to be measured was poured into a transparent test tube, and the appearance of the test tube was visually observed and evaluated according to the following criteria. A: Transparent, no opacity is observed. F: Opaque and cloudy. (7) Permeability of the lubricating oil composition The transmittance of the lubricating oil composition to be measured was measured at a wavelength of 600 nm in accordance with JIS K0115.

[0088] Examples 1 to 2, Comparative Examples 1 to 4 Lubricating oil compositions were prepared by adding base oils and additive mixtures of the types and amounts shown in Table 1. Details of each component used in the preparation of the lubricating oil compositions are as follows. <Base oil> ·"Mineral oil A": 40℃ kinematic viscosity = 8.1mm 2 / s paraffinic mineral oil. ·"Mineral oil B": 40℃ kinematic viscosity = 1.6mm 2 / s paraffinic mineral oil. ·"Mineral oil C": 40℃ kinematic viscosity = 31.4mm 2 / s paraffinic mineral oil. ·"Mineral oil D": 40℃ kinematic viscosity = 44.4mm 2 / s paraffinic mineral oil. · "Synthetic oil": 40℃ kinematic viscosity = 8.0mm 2 / s polyalphaolefin. ·"High polar base oil": 40℃ kinematic viscosity = 8.6mm 2 / s of ethylene glycol. <Additive mixture> "Additive Mixture": an additive mixture comprising an extreme pressure agent, an antiwear agent, a metal deactivator, a detergent, a dispersant, and an antifoam agent.

[0089] The lubricating oil compositions thus prepared were subjected to the measurements and evaluations of the various physical properties (1) to (6) above. The results are shown in Table 1.

[0090] [Table 1]

[0091] From Table 1, it can be seen that the lubricating oil compositions of Examples 1 and 2 are lubricating oil compositions that satisfy requirements (I) to (III) and are suitable for use in controlling the temperatures of at least the secondary battery, the electric motor, and the reducer by being circulated in a circulation circuit connected to at least the secondary battery, the electric motor, and the reducer. [Explanation of symbols]

[0092] 100 Deterioration Measurement System 10 Vehicles 11 Secondary battery (battery) 12 Electric motor 13 Reducer 14 PCU 100 Circulation System 111 Battery cooling jacket 111a Jacket Entrance 111b Jacket exit 112 Motor cooling jacket 112a Jacket entrance 112b Jacket outlet 120 Circulation circuit 121 First Route 121a First inlet pipe 121b Second Outlet Pipe 121d exit 122 Second Route 122a Second inlet pipe 122b Second Outlet Pipe 122d exit 130 Oil pump 140 Oil Tank 141 Cooling jacket 141a Jacket entrance 141b Jacket Exit 150 Radiator (oil cooler) 160 Control valve 200 Second Circulation System 220 Circulation circuit 221 First Route 221a First inlet downstream pipe 221b First Outlet Pipe 221d exit 221e First inlet pipe 222 Second Route 222a Second inlet downstream pipe 222b Second Outlet Pipe 222d exit 222e Second inlet precursor 231 First Oil Pump 232 Second Oil Pump 233 Pump 251 Oil cooler 300 The Third Circulation System 320 circulation circuit 321 First Route 321a First inlet pipe 321b First Outlet Pipe 321d exit 322 Second Route 322a Second inlet pipe 322b Second Outlet Pipe 322d exit 333 Pump 351 Oil cooler 400 The Fourth Circulation System 420 Circulation circuit 421 First Route 421a First inlet downstream pipe 421b First Outlet Pipe 421d exit 421e First inlet pipe 422 Second Route 422a Second inlet downstream pipe 422b Second Outlet Pipe 422d exit 422e Second inlet precursor 431 First Oil Pump 432 Second Oil Pump 433 Pump 435 Third Route 500 The Fifth Circulation System 520 Circulation circuit 521 First Route 521a First inlet pipe 521b First Outlet Pipe 521d exit 522 Second Route 522a Second inlet pipe 522b Second Outlet Pipe 522c exit 560 Control Valve

Claims

1. A lubricating oil composition which is circulated in a circulation circuit connected to at least a secondary battery, an electric motor, and a reducer, and is used to control temperatures of at least the secondary battery, the electric motor, and the reducer, In accordance with the "Cooling Performance Test Method: Method A" specified in JIS K2242:2012, the initial surface temperature T ０ The surface temperature T of the silver rod after 12 seconds from the time when the silver rod having a temperature of 200°C was placed in the lubricating oil composition at 80°C １２ (°C), and T ０ -T １２ The silver rod temperature change ΔT calculated from is 70 ° C or more, The flash point measured by the Cleveland Open Circuit (C.O.C.) method in accordance with JIS K2265-4:2007 is 100°C or higher, The volume resistivity measured in accordance with JIS C2101:1999 is 1.0 × 10 ７ Ω·cm or more.

2. Kinematic viscosity at 30°C: 5.0 to 40.0 mm ２ 2. The lubricating oil composition of claim 1, wherein

3. 2. The lubricating oil composition of claim 1, wherein the lubricating oil composition comprises a base oil and one or more lubricating oil additives selected from antiwear agents, metal deactivators, metal detergents, dispersants, and antifoam agents.

4. 2. The lubricating oil composition of claim 1, which has a transmittance of 90% or greater.

5. 5. A circulation system comprising a circulation circuit connected to at least the secondary battery, the electric motor, and the reducer, the circulation circuit being capable of circulating the lubricating oil composition according to any one of claims 1 to 4, and controlling the temperatures of at least the secondary battery, the electric motor, and / or the reducer.

6. The circulation system according to claim 5 , wherein the circulation circuit further comprises a first path connected to the secondary battery and a second path connected to the electric motor and the reducer.

7. The circulation system of claim 6 , wherein the first path and the second path are both connected to the same radiator.

8. The circulation system according to claim 6 , wherein the first path and the second path are connected in parallel.

9. The circulation system according to claim 1 , wherein at least a portion of the circulation circuit connects the secondary battery, the electric motor, and the reducer in series.

10. The circulation system of claim 6 , wherein the first path and / or the second path includes an oil pump.

11. The circulation system according to claim 6 , wherein the first path and the second path are both connected to the same oil tank.

12. The circulation system of claim 6 , wherein the first path and the second path are both connected to the same oil pump.

13. The circulation system of claim 6 , further comprising a control valve disposed at a junction between the first path and the second path.

14. The circulation system according to claim 13 , wherein the control valve opens and closes depending on the temperature of the secondary battery.

15. The circulation system of claim 13 , wherein the control valve opens and closes depending on the temperature of the electric motor and the reducer.

16. A circulation system as described in claim 6, further comprising a control valve that controls the flow of the lubricating oil composition from the oil cooler to the first path and / or the second path.

17. A circulation system as described in Claim 16, wherein the control valve opens and closes depending on the temperature of the secondary battery.

18. A circulation system as described in Claim 16, wherein the control valve opens and closes depending on the temperature of the electric motor and the reducer.

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