JP7311395B2 - power transmission device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a power transmission device, and more particularly to a power transmission device including a power transmission unit and a case.

Conventionally, a power transmission device of this type has been proposed that includes a power transmission unit (automatic transmission), a case, an electric pump, an outer pipe (discharge passage), and a pipe inside the case (internal passage). (See Patent Document 1, for example). The case accommodates the power transmission unit. The electric pump is arranged outside the case. The outer pipe is connected to the oil discharge port of the electric pump and the case inner pipe. The in-case piping is arranged inside the case. In this device, the oil discharged from the electric pump outside the case is discharged to the outer pipe. The oil is supplied to an oil cooler arranged outside the case via a pipe inside the case.

JP 2014-114823 A

In the power transmission device described above, since the discharge port of the electric pump and the outer pipe are arranged outside the case, the connection between the discharge port and the outer pipe and the connection between the outer pipe and the pipe inside the case lead to the inside of the case. Air may enter the piping.

A main object of the power transmission device of the present invention is to suppress the entry of air into the pipes in the case.

The power transmission device of the present invention employs the following means in order to achieve the above main object.

The power transmission device of the present invention is
a power transmission unit that transmits power;
a case in which the power transmission unit is housed and a coolant is stored in the bottom;
A power transmission device comprising
an electric pump having a refrigerant suction port and a refrigerant discharge port, the electric pump being fixed to the outside of the case with the suction port and the discharge port directed toward the inside of the case;
A first end, which is one end of both ends, is arranged inside the case and communicates with the discharge port, and a second end, which is the opposite end of the first end, is connected to the discharge port. a pipe inside the case, the end of which communicates with an outer pipe arranged outside the case;
with
The pipe inside the case is arranged so that the first and second ends are positioned lower than the liquid level of the refrigerant stored in the bottom of the case,
This is the gist of it.

In the power transmission device of the present invention, the electric pump is fixed to the outside of the case with the suction port and the discharge port directed toward the inside of the case. The pipe inside the case is arranged inside the case, the first end, which is one of both ends, communicates with the discharge port, and the first end, which is the opposite end of the first end, is connected to the discharge port. The two ends communicate with an outer pipe arranged outside the case. Then, the pipe inside the case is arranged such that the first and second ends are located at positions lower than the liquid level of the refrigerant stored in the bottom of the case. Accordingly, since the first and second ends are arranged in the refrigerant, it is possible to suppress air from entering the pipe inside the case.

In such a power transmission device of the present invention, the pipe inside the case may be arranged so that there is a height difference between the first end and the second end. In this way, when air is mixed in the piping inside the case, the air can easily move to the lower end of the first end and the second end, so that the air can be more easily removed from the piping inside the case. be able to.

Further, in the power transmission device of the present invention, a communication member having a bottom suction port for sucking refrigerant stored in the bottom of the case and communicating with the suction port of the electric pump is provided, and the piping in the case is , may be positioned higher than the bottom inlet. Since the low-temperature refrigerant has a higher density than the high-temperature refrigerant, relatively low-temperature oil accumulates in the lower portion of the case, and relatively high-temperature oil accumulates near the liquid surface. Since the bottom suction port is located at a position lower than the case inner pipe, the temperature of the refrigerant supplied to the case inner pipe is lower than the temperature of the refrigerant around the case inner pipe. Therefore, the relatively low-temperature refrigerant in the pipe and the relatively high-temperature refrigerant around the case inside pipe can be heat-exchanged through the case inside pipe to cool the refrigerant around the case inside pipe. As a result, it is possible to suppress an increase in the temperature of the coolant near the liquid surface.

1 is a configuration diagram showing an outline of the configuration of a power transmission device 20 as an embodiment of the invention; FIG. 2 is a schematic external view showing an outline of the external appearance of the power transmission device 20; FIG. FIG. 2 is an external schematic diagram showing an outline of the external appearance of a main part of the power transmission device 20; FIG. 4 is a schematic diagram showing an outline of a state in which the main part shown in FIG. 3 is viewed from the inside of a case 24;

Next, a mode for carrying out the present invention will be described using examples.

FIG. 1 is a configuration diagram showing an outline of the configuration of a power transmission device 20 as one embodiment of the present invention. FIG. 2 is a schematic external view showing an outline of the external appearance of the power transmission device 20. As shown in FIG. In FIG. 2, a case-outside pipe 317 and an oil cooler 318, which will be described later, are not shown. FIG. 3 is a schematic external view showing an outline of the external appearance of the main parts of the power transmission device 20. As shown in FIG. FIG. 4 is a schematic diagram showing a schematic view of the essential parts shown in FIG.

The power transmission device 20 includes a power transmission unit 22, a case 24, and an oil cooling device 30, as shown in FIG.

The power transmission unit 22 is formed as a device that transmits power from the input member to the output member, and has planetary gears, friction engagement elements, and the like. Examples of the power transmission unit 22 include an automatic transmission that changes the speed of power from an engine as an input member and transmits the power to an axle connected to a drive shaft as an output member.

As shown in FIG. 2 , the case 24 accommodates the power transmission unit 22 inside, and stores working oil serving as a coolant for cooling the power transmission unit 22 in a bottom portion 240 .

Oil cooling device 30 is configured to cool power transmission unit 22 using hydraulic oil. The oil cooling device 30 includes a strainer 300, an electric oil pump (electric OP) 310, an inner case pipe 316, an outer case pipe 317, and an oil cooler 318, as shown in FIG.

The strainer 300 is composed of a wire mesh having a coarse mesh or a notched wire, and removes foreign substances contained in the refrigerant sucked from the suction port 300a. The strainer 300 is arranged at a position lower than the liquid surface Ls of the hydraulic oil stored in the bottom portion 240 of the case 24 and lower than the electric oil pump 310, as shown in FIG. The liquid level Ls varies in height depending on the operating state of the electric oil pump 310, the temperature of the power transmission unit 22, and the like. The strainer 300 is arranged at a position lower than the lowest position when the height of the liquid surface Ls fluctuates.

Electric oil pump 310 is configured as a pump driven by electric power, and as shown in FIG. Dispense. Hydraulic oil sucked up through the strainer 300 is relatively clean because foreign matter has been removed by the strainer 300. Foreign matter is likely to be mixed in the flow path between. Therefore, it is desirable to arrange the electric oil pump 310 near the strainer 300 , that is, near the bottom 240 of the case 24 . In the embodiment, the electric oil pump 310 has an opening (not shown) formed in a predetermined range including the bottom portion 240 of the case 24, and the hydraulic oil suction port 310d and the hydraulic oil discharge port 310e are directed toward the inside of the case 24. The suction port 310d and the discharge port 310e are fitted so as to be lower than the liquid surface Ls of the hydraulic oil and higher than the discharge port (not shown) of the strainer 300. As shown in FIG. Electric oil pump 310 has fixed portions 310a to 310c. Each fixed part 310a-310c is fixed to the outside of the case 24 by bolts 312a-312c so that no gap is formed between the fixed parts 310a-310c.

As shown in FIG. 1 , the case internal piping 316 constitutes part of a supply flow path for supplying the hydraulic oil from the electric oil pump 310 to the power transmission unit 22 . The details of the configuration of the case internal piping 316 will be described later.

As shown in FIG. 1 , the case-outside pipe 317 constitutes a supply flow path for supplying hydraulic oil from the electric oil pump 310 to the power transmission unit 22 together with the case-inside pipe 316 . An oil cooler 318 of the cooling device 40 is attached to the pipe 317 outside the case.

The oil cooler 318 is arranged outside the case 24 and is attached to the case outside pipe 317 as shown in FIG. The oil cooler 318 adjusts the temperature of the hydraulic oil by exchanging heat between the hydraulic oil flowing in the case-outside piping 317 and the cooling water flowing in the piping 402 of the cooling device 40 . A radiator 404 that exchanges heat between outside air and cooling water, an electric water pump 406 that pumps the cooling water, and the like are attached to the piping 402 of the cooling device 40 . The cooling device 40 adjusts the temperature of the cooling water by adjusting the output of the electric water pump 406 . When the power transmission unit 22 is an automatic transmission in which power from the engine as an input member is changed and transmitted to an axle connected to a drive shaft as an output member, the cooling device 40 may be used as the cooling device 40. Examples include an engine cooling device that cools the engine using water.

In the power transmission device 20 configured in this manner, the hydraulic oil stored in the bottom 240 of the case 24 is sucked up through the strainer 300 using the electric oil pump 310 and supplied to the pipe 316 inside the case and the pipe 317 outside the case. . The hydraulic oil in the case-outside pipe 317 is temperature-controlled by the oil cooler 318 and supplied to the power transmission unit 22 . The hydraulic oil supplied to the power transmission unit 22 lubricates and cools the parts that make up the power transmission unit 22, such as planetary gears and frictional engagement elements, and then flows into the gap between the case 24 and the power transmission unit 22. through the return channel 330 to the bottom 240 of the case 24 . That is, the hydraulic oil circulates through the bottom portion 240 of the case 24, the strainer 300, the electric oil pump 310, the oil cooler 318, the power transmission unit 22, the return passage 330, and the bottom portion 240 of the case 24 in this order.

Here, the case internal piping 316 will be described. As shown in FIG. 4, the pipe 316 inside the case has a first end 316a, which is one of both ends, connected to and communicates with a discharge port 310e of the electric oil pump 310, and an end opposite to the first end 316a. A second end portion 316b, which is an end portion, is connected to and communicates with the pipe 317 outside the case. The pipe 316 inside the case has first and second ends 316a and 316b lower than the liquid level Ls of the refrigerant, and the first end 316a is higher than the second end 316b. It is arranged so as to be higher than the mouth 300a.

In the power transmission device 20 of the embodiment, the first and second ends 316a and 316b of the pipe 316 inside the case are placed at a position lower than the liquid level Ls of the coolant, that is, the first and second ends 316a and 316b are placed in the coolant. are placed in As a result, it is possible to suppress the entry of air into the case inner pipe 316 from the first and second end portions 316a and 316b.

In addition, since the pipe 316 in the case is arranged so that the first end 316a is higher than the second end 316b, when air is mixed in the pipe 316 in the case, the air can be removed from the lower end. It becomes easier to move to the second end 316b. As a result, the air inside the pipe 316 inside the case can be easily removed. Further, since it is possible to suppress the movement of air to the electric oil pump 310 side, it is possible to suppress air entrapment of the electric oil pump 310 .

Furthermore, the pipe 316 in the case is arranged so as to be higher than the refrigerant suction port 300 a of the strainer 300 as a whole. Since the low-temperature refrigerant has a higher density than the high-temperature refrigerant, relatively low-temperature oil accumulates in the lower portion of the case 24, and relatively high-temperature oil accumulates near the liquid surface Ls. Since the suction port 300 a of the strainer 300 is located lower than the case inner pipe 316 , the temperature of the refrigerant supplied to the case inner pipe 316 is lower than the temperature of the refrigerant around the case inner pipe 316 . Therefore, the relatively low temperature refrigerant in the pipe and the relatively high temperature refrigerant around the case inside pipe 316 can be heat-exchanged through the case inside pipe 316 to cool the refrigerant around the case inside pipe 316 . As a result, it is possible to suppress an increase in the temperature of the coolant near the liquid surface Ls.

In the power transmission device 20 of the embodiment described above, the electric oil pump 310 is fixed outside the case 24 with the hydraulic oil suction port 310d and the hydraulic oil discharge port 310e directed toward the inside of the case 24 . A first end 316a, one of both ends, of the pipe 316 inside the case communicates with the discharge port 310e of the electric oil pump 310, and a second end 316b, which is the end opposite to the first end 316a, communicates with the discharge port 310e of the electric oil pump 310. It communicates with the pipe 317 outside the case. The pipe 316 in the case is arranged so that the first and second ends 316a and 316b are lower than the liquid level Ls of the refrigerant. As a result, it is possible to prevent air from entering the case internal piping 316 .

In the power transmission device 20 of the embodiment, the in-case pipe 316 is arranged such that the first end 316a is higher than the second end 316b. However, the in-case pipe 316 may be arranged such that the second end 316b is higher than the first end 316a, or the first end 316a and the second end 316b are at the same height. may be placed.

In the power transmission device 20 of the embodiment, the in-case pipe 316 as a whole is arranged so as to be higher than the refrigerant suction port 300 a of the strainer 300 . However, only a part of the pipe 316 inside the case may be arranged so as to be higher than the refrigerant suction port 300a of the strainer 300, or the pipe 316 inside the case may be arranged so as to be lower than the refrigerant suction port 300a of the strainer 300. may be placed.

In the power transmission device 20 of the embodiment, the suction port 310d and the discharge port 310e of the electric oil pump 310 are arranged at a position lower than the fluid level Ls of the hydraulic oil and higher than the discharge port (not shown) of the strainer 300. , the electric oil pump 310 is fixed to the case 24 . However, it is sufficient that at least the discharge port 310e is arranged lower than the liquid level Ls of the hydraulic oil, and the suction port 310d may be arranged higher than the liquid level Ls of the hydraulic oil. Moreover, both the suction port 310d and the discharge port 310e may be arranged lower than the discharge port of the strainer 300. FIG.

In the power transmission device 20 of the embodiment, the oil cooling device 30 lubricates and cools the power transmission unit 22 using hydraulic oil. However, if the power transmission unit 22 is not lubricated, it may be cooled with a coolant such as cooling water that is different from the hydraulic oil. In this case, instead of the electric oil pump 310, an electric pump such as an electric water pump that discharges the refrigerant to the pipe 316 inside the case may be used.

The correspondence relationship between the main elements of the embodiments and the main elements of the invention described in the column of Means for Solving the Problems will be described. In the embodiment, the power transmission unit 22 corresponds to the "power transmission unit", the case 24 corresponds to the "case", the electric oil pump 310 corresponds to the "electric pump", and the pipe inside the case 316 corresponds to the "pipe inside the case". Equivalent to

Note that the correspondence relationship between the main elements of the examples and the main elements of the invention described in the column of Means for Solving the Problems is the Since it is an example for specifically explaining the mode for solving the problem, it does not limit the elements of the invention described in the column of the means for solving the problem. That is, the interpretation of the invention described in the column of Means to Solve the Problem should be made based on the description in that column, and the Examples are based on the description of the invention described in the column of Means to Solve the Problem. This is only a specific example.

Although the embodiments for carrying out the present invention have been described above, the present invention is not limited to such embodiments at all, and can be modified in various forms without departing from the scope of the present invention. Of course, it can be implemented.

INDUSTRIAL APPLICABILITY The present invention can be used in the power transmission device manufacturing industry and the like.

20 power transmission device 22 power transmission unit 24 case 30 oil cooling device 40 cooling device 240 bottom portion 300 strainer 310 electric oil pump 310a to 310c fixed portion 310d suction port 310e discharge port 312a to 312c Bolt, 316 Piping inside the case, 317 Piping outside the case, 318 Oil cooler, 330 Return channel, 402 Piping, 404 Radiator, 406 Electric water pump.

Claims (1)

a power transmission unit that transmits power;
a case in which the power transmission unit is housed and a coolant is stored in the bottom;
A power transmission device comprising
an electric pump having a refrigerant suction port and a refrigerant discharge port, the electric pump being fixed to the outside of the case with the suction port and the discharge port directed toward the inside of the case;
A first end, which is one end of both ends, is arranged inside the case and communicates with the discharge port, and a second end, which is the opposite end of the first end, is connected to the discharge port. a pipe inside the case, the end of which communicates with an outer pipe arranged outside the case;
with
The pipe inside the case is arranged so that the first and second ends are positioned lower than the liquid level of the refrigerant stored in the bottom of the case,
power transmission.

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