JPH09291901A - Hydraulic system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To directly cool stored hydraulic oil inside of a tank by a self-cooling fan incorporated in a motor and to heighten cooling efficiency of the stored hydraulic oil. SOLUTION: A cover member 14 is formed is provided between an oil tank 1 and a motor 2, the member having cavities 9A and 9B formed therein, the cavities 9A ands 9B having both ends open to side walls of an oil tank passing through a portion between a soaking position of an intake tube 5 and a soaking position of a return tube, and a communication passage formed therein, the passage communicating the cavities 9A and 9B and a fan 4 of the motor 2 by covering the open one end of the cavities 9A and 9B communicating to the outside of the oil tank 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor having a fan for self-cooling on an upper plate of an oil tank formed in a substantially square shape for storing hydraulic oil therein, and a hydraulic pump driven by the electric motor. The present invention relates to a hydraulic device that is arranged and cools stored hydraulic oil inside an oil tank by a fan of an electric motor.

[0002]

2. Description of the Related Art Conventionally, as a hydraulic device of this type, a heat pipe having one end immersed in a stored hydraulic oil inside an oil tank to serve as a heat receiving portion and the other end protruding from the oil tank to serve as a heat radiating portion is used as an oil tank. It is known that the heat radiating portion of the heat pipe is arranged at a position where the cooling air is generated by a fan for self-cooling included in the electric motor, which is penetrated through the upper plate to cool the stored working oil in the oil tank. (For example, the actual development 61-160
See Japanese Patent No. 308. )

[0003]

However, in such a conventional hydraulic system, the positions of the heat radiating portion and the heat receiving portion are limited due to the indirect cooling of the stored hydraulic oil via the heat pipe, which is still satisfactory. The cooling effect of the stored hydraulic oil could not be obtained.

According to the present invention, the stored hydraulic oil in the oil tank is directly cooled by a self-cooling fan provided in the electric motor,
An object is to provide a hydraulic device that enhances the cooling effect of stored hydraulic oil.

[0005]

According to the hydraulic system of the present invention,
An electric motor that has a fan on the upper plate of an oil tank that stores hydraulic oil inside and that is self-cooling with cooling air from the fan, and sucks the stored hydraulic oil that is driven by this electric motor to externally A hydraulic pump that discharges to the load is arranged, and a suction pipe of the hydraulic pump and a return pipe that circulates the hydraulic oil from the external load inside the oil tank are pierced through the upper plate, respectively, and the tip side of the hydraulic pump is placed in the stored hydraulic oil. The suction pipe and the return pipe, which are soaked in water and immersed in the stored hydraulic oil, have the tips of the suction pipe and the return pipe that are horizontally spaced from each other inside the oil tank. A cavity is formed between the oil tank and the position, the both ends of which open to the side wall of the oil tank. The cavity cuts off from the inside of the oil tank and communicates with the outside of the oil tank. Cavity that covers the outside of the electric motor fan The cover member formed therein a communication passage communicating between the fan motor comprising provided over between the oil tank and the motor. In this case, a plurality of cavities may be provided. Also, a single cavity may be provided. Then, the member forming the cavity may be provided in a bellows shape.

In the structure of the present invention, when the hydraulic pump is driven by the electric motor, the hydraulic pump sucks the stored hydraulic oil from the suction pipe and discharges it to the external load, and the hydraulic oil from the external load flows through the return pipe to the oil. Return to the inside of the tank. Then, the electric motor cools itself by generating cooling air by the fan. At this time, due to the suction action of the fan of the electric motor, cold air outside is sucked from the opening of the cavity not covered with the cover member through the inside of the cavity and the communication passage of the cover member, and returns to the inside of the oil tank from the return pipe to return to the hydraulic pressure. The hydraulic oil drawn from the suction pipe of the pump passes around the cavity before being sucked from the suction pipe, and the hydraulic oil passing through the cavity is dissipated by the suction of the fan through the inside of the cavity, and at the same time, passes through the inside of the cavity. It is cooled by air. Therefore, the stored hydraulic oil in the oil tank can be directly cooled by the self-cooling fan of the electric motor, and the cooling effect of the stored hydraulic oil can be enhanced.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show a first embodiment of a hydraulic system according to the present invention, in which 1 is an oil tank, which is formed in a box shape of a substantially square shape with an opening at the top, and is provided with hydraulic oil stored therein. The opening is closed by the upper plate 1A.
On the upper plate 1A of the oil tank 1, an electric motor 2 and a hydraulic pump 3 that is driven by the electric motor 2 and that sucks the stored hydraulic oil and discharges it to an external load (not shown) are connected to each other. The electric motor 2 has a fan 4 for self-cooling on the back side opposite to the head to which the hydraulic pump 3 is connected, and is self-cooled by cooling air generated by the rotation of the fan 4. Reference numeral 5 denotes a suction pipe of the hydraulic pump 3, which is provided by penetrating the upper plate 1A as shown in FIG. 2 and immersing the tip side having the strainer 6 in the stored hydraulic oil. Reference numeral 7 denotes a return pipe for returning hydraulic oil from an external load to the inside of the oil tank 1. The return pipe is provided so as to penetrate the upper plate 1A and its tip side is immersed in the stored hydraulic oil. The tanks 1 are arranged in the tank 1 at intervals in the horizontal direction.

Reference numeral 8 denotes a quadrilateral tubular member having a cavity 9 formed therein, and four tubular members having the same shape as the tubular member 8 at symmetrical positions vertically and horizontally about the tubular member 8. Member 8A,
8B, 8C, 8D are arranged, and these five tubular members 8,
, 8D pass through the inside of the oil tank 1 between the immersion position of the suction pipe 5 and the immersion position of the return pipe 7, and both ends thereof are welded and fixed to the side wall of the oil tank 1. , 9D in the cylindrical members 8, ..., 8D are opened at both ends to the side wall of the oil tank 1 to communicate with the outside of the oil tank 1, and the cylindrical members 8 ,.
, 8D is provided so as to be cut off from the inside of the oil tank 1.

Reference numeral 10 denotes a first cover member, which is a cavity 9 ,.
9D is attached to the outer surface of the side wall of the oil tank 1 where one end is open, and one end of the cavity 9, ..., 9D is covered to form a communication passage 11 inside and extends to an upper position facing the fan 4 of the electric motor 2. Are provided. Reference numeral 12 is a second cover member, which is an electric motor 2
The fan 4 is attached to the back portion so as to cover the outside thereof, and is connected to the upwardly extending portion of the first cover member 10 with the seal member 13 interposed. Then, the first cover member 10 and the second cover member 12 are provided between the oil tank 1 and the electric motor 2 to communicate with the outside of the oil tank 1, and the one end opening of the cavities 9, ..., 9D and the fan 4 of the electric motor 2. Cavity 9 covering the outside,
.., 9D and the fan 4 of the electric motor 2 constitute a cover member 14 having a communication passage 11 formed therein. still,
Instead of the second cover member 12, the cover member 14 may be a cover member having a general electric motor covering a fan.

Reference numeral 15 is an oil filler port provided with an air breather penetrating the upper plate 1A, 16 is an oil level gauge provided on the upper side wall of the oil tank 1, 17 is an oil drain port provided on the lower side wall of the oil tank 1.
Reference numeral 18 is a pressure gauge branched and connected to the discharge side of the hydraulic pump 2.

Next, the operation of this structure will be described. When the hydraulic pump 3 is driven by the electric motor 2, the hydraulic pump 3
Sucks the stored hydraulic oil from the suction pipe 5 and discharges it to the external load, and the hydraulic oil from the external load flows through the return pipe 7 and returns to the inside of the oil tank 1, and the temperature of the stored hydraulic oil inside the oil tank 1 is Increases until heating and heat dissipation are in equilibrium.

The electric motor 2 is self-cooled by the cooling air generated by the rotation of the fan 4, and at this time, the cold air outside is not covered by the cover member 14 due to the suction action of the fan 4 of the electric motor 2. From the opening, cavity 9, ..., 9
Before the working oil sucked through the communication passage 14 of the cover member 14 in the inside of D and returned to the inside of the oil tank 1 from the return pipe 7 and sucked from the suction pipe 5 of the hydraulic pump 3 is sucked from the suction pipe 5. , Cylindrical member 8, ..., 8D outside cavity 9, ..., 9
The hydraulic oil passing through the periphery of D and around the cavities 9, ..., 9D is dissipated by the suction of the fan 4 through the cavities 9, ..., 9D from the tubular members 8 ,.
..., cooled by cold air passing inside 9D. Therefore, the stored working oil in the oil tank 1 can be directly cooled by the self-cooling fan 4 provided in the electric motor 2, and the cavity 9,
, 9D is easy to provide the optimum one according to the application, and the cooling effect of the stored hydraulic oil can be enhanced to obtain the cooling effect according to the application. 9D and the fan 4 of the electric motor 2 are communicated with each other by the communication passage 11 of the cover member 14, the positions of the cavities 9, ..., 9D are restricted by the fan 4 of the electric motor 2. Can be formed without a cavity 9, ..., 9
D can be easily formed at the optimum position passing between the suction pipe 5 immersion position and the return pipe 7 immersion position for enhancing the cooling effect of the stored hydraulic oil. Furthermore, in order to form the cavities 9, ..., 9D between the immersion position of the suction pipe 5 and the immersion position of the return pipe 7, the oil tank 1 may be an existing one having a substantially square shape, and has a special shape. The complexity of production can be reduced without need. Furthermore, since a plurality of (five) cavities 9, ..., 9D are provided, the hydraulic oil passing around the cavities 9, ..., 9D is radiated and cooled in the respective cavities 9, ..., 9D, and stored. The cooling effect of hydraulic oil can be further enhanced.
Then, by closing an appropriate number of cavities among the plurality of cavities 9, ..., 9D or opening the closed cavities, it is possible to change the cooling effect and easily respond to the application.

FIGS. 5 and 6 show a second embodiment of the hydraulic system according to the present invention. The same parts as those of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. Only different parts will be described. The cylindrical members 20, ..., 20D formed inside the cavities 19, ..., 19D are provided in a circular bellows shape. With such a configuration, substantially the same operation as that of the hydraulic device of the first embodiment can be obtained, and in addition to the effects of the first embodiment, the tubular member 20 forming the cavities 19, ..., 19D,
..., because the 20D is provided in a bellows shape, the cavity 19,
..., the cylindrical member 20 that comes into contact with the hydraulic oil passing around 19D,
The contact area of 20D can be increased, and the effect of cooling the stored hydraulic oil can be further enhanced as compared with the hydraulic device of the first embodiment.

7 and 8 show a third embodiment of the hydraulic system according to the present invention. The same parts as those of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. Only different parts will be described. The tubular member 22 having the cavity 21 formed inside is provided as a single quadrilateral. With such a configuration, an operation substantially similar to that of the hydraulic device according to the first embodiment can be obtained. Further, the suction pipe 5 soaked position and the return pipe 7 which can enhance the cooling effect of the stored hydraulic oil and enhance the cooling effect of the stored hydraulic oil in the cavity 21.
The oil tank 1 can be easily formed at the optimum position passing through the immersion position, and the oil tank 1 does not require a special shape, and the complexity of production can be reduced. In addition to obtaining the function and effect, since the single cavity 21 is provided, it can be easily formed with one cavity 21.
The hydraulic device of the embodiment has an operation effect that can be manufactured more easily.

FIG. 9 shows a fourth embodiment of the hydraulic system according to the present invention. The same parts as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. Only different parts will be described. The tubular member 24 having the cavity 23 formed inside is provided as a single rectangle in the oil tank 1 with two horizontal sides being short sides and two vertical sides being long sides. With such a configuration, an operation substantially similar to that of the hydraulic device according to the first embodiment can be obtained. And, the cooling effect of the stored hydraulic oil can be enhanced, and
The cavity 23 can be easily formed at an optimum position passing between the immersion position of the suction pipe 5 and the immersion position of the return pipe 7 for enhancing the cooling effect of the stored hydraulic oil, and further, the oil tank 1 requires a special shape. The first that can reduce the complexity of production without
It is possible to obtain substantially the same operational effects as the embodiment. Furthermore, since a single hollow 23 is provided in the oil tank 1 as a rectangle having two horizontal sides as short sides and two vertical sides as long sides, one cavity 23 can be easily formed. It can be applied to the small oil tank 1 at the same time.

[0016]

As described above, according to the present invention, a cavity is formed inside the oil tank, the cavity passing between the immersion position of the suction pipe and the immersion position of the return pipe and having both ends open to the side wall of the oil tank. And a fan for self-cooling included in the electric motor, by providing a cover member that covers the outside of the fan of the electric motor and internally forms a communication passage that communicates between the cavity and the fan of the electric motor, between the oil tank and the electric motor. Thus, the stored hydraulic oil inside the oil tank can be directly cooled, and it is easy to provide the optimum cavity according to the application, and the cooling effect of the stored hydraulic oil can be enhanced to obtain the cooling effect according to the application. Further, since the cavity and the fan of the electric motor are communicated with each other by the communication passage of the cover member, the cavity can be formed without being restricted by the position of the fan of the electric motor, and the cavity can improve the cooling effect of the stored hydraulic oil. It can be easily formed at the optimum position passing between the pipe immersion position and the return pipe immersion position. Furthermore, in order to form the cavity between the immersion position of the suction pipe and the immersion position of the return pipe, the oil tank may be an existing one having a substantially square shape, which does not require a special shape and complicates the manufacturing. Can be reduced.

Further, by adopting a structure in which a plurality of cavities are provided, the working oil passing around the cavities is radiated and cooled in each of the cavities, and the cooling effect of the stored working oil can be further enhanced.

Further, by adopting the structure in which a single cavity is provided, the cavity can be formed easily, and the production of the hydraulic device can be simplified.

Further, by adopting the structure in which the member forming the cavity is provided in a bellows shape, the contact area of the member forming the cavity in contact with the hydraulic oil passing around the cavity can be increased, and the cooling effect of the stored hydraulic oil can be improved. It can be further enhanced.

[Brief description of drawings]

FIG. 1 is a front view showing a cross section of a part of a hydraulic device according to a first embodiment of the present invention.

FIG. 2 is a right side view of FIG.

FIG. 3 is a left side view of FIG.

FIG. 4 is a hydraulic circuit diagram of FIG. 1.

FIG. 5 is a front view, partly in section, of a hydraulic system showing a second embodiment of the present invention.

FIG. 6 is a right side view of FIG.

FIG. 7 is a front view, partly in section, of a hydraulic system showing a third embodiment of the present invention.

FIG. 8 is a right side view of FIG. 7;

FIG. 9 is a right side view showing a fourth embodiment of the present invention.

[Explanation of symbols]

 1 Oil Tank 1A Upper Plate 2 Electric Motor 3 Hydraulic Pump 4 Fan 5 Suction Pipe 7 Return Pipe 8, ..., 8D, 19, ..., 19D, 21, 23 Cavity 11 Communication Passage 14 Cover Member

Claims (4)

[Claims] 1. An electric motor having a fan on an upper plate of an oil tank formed in a substantially square shape for storing hydraulic oil therein and self-cooling with cooling air by the fan, and a stored hydraulic oil driven by the electric motor. A hydraulic pump that sucks in and discharges the oil to an external load is installed, and a suction pipe of the hydraulic pump and a return pipe that circulates the hydraulic oil from the external load into the oil tank are provided through the upper plate, and the tip side is Provided by being immersed in the stored hydraulic oil, the suction pipe and the return pipe, which are soaked in the stored hydraulic oil, have the distal ends arranged horizontally in the oil tank with a space therebetween.
A cavity is formed inside the oil tank that passes between the immersion position of the suction pipe and the immersion position of the return pipe and has both ends open to the side wall of the oil tank. This cavity blocks the inside of the oil tank and communicates with the outside of the oil tank. A cover member is provided between the oil tank and the electric motor, the cover member having an opening at one end of the cavity communicating with the outside of the oil tank and a communication passage that covers the outside of the fan of the electric motor and communicates between the cavity and the fan of the electric motor. A hydraulic system characterized in that 2. The hydraulic system according to claim 1, wherein a plurality of cavities are provided. 3. The hydraulic system according to claim 1, wherein a single cavity is provided. 4. The hydraulic device according to claim 1, wherein the member forming the cavity is provided in a bellows shape.