Air-cooled hydraulic device

Abstract

Provided is an air-cooled hydraulic device having a structure in which a cooling fan is attached to a motor shaft of an electric motor, the air-cooled hydraulic device being provided with a cover that effectively treats air on a radiator side by means of the cooling fan and that improves the cooling efficiency of a hydraulic unit. The air-cooled hydraulic device is provided with: a hydraulic pump; a motor that drives the hydraulic pump; an oil tank; the radiator is used for cooling discharged liquid or returned oil returned to the oil tank; a cooling fan attached to a motor shaft of the electric motor and disposed between the electric motor and the heat sink; and a cover covering the cooling fan, the cover including a rectangular portion surrounding the entire ventilation portion of the motor-side surface of the heat sink, and a cylindrical portion enclosing the cooling fan, the cylindrical portion having a diameter slightly larger than the nominal diameter of the cooling fan. An opening edge portion of the cylindrical portion is provided so as to face a radiator-side surface of the motor.

Description

TECHNICAL FIELD

[0001] The present application relates to an air-cooled hydraulic device, and particularly to an improvement of a hydraulic device in which a radiator is cooled by air current of a cooling fan of an electric motor that drives a hydraulic pump. BACKGROUND

[0002] In order to prevent the temperature of the hydraulic device's working oil from rising, a water-cooled or air-cooled cooler is used. For example, a structure using an air-cooled cooler is disclosed in Patent Document 1. In the air-cooled hydraulic device described in Patent Document 1, a structure is shown in which the surface of a radiator is disposed close to a cooling fan of an electric motor that drives a pump. In Patent Document 1, the radiator is cooled by the air current of the cooling fan of the electric motor.

[0003] In addition, the applicant discloses an air-cooled hydraulic device in which a cover is provided between the fan cover of the electric motor and the radiator in Patent Document 2. The cover is structured such that one end has a square-shaped opening portion that is open to the square-shaped radiator surface of the air-cooled cooler, and the other end has a hole into which the front end of the fan cover of the electric motor is inserted. Thus, even with a square-shaped radiator, the structure is simple, and existing coolers and electric motors can be used. In addition, it is described in Patent Document 2 that an air-cooled hydraulic device can be provided that has high thermal efficiency and can exhibit performance corresponding to the cooling capacity.

[0004] Prior art documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Realization Hei 49-50804

[0007] Patent Document 2: Japanese Patent No. 3672153 SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] In the air-cooled hydraulic device described in Patent Document 2, the use of the cooling fan is premised to be for the purpose of cooling the electric motor. Thus, the proportion of the effect of the cooling fan is on the cooling of the electric motor, and the cooling of the radiator is secondary.

[0010] However, depending on the method of use of the hydraulic unit, the efficiency of the electric motor, and the heat resistance of the electric motor, it can not necessarily be structured to primarily cool the electric motor. That is, since an improvement in the cooling performance of the radiator is required, it is effective to increase the proportion of the cooling of the radiator by the cooling fan mounted to the motor shaft.

[0011] Therefore, an object of the present application is to provide an air-cooled hydraulic device which is a structure in which a cooling fan is installed to a motor shaft of a motor, in which the air-cooled hydraulic device efficiently handles air on a radiator side using the cooling fan, and which has a cover that improves the cooling efficiency of a hydraulic unit.

[0012] Solution to Problem

[0013] To solve the above problem, the air-cooled hydraulic device according to the present application is characterized by including: a hydraulic pump; a motor that drives the hydraulic pump; a tank; a radiator that cools discharge oil or return oil that returns to the tank; a cooling fan that is installed to a motor shaft of the motor and is disposed between the motor and the radiator; and a cover that covers the cooling fan, the cover being configured to include a rectangular portion that surrounds the entire air-permeable portion of a surface of the motor side of the radiator and a cylindrical portion that encloses the cooling fan, the diameter of the cylindrical portion being slightly larger than the nominal diameter of the cooling fan, and an opening edge portion of the cylindrical portion being disposed so as to face a surface of the radiator side of the motor.

[0014] The cooling fan is configured to transport air on the radiator side toward the motor side. Further, it is preferable that, on the opening side of the cylindrical portion, a gap through which the air transported toward the motor side passes is provided, and a finger guard that prevents fingers from intruding from the opening of the cylindrical portion is installed.

[0015] Effects of the Invention

[0016] According to the present application, an air-cooled hydraulic device which is a structure in which a cooling fan is installed to a motor shaft of a one-way rotary pump, in which the air-cooled hydraulic device has a cover that, in particular, can exhibit a high cooling efficiency with respect to a radiator. BRIEF DESCRIPTION OF DRAWINGS

[0017] FIGS. 1(a) and 1(b) are side views of an air-cooled hydraulic device according to an embodiment of the present application.

[0018] FIGS. 2(a) and 2(b) are perspective views of the air-cooled hydraulic device.

[0019] FIGS. 3(a) and 3(b) are views that explain the cover.

[0020] Figure 4 is an exploded perspective view from the motor to the radiator.

[0021] FIGS. 5(a) and 5(b) are views that show each part of an embodiment of the air-cooled hydraulic device.

[0022] FIGS. 6(a) and 6(b) are analysis diagrams of fluid simulation in a case in which the diameter of the cylindrical portion is changed.

[0023] Figures 7(a) to 7(d) is a graph of analysis of fluid simulation in the case where the length of the cylindrical portion is changed.

[0024] Fig. 8(a), Fig. 8(b) are graphs of analysis of fluid simulation in the case where the cooling fan is discharged with respect to the radiator.

[0025] Figure 9 is a perspective view of an air-cooled hydraulic device which is a modification of the embodiment of the present application.

[0026] Explanation of Reference Numerals

[0027] 100, air-cooled hydraulic device; 110, oil tank; 120, hydraulic pump; 130, electric motor; 130a, motor shaft; 132, bolt; 140, radiator; 150, cooling fan; 160, cover; 170, rectangular portion; 172, bracket; 180, cylindrical portion; 190, finger guard; 192, foot of finger guard. DETAILED DESCRIPTION

[0028] Hereinafter, a preferred embodiment of the present application will be explained in detail with reference to the drawings. The dimensions, materials, other specific numerical values and the like shown in the embodiment are nothing more than examples for making the application easy to understand, and do not limit the present application unless otherwise specified. Further, in the present specification and drawings, elements having substantially the same function and configuration are designated by the same reference numerals, and repeated explanation is omitted, and illustration or explanation of elements having no direct relation with the present application is omitted.

[0029] Fig. 1(a), Fig. 1(b) are side views of an air-cooled hydraulic device 100 of the embodiment of the present application. Fig. 1(a) is a whole structure view. Fig. 1(b) is a view in which the cover and the finger guard are omitted. Fig. 2(a), Fig. 2(b) are perspective views of the air-cooled hydraulic device. Fig. 2(a) is a perspective view taken from the hydraulic pump 120 side. Fig. 2(b) is a perspective view taken from the radiator side.

[0030] In the air-cooled hydraulic device 100, an electric motor 130 assembled integrally with a hydraulic pump 120 is fixed to the upper cover of an oil tank 110 that stores hydraulic oil. When the electric motor 130 is operated, the hydraulic pump 120 is activated to deliver hydraulic oil. As shown in Fig. 2(a), the electric motor 130 has a substantially cylindrical main body. One end of a motor shaft 130a of the electric motor 130 is connected to the hydraulic pump 120. As shown in Fig. 1(b), the electric motor 130 is provided with a cooling fan 150 at the other end. That is, the cooling fan 150 is directly attached to the motor shaft 130a of the electric motor 130. Further, when the electric motor 130 drives the hydraulic pump 120, the cooling fan 150 also rotates. The cooling fan 150 is located between the radiator 140 and the electric motor 130. As will be described later, the structure of the cooling fan 150 that rotates in a manner to cause air to flow (suck in) from the radiator 140 toward the electric motor 130 side is more effective than a structure that causes air to flow (blow out) in the opposite direction.

[0031] The radiator 140 is disposed on the opposite side of the hydraulic pump 120 with respect to the electric motor 130. The radiator 140 cools the discharged hydraulic oil generated during operation and returns it to the oil tank 110. The radiator 140 is a simple laminated structure, and is a square radiator as shown in Fig. 2(b).

[0032] Further, as is apparent from a comparison between Figs. 1(a) and 1(b), a cover 160 that covers the cooling fan 150 is attached between the radiator 140 and the electric motor 130.

[0033] Figs. 3(a) and 3(b) are views that explain the cover 160. Fig. 3(a) is a three-view drawing, and Fig. 3(b) is a perspective view. Figure 4 is an exploded perspective view from the electric motor to the radiator.

[0034] The lid 160 has a rectangular portion 170 and a cylindrical portion 180. The rectangular portion 170 of the lid 160 is substantially the same size in the height direction and the width direction with respect to the air-permeable portion of the square-shaped heat sink 140. Further, the width direction refers to a direction orthogonal to the direction from the motor 130 toward the heat sink 140. In other words, the rectangular portion 170 is provided to surround the entire air-permeable portion of the surface of the motor 130 side of the heat sink 140. A bracket 172 for mounting the rectangular portion 170 to the heat sink 140 is connected to the rectangular portion 170. The bracket 172 is formed integrally with the rectangular portion 170 or continuously with the upper surface of the rectangular portion 170. Alternatively, the bracket 172 can also be provided as a separate body with respect to the rectangular portion 170 and mounted to the rectangular portion 170. The bracket 172 is provided to protrude from the portion where the rectangular portion 170 and the heat sink 140 are in contact with each other, or the portion where the two overlap each other, toward the side opposite to the motor 130. Further, the bracket 172 is provided to at least one side (surface) of the sides (surfaces) that divide the rectangular portion 170. In the present embodiment, the bracket 172 protrudes toward the side opposite to the cylindrical portion 180, that is, the heat sink 140 side of the upper surface of the rectangular portion 170. In addition, the bracket 172 is formed in a plate shape. In addition, the bracket 172 is bent downward at the protruding end side, so as to at least partially abut against the surface of the heat sink 140 on the side opposite to the rectangular portion 170. According to this structure, the bracket 172 is engaged in a manner that sandwiches the upper surface of the heat sink 140 as a whole. Further, since the bracket 172 is provided to sandwich the heat sink 140 on the upper surface side as such, the length of the bracket 172 that protrudes from the portion where the bracket 172 and the rectangular portion 170 are in contact with each other corresponds to the length of the short side of the upper surface of the heat sink 140 (the length in the direction from the motor 130 toward the heat sink 140). For example, the length of the short side of the upper surface of the heat sink 140 can be formed to be slightly longer than the bracket 172, and the bent portion of the bracket 172 at the front end side can be bent inward and abut against the side surface of the heat sink 140. In this way, by embedding the heat sink 140 in the bracket 172, the rectangular portion 170 is arranged in close contact with the heat sink 140. Thus, since the air current generated by the cooling fan 150 passes through the entire surface of the heat sink 140, a higher cooling efficiency can be obtained. Further, as shown in FIG. 3(a), the bracket 172 is formed to have a length (for example, the same length) corresponding to the width direction of one surface of the rectangular portion 170. However, the structure is not limited to this, and other structures can also be used. For example, only the bracket portions that sandwich the heat sink 140 at both ends in the width direction shown in FIG. 3(a) can be left, and the other portions can be omitted. In addition, the length of the bracket 172 in the width direction shown in FIG. 3(a) can be formed to be shorter than the width of the upper surface of the heat sink 140. In addition, the bracket portions that sandwich the heat sink 140 in the bracket 172 can be formed at both ends without being divided, and the bracket portions can be continuously provided in the width direction. In addition, the bracket 172 can be provided to the side surface of the rectangular portion 170.

[0035] The cylindrical portion 180 of the cover 160 houses the cooling fan 150. In the drawings, the diameter of the cooling fan 150 is larger than the diameter of the motor 130. Further, the diameter of the motor 130 refers to such a dimension as shown in Fig. 5(b) except for the height of the support portion (leg) provided on the bottom surface side of the motor 130. In addition, the diameter of the cylindrical portion 180 is slightly larger than the nominal diameter of the cooling fan 150 (the outer edge of the rotating cooling fan) and is the dimension of the face facing the radiator 140 side of the motor 130 (see Fig. 1(a)). That is, the opening of the cylindrical portion 180 toward the motor 130 side faces the end portion (or face) of the motor 130 on the radiator 140 side, and approaches the end portion to the extent that the finger protector 190 can be disposed (the opening end of the cylindrical portion 180 approaches the outer peripheral surface of the motor 130 to the extent that it does not overlap (does not cover) the outer peripheral surface of the motor 130). In other words, the opening end of the cylindrical portion 180 does not overlap the outer peripheral surface of the motor and reaches a position adjacent to the end face of the motor 130 in the axial direction. That is, it is the length that does not reach the motor 130 in the axial direction. Further, it is the direction from the radiator 140 toward the motor 130. In addition, the end face of the motor 130 refers to the end face on the radiator 140 side in the motor 130. Thus, it is possible to prevent the occurrence of a flow in which air blown out from the cooling fan 150 returns to the radiator 140 side (the suction side of the radiator). Further, the diameter of the cylindrical portion 180 is uniform in the axial direction. However, as for the diameter of the cylindrical portion 180, other structures can also be possible. For example, it can be possible that the diameter of the cylindrical portion 180 increases from the opening side toward the rectangular portion 170 side, and the gradient thereof is within a range of 5° or less. It can also be possible that, conversely, the diameter of the cylindrical portion 180 decreases from the opening side toward the rectangular portion 170 side, and the gradient thereof is within a range of 5° or less. These other examples are also included in the case of "the diameter is substantially uniform".

[0036] In addition, as for the diameter of the cylindrical portion 180, the above description can be said to be that the height of the opening portion of the cylindrical portion 180 is slightly higher than the height of the main body of the motor 130 in the state of being mounted to the unit. The height of the main body refers to the height including the support portion (leg), and becomes such a height (diameter) in correspondence with the dimension of the cooling fan 150. Thus, the motor 130 does not block the opening of the cylindrical portion 180 and does not hinder the flow of air, and therefore a higher cooling efficiency can be obtained.

[0037] Further, a gap that allows air to pass toward the motor 130 side is provided in the opening of the cylindrical portion 180. Furthermore, a finger guard 190 that prevents fingers from intruding from the opening is attached to the cylindrical portion 180. The finger guard 190 has a mesh-like structure in which wires are arranged at a predetermined interval. In terms of the interval of the wires, an interval of 4 mm or less is preferable in order to prevent the intrusion of fingertips. Thus, it is possible to prevent the fingers of the operator from coming into contact with the cooling fan 150, and it is possible to improve safety. In addition, by covering the radiator side of the main body of the motor 130 with the cylindrical portion 180, it is also possible to prevent the intrusion of fingertips. However, in the case where protection of the fingertips is achieved using such a structure, it is known that the flow of air is hindered as described later. That is, as a result, the cooling performance of the radiator is degraded. Thus, in the present embodiment, in order to prevent the intrusion of fingertips and to allow the smooth flow of air, such a finger guard is employed.

[0038] Further, if the outer diameter of the finger guard 190 is the same diameter or more than the outer diameter of the cylindrical portion 180, it is possible to prevent the fingers of the operator from coming into contact with the edge of the cylindrical portion 180. Thus, it is possible to further improve safety.

[0039] In the present embodiment, the leg 192 of the finger guard is configured to be attached to the bolt 132 of the motor 130. However, it can also be configured to attach the finger guard 190 to the cylindrical portion 180 of the cover 160.

[0040] Figs. 5(a) and 5(b) are diagrams that show each part of the embodiment of the air-cooled hydraulic device. Fig. 5(a) shows the cover 160. Fig. 5(b) shows the interval between the radiator 140 and the motor 130 and the cooling fan 150. The numerical values described below are merely examples for illustrating the size relationship and do not limit the present application.

[0041] In the example of the present embodiment shown in Fig. 5(a), the length LI of the rectangular portion 170 of the cover 160 is formed to be 20% to 23% shorter than the length L2 of the cylindrical portion 180. Further, in the length L3 of the entire cover 160, the length LI of the rectangular portion 170 is about 42% to 44% of the length L3, and the length L2 of the cylindrical portion 180 is about 56% to 58% of the length L3. Furthermore, the length refers to the length in the direction from the motor 130 toward the radiator 140 shown in Figs. 1(a) and 1(b) (the left-right direction in Figs. 1(a) and 1(b); the same applies hereinafter).

[0042] Further, the inner diameter Φ1 of the cylindrical portion 180 is formed to be about 20 to 21% larger than the diameter Φ2 of the cooling fan. The diameter of the cooling fan covers the entire air-permeable portion of the surface of the motor 130 side of the radiator 140. The height of the cylindrical portion 180 is set based on the height of the rectangular portion 170. This is to achieve a balance between making the diameter of the cooling fan larger and making the length L2 of the cylindrical portion 180 shorter (to prevent the air-cooled hydraulic device from becoming larger). If the height difference between the cylindrical portion 180 and the rectangular portion 170 is large, a taper for eliminating the difference is required. As a result, the cylindrical portion 180 becomes longer. Further, as described above, the rectangular portion 170 of the cover 160 is configured to cover the air-permeable portion of the radiator 140. Thus, it is also considered that the cooling fan is housed in the cylindrical portion 180. That is, the diameter of the cooling fan becomes the size that covers the entire air-permeable portion of the radiator 140. The inner diameter Φ1 of the cylindrical portion 180 is configured to be a diameter that is not larger than the diameter Φ2 of the cooling fan.

[0043] Further, the length L2 of the cylindrical portion 180 of the cover 160 is 5 to 6.5% shorter than the thickness (length in the above-described direction) L4 of the cooling fan. Further, in Figs. 5(a) and 5(b), the length L3 of the cover 160 is about 4 to 5% shorter than the interval between the radiator 140 and the motor 130.

[0044] That is, the inner diameter Φ1 of the cylindrical portion of the cover 160 is set to be about 21.5 to 22.5% larger than the outer diameter Φ3 of the radiator side end surface of the main body of the motor 130. Further, in Figs. 5(a) and 5(b), the length L3 of the cover 160 is about 4 to 5% shorter than the interval L5 between the radiator 140 and the motor 130. As a result, the interval from the opening of the cylindrical portion 180 to the motor 130 is set to be about 5 to 6% shorter than the interval L5 between the radiator 140 and the motor 130.

[0045] Figs. 6(a) and 6(b) are analysis diagrams of fluid simulation in a case where the diameter of the cylindrical portion is changed. Fig. 6(a) is a diagram showing Comparative Example 1, and Fig. 6(b) is a diagram showing the above-described embodiment.

[0046] In Comparative Example 1 shown in Fig. 6(a), the outer diameter of the cylindrical portion 180 is increased by about 2.9% compared to the embodiment (Fig. 6(b)). Since the gap between the cover 160 and the cooling fan 150 becomes larger, the vortex that is wound in the inside of the cover 160 becomes larger. Therefore, the amount of air that passes through the radiator 140 becomes less. Further, since the work amount of the cooling fan 150 decreases, the driving torque decreases. Further, the airflow that reaches the surface of the motor 130 becomes shorter.

[0047] According to Fig. 6(a), if the diameter of the cylindrical portion 180 is not larger than the diameter of the cooling fan 150, air on the radiator 140 side is efficiently drawn in.

[0048] Figures 7(a) to 7(d) Fig. 7(a) is a graph showing Comparative Example 2. Fig. 7(b) is a graph showing Comparative Example 3. Fig. 7(c) is a graph showing the above-described embodiment. Fig. 7(d) is a graph showing Comparative Example 4.

[0049] In Comparative Example 2 shown in Fig. 7(a), the length of the cylindrical portion 180 is shorter than that of the embodiment (Fig. 7(c)), and does not cover the entire length of the cooling fan 150. The length difference is 58.6% shorter than that of the embodiment. In Comparative Example 3 shown in Fig. 7(b), the length of the cylindrical portion 180 is shorter than that of the embodiment (Fig. 7(c)), and the length difference is 29.3% shorter than that of the embodiment. In Comparative Example 2 and Comparative Example 3, air blown from the cooling fan 150 returns to the radiator 140 side (the air intake side of the radiator).

[0050] In Comparative Example 4 shown in Fig. 7(d), the length of the cylindrical portion is 58.6% longer than that of the embodiment (Fig. 7(c)). Comparative Example 4 is a state in which the cylindrical portion 180 covers the end portion of the motor 130. If the cylindrical portion 180 of the cover 160 is lengthened, the gap between the cylindrical portion 180 and the motor becomes small, and the load on the downstream side of the cooling fan 150 increases. Thus, the air volume through the radiator 140 decreases. In addition, since the work amount of the cooling fan 150 increases, the driving torque increases.

[0051] According to Figs. 7(a) and 7(b), the length of the cylindrical portion 180 is preferably in a state in which the opening portion of the cylindrical portion 180 on the motor 130 side is close to the motor 130. In addition, according to Fig. 7(d), the length of the cylindrical portion 180 is preferably in a state in which the cylindrical portion 180 does not overlap the end portion of the motor 130.

[0052] That is, the opening of the cylindrical portion 180 on the motor 130 side is close to the end portion (or surface) of the motor 130 on the radiator side to the extent that a finger guard can be disposed. Such a structure can prevent the occurrence of a flow in which air blown from the cooling fan 150 returns to the radiator 140 side (the air intake side of the radiator). In addition, the cylindrical portion 180 does not overlap the motor 130 (does not cover the motor 130). With such a structure, it is possible to prevent a decrease in the air volume through the radiator 140 and an increase in the driving torque of the cooling fan 150.

[0053] Figures 8(a) and 8(b) are analysis diagrams of fluid simulation of the situation where air is discharged from the cooling fan relative to the radiator. Figure 8(a) is a diagram showing the above-described embodiment, and Figure 8(b) is a diagram showing Comparative Example 5. In Comparative Example 5 shown in Figure 8(b), compared to the embodiment shown in Figure 8(a), the orientation of the cooling fan 150 is reversed, the direction of airflow is reversed, and air flows towards the radiator 140 in the direction opposite to the motor 130.

[0054] Referring to Figure 8(b), it can be seen that vortices form in the airflow between the cooling fan 150 and the radiator 140, preventing it from passing through the radiator 140. As a result, the airflow through the radiator is drastically reduced. Therefore, it can be seen that the structure of the cooling fan 150 that rotates to make air flow (intake) from the radiator 140 toward the motor 130 is more effective than making air flow (exhaust) in the opposite direction.

[0055] Next, refer to Figure 9 This illustrates a variation of the above embodiment. In the above embodiment, the rectangular portion 170 of the cover 160 is approximately the same size in both the height and width directions as respect to the venting portion of the square radiator 140. However, in this variation, as... Figure 9 As shown, the supports at both ends of the radiator 140 are also covered by the rectangular portion 170. The two ends of the radiator 140 refer to the two ends in the width direction orthogonal to the direction from the radiator 140 toward the motor 130. Supports for fixing the radiator 140 are provided at each end of the radiator 140. In the modified example, the rectangular portion 170 not only surrounds the vent portion of the radiator 140, but also includes the support portion within the radiator 140.

[0056] Furthermore, other variations are explained. In the above embodiment, the rectangular portion 170 of the cover 160 is clamped and fixed to the upper surface of the square radiator 140 using a bracket 172. However, in this second variation, the bracket 172 is not provided; instead, the rectangular portion 170 and the radiator 140 are fixed together by other structures. That is, at least a portion of the edge of the rectangular portion 170 on the radiator 140 side is connected using a sealing member, adhesive, or other connecting member at a portion opposite to at least a portion of the edge of the rectangular portion side in the radiator. This connecting member can suppress the leakage of air flowing from the side of the motor 130 of the radiator 140 toward the motor 130 side based on the cooling fan 150 from between the radiator 140 and the rectangular portion 170.

[0057] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but it is obvious that the present application is not limited to the example. It is apparent to those skilled in the art that various changes or modifications can be conceived within the scope recited in the claims, and it is understood that such various changes or modifications naturally belong to the technical scope of the present application.

[0058] Industrial Applicability

[0059] The present application can be utilized as an air-cooled hydraulic device provided with a cooling fan between a motor and a radiator.

Claims

1. An air-cooled hydraulic device, characterized in that, This air-cooled hydraulic device features: Hydraulic pump; An electric motor drives the hydraulic pump; tank; A radiator that cools the drained or returned oil flowing back to the oil tank; A cooling fan, mounted on the motor shaft of the electric motor and positioned between the electric motor and the radiator; and A cover that covers the cooling fan. The cover is configured to include a rectangular portion and a cylindrical portion. The rectangular portion directly or indirectly surrounds the entire ventilated portion of the motor-side surface of the radiator. The cylindrical portion encloses the cooling fan, and the cylindrical portion is configured to have a predetermined gap in its inner circumferential surface so that it does not contact the cooling fan, and the opening edge of the cylindrical portion faces the radiator side of the motor.

2. The air-cooled hydraulic device according to claim 1, characterized in that, The rectangular portion is configured to fit snugly against the heat sink.

3. The air-cooled hydraulic device according to claim 1, characterized in that, The edge of the rectangular portion on the heat sink side contacts the edge of the ventilated portion of the heat sink. The air-cooled hydraulic device is provided with a bracket that protrudes from at least one of the faces constituting the rectangular portion. The bracket secures the rectangular portion to the radiator by clamping a portion of the radiator together with the rectangular portion.

4. The air-cooled hydraulic device according to claim 1, characterized in that, The rectangular portion is connected at least partially to the edge portion on the heat sink side and at least partially to the opposite portion of the edge portion on the rectangular portion side of the heat sink using a connecting member. This connecting member is used to suppress airflow from the motor side of the radiator toward the motor side, based on the cooling fan, from leaking between the radiator and the rectangular portion.

5. The air-cooled hydraulic device according to claim 1, characterized in that, In a width direction orthogonal to the direction from the radiator toward the motor, support pillars are provided at both ends of the radiator to fix it. The rectangular portion not only surrounds the ventilated portion of the radiator, but also includes the support portion that surrounds it on the inland side.

6. The air-cooled hydraulic device according to claim 1, characterized in that, The nominal diameter of the cooling fan is larger than the diameter of the motor. The diameter of the cylindrical section is uniform in the axial direction.

7. The air-cooled hydraulic device according to claim 1, characterized in that, The opening end of the cylindrical portion does not overlap with the outer peripheral surface of the motor, and the opening end of the cylindrical portion reaches a position adjacent to the end face of the motor in the direction from the radiator toward the motor.

8. The air-cooled hydraulic device according to claim 1, characterized in that, The diameter of the cooling fan is the size of the entire ventilated portion that covers the heat sink.

9. The air-cooled hydraulic device according to any one of claims 1 to 8, characterized in that, The cooling fan is configured to deliver air from the radiator side toward the motor side. On the opening side of the cylindrical part, a gap is provided to allow air supplied to the motor side to pass through, and a finger protector is installed to prevent fingers from entering through the opening of the cylindrical part.

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