Hydraulic pump with integrated tank

Abstract

To provide a hydraulic pump with an integrated tank that can be used in both horizontal and vertical orientations, and that is capable of preferably preventing hydraulic fluid from entering a breather in either case.SOLUTION: A hydraulic pump 100 with an integrated tank is configured to comprise a pump 110 that delivers hydraulic fluid, a tank 120 arranged integrally with the pump to store the hydraulic fluid, an end cover 140 that seals an end of the tank, a breather 160 provided on the end cover, a return pipe 112 projecting from the pump toward the inside of the tank, a partition cylinder 170 attached to the end cover inside the tank and arranged to surround an outlet of the return pipe, and a slit 172a formed in the partition cylinder on the side opposite to an inlet of the breather.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a tank-integrated hydraulic pump that is integrated with a tank. [Background technology]

[0002] Conventionally, there has been known a tank-integrated hydraulic pump that integrates a pump used as a hydraulic source for industrial machinery or the like with a tank that stores hydraulic oil (see, for example, Patent Document 1). In the tank-integrated piston pump of Patent Document 1, the tanks are arranged on the left and right sides of the pump. Holes are formed in the upper surface of the end cover, and when the tank is used as the top to lift the tank-integrated piston pump, eyebolts are fitted into the holes to lift the pump.

[0003] The tank is provided with a breather for allowing air to flow in and out of the tank. For example, Patent Document 2 discloses "a breather device for a hydraulic oil tank for a forklift, characterized in that a breather pipe is fixed to the top of the hydraulic oil tank so that its base end opening communicates with the interior of the forklift hydraulic oil tank, and a blowout prevention member is provided inside the hydraulic oil tank, the blowout prevention member having a bottom plate below the base end opening of the breather pipe, front and rear side plates in the front-to-rear direction, and left and right side plates in the left-to-right direction." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-036744 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-360768 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 2, the blowout prevention member is formed by bending a single metal plate into a rectangular box shape, and has a bottom plate and front, rear, and left and right side plates. The bottom plate is rectangular, and each side plate is formed by bending upward from each of the front, rear, and left and right sides, with a certain gap formed between adjacent side plates. With a configuration such as that in Patent Document 2, oil may seep into the inside of the blowout prevention member through the gaps between the side plates, and sufficient blowout prevention effect may not be achieved.

[0006] Furthermore, tank-integrated hydraulic pumps are often assumed to be horizontally mounted, as in Patent Document 1, but in recent years, many pumps can be used both horizontally (horizontally mounted) and vertically (vertically mounted). A structure such as the blowout prevention member in Patent Document 2 can be applied to horizontal mounting, but cannot be applied to vertical mounting.

[0007] In view of the above problems, the present invention aims to provide a tank-integrated hydraulic pump that can be used in both horizontal and vertical mounting and that can effectively prevent hydraulic oil from entering the breather in either case. [Means for solving the problem]

[0008] In order to solve the above problems, a typical configuration of a tank-integrated hydraulic pump according to the present invention is characterized by comprising a pump that delivers hydraulic oil, a tank that is disposed integrally with the pump and that stores the hydraulic oil, an end cover that seals the end of the tank, a breather provided on the end cover, a return pipe that protrudes from the pump into the tank, a partition cylinder that is attached to the end cover inside the tank and disposed so as to surround the outlet of the return pipe, and a slit formed in the partition cylinder on the side opposite to the inlet of the breather.

[0009] The return pipe preferably has an L-shaped end and an outlet of the return pipe facing away from the slit. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a tank-integrated hydraulic pump that can be used in both horizontal and vertical mounting and that can effectively prevent hydraulic oil from entering the breather in either case. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an overall perspective view of an exploded state of a tank-integrated hydraulic pump according to an embodiment of the present invention. FIG. [Figure 2] FIG. 2 is a diagram illustrating an example of the tank-integrated hydraulic pump of FIG. 1 after assembly, in a horizontal arrangement. [Figure 3] FIG. 10 is a diagram illustrating a partition cylinder. [Figure 4] FIG. 2 is a diagram illustrating an example of the tank-integrated hydraulic pump of FIG. 1 after assembly, in a vertical arrangement. [Figure 5] 10A and 10B are diagrams illustrating other configurations of the partition cylinder. DETAILED DESCRIPTION OF THE INVENTION

[0012] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Dimensions, materials, and other specific values ​​shown in the embodiments are merely examples for facilitating understanding of the invention and, unless otherwise specified, do not limit the present invention. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present invention are not shown or described.

[0013] Fig. 1 is an overall perspective view of an exploded state of a tank-integrated hydraulic pump 100 according to this embodiment. As shown in Fig. 1, the tank-integrated hydraulic pump 100 of this embodiment includes a pump 110 that delivers hydraulic oil, and a tank 120 that is disposed integrally with the pump 110 and stores the hydraulic oil. A motor 130 that is a drive source for the pump 110 is disposed on the opposite side of the tank 120 in the pump 110.

[0014] (When the tank-integrated hydraulic pump 100 is placed horizontally) Figure 2 is a diagram illustrating an example of the tank-integrated hydraulic pump 100 of Figure 1 after assembly when it is placed horizontally. Figure 2(a) is an external view of the tank-integrated hydraulic pump 100. Figure 2(b) is a cross-sectional view showing the internal structure of the tank-integrated hydraulic pump 100. In the example shown in Figure 2, the tank-integrated hydraulic pump 100 is placed horizontally on a wall by the base 110a of the pump 110.

[0015] As shown in Figure 2, the end of the tank 120 is sealed by an end cover 140. The end cover 140 is connected to the pump 110 with four bolts 150. The end cover 140 is formed with mounting holes 142 for attaching a breather 160. The breather 160 is a pipe for allowing air to flow in and out of the tank 120. The breather 160 may incorporate a separator for removing droplets and a filter for preventing the entry of debris and dust from the outside, as necessary.

[0016] 2(b), a return pipe 112 from the pump 110 is disposed so as to protrude into the tank 120. Furthermore, as a feature of this embodiment, a partition cylinder 170 is disposed in the tank 120.

[0017] 3A and 3B are diagrams illustrating the partition tube 170, with FIG. 3A being a perspective view observed from the opening side and FIG. 3B being a perspective view observed from the mounting surface 174 side. The partition tube 170 is configured to include a substantially cylindrical surface 172 having a slit 172a and a mounting surface 174 (bottom surface) located on one end surface of the cylindrical surface 172 (the right surface in FIG. 2, the upper surface in FIG. 4). The partition tube 170 of this embodiment can be produced, for example, by forming a slit in part of a cylindrical member with a bottom. A screw hole 174a is formed in the mounting surface 174 to secure the partition tube 170 to the end cover 140.

[0018] The partition cylinder 170 is disposed in the tank 120 so that its cylindrical surface 172 surrounds the outlet 112a of the return pipe, and is attached to the end cover 140 at a mounting surface 174. In other words, the outlet 112a of the return pipe is disposed so as to open within the cylindrical surface 172. The slit 172a formed in the partition cylinder 170 is disposed so as to be located on the opposite side from the inlet 162 of the breather 160.

[0019] According to the above configuration, the hydraulic oil returning from the return pipe 112 to the tank 120 is sprayed from the return pipe 112 toward the mounting surface 174, where the momentum of the flow is killed when the hydraulic oil hits the mounting surface 174. The hydraulic oil containing air bubbles attempts to rise upward and flows back toward the pump 110 along the mounting surface 174 and the cylindrical surface 172. The hydraulic oil then flows between the tank 120 and the cylindrical surface 172 toward the breather 160, and reaches the inlet 162 of the breather 160.

[0020] That is, according to the tank-integrated hydraulic pump 100 of this embodiment, a labyrinth structure can be formed in the tank 120 by the cylindrical surface 172 of the partition cylinder 170. This reduces the flow rate of the hydraulic oil and lengthens the path from the outlet 112a of the return pipe to the inlet 162. Therefore, it is possible to effectively prevent the hydraulic oil from entering the breather 160.

[0021] (When the tank-integrated hydraulic pump 100 is placed vertically) Figure 4 is a diagram illustrating an example of the assembled tank-integrated hydraulic pump 100 of Figure 1 in a vertically arranged state. Figure 4(a) is a cross-sectional view of the tank-integrated hydraulic pump 100. Figure 4(b) is a cross-sectional view taken along CC in Figure 4(a).

[0022] In the case of vertical arrangement, components common to the tank-integrated hydraulic pump 100 in the case of horizontal arrangement in Fig. 1 are denoted by the same reference numerals and description thereof will be omitted. Below, differences from the tank-integrated hydraulic pump 100 in the case of horizontal arrangement in Fig. 1 will be described.

[0023] In the example shown in Fig. 4(a), the tank-integrated hydraulic pump 100 is arranged perpendicular to the wall by the base 110a of the pump 110. In the example shown in Fig. 2, the breather 160 uses an L-shaped bent pipe, whereas in the example shown in Fig. 4(a), the breather 160A uses an I-shaped straight pipe.

[0024] In the example shown in FIG. 4(a), an L-shaped elbow pipe 117 is attached to the end of the return pipe 116, and the outlet 116a of the return pipe 116 faces the cylindrical surface 172 on the side opposite the slit 172a. With this configuration, the hydraulic oil returning from the return pipe 112 to the tank 120 is sprayed from the outlet 116a of the return pipe 116 toward the cylindrical surface 172, where it hits the cylindrical surface 172 and loses its momentum. The hydraulic oil containing air bubbles tends to rise upward, flowing along the cylindrical surface 172 and the mounting surface 174 and exiting the partition tube 170 through the slit 172a. The hydraulic oil then passes between the tank 120 and the cylindrical surface 172 and reaches the inlet 162 of the breather 160, as shown in FIG. 4(b).

[0025] Even with the configuration described above, a labyrinth structure can be formed in the tank 120 by the partition cylinder 170 and the cylindrical surface 172, and the same effect as in the case of horizontal arrangement can be obtained. Therefore, the tank-integrated hydraulic pump 100 of this embodiment can be used in both horizontal and vertical installations, and in either case, it is possible to effectively prevent hydraulic oil from entering the breather.

[0026] (Other configurations of the partition tube) Figure 5 is a diagram illustrating another configuration of the partition tube. While the partition tube 170 shown in Figure 1 is substantially cylindrical, the partition tube 180 shown in Figure 5 is substantially polygonal. In detail, the partition tube 180 has polygonal surfaces made by bending a flat plate (using sheet metal), and the edges of the polygonal surfaces are not joined. In other words, the polygonal surfaces 182 of the partition tube 180 do not extend around the entire circumference, forming slits 182a.

[0027] 5 has no bottom surface and has a mounting tab 184 bent from sheet metal. A screw hole 184a is formed in the mounting tab 184 for fixing the partition tube 180 to the end cover 140. Although the partition tube 180 does not have a bottom plate, by attaching the partition tube 180 to the end cover 140, the end cover 140 serves as the bottom plate of the partition tube 180. With the above configuration, the partition tube 180 can obtain the same effect as when the partition tube 170 is provided in the tank-integrated hydraulic pump 100.

[0028] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such examples. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the claims, and it is understood that such modifications and alterations naturally fall within the technical scope of the present invention. [Industrial Applicability]

[0029] The present invention can be used as a tank-integrated hydraulic pump that is integrated with a tank. [Explanation of symbols]

[0030] 100...Tank-integrated hydraulic pump, 110...Pump, 112...Return pipe, 116...Return pipe, 116a...116a, 117...Elbow pipe, 120...Tank, 130...Motor, 140...End cover, 142...Mounting hole, 160, 160A...Breather, 162...Inlet, 170...Partition tube, 172...Cylindrical surface, 172a...Slit, 174...Mounting surface, 174a...Threaded hole, 180...Partition tube, 182a...Slit, 184...Mounting tab, 184a...Threaded hole

Claims

1. a pump for delivering hydraulic oil; a tank that is integrally disposed with the pump and stores the hydraulic oil; an end cover that seals an end of the tank; a breather provided on the end cover; a return pipe protruding from the pump into the tank; a partition cylinder attached to the end cover within the tank and arranged to surround an outlet of the return pipe; a slit formed in the partition cylinder on the opposite side to the breather inlet; A tank-integrated hydraulic pump comprising:

2. 2. The tank-integrated hydraulic pump according to claim 1, wherein the return pipe has an end that is L-shaped, and the outlet of the return pipe faces away from the slit.

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