Hydraulic motor

Abstract

The present invention provides a hydraulic motor that allows for efficient routing of piping and wiring when a sensor is installed to detect the motor's rotation. [Solution] The hydraulic motor 100 of the present invention comprises a cylinder barrel 110 supported in a housing 102 so as to be rotatable together with a shaft 104, a plurality of pistons 112 inserted into the cylinder barrel 110 so as to be axially slidable, a swash plate 120 for changing the stroke of the pistons 112, a control piston 130 for adjusting the angle of the swash plate 120, a valve body 140 provided with an inlet port and an outlet port, a female thread 104b formed at the valve body 140 side end of the shaft 104 of the cylinder barrel 110, a shaft member (hexagonal bolt 144) with irregularities on its outer circumference attached to the female thread 104b, and a sensor 160 for detecting the irregularities of the shaft member, the sensor 160 being positioned between the inlet port and the outlet port.

Description

Technical Field

[0001] The present invention relates to a hydraulic motor.

Background Art

[0002] Hydraulic motors are used as driving sources for traveling or slewing in construction machinery and industrial machinery. A sensor for detecting the rotation of the motor is provided in the hydraulic motor. For example, Patent Document 1 discloses "a hydraulic motor including a casing, a rotatable cylinder block housed in the casing, a cylinder block side friction plate whose rotation relative to the cylinder block is restricted around the rotation axis of the cylinder block, a casing side plate whose rotation is restricted relative to the casing and which at least partially overlaps the cylinder block side friction plate in the rotation axis direction, a pressing mechanism for pressing the cylinder block side friction plate and the casing side plate against each other along the rotation axis direction, and a detector fixed to the casing for detecting the rotation of at least one of the cylinder block side friction plates."

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the hydraulic motor of Patent Document 1, a detector for detecting the rotation of the cylinder block side friction plate is provided on a fixed block of the casing on the outer peripheral side of the cylinder block. With this configuration, since the detector is arranged at a location far from the piping port portion of the valve body for hydraulic piping of the hydraulic motor, the positions and directions of the hydraulic piping and the wiring of the detector do not match. Then, there is a problem that the handling of the piping and wiring becomes complicated when assembling the hydraulic motor to construction machinery or the like.

[0005] In view of these problems, the present invention aims to provide a hydraulic motor that allows for good routing of piping and wiring when a sensor for detecting the rotation of the motor is installed. [Means for solving the problem]

[0006] To solve the above problems, a typical configuration of the hydraulic motor according to the present invention includes a cylinder barrel supported in a housing so as to be rotatable together with a shaft, a plurality of pistons inserted into the cylinder barrel so as to be axially slidable, a swash plate for changing the stroke of the pistons, a control piston for adjusting the angle of the swash plate, a valve body provided with an inlet port and an outlet port, a female thread formed at the valve body side end of the shaft of the cylinder barrel, a shaft member with irregularities on its outer circumference attached to the female thread, and a sensor for detecting the irregularities on the shaft member, wherein the sensor is positioned between the inlet port and the outlet port.

[0007] It is preferable that the connection direction of the hydraulic piping between the inlet and outlet ports is the same as the connection direction of the wiring of the sensor.

[0008] The maximum diameter of the head of the hexagonal bolt should be smaller than the diameter of the shaft. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a hydraulic motor that allows for good routing of piping and wiring when a sensor for detecting the rotation of the motor is installed. [Brief explanation of the drawing]

[0010] [Figure 1] This is a diagram illustrating the hydraulic motor according to this embodiment. [Figure 2] This is an enlarged view of the main part of Figure 1(a). [Figure 3] This is a diagram illustrating the placement of the sensors. [Figure 4] This diagram illustrates the state after the valve body has been removed. [Modes for carrying out the invention]

[0011] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. The dimensions, materials, and other specific numerical values ​​shown in these embodiments are merely illustrative to facilitate understanding of the invention and do not limit the present invention unless otherwise specified. In this specification and drawings, elements having substantially the same function or configuration are denoted by the same reference numerals to avoid redundant explanations, and elements not directly related to the present invention are not shown or described.

[0012] Figure 1 is a diagram illustrating the hydraulic motor 100 according to this embodiment. Figure 1(a) is a top view of the hydraulic motor 100. Figure 1(b) is a cross-sectional view AA of the hydraulic motor 100, and is a side cross-sectional view illustrating the internal structure of the hydraulic motor 100.

[0013] The hydraulic motor 100 shown in Figures 1(a) and 1(b) is used as a drive source for travel in construction machinery, industrial machinery, etc. As shown in Figure 1(a), the hydraulic motor 100 of this embodiment comprises a housing 102 and a valve body 140 provided adjacent to the housing 102.

[0014] The valve body 140 is provided with two inlet and outlet ports 152 and 154. Depending on the rotation direction of the hydraulic motor 100, one functions as an inlet port and the other as an outlet port. Drain ports 156 and 158 are located outside the inlet and outlet ports 152 and 154, respectively.

[0015] Inside the housing 102 is a cylinder barrel 110 that is rotatably supported together with the shaft 104. Multiple pistons 112 are inserted into the cylinder barrel 110, which are slidable in the axial direction 1 of the shaft 104. The multiple pistons 112 are arranged in a line in the circumferential direction of the cylinder barrel 110.

[0016] When hydraulic fluid is supplied from the inlet port (one of the inlet / outlet ports 152 and 154), the piston 112 attempts to protrude from the cylinder barrel 110, causing the cylinder barrel 110 to rotate. As the cylinder barrel 110 rotates, the piston 112 is pushed in by the swash plate 120, and the hydraulic fluid is discharged from the outlet port (the other of the inlet / outlet ports 152 and 154).

[0017] The swash plate 120 is a component that changes the stroke of the piston 112. The head 112a of the piston 112 is attached to the swash plate 120 via a piston shoe 114 that abuts against and slides against the swash plate 120. The angle of the swash plate 120 is adjusted by a control piston 130. In detail, the swash plate 120 is supported within the housing 102 so as not to rotate relative to the rotation of the shaft 104, and changes the stroke length of the piston 112 by being pushed and tilted by the control piston 130.

[0018] Figure 2 is an enlarged view of the main part of Figure 1(b). In the valve body 140, the end 104a of the shaft 104 of the cylinder barrel 110 is supported by a bearing 142. A female thread 104b is formed on the valve body 140 side end 104a of the shaft 104, and a hexagonal bolt 144 is attached to the female thread 104b as a shaft member. The hexagonal bolt 144 has a hexagonal head 144a, and is a shaft member with irregularities on its outer circumference (hexagonal irregularities of the head 144a) relative to the shaft of the bolt. The hexagonal bolt 144 is also fixed by a nut 146 (which functions as a double nut).

[0019] As shown in Figures 1(b) and 2, a sensor 160 is attached to the valve body 140 to detect protrusions of the shaft member (heads 144a of the hexagonal bolts 144). Examples of the sensor 160 include proximity sensors such as magnetic or eddy current sensors.

[0020] FIG. 3 is a diagram for explaining the arrangement of the sensor 160. FIG. 3(a) is a top view excerpting the valve body 140 of FIG. 1(a). FIG. 3(b) is a front view of FIG. 1(b) observed from the B direction. As shown in FIGS. 3(a) and (b), as a feature of the hydraulic motor 100 of the present embodiment, the sensor 160 is arranged between two inflow / outflow ports 152 and 154 (inflow port and outflow port).

[0021] According to the above configuration, since the head 144a of the hexagonal bolt protrudes from the shaft 104, the sensor 160 can be arranged on the valve body 140. And the sensor 160 and the two inflow / outflow ports 152 and 154 are arranged at adjacent positions. Specifically, there are two inflow / outflow ports 152 and 154 between two drain pipes 176 and 178, and the sensor 160 is arranged in the center thereof, and they are arranged in a row. Thereby, since the positions of the hydraulic pipes and the wiring of the sensor are aligned, the restrictions on the layout of the hydraulic motor 100 can be reduced.

[0022] And particularly as shown in FIG. 3(b), the connection directions of the hydraulic pipes 172 and 17, of the two inflow / outflow ports 152 and 154 (inflow port and outflow port) are the same as the connection direction of the wiring 162 of the sensor 160. Also, the two drain pipes 176 and 178 also have the same connection direction as the wiring 162 of the sensor 160 and the hydraulic pipes 172 and 174 of the two inflow / outflow ports 152 and In this way, when providing the sensor 160, the wiring 162, the hydraulic pipes 172 and 174, and the drain pipes 176 and 178 can be routed together, and it is possible to route them well.

[0023] Also, as shown in FIG. 2, in the hydraulic motor 100 of the present embodiment, the maximum diameter d1 of the head 144a (the unevenness on the outer peripheral part of the shaft member) of the hexagonal bolt 144 is set to be smaller than the diameter d2 of the shaft.

[0024] Figure 4 illustrates the state after the valve body 140 has been removed. As clearly shown in Figure 4, when removing the valve body 140 from the housing 102, the head of the hexagonal bolt 144 can pass through the inner ring of the bearing 142 that supports the shaft 104. Therefore, the valve body 140 can be easily removed.

[0025] Then, as described above, the valve body 140 is removed, exposing the hexagonal bolt 144. This makes it possible to rotate the hexagonal bolt 144 and easily adjust the position of its head 144a to a position that is easily detected by the sensor 160. In other words, separate from the fact that the nut 146 fixes the structure on the valve body end side of the hydraulic motor 100, the hexagonal bolt 144 protrudes axially from the nut 146, and the protruding side has irregularities (for example, the head 144a), which allows for fine adjustment of the axial position of the part to be detected by the sensor 160. It should be noted that other configurations with irregularities can also be used for the part to be detected by the sensor 160. One example is a male spline.

[0026] Preferred embodiments of the present invention have been described above with reference to the attached drawings, but it goes without saying that the present invention is not limited to such examples. It will be clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention. [Industrial applicability]

[0027] This invention can be used as a hydraulic motor for construction machinery, industrial machinery, and the like. [Explanation of Symbols]

[0028] 100... Hydraulic motor, 102... Housing, 104... Shaft, 104a... End, 104b... Female thread, 110... Cylinder barrel, 112... Piston, 114... Piston shoe, 120... Swash plate, 130... Control piston, 140... Valve body, 142... Bearing, 144... Hex bolt, 144a... Head, 146... Nut, 152... Inlet / outlet port, 154... Inlet / outlet port, 156... Drain port, 158... Drain port, 160... Sensor, 162... Wiring, 172... Hydraulic piping, 174... Hydraulic piping, 176... Drain piping, 178... Drain piping

Claims

1. A cylinder barrel supported within the housing so as to be rotatable together with the shaft, Multiple pistons are inserted into the cylinder barrel so as to be slidable in the axial direction, A swash plate that changes the stroke of the aforementioned piston, A control piston for adjusting the angle of the swash plate, A valve body provided with an inlet port and an outlet port, A female thread formed on the valve body side end of the cylinder barrel shaft, A shaft member having irregularities on its outer circumference attached to the female thread, A sensor for detecting irregularities in the shaft member, Equipped with, A hydraulic motor characterized in that the sensor is positioned between the inlet port and the outlet port.

2. The hydraulic motor according to claim 1, characterized in that the connection direction of the hydraulic piping between the inlet port and the outlet port is the same as the connection direction of the wiring of the sensor.

3. The hydraulic motor according to claim 1, characterized in that the maximum diameter of the irregularities on the outer circumference of the shaft member is smaller than the diameter of the shaft.

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