US-20260126032-A1 - HYDRAULIC MOTOR

US20260126032A1US 20260126032 A1US20260126032 A1US 20260126032A1US-20260126032-A1

Abstract

A configuration of a hydraulic motor according to the present disclosure includes: a cylinder barrel rotatably supported in a housing together with a shaft; a plurality of pistons slidably inserted into the cylinder barrel in an axial direction; a swash plate for changing strokes of the pistons; a control piston for adjusting an angle of the swash plate; a valve body provided with an inflow port and an outflow port; a female thread formed at an end portion of the shaft of the cylinder barrel on a valve body side; a shaft member (hexagonal bolt) having irregularities on an outer peripheral portion and attached to the female thread; and a sensor disposed between the inflow port and the outflow port and detecting the irregularities of the shaft member.

Inventors

Takaya Yokota

Assignees

NACHI-FUJIKOSHI CORP.

Dates

Publication Date: 20260507
Application Date: 20251030
Priority Date: 20241106

Claims (3)

1 . A hydraulic motor comprising: a cylinder barrel rotatably supported in a housing together with a shaft; a plurality of pistons slidably inserted in an axial direction into the cylinder barrel; a swash plate for changing strokes of the pistons; a control piston for adjusting an angle of the swash plate; a valve body provided with an inflow port and an outflow port; a female thread formed at an end portion of the shaft of the cylinder barrel on the valve body side; a shaft member having irregularities on an outer peripheral portion and attached to the female thread; and a sensor arranged between the inflow port and the outflow port and detecting the irregularities of the shaft member.
2 . The hydraulic motor according to claim 1 , wherein a connection direction of hydraulic piping of the inflow port and the outflow port and a connection direction of wiring of the sensor are the same.
3 . The hydraulic motor according to claim 1 , wherein a maximum diameter of the irregularities on the outer peripheral portion of the shaft member is smaller than a diameter of the shaft.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2024-194479, filed Nov. 6, 2024; the entire contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a hydraulic motor. Background Art Hydraulic motors, which are employed as driving power sources for traveling or for slewing, are used in construction machines and industrial machines. A hydraulic motor is provided with a sensor that detects a rotation of the motor. For example, Patent Document 1 discloses “a hydraulic motor including a casing, a cylinder block accommodated in the casing and capable of rotating, a cylinder block-side friction plate, rotation of which relative to the cylinder block about a rotation axis of the cylinder block is restricted, a casing-side plate, rotation of which relative to the casing is restricted, at least partially overlapping with the cylinder block-side friction plate in a rotational axis direction, a pressing mechanism that presses 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 and detecting rotation of at least one of the cylinder-block-side friction plates.” Patent Document 1: Japanese U.S. Pat. No. 7,281,918 SUMMARY OF THE INVENTION The hydraulic motor of Patent Document 1 includes the detector for detecting rotation of the cylinder block-side friction plate. The detector is provided in a fixing block of the casing on an outer peripheral side of the cylinder block. With this configuration, the detector is arranged at a position away from a piping port portion of a valve body that performs hydraulic piping of the hydraulic motor, so that the position and orientation/direction of the hydraulic piping and wiring of the detector become inconsistent. As a result, when the hydraulic motor is assembled into a construction machine or the like, there arises a problem in that routing of the piping and wiring becomes complicated. The present disclosure has been made in view of foregoing problems. it is desirable to improve the efficiency of routing of piping and wiring when providing a sensor for detecting the rotation of the motor. A representative configuration of a hydraulic motor according to the present disclosure includes: a cylinder barrel rotatably supported in a housing together with a shaft; a plurality of pistons slidably inserted into the cylinder barrel in an axial direction; a swash plate for changing strokes of the pistons; a control piston for adjusting an angle of the swash plate; a valve body provided with an inflow port and an outflow port; a female thread formed at an end portion of the shaft of the cylinder barrel on a valve body side; a shaft member having irregularities on an outer peripheral portion thereof and attached to a female thread; and a sensor disposed between the inflow port and the outflow port and detecting the irregularities of the shaft member. The connection direction of the hydraulic piping of the inflow port and the outflow port may be the same as a connection direction of wiring of the sensor. A maximum diameter of the irregularities on the outer peripheral portion of the shaft member may be smaller than a diameter of the shaft. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a diagram illustrating a hydraulic motor according to an embodiment of the present disclosure. FIG. 1B is a sectional view taken along line A-A of FIG. 1A. FIG. 2 is an enlarged view of a principal portion of FIG. 1A. FIG. 3A is a diagram illustrating an arrangement of a sensor. FIG. 3B is a front view of FIG. 1B as viewed from direction B. FIG. 4 is a diagram illustrating a state in which a valve body is removed. DETAILED DESCRIPTION The embodiments will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and unless otherwise specified, do not limit the embodiments. In the present specification and drawings, elements having substantially the same functions and configurations are denoted by the same reference numerals so that redundant descriptions are omitted, and elements not directly related to the embodiments are omitted from illustration or description. FIG. 1 is a diagram illustrating a hydraulic motor 100 according to an embodiment of the present disclosure. FIG. 1A is a top view of the hydraulic motor 100. FIG. 1B is a sectional view taken along line A-A of the hydraulic motor 100. FIG. 1B is also a side sectional view illustrating the internal structure of the hydraulic motor 100. The hydraulic motor 100 shown in FIGS. 1A and 1B is used as a drive source for traveling in construction machinery, industrial machinery, and the like. As shown in FIG. 1A, the hydr