JPH04337152A - Oil hydraulic motor with reduction gear - Google Patents

Abstract

PURPOSE:To obtain an oil hydraulic motor with a reduction gear applicable to a small construction machine, having a short length in the axial direciton and used in a driving gear of a crawler in the construction machine. CONSTITUTION:An oil hydraulic motor 30 of a reduction gear-provided oil hydraulic motor is formed into a circumscribed meshing type geared motor 30 in which two gears 31a, 31b are circumscribe-meshed with a single gear 36. In this oil hydraulic motor 30, each output shaft 32a, 32b of two gears 31a, 31b, circumscribed to the single gear 36, is connected to an external gear 29 of a differential reduction gear through eccentric shafts 33a, 33b to synchronize these eccentric shafts 33a, 33b. This external gear 29 serves as a sheet of the external gear 29 between an internal gear 27 of the reduction gear provided in a driven member 25 and the eccentric shafts 33a, 33b actuated by the two output shafts 32a, 32b of the oil hydraulic motor 30.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic motor equipped with a reduction gear for use in a drive device for a crawler of a construction machine.

0002

[Prior art] Conventionally, this type of hydraulic motor with a reduction gear has
There is one shown in FIG. 7 (Utility Model Application Publication No. 54-42867).

In FIG. 7, reference numeral 1 denotes a crawler support body connected to the body of a crawler that is connected to the body of a construction machine, and a main body 5 of a hydraulic motor 3 with a reduction gear is fixed to a flange 2 of the crawler support body 1. .

The hydraulic motor 3 with a reduction gear includes a plunger motor 4 inside a main body 5 fixed to the flange 2.
It stores. An output shaft 6 of the plunger motor 4 protrudes toward one end of the main body 5 and is connected to a speed reducer 7 provided at one end of the main body 5. This speed reducer 7 has its output section 12 supported by the main body 5 with a bearing 10,
A plurality of bolts 1 on a sprocket 8 that engages with a crawler 9
They are connected by 1.

The plunger motor 4 has an output shaft 6 supported by a main body 5 connected to a cylinder block 4c in which a plurality of pistons 4a are slidably fitted, and the tips of the pistons 4a are fixed to the main body 5. It is configured to abut against the swash plate 4b. When pressure oil is supplied to and discharged from the cylinder block 4c from the supply and discharge pipes 13a and 13b fixed to the other end of the main body 5, the piston 4a is pressed against the swash plate 4b by the pressure of this hydraulic pressure, and the reaction force Rotate the output shaft 6.

The reduction gear 7 connects an external gear 7a fixed to the output shaft 6 and an internal gear 12a fixed to the output section 12 by an integral gear consisting of an external gear 7c' and an external gear 7c. It is a planetary gear type reducer connected by External gear 7c', 7
c is supported by arm 7b, external gear 7c' meshes with internal gear 7d fixed to main body 5, and external gear 7c meshes with internal gear 12a. In this reducer 7, when the external gear 7a is rotated by the output shaft 6, deceleration is performed while this rotation is transmitted to the internal gear 12a via the external gear 7c' and the external gear 7c. be exposed.

In the hydraulic motor 3 with a speed reducer having the above configuration, one of the supply and discharge pipes 13a and 13b is connected to a pressure fluid source and the other to a tank, and the pressure fluid from the pressure fluid source is connected to these. When the piston 4a is supplied or discharged, the piston 4a is pressed against the swash plate 4b, and the plunger motor 4 rotates together with the output shaft 6 by the reaction force. This rotation is reduced by each gear of the reducer 7 and transmitted from the output section 12 of the reducer 7 to the sprocket 8, thereby driving the crawler 9. In the conventional hydraulic motor 3 with a reduction gear described above, the rotation of the plunger motor 4 is reduced by the reduction gear 7 and transmitted to the sprocket 8, so even if the plunger motor 4 is a plunger motor having characteristics of high rotation and low torque, By converting the output into a high-torque, low-rotation output in the reducer 7, the plunger motor 4 and the reducer 7 can be made smaller.

[0008] In this prior art, the reduction gear 7 is a reduction gear using a planetary gear mechanism constituted by a large number of gears, but as disclosed in Japanese Patent Application Laid-Open No. 56-39341, this reduction gear 7 is connected to the internal gear 12a of the output section 12.
It may be a differential gear type speed reducer in which two external gears mesh with each other, the number of teeth of the external gear is one less than the number of teeth of the internal gear 12a, and the difference in the number of teeth is used to reduce the speed.

[0009]

[Problems to be Solved by the Invention] In the above-mentioned conventional technology, the rotation of the output shaft 6 of the plunger motor 4 is decelerated by the reducer 7, and the rotation is transmitted to the sprocket 8 provided on the outer periphery of the main body 5 of the plunger motor 4. By making the plunger motor 4 high-speed and low-torque and reducing the size of the plunger motor 4, the entire hydraulic motor 3 with a speed reducer is made smaller.

However, the basic structure of the plunger motor 4 is to supply and discharge pressure oil to and from the cylinder block 4c, press the piston 4a against the swash plate 4b, and rotate the output shaft 6 by the reaction force. Therefore, it is necessary to arrange the plunger that reciprocates in order to obtain rotational force and the swash plate that the plunger comes into contact with in the axial direction, which increases the overall length of the hydraulic motor 3 with a reduction gear.

When installing the hydraulic motor 3 with a reduction gear on the crawler of a construction vehicle, if some parts of the hydraulic motor 3 with a reduction gear protrude from the width of the crawler 9, they may protrude from the crawler while the construction vehicle is running. The part of the hydraulic motor with a reduction gear may collide with an obstacle (such as a rock) on the road surface and be destroyed. For this reason, the hydraulic motor 3 with reducer
must be stored within the width of the crawler 9. and,
The width of the crawler 9 becomes narrower as construction machinery becomes smaller.
Therefore, if the axial dimension of the hydraulic motor 3 with a reduction gear is long, there is a problem that it becomes difficult to apply it to small-sized construction machines.

0012

[Means for Solving the Problems] The technical means of the present invention for solving the problems of the prior art described above is that the fixing member 22
a hydraulic motor 30 that is fixed to and operated by supplying and discharging pressure oil; and a driven member 25 that operates relative to the fixed member 22.
and a reducer 28 fixed to and connected to the output side of the hydraulic motor 30, and the reducer 28 is connected to the driven member 2.
5, and an external gear 29 that meshes with the internal gear 27, has fewer teeth than the internal gear 27, and is connected to the output side of the hydraulic motor 30. In the hydraulic motor 20 with a reducer that uses a differential gear type reducer and reduces the rotation of the hydraulic motor 30 and transmits the reduced rotation to the driven member 25, the hydraulic motor 30 is arranged in one gear 36 and two gears 31a and 31b. A gear motor 30 of the externally meshing type in which the gears 36 and 36 are externally meshed is used, and this hydraulic motor 30 is formed by two gears 3 that are externally engaged with the one gear 36.
1a, 31b are connected to the external gear 29 of the differential reducer via eccentric shafts 33a, 33b to synchronize the eccentric shafts 33a, 33b. The internal gear 27 of the reducer 28 provided in the fixed member 22 and the hydraulic motor 3
Eccentric shaft 33 that operates with two output shafts 32a and 32b of 0
A and 33b are characterized by a single external gear 29.

[0013]

[Operation] In the technical means of the present invention described above, since the hydraulic motor is a gear motor of the externally meshing type with two gears in one gear, there is no need to operate in the axial direction like a plunger motor. Furthermore, since the reducer is configured to consist of an internal gear of the reducer and a single external gear between the eccentric shaft operated by the two output shafts of the hydraulic motor, this technical Even in the reduction gear according to this method, the eccentric shaft, the external gear, and the internal gear which is the output side of the reduction gear can be arranged on the same plane. Therefore, since there is no need for a mechanism that operates in the axial direction for both the mechanism required for rotational output and the reducer that reduces the output, the axial length of the hydraulic motor with reducer is reduced to the minimum required for rotation. It can be of limited length.

[0014]

Embodiments Examples of the present invention will be described below with reference to FIGS. 1 to 4.

In FIG. 1, a hydraulic motor 20 with a reduction gear according to the present invention is fixed to a flange 2 of a crawler support 1, which is a traveling device of a construction machine, with a plurality of bolts. Its details are shown in detail in FIG. 2, which is a sectional view taken along the line A--A in FIG. In addition, in FIG. 1, 40 is a high/low speed switching valve whose details are shown in FIGS. 5 and 6. A supply/discharge line 45a, a supply/discharge line 45b, a pilot line P, and a drain line D are connected to this high/low speed switching valve.

In FIG. 2, a hydraulic motor 20 with a reduction gear
includes a first main body 21 fixed to the flange 2 with bolts, a second main body 22 fixed to the first main body 21, and the first main body 21 fixed to the flange 2 with bolts.
It has an outer cylinder 25 supported by the main body 21 and the second main body 22 via bearings 24a and 24b.

At the right end of the second main body 22, there is provided a reduction gear 28, which has an internal gear 27 provided in an outer cylinder 25 and an external gear 29 that meshes with the internal gear 27, the details of which are shown in FIG. is provided. A sprocket 8 that meshes with the crawler 9 is fixed to the outer cylinder 25 with a plurality of bolts, and an internal gear 27 constituting a reduction gear 28 whose details are shown in FIG. 4 is provided inside the outer cylinder 25. Further, in the center of the third main body 30a, a hydraulic motor 30 is provided, which has two external gears 31a and 31b that mesh with one central intermediate gear 36, and is shown in detail in FIG. 3. .

The external gear 31a and the external gear 31b of the hydraulic motor 30 are attached such that an output shaft 32a and an output shaft 32b protrude from the right end of the second main body 22,
The output shaft 32a and the output shaft 32b are connected to the reduction gear 28.
The eccentric shaft 33a and the eccentric shaft 33 that rotate the external gear 29 of
It is constructed integrally with b.

In the hydraulic motor 20 with a reduction gear, when pressure oil is supplied to and discharged from the hydraulic motor 30 and its output shaft 32a and output shaft 32b rotate, the eccentric shaft 33a and the eccentric shaft 33b also rotate at the same time, and the external gear is rotated. 29 engages with the internal gear 27 while eccentrically moving (revolving), differentially decelerating the signal, and transmitting the signal to the outer cylinder 25.

As shown in FIG. 2, the hydraulic motor 30 includes an intermediate gear 36 provided on a shaft 35 rotatably held in the second body 22 by bearings, and fixed to the output shafts 32a and 32b. Two external gears 31a and 31b that mesh with the intermediate gear 36 are housed in the inner hole 38 of the third main body 30a. Further, the intermediate gear 3
As shown in FIG. 3, ports 39a1 to 39d1 are provided at the meshing portions between the external gear 6 and the external gear 31a and the external gear 31b.
are provided, and these ports 39a1 to 39d
1 is connected to each supply/discharge port 39a to supply/discharge port 39d of the high/low speed switching valve 40 shown in FIGS. Connect to the source.

As shown in FIG. 5, the high/low speed switching valve 40 has a spool 42 slidably fitted into a main body 41, and a spring at the right end of the spool 42 that presses the spool 42 to the left. A spring chamber 43 is provided with a spring chamber 43a, and a pilot chamber 44 with a port 44p open to the pilot is provided at the left end. The main body 41 includes supply/discharge ports 39a to 39d connected to ports 39a1 to 39d1 of the hydraulic motor 30, and ports 45a and 45b connected to a pressure fluid source or tank via a directional switching valve (not shown). , a drain port 45d to which the drain is connected, and a pilot port 4 to which the pilot is connected.
4p is provided.

The spool 42 of the high/low speed switching valve 40 is
When no pilot oil pressure acts on the pilot port 44p, it is held in the position shown by the switching position 42a by the spring 43a (the upper spool position in FIG. 5). In this switching position, as shown in switching position 42a in FIG. 6, supply/discharge port 39a and supply/discharge port 39b are connected to port 45a,
The supply/discharge port 39c and the supply/discharge port 39d are connected to the port 45b.
Connect to.

In the above-mentioned switching position 42a, the hydraulic motor 30 is in the position shown in FIG.
The supply/discharge port 39a1 and the supply/discharge port 39b1 are connected to a pressure fluid source via the supply/discharge port 39a and the supply/discharge port 39b of the high/low speed switching valve 40, and the port 39c1 and port 39d1 of the hydraulic motor 30 are connected to the pressure fluid source. , is connected to the tank via the supply/discharge port 39c and the supply/discharge port 39d of the high/low speed switching valve 40. The hydraulic motor 30 then rotates synchronously in the direction indicated by the arrow in FIG. This switching position 42a of the high/low speed switching valve 40 connects the two gear motors of the hydraulic motor 30 in parallel with respect to the pressure fluid. Therefore, the external gear 31a and the external gear 31 of the hydraulic motor 30
The rotation b is performed by the two gear motors of the hydraulic motor 30 using two parts of the pressure oil discharged from the pressure fluid source. As a result, the number of revolutions of the hydraulic motor 30 is half that of when one hydraulic motor is connected to the pressure fluid source, and the torque is twice as high.

The spool 42 of the high/low speed switching valve 40 is
When the pilot oil pressure acts on the pilot port 44p, the pilot oil pressure holds it at the position shown in the switching position 42b (lower spool position in FIG. 5). This switching position is as shown in switching position 42b in FIG.
is connected to port 45a, and port 39d is connected to port 45b.
Connect to.

At the switching position 42b described above, FIG.
As shown in , the port 39a1 of the hydraulic motor 30 is connected to the pressure fluid source via the port 39a of the high/low speed switching valve 40, and the supply/discharge port 39c1 of the hydraulic motor 30 is connected to the supply/discharge port of the high/low speed switching valve 40. It is connected to the tank via 39d. In addition, the high/low speed switching valve 40 has a supply/discharge port 39b and a supply/discharge port 39 as shown in a switching position 42b in FIG.
Connect c. Therefore, port 39 of hydraulic motor 30
The pressure oil supplied to a1 is applied to the external gear 31a and the intermediate gear 3.
6 and rotate in the direction of the arrow. Pressure oil sent to the port 39c1 by this rotation is supplied to the port 39b1 via the high/low speed switching valve 40, so the external gear 31b and the intermediate gear 36 are rotated in the direction of the arrow, and this rotation causes the port 39d1, high/low speed switching valve 40
is discharged into the tank via. This connection is such that two hydraulic motors are connected in series to a source of pressure fluid.

In this way, the high/low speed switching valve 40 is at the switching position 4.
2b, the two hydraulic motors of the hydraulic motor 30 are connected in series, so that the rotation of the external gear 31a and the external gear 31b of the hydraulic motor 30 is
Since the discharge pressure oil from the pressure fluid source is supplied to each of the two gear motors 0, the discharge pressure oil from the pressure fluid source is not divided into two. Therefore, the rotation of the output shafts 32a and 32b is twice that of the switching position 42a of the high-low speed switching valve 40 described above, and the torque is 1/2.

The reducer 28 connected to the output shaft 32a and output shaft 32b of the hydraulic motor 30 includes an internal gear 27 provided in the outer cylinder 25 and an external gear 2 that meshes with the internal gear 27.
9 and an eccentric shaft 33a that applies a rocking motion to this external gear 29.
, and an eccentric shaft 33b. The number of teeth of the internal gear 27 is at least one more than the number of teeth of the external gear 29, and the difference in the number of teeth determines the reduction ratio (reduction ratio = number of teeth of the internal gear 27 - external gear 29). The number of teeth of the internal gear 29/the number of teeth of the internal gear 29) is determined. Further, the eccentric shaft 33a is connected to the output shaft 3.
2a, and the eccentric shaft 33b is integrally formed with the output shaft 32b. Therefore, the eccentric shaft 33a, the eccentric shaft 33b
is connected to the flange 2 via the second body 22 and the first body 21. Further, the outer cylinder 25 is connected to the sprocket 8.

Next, the reduction gear 28 shown in FIG. 4 will be explained. Assuming that the difference in the number of teeth between the internal gear 27 and the external gear 29 is 2, and when the external gear 29 is rotated in the direction of the arrow by the rotation of the hydraulic motor 30, the teeth of the internal gear 27 are Only two sheets are sent in the direction of the arrow. Therefore, the reduction ratio in this case is 2/29.

A spring brake device 50 is provided on the external gear 29 and the first main body 21 of the reducer 28 in FIG. This spring brake device includes a brake shoe 51 that presses the external gear 29 against the outer cylinder 25 at its center, and a brake piston 53 that is provided on the first main body 21 and applies a braking force to the brake shoe 51. However, the force of the brake piston 53 is transmitted by a rod 54 that is slidably fitted into the shaft 35 of the intermediate gear 36.

The brake piston 53 of the spring brake device 50 has a large diameter portion 53a that is slidably fitted into the inner hole 55 of the first body 21, and a large diameter portion 53a that is concentric with the inner hole 55 of the second body 22.
A small diameter portion 53 that slidably fits into an inner hole 57 provided in the
It is composed of b. A spring 56 is provided in the large diameter portion 53a of the brake piston 53, and a pressure chamber 58 is provided between the first body 21 and the second body 22, which is constantly connected to the high pressure side of the high/low speed switching valve 40. It is provided.

In the spring brake device 50, pressure oil is supplied to the hydraulic motor 30 from a pressure fluid source to the high/low speed switching valve 40.
When the pressure oil is supplied through the pressure chamber 58, the pressure oil on the high pressure side enters the pressure chamber 58.
The brake piston 53 is moved to the left against the pressing force of the spring 56, and the braking force applied to the brake shoe 51 is released. Further, when the supply and discharge of pressure oil to the hydraulic motor 30 is stopped, the pressure oil in the pressure chamber 58 is also discharged, so that the brake shoe 51 is pressed by the pressing force of the spring 56, and the external gear 29 is pushed against the cover 52. to apply a brake to the hydraulic motor 20 with brake force reducer.

The operation of this embodiment having the above configuration will be described.

[0033] If the directional control valve (not shown) is not operated,
If both ports 45a and 45b of the high/low speed switching valve 40 are cut off from the pressure fluid source and the tank, the spring brake device 50 of the hydraulic motor 30 will cause the pressure oil in the pressure chamber 58 to flow out from the drain to the tank. , the pressing force of the spring 56 acts on the brake shoe 51 via the brake piston 53 and the rod 54, and the brake shoe 51 presses the external gear 29 against the lid 52, causing the brake to be applied to the hydraulic motor 20 with a reduction gear. .

Next, the directional switching valve (not shown) is operated, and the port 45a of the high/low speed switching valve 40 is connected to the pressure fluid source, the port 45b is connected to the tank, and the high/low speed switching valve 40 is connected to the pressure fluid source.
Pilot hydraulic pressure is not supplied to the pilot port 44p of the spool 42, and the spring 43a is in the switching position 42a.
(At this time, the high/low speed switching valve 40
is at the switching position 42a in FIG. 6). Under these conditions, pressure fluid from the pressure fluid source is directed to port 45.
It is supplied from the supply/discharge port 39a to the supply/discharge port 39a, and from the supply/discharge port 39a to both the supply/discharge port 39a1 and the supply/discharge port 39b1 of the hydraulic motor 30. Further, both the supply/discharge port 39c1 and the supply/discharge port 39d1 of the hydraulic motor 30 are connected to the tank by a directional switching valve via the port 45b of the high/low speed switching valve 40.

When the pressure fluid is supplied to the hydraulic motor 30 as described above, the high pressure side is supplied to the pressure chamber 58 of the spring brake device 50, and the brake piston 53 is moved to the left against the spring 56. , the pressing force on the brake shoe 51 is released and the brake applied to the hydraulic motor 20 with a reduction gear is released.

When pressure fluid is supplied to and discharged from the hydraulic motor 30 as described above by the high/low speed switching valve 40, the hydraulic motor 30
The external gear 31a and the external gear 31b rotate as shown by the arrows. In this rotation, the two gear motors of the hydraulic motor 30 are connected in parallel to the pressure fluid source, so the pressure fluid supplied from the pressure fluid source at this time is divided into two and the hydraulic motor 30 is supplied to two gear motors. Therefore, the hydraulic motor 30 outputs low rotation and high torque.

The output of the hydraulic motor 30 is connected to its output shaft 32a.
, is transmitted to the eccentric shaft 33a and eccentric shaft 33b of the reducer 28 through the output shaft 32b, and the external gear 29 is transmitted to the hydraulic motor 30.
is rotated in the direction of rotation (direction of the arrow). When the external gear 29 rotates once, the internal gear 27 has two teeth in the same direction as the rotation direction of the external gear 29 (when the difference in the number of teeth between the internal gear 27 and the external gear 29 is 1). ) can be rotated. In this way, the rotation of the hydraulic motor 30 is reduced by the reducer 28 and transmitted to the outer cylinder 25. Outer cylinder 2
When the rotation of the hydraulic motor 30 is transmitted to the crawler 9 through the sprocket 8, the outer cylinder 25 is transmitted to the crawler 9 through the sprocket 8.
to drive.

The above description has been made regarding the operation when the port 45a of the high/low speed switching valve 40 is connected to a pressure fluid source and the port 45b is connected to a tank by a directional switching valve (not shown). The difference is that when port 45a of 40 is connected to a tank and port 45b is connected to a pressure fluid source, the direction of rotation of hydraulic motor 30 and reducer 28 is opposite to that shown in the figure. Since the other operations are the same, a detailed explanation of the operations will be omitted.

Furthermore, the above description has been made regarding the operation when the high/low speed switching valve 40 is in the switching position 42a with no pilot oil pressure acting on the pilot port 45p of the high/low speed switching valve 40. When the pilot oil pressure acts on the pilot port 45p of the high/low speed switching valve 40, the high/low speed switching valve 40 switches to the switching position 42b. Connected to port 45a, supply/discharge port 39
The supply/discharge port 39b1 is connected to c1, and the supply/discharge port 39
d1 is connected to the port 45b of the high/low speed switching valve 40.

When the port 45a of the high/low speed switching valve 40 is connected to a pressure fluid source and the port 45b is connected to a tank, the pressure oil from the port 45a moves the external gear 31a of the hydraulic motor 30 in the direction of the arrow. Port 3 on the side that rotates and discharges pressure oil
Discharge to 9c1. This pressure oil is supplied to the discharge side port 39c.
1 to the port 39b1, the external gear 31b of the hydraulic motor 30 is rotated in the direction of the arrow, and the pressure oil flows into the port 39d.
Discharge to 1. This pressure oil flows out from the directional switching valve to the tank via the port 45a of the high/low speed switching valve 40. Due to this pressure fluid flow, the pressure fluid source from the pressure fluid source is supplied to each gear motor of the hydraulic motor 30, so that the rotation speed of the hydraulic motor 30 is adjusted to the switching position of the high/low speed switching valve 40. 42a, and the torque is 1/2.

In the case of the conventional technology in which the driving source is a plunger motor, for example, as disclosed in JP-A-59-175605, the angle of the swash plate is changed as a mechanism for changing the rotation speed of the plunger motor. It is necessary to provide a mechanism for supplying and discharging pressure oil to this mechanism. Moreover, since the mechanism for changing the angle of the swash plate needs to be provided in the axial direction of the plunger motor, the axial dimension of the hydraulic motor with a reduction gear increases accordingly. In this regard, according to this embodiment, the two gear motors are constructed of the intermediate gear 36 of the hydraulic motor 30 and the two external gears 31a and 31b that mesh with both sides of the intermediate gear 36, so that the rotation thereof The number can be changed in two stages by switching the four supply/discharge ports in parallel or in series with the pressure fluid source using the low-speed switching valve 40. Therefore, since there is no need to add a mechanism for changing the rotation speed, the axial dimension can be shortened accordingly.

[0042] Furthermore, the spring brake device in the case of the prior art in which the driving source is a plunger motor is
It is necessary to provide it on the rotating shaft of the plunger motor as disclosed in No. 415, or on the outer periphery of the cylinder block of the plunger motor as shown in Japanese Utility Model Application No. 63-196802. However, in the technique disclosed in Japanese Utility Model Publication No. 56-27415, the axial dimension increases by the amount of the spring brake device. In addition, in the case of the technology disclosed in Utility Model Application No. 63-196802, on the outer periphery of the cylinder block,
Since a spring brake device is provided, the dimensions extend in the radial direction.

In this regard, in the above embodiment, the brake shoes constituting the spring brake device are configured to come into contact with the external gear of the reduction gear, and the brake piston that applies the braking force to the brake shoes is connected to the hydraulic motor. The brake piston can be placed on the same plane as the bearing provided between the outer cylinder and the first body, and the brake shoes can also be placed on the same plane as the two eccentric shafts. By providing a spring brake device, it is not necessary to increase the axial or radial dimensions as in the above-mentioned two prior art techniques.

[0044]

Effects of the Invention In the hydraulic motor with a speed reducer of the present invention, the hydraulic motor is a gear motor of the externally meshing type in which two gears are externally engaged with one gear, and this hydraulic motor is externally engaged with the one gear. The output shaft of each of the two gears connected to the external gear of the differential reducer via an eccentric shaft synchronizes the eccentric shaft, and the external gear is connected to the external gear of the differential reducer provided in the fixed member. Since it is a single external gear between the internal gear and the eccentric shaft operated by the two output shafts of the hydraulic motor, the rotation of the gear motor is connected between the shafts supporting the gears of the hydraulic motor. It is possible to incorporate a mechanism to control this, which has the effect of shortening the axial dimension.

[0045] Since the axial and radial dimensions can be made small in this way, there is an effect that it can be applied to construction machines having narrower crawlers. Further, when used in a large construction machine, the excess portion in the axial direction can be used to install necessary parts for the traveling device.

[Brief explanation of drawings]

FIG. 1 is a front view of a hydraulic motor with a reduction gear according to an embodiment of the present invention installed in a traveling device of a construction machine.

FIG. 2 is a vertical sectional view taken along line AA of the hydraulic motor with a reduction gear according to the embodiment of the present invention shown in FIG. 1;

FIG. 3 is a BB sectional view of a vertical sectional view of the hydraulic motor with a speed reducer according to the embodiment of the present invention shown in FIG. 2;

FIG. 4 is a cross-sectional view taken along the line CC of the longitudinal cross-sectional view of the hydraulic motor with a speed reducer according to the embodiment of the present invention shown in FIG. 2;

5 is a cross-sectional view taken along line DD of a high-low speed switching valve in a longitudinal cross-sectional view of the hydraulic motor with a speed reducer according to the embodiment of the present invention shown in FIG. 2;

6 is a longitudinal sectional view of the hydraulic motor with a speed reducer according to the embodiment of the present invention shown in FIG. 5, showing hydraulic symbols of the high-low speed switching valve; FIG.

FIG. 7 is a longitudinal cross-sectional view of a conventional hydraulic motor with a speed reducer.

[Explanation of symbols]

1...Crawler support body 2...Flange 20...Hydraulic motor with reducer 22...Second main body (fixing member) 30...Gear motor 31a, 31b...external gear 36...Intermediate gear 25...Outer cylinder (driven member) 28...Reducer 28 27...Internal gear 29...External gear 33a. 33b...eccentric shaft

Claims (1)

[Claims] Claims: 1. A hydraulic motor 30 fixed to a fixed member 22 and operated by supplying and discharging pressure oil, and a driven member 25 fixed to a driven member 25 operating relative to the fixed member 22, on the output side of the hydraulic motor 30. an internal gear 2 having a coupled reducer 28 and fixing the reducer 28 to the driven member 25;
7 and an external gear 29 that meshes with the internal gear 27, has fewer teeth than the internal gear 27, and is connected to the output side of the hydraulic motor 30. , in a hydraulic motor 20 with a reducer that reduces the rotation of the hydraulic motor 30 and transmits it to the driven member 25, the hydraulic motor 30 is connected to one gear 36 and two gears 3.
A gear motor 30 of the externally meshing type in which the gears 1a and 31b are externally meshed is used, and the output shafts 32a and 32b of each of the two gears 31a and 31b that are circumscribed to the one gear 36 are connected to the differential reducer. The eccentric shaft 33 is connected to the external gear 29 via the eccentric shafts 33a and 33b.
a, 33b, and the external gear 29 is connected to the internal gear 27 of the reducer 28 provided in the fixed member 22 and the two output shafts 32a of the hydraulic motor 30.
, 32b, and eccentric shafts 33a, 33b operated by a single external gear 29.