JP2000136852A - Planetary gear reduction gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate necessity of a carrier in a planetary gear type reduction gear mechanism of a final stage, simplify and miniaturize a structure implanting supporting shaft of a planetary gear in the final stage planetary gear type reduction gear mechanism on a front end part of a supporting member of a rotary source at required positions in parallel with a rotary axis. SOLUTION: A planetary gear reduction gear 1 assembled with a vehicular driving device provided with a crawler belt traveling device, is composed of three stages of reduction planetary gear mechanisms, the planetary gear reduction mechanism 6 of a final stage (third stage) is arranged on the co-axial core with a driving shaft 3. The reduction gear mechanism 6 is engaged integratedly with a carrier of the second stage of planetary gear reduction mechanism 5, and is provided with a sun gear 6a for transmitting only revolution and a plurality of planetary gears 6b are arranged around the sun gear 6a. In this case, each planetary gear 6b is journaled to a supporting shaft 17 protruded on a prescribed position in parallel with an axis of the driving shaft 3 on a front end of a motor case 2 through a bearing 18. It is thus possible to eliminate a necessity of a carrier for the planetary gear 6b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planetary gear speed reducer, and more particularly to a planetary gear speed reducer which has a simplified structure by eliminating a carrier at the last stage, and is reduced in size and weight.

[0002]

2. Description of the Related Art Hitherto, crawler traveling devices such as a hydraulic excavator and a bulldozer have incorporated therein a planetary gear reduction device directly connected to a hydraulic motor as a driving device. An example is shown in FIG. 2 in a sectional view of a conventional planetary gear reduction device.

As shown in FIG. 2, the planetary gear reduction device 100 comprises a three-stage gear reduction mechanism, and a hydraulic motor 102 is mounted on an inner end of a motor case 101 fixed to a body frame or the like. The sun gear 105 of the first-stage gear reduction mechanism 104 is integrally provided at the tip of the drive shaft 103 from the hydraulic motor, and the first to third-stage gear reduction mechanisms are connected to the motor case 1.
And a ring gear 11 directly connected to a front end of a rotary drum 122 rotatably supported via a bearing 124 by a coaxial core.
7, 106.

The first stage gear reduction mechanism 104 is disposed around the sun gear 105 so as to mesh with the sun gear 105 at the end of the drive shaft 103 from the hydraulic motor 102 and the internal gear 107 of the ring gear 106. Planetary gear 108
And these planetary gears 108 are rotatably supported by support pins 109.
a carrier 109 that supports through the a and revolves integrally with the planetary gear 108 and transmits only the revolution to the sun gear 111 of the next stage.

A second-stage gear reduction mechanism 110 is loosely fitted to the drive shaft 103 and engages with the first-stage carrier 109 to transmit only revolutions. A planetary gear 112 meshed with the internal gear 107 of the ring gear 106 and disposed around the sun gear 111, and the planetary gears 112 are rotatably supported via support pins 113 a and are integrally formed with the planetary gears 112. And a carrier 113 that revolves and transmits only the revolution to the next stage sun gear 116.

The gear reduction mechanism 115 at the final stage (third stage) is loosely fitted to the drive shaft 103 and engages with the second stage carrier 113 to transmit only the revolution of the carrier 113. A sun gear 116, a planetary gear 119 disposed around the sun gear 116 so as to mesh with the sun gear 116 and the internal gear 118 of the ring gear 117,
These planetary gears 119 are rotatably supported via support pins 120a, and fixedly mounted so that their ends are engaged with teeth provided at the distal end of the motor case 101 so as to be positioned in the rotational direction. And a carrier 120.

[0007] The planetary gear reduction device 100 constructed as described above.
Is transmitted from the hydraulic motor 102 to the first-stage gear reduction mechanism 104 via the drive shaft 103, and is transmitted from the gear reduction mechanism 104 to the second-stage gear reduction mechanism 110 at a reduced speed. Third stage gear reduction mechanism 1
15 is transmitted to the internal gear 11 in the third-stage gear reduction mechanism 115.
The sprocket (gear) 125 which is transmitted to the ring gear 117 via the shaft 8 and is attached to the flange portion 123 of the rotary drum 122 directly connected to the ring gear 117 is rotated at a required speed to operate a target driving body. Has become.

As another example, there is a planetary gear reduction device 130 shown in FIG. This planetary reduction gear device 130
Is provided with a two-stage planetary gear reduction mechanism, but is similar to the planetary gear reduction device 100. Therefore,
The description is given by attaching the reference numerals only to the parts necessary for the description, and the description and description of the reference numerals are omitted for the other parts. Also in this planetary reduction gear device 130, the planetary gear 132 of the final stage planetary gear reduction mechanism 131 is a motor case 133.
The ring gear 135 is supported by a carrier 134 engaged with and fixed to the tip of the ring gear 135 via a support shaft pin 135 and meshes with an internal gear 136 of the ring gear 135 and a sun gear 137 loosely fitted on a rotating shaft. Hub 138 directly connected to 135
, The sprocket 139 is driven to reduce the speed.

[0009]

In the above-mentioned conventional planetary reduction gear devices 100 and 130, both the final stage planetary gear reduction mechanisms require a carrier for supporting the planetary gears. For this reason, the number of parts increases, and it is inevitable that the processing of the parts requires a lot of construction costs and increases the cost. Moreover, the planetary gear carrier 120 (1) in the final stage planetary gear reduction mechanism.
As a means for fixing (34), a screw structure is adopted so that it can be fixed to the motor case in a minimum space. For this reason, it is necessary to increase the processing accuracy in order to match the axis of the carrier with the axis of the rotary shaft in the work, and there is a problem that the processing cost is increased to secure the processing accuracy.

[0010] As described above, the planetary gear carrier 120 in the final stage gear reduction mechanism 115 (131).
The necessity of (134) not only increases the number of parts, but also increases the torque in the final stage, so that a rigid structure is required. As a result, the weight of the planetary gear reduction device is increased, which leads to an increase in energy consumption of the entire crawler traveling device to be mounted.
Therefore, there is a need for improvement in order to promote energy saving.

As an attempt to solve such a problem, in order to reduce the number of parts, it is conceivable to omit the carrier of the planetary gear in the final gear reduction mechanism. Japanese Patent Application Laid-Open No. 58-81253 discloses a configuration in which the planetary gear carrier is eliminated in such a planetary gear reduction device.

However, in the planetary gear reducer disclosed in this publication, the planetary gear is mounted on a support member, which is called a gear carrier, which is non-rotatably mounted on a vehicle housing, as a planetary gear arrangement portion in a circumferential direction. It is necessary to provide independent cutouts in each of the cutouts, and it is necessary to arrange the support shaft pin holes orthogonal to each cutout. There is a problem that the handling is troublesome, and it is very complicated and difficult to machine, and it is naturally difficult to increase the accuracy.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the carrier in the last stage planetary gear reduction mechanism is omitted to reduce the number of parts, thereby simplifying the structure and miniaturizing the structure. It is an object of the present invention to provide an intended planetary gear reduction device.

[0014]

In order to achieve the above-mentioned object, a planetary gear reduction device according to the present invention comprises a hub of a reduction output wheel directly connected to a final stage output portion of a planetary gear reduction mechanism. In the planetary gear reduction device rotatably supported on the support member of the rotation source, the support shaft of the planetary gear in the final stage planetary gear reduction mechanism, at the front end of the support member of the rotation source, parallel to the rotation axis And is planted at required places.

According to the present invention thus configured, since the carrier of the planetary gear in the planetary gear reduction mechanism at the last stage can be omitted, the number of parts involved can be reduced, and By eliminating the carrier, the planetary gear reduction mechanism of the preceding stage can be configured closer to the final stage, so that the size can be reduced and the weight can be reduced. It is. In addition, the weight of the device to be mounted is reduced by the weight reduction, and when incorporated in a vehicle or the like, an effect of contributing to a reduction in energy during movement accompanying the traveling can be obtained.

In addition, since the carrier of the last stage planetary gear is conventionally fixed to the support member by a meshing locking structure or the like for stopping the carrier, the machining accuracy of the meshing locking structure at the locking portion is improved. Although the necessity and high workability were required and the construction cost increased, the processing can be facilitated by using a support shaft at the end of the support member and the production cost can be reduced. The effect is that it can be reduced.

The support shaft of the planetary gear in the planetary gear reduction mechanism of the last stage is preferably press-fitted and fixed to a base in a mounting hole provided at an end of the support member. Alternatively, the support shaft is attached to a mounting hole provided at an end of the support member,
It may be fixed by meshing with a screw or a spline groove. In the case where the support shaft is fixed by a screw, it is preferable to prevent the support shaft screwing portion from being loosened by a push screw from the outside of the support member.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a specific embodiment of a planetary gear reduction device according to the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing one embodiment of the planetary gear reduction device according to the present invention. The planetary gear reduction device 1 in this figure is composed of a three-stage reduction planetary gear mechanism, is incorporated in a drive device of a vehicle having a crawler traveling device, and is fixed to a crawler traveling device frame (not shown) of a vehicle body. A hydraulic motor (not shown) is built in the inner end side of the motor case 2, and a sun gear 4 a of a first-stage planetary gear reduction mechanism 4 is provided at the tip of a drive shaft 3 directly connected to an output shaft of the hydraulic motor. Are provided integrally, and from the first stage to the third stage
The planetary gear reduction mechanisms 4, 5, 6 up to the stage (final stage)
A rotation support portion 1 formed on an outer peripheral portion of the motor case 2
0 is provided inside a ring gear 13 which is directly connected to a front end of a hub 12a of a starting wheel 12 rotatably supported via bearings 11 and 11 via a coaxial core. A cover 14 is attached to the front end of the ring gear 13 so that the inside is sealed.

The first stage planetary gear reduction mechanism 4 is configured to mesh with a sun gear 4a at the tip of a drive shaft 3 from a hydraulic motor and an internal gear 4b formed on the inner periphery of the cover 14. A plurality of planetary gears 4c arranged around the sun gear 4a, the planetary gears 4c are rotatably supported via support pins 4d, and revolve integrally with the planetary gears 4c so that only the orbital rotation is performed at the next stage of the sun. And a carrier 4e that transmits the gear 5a.

The second stage planetary gear reduction mechanism 5 is loosely fitted on the drive shaft 3 on the same axis as the first stage carrier 4e.
And a plurality of planetary gears 5b meshing with the sun gear 5a and the internal gear 15 of the ring gear 13 and disposed around the sun gear 5a. Support pin 5c for rotating planetary gear 5b
And a carrier 5d that revolves integrally with the planetary gear 5b and transmits only the revolution to the next stage sun gear 6a.

The final stage (third stage) planetary gear reduction mechanism 6
A sun gear 6a which is arranged coaxially with the drive shaft 3 and is integrally engaged with the second stage carrier 5d to transmit only the revolution; and the sun gear 6a and the ring gear 1
3 and a plurality of planetary gears 6b disposed around the sun gear 6a so as to mesh with the internal gear 15 of the third embodiment.
The planetary gears 6b are rotatably supported via needle bearings 18 on support shafts 17 provided at predetermined positions at the front end of the motor case 2 in parallel with the axis of the drive shaft 3. Note that reference numeral 19 in the figure denotes a retaining ring.

A support shaft 17 for supporting the planetary gear 6b
The base end is press-fitted into the mounting holes 22 drilled at a predetermined depth from the axis of the front end surface of the motor case 2 at a predetermined radius from the axis thereof and equally divided into the number of the arranged planetary gears 6b. Hole 1 that is formed and fixed, and is formed through the axis.
A bolt 21 is inserted through 7 a and screwed and fastened to a screw hole 23 formed in the bottom of a mounting hole 22 provided in the motor case 2 to prevent the motor 21 from coming off.

According to the thus configured planetary gear reduction device 1 of the present embodiment, the planetary gear 6b of the final stage planetary gear reduction mechanism 6 is attached to the motor case 2 by the mounting hole provided at a predetermined position. Since the support shaft 17 having the base fixed to the base 22 is freely rotatably supported via the needle bearing 18, the carrier of the planetary gear can be omitted. As a result, it can be formed smaller by the space of the carrier that has been required conventionally, and the entire planetary gear reduction device can be reduced in size. As a result, the effect of contributing to the reduction of energy consumption during traveling can be obtained by reducing the load weight acting on the drive unit.

In addition, since the support shafts 17 of the planetary gears 6b constituting the planetary gear reduction mechanism 6 at the final stage can be simultaneously formed with the mounting holes 22 when the motor case 2 is processed, the mounting operation of the support shafts 17 can be performed. Although required, the number of processing steps is greatly reduced, and production costs can be reduced. When the support shafts 17 are mounted, the base is press-fitted into the mounting holes 22 to be fixed, so that the assembling operation is easy and the number of working steps can be reduced. Also, as shown in FIG. 1, if a hole 17a is formed through the axis of the support shaft 17 and the bolt 17 is used to prevent the hole 17a from coming off, it may be loosened and come out. Is safe. Therefore, if the support shaft 17 can be securely fixed to the motor case 2, there is no need to prevent the bolt 21 from coming off.

As a fixing means for fixing the support shaft 17 to the front end face of the motor case 2, a spline groove (not shown) is formed as a support shaft mounting hole, and the support shaft mounting hole is formed at the base end of the support shaft. May be formed so as to match the spline grooves provided in the first and second embodiments, and the splines may be fixed by fitting them. Further, as the mounting means for the support shaft of the planetary gear, a screw hole for mounting the support shaft is provided on the motor case side, and a support shaft with a screw formed on the base is screwed into the screw hole. It may be fixed. In such a case, it is safe to prevent the support shaft screwed from the outer surface of the motor case from loosening with a push screw.

According to the planetary gear reduction device of the present invention, as described above, the planetary gear reduction device can be formed smaller by the space of the carrier, so that the entire planetary gear reduction device can be downsized. Is fixedly arranged without a separate component such as a conventional carrier, so that even if a large load is received, it is possible to provide a more safely supported and durable planetary gear reduction device. it can.

The starting wheel 12 in the present embodiment corresponds to a deceleration output wheel of the present invention, and the motor case 2 corresponds to a support member of a rotation source.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of a planetary gear reduction device according to the present invention.

FIG. 2 is a sectional view of a conventional planetary gear reduction device.

FIG. 3 is a sectional view of a conventional planetary gear reduction device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Planetary gear reduction device 2 Motor case 3 Drive shaft 4 First stage planetary gear reduction mechanism 5 Second stage planetary gear reduction mechanism 6 Final stage planetary gear reduction mechanism 6a Final stage sun gear 10 Rotation support part 12 Starting wheel 12a Starting wheel hub 13 Ring gear 15 Internal gear 17 Planetary gear support shaft 18 Needle bearing 22 Support shaft mounting hole

Claims (3)

[Claims] 1. A planetary gear reduction device comprising a hub of a reduction output wheel directly connected to a final stage output portion of a planetary gear reduction mechanism rotatably supported on a support member of a rotation source. A planetary gear reduction device characterized in that a support shaft of a planetary gear in a final-stage planetary gear reduction mechanism is implanted at a required position parallel to a rotation axis at a front end of the planetary gear reduction mechanism. 2. The planetary gear according to claim 1, wherein a support shaft of the planetary gear in the final stage planetary gear reduction mechanism has a base portion press-fitted and fixed to a mounting hole provided at an end of the support member. Gear reducer. 3. The support shaft of the planetary gear in the last stage planetary gear reduction mechanism is fixed to a mounting hole provided at an end of the support member by meshing with a screw or a spline groove. 3. The planetary gear reduction device according to claim 1.