JP2012207692A - Drive device for construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive device premised on a planetary gear system and structure supporting planetary gears by a spider in a cantilevered manner, in which energy loss is reduced by reducing agitation resistance caused by the planetary gears swimming through a lubricating oil during an operation.SOLUTION: A gear cover 34 is disposed in a casing 14, the gear cover 34 rotating together with planetary gears 28 and a spider 26 of a planetary gear mechanism 22 around the revolution center of the planetary gears 28 while covering three elements of a sun gear 24, the planetary gears 28 and the spider 26. The gear cover 34 comprises a disk-like part 35 covering the three elements from above and a cylindrical part 36 covering the three elements from the outer circumferential side thereof. The cylindrical part 36 includes notches 39 that permit meshing between the planetary gears 28 and a ring gear 30.

Description

  TECHNICAL FIELD The present invention relates to a drive device for reducing the rotational force of a hydraulic or electric motor as a drive source in a construction machine such as a hydraulic excavator and transmitting it to a driven part such as an upper swing body by decelerating with a planetary gear type reduction unit. is there.

  The background art will be described by taking an excavator turning drive device as an example.

  The excavator is mounted on a crawler-type lower traveling body so that the upper swing body can swing around an axis that is perpendicular to the ground, and a work attachment is attached to the upper swing body.

  In this excavator, a swing drive device that swings the upper swing body is a hydraulic or electric motor as a drive source, and the rotational force of the motor is reduced by a gear reduction mechanism and transmitted to the upper swing body that is a driven part. It consists of a deceleration unit.

  The motor and the speed reduction unit are provided side by side in the apparatus axis direction with their center axes (motor shaft and speed reduction output shaft) coinciding with each other, and are attached to the upper frame with the motor placed in a vertical position.

  The reduction unit is composed of one to a plurality of planetary gear mechanisms including a sun gear, a plurality of planetary gears, and a ring gear. The output of the reduction unit is provided on a pinion provided on the output shaft and a lower frame of the lower traveling body. Is transmitted to the upper swing body through the swivel gear.

  Lubricating oil is injected into the casing of the speed reduction unit, and a gear mechanism such as a planetary gear mechanism is lubricated and cooled.

  Such a swivel drive device is shown in Patent Document 1.

JP 2007-39990 A

  FIG. 5 schematically shows the configuration of a reduction unit (planetary gear mechanism) in a conventional turning drive device.

  A plurality (three in the illustrated example) of planetary gears 2 are arranged around a sun gear 1 driven by a motor (not shown), and the planetary gears 2 mesh with the sun gear 1 while rotating around the planetary gear shafts 3. A deceleration action is performed by revolving around the motor shaft (sun gear shaft) 5 by meshing with the ring gear 4 formed on the inner periphery of the casing.

  Each planetary gear 2... Is attached to a plate-like spider (also called a carrier; hatched for easy understanding) in a cantilever state in which only one end side of the planetary gear shaft 3 is supported. 6 and revolution rotation.

  In other words, the revolution rotation of the planetary gears 2 is transmitted to the spider 6, and the rotation of the spider 6 is transmitted to the next stage planetary gear mechanism or the reduction output shaft.

  In the speed reduction unit in which the lubricating oil is injected into the casing, the lubricating oil accumulates in the space between the planetary gears 2 indicated by a two-dot chain line, and the planetary gears 2 rotate (revolve) while scraping the accumulated oil. During operation, the stirring resistance by this scraping works.

  In particular, in a vertical drive device in which a motor and a speed reduction unit are arranged vertically, the planetary gear mechanism is always submerged in the lubricating oil, so this agitation resistance is large, resulting in a problem of energy loss.

  Also, the planetary gear mechanism that rotates at high speed, especially the higher speed (especially the first stage), the greater this energy loss becomes, and this is a problem to be solved.

  In addition, according to the double-supported structure in which both sides of each planetary gear shaft 3 are supported by spiders, since the pillars connecting the upper and lower spiders are located between the planetary gears 2. Stirring resistance is small compared to the holding structure.

  However, in this double-sided structure, the spider is significantly heavier than the cantilevered structure, and there are disadvantages such as increased rotational moment of inertia and acceleration / deceleration load. It is not a good idea in terms of reducing energy loss.

  In view of this, the present invention uses a planetary gear type speed reduction unit and assumes a structure in which the planetary gear is cantilevered by a spider. During operation, the planetary gear scrapes the lubricating oil and reduces the agitation resistance to reduce energy loss. Provided is a drive device for a construction machine.

  As means for solving the above problems, in the present invention, a hydraulic or electric motor as a drive source and a reduction unit that decelerates the rotational force of this motor and transmits it to the driven part are mutually connected to the motor shaft and the deceleration output. Provided side by side in the apparatus axis direction in a state where the shaft centers coincide with each other, and the speed reduction unit is constituted by one to a plurality of planetary gear mechanisms including a sun gear, a plurality of planetary gears and a ring gear, and each planetary gear is connected to a planetary gear shaft. In a drive device for a construction machine that is attached to a spider in a cantilever state in which only one end side is supported and in which lubricating oil is injected into the casing of the speed reduction unit, the sun gear, planetary gear, and spider of the planetary gear mechanism in the casing With the planetary gear and spider centered on the revolution center of the planetary gear A gear cover that rotates on the body, and the gear cover includes a disk-shaped portion that covers the three members from the free end side of the planetary gear shaft and a cylindrical portion that covers the three members from the outer peripheral side. And a notch for allowing the ring gear to mesh.

  According to this structure, the sun gear, the planetary gear and the spider are covered with a gear cover so that the lubricating oil between the planetary gears is confined in the cover and rotated integrally with the planetary gear, so the lubricating oil between the planetary gears is scraped. Stirring resistance due to is hardly generated.

  Therefore, since the stirring resistance of the planetary gear mechanism in operation can be made much smaller than before, energy loss due to the stirring resistance during operation can be greatly reduced.

  Further, the gear cover only needs to be strong enough to withstand the resistance of the rotating oil and the centrifugal force, and thus can be lightened by a sheet metal or a synthetic resin material. For this reason, there is no problem that the rotational moment of inertia and the acceleration / deceleration load significantly increase unlike the double-supported structure.

  Furthermore, unlike the double-supported structure in which the planetary gear is incorporated from the outer peripheral side, the planetary gear can be assembled by being inserted from the free end side of the planetary gear shaft, and stirring resistance can be suppressed in that an extra assembly gap is not required.

  In the present invention, it is desirable that the motor and the speed reduction unit are attached to the frame of the machine in a vertically arranged posture with the motor facing up.

  Preferably, the speed reduction unit is constituted by a plurality of planetary gear mechanisms, and the gear cover is provided at least on the planetary gear mechanism having the highest speed.

  That is, if the present invention is applied to a vertical drive device in which the planetary gear mechanism is submerged in the lubricating oil or the high-speed stage of the planetary gear mechanism, the effect of reducing the energy loss becomes particularly remarkable.

  On the other hand, in the present invention, it is desirable that the gear cover is provided with a large number of through-holes that serve as passages for lubricating oil.

  According to this configuration, since the lubricating oil enters and exits the inside and outside of the gear cover, that is, circulates, abnormal temperature rise and deterioration due to the lubricating oil being fixed inside the gear cover can be prevented.

  According to the present invention, energy loss due to stirring resistance during operation can be reduced, excessive heat generation of the lubricating oil and gears can be suppressed, and energy can be saved.

It is a partial cross section side view of the turning drive device concerning the embodiment of the present invention. FIG. 2 is a partially enlarged view of FIG. 1. It is the III-III sectional view taken on the line of FIG. It is a perspective view of the gear cover in an embodiment. It is a figure which shows typically the structure of the conventional turning drive device.

  The embodiment is applied to an excavator turning drive device.

  However, in the present invention, the motor and the deceleration unit are arranged in the direction of the apparatus axis in a state where the centers of the motor shaft and the deceleration output shaft coincide with each other like the turning drive device such as the traveling drive device of the lower traveling body and the drive device of the winch. The present invention can be similarly applied to other drive devices that are provided side by side and in which lubricating oil is injected into the casing of the speed reduction unit, and also to drive devices having the above-described configuration in construction machines other than excavators. .

  In the following, the case where the present invention is applied to a vertical drive device in which the effect of the present invention is particularly remarkable is taken as an example. However, the present invention is also applied to a horizontal drive device in which a motor and a speed reduction unit are located on the left and right. Can be applied.

  As shown in FIG. 1, the swing drive device includes a hydraulic or electric motor 11 as a drive source, and a speed reduction unit 12 that decelerates the rotational force of the motor 11 and transmits it to an upper swing body that is a driven part. It is arranged side by side in the apparatus axial direction.

  The motor 11 includes a motor housing 13, and the speed reduction unit 12 includes a cylindrical casing 14. The motor 11 faces upward, and the centers of the motor shaft 15 and the speed reduction output shaft 16 coincide with the apparatus axial direction (vertical direction). In the vertically placed state, the flange 13 a provided at the lower end of the motor housing 13 and the casing 14 are connected by a plurality of connecting bolts 17.

  At the lower end of the speed reduction unit 12, a shaft support portion 18 provided with a bearing for rotatably supporting the speed reduction output shaft 16 is provided, and a mounting flange 19 provided on the lower outer periphery of the shaft support portion 18 pivots upward. It is attached to the upper frame 20 of the body by attachment bolts 21.

  The speed reduction unit 12 is configured by coaxially arranging one to a plurality of stages of planetary gear mechanisms (two stages in the example, hereinafter described in this case) 22 and 23 on the same axis in the casing 14. Lubricating oil is injected over almost the entire length range.

  Both planetary gear mechanisms 22 and 23 are formed on the inner periphery of the casing 14 and the plurality of planetary gears 28 and 29 provided around the sun gears 24 and 25 via the spiders 26 and 27, respectively. And the planetary gears 28 and 29 rotate around the planetary gear shafts 31 and 32 and rotate around the motor shaft 15 to reduce the motor rotation, and the output is reduced output. It is transmitted to the upper frame 20 (upper swivel body) which is a driven part via a pinion 33 provided at the lower end of the shaft 16 and a swivel gear (ring gear, not shown) meshing therewith.

  The spiders 26 and 27 are formed in a substantially triangular plate shape (see FIG. 3), and the planetary gear shafts 31 and 32 are attached to the apex portions of the triangles on the upper surfaces of the spiders 26 and 27, respectively.

  That is, each planetary gear 28, 29 is cantilevered from below by the spiders 26, 27.

  In this swivel drive device, a gear cover 34 is provided in the casing 14 to cover the sun gear 24, the planetary gear 28... And the spider 26 of the first (upper) planetary gear mechanism 22, which is a high speed stage.

  Details of the gear cover 34 will be described with reference to FIGS. In addition, in order to avoid complication of FIG. 1, the code | symbol about each part of a gear cover is attached | subjected only to FIGS.

  The gear cover 34 includes a disk-shaped portion 35 that covers the three members from the upper surface side (the free end side of the planetary gear shaft 31) and a cylindrical portion 36 that covers the three members from the outer peripheral side.

  A motor shaft hole 37 is provided at the center of the disk-shaped portion 35, and the disk-shaped portion 35 is attached to each planetary gear shaft 31 with cover mounting bolts 38 with the motor shaft 15 passing through the motor shaft hole 37. It has been.

  Thus, the gear cover 34 is attached in a state where the disk-shaped portion 35 is the upper surface and the cylindrical portion 36 is the side surface, and the gear cover 34 rotates integrally with the planetary gears 28 and the spider 26 around the motor shaft 15.

  In addition, a notch 39 is provided at the meshing portion of the planetary gears 28 and the ring gear 30 in the cylindrical portion 36 of the gear cover 34 to allow the meshing with the ring gear 30 by projecting a part of the planetary gears 28. A large number of through-holes 40 are provided in the entire area of the portion 35 and the cylindrical portion 36 to serve as a passage for lubricating oil.

  The through holes 40 may be small round holes as shown in the figure, slits that are vertically or horizontally or obliquely long, or a combination thereof.

  Further, it may be provided only on one of the disk-shaped part 35 and the cylindrical part 36.

  According to this configuration, since the lubricating oil between the planetary gears is integrally rotated with the planetary gears 28 while confined in the gear cover 34, the stirring resistance caused by scraping the lubricating oil between the planetary gears hardly occurs.

  Therefore, the stirring resistance of the planetary gear mechanism 22 can be made much smaller than before, so that energy loss due to the stirring resistance during operation can be greatly reduced.

  In particular, according to this embodiment, the planetary gear mechanism 22 is always submerged in the lubricating oil, so that the planetary gear mechanism 22 is applied to a vertical swivel drive device having a large agitation resistance, and the high-speed first stage planetary gear mechanism 22 is applied. By applying, the effect of reducing energy loss becomes remarkable.

  Further, the gear cover 34 only needs to be strong enough to withstand the resistance of the rotating oil and the centrifugal force, and thus can be lightened by a sheet metal or a synthetic resin material. For this reason, there is no problem that the rotational moment of inertia and the acceleration / deceleration load significantly increase unlike the double-supported structure.

  Further, unlike the double-sided structure in which the planetary gears 28 are incorporated from the outer peripheral side, the planetary gears 28 can be assembled by being inserted from the free end side of the planetary gear shaft 31, and the stirring resistance is suppressed in that an extra assembly gap is not required. be able to.

  In addition, since the lubricating oil inside and outside the gear cover 34 enters and exits (circulates) through the through-holes 40 due to centrifugal force or convection during operation or immediately after stopping, the lubricating oil is fixed inside the gear cover 34. Abnormal temperature rise and deterioration can be prevented.

  Incidentally, the gear cover 34 may also be provided in the second stage planetary gear mechanism 23.

  The present invention can also be applied to the case where the reduction unit 12 is constituted by one or three or more planetary gear mechanisms and the case where the planetary gear mechanism has four or more planetary gears (four-axis type). it can.

  In the case of the 4-axis type, the notches 39 may be provided at the four positions of the cylindrical portion 36 in the gear cover 34.

  Further, when the spider is positioned on the planetary gear, the gear cover 34 may be attached to the spider.

DESCRIPTION OF SYMBOLS 11 Motor 12 Deceleration unit 14 Deceleration unit casing 15 Motor shaft 16 Deceleration output shaft 20 Upper frame as driven part 22 First stage planetary gear mechanism 23 Second stage planetary gear mechanism 24 Sun gear of first stage planetary gear mechanism 26 Same , Spider 28, planetary gear 30, ring gear 31 planetary gear shaft 34 gear cover 35 gear cover disk-shaped portion 36, cylindrical portion 37, motor shaft hole 38 cover mounting bolt 39 gear cover notch 40, through hole

Claims (4)

  A hydraulic or electric motor as a drive source and a deceleration unit that decelerates the rotational force of this motor and transmits it to the driven part are aligned in the direction of the device axis with the center of each motor shaft and the deceleration output shaft aligned. The reduction gear unit is configured by one to a plurality of planetary gear mechanisms including a sun gear, a plurality of planetary gears, and a ring gear, and each planetary gear is attached to the spider in a cantilever state in which only one end side of the planetary gear shaft is supported. In a construction machine drive device that is mounted and injecting lubricating oil into the casing of the speed reduction unit, the planetary gear revolution center is covered with the sun gear, planetary gear, and spider of the planetary gear mechanism in the casing. It has a gear cover that rotates integrally with the planetary gear and spider as the center. It consists of a disk-shaped part that covers the three parts from the free end side of the planetary gear shaft and a cylindrical part that covers the three parts from the outer peripheral side, and this cylindrical part is provided with a notch for allowing the planetary gear and the ring gear to mesh. A construction machine drive device characterized by that.   2. The drive device for a construction machine according to claim 1, wherein the motor and the speed reduction unit are attached to the frame of the machine in a vertically placed posture in which the motor is faced up and down.   3. The construction machine drive device according to claim 1, wherein the speed reduction unit includes a plurality of stages of planetary gear mechanisms, and the gear cover is provided at least in the highest speed planetary gear mechanism.   The drive device for a construction machine according to any one of claims 1 to 3, wherein the gear cover is provided with a large number of through-holes that serve as passages for lubricating oil.

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