JPS5819826B2 - Dokoukikai - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sealed, continuously lubricated gear drive mechanism particularly suitable for use in fluid-operated excavators.

Conventional power transmission mechanisms used in excavators include a motor-driven pivot pinion that engages and rotates a fixed ring gear to selectively rotate the upper unit relative to the movable lower carriage.

This suspension pinion and its associated ring gear are generally not enclosed and are therefore exposed to dust and other foreign matter generated during operation of the excavator.

The slewing pinion is typically lubricated by applying copious amounts of grease by hand.

This grease tends to trap dust and foreign matter and cause excessive gear wear.

Previous attempts to provide closed, continuous lubrication of the slewing pinion and associated ring gear have generally been unsuccessful due to the need to maintain large amounts of lubricating oil on the excavator.

Additionally, excavators typically use a swivel joint to connect a hose that communicates working fluid from the upper unit to the lower carriage.

This swivel joint is usually provided on the lower carriage at the center of the ring gear, and its upper end extends upwardly beyond the upper end of the ring gear, so that if a normal housing is installed over the ring gear, it will interfere with the joint.

Additionally, excavators often operate on slopes, which can lead to lubricant leakage on the lower side of the housing.

Accordingly, it is an object of the present invention to provide an improved case for a ring gear and pinion drive mechanism.

The object of the present invention is to provide a case for a gear drive mechanism that provides a substantially dust-free operating atmosphere for the gears.

Another object of the present invention is to provide a case for a gear 1 drive machine in which a substantially liquid-tight lubrication chamber is formed around the ring gear and pinion.

Another object of the present invention is to provide a case for a gear drive mechanism that continuously maintains a substantially uniform distribution of lubricant when tilted to the ground.

Another object of the present invention is to provide a case for a gear drive mechanism that is arranged substantially concentrically with the ring gear and uses the ring gear as one side wall.

Other objects and advantages of the invention will become apparent from reference to the accompanying drawings and the following description.

Referring to FIG. 1, an earthmoving machine such as a fluid-operated excavator 10 has an upper unit 11 rotatably mounted on a movable lower carriage 12 by a pivot bearing 13.

The lower unit has a mounting ring 14 fixed below the frame 15, and the lower carriage has a support ring 16 fixed thereon.

The lower gear ridge is mounted on a standard laterally spaced endless rack.

Referring to FIG. 3, the pivot bearing 13 has an inner ring member 17 secured on the support ring 16 by bolts 18.

The inner ring member is disposed within the outer ring member 19 concentrically with its vertical central axis X, and the outer ring member is attached to the mounting ring 14 by bolts 20.

Corresponding races 21 and 22 are formed on the inner and outer ring members, respectively, and these races share a common axis X (Fig. 2).
a series of circumferentially disposed ball bearings 23 that produce relative rotational movement between both ring members about
It houses bearing means consisting of.

The inner ring member forms a reaction ring gear comprising a plurality of teeth 24 facing radially inwardly toward this axis.

Annular lip seal members 25, 26 are secured to the inner and outer ring members, respectively, and maintained in sealing sliding contact with the other ring member.

These seals work together to prevent dirt and other foreign matter from entering the races and bearings.

Referring again to FIG. 1, a power transmission mechanism 27 powered by a fluid motor 28 is provided in the upper unit for selectively rotating the upper unit on the lower carriage.

The power transmission mechanism terminates in a vertically arranged pivot or output shaft 29 on which a pivot pinion 30 is mounted (FIG. 4).

The pivot pinion is selectively driven into rotation relative to a relatively stationary inner ring member or reaction ring gear 17.

Referring to FIGS. 2-5, the case 31 of the present invention has a horizontally disposed annular top wall 32 extending radially inside from the pivot bearing 13. As shown in FIGS.

This upper wall has a flat outer flange 33 fixed sealingly between the outer ring member 19 of the swivel bearing and the mounting ring 14 of the upper unit 11.

A horizontally disposed annular lower wall 34 is provided below the earthen wall with a gap in the vertical direction, and the lower wall is provided with an outer ring member 34 sealed and fixed between the inner ring member 1γ of the bearing and the support ring 16. It has a flange 35.

The lower wall extends radially inwardly from the pivot bearing and has an upwardly extending inner wall 36 disposed generally vertically between the earth wall and the lower wall and concentric with the pivot bearing.

A standard liquid backing compound (not shown) may be pre-applied to both sides of the flanges 33,35 to form a leak-tight seal prior to assembly of the earthen wall and bottom wall.

An annular sealing means, such as a lip seal member 37, is secured to the upper edge of the side wall 36 for sealing engagement with the earthen wall.

The sealing member 37 together with the sealing member 25,26 is connected to the wall 32,
34, 36 and the outer ring member 19 completely seals off the annular chamber 38 formed by the wall means.

As shown in FIGS. 2 and 4, a hole 39 is formed in the top wall 32 to allow the swivel pinio 30 to be guided into the chamber 38 through the hole.

The annular seal member 40 is positioned between the middle end of the tubular housing rotatably supporting the pivot shaft 29 and the upper seat 32 to form a liquid-tight joint therebetween.

A cylindrical U-shaped cross-sectional dish or tray 41 is disposed within the chamber 38 and spaced from the wall means defining the chamber, the dish having a pair of radially spaced inverted plates 42, 43. These side walls extend vertically downward from a horizontally disposed continuous bottom wall 44 disposed vertically below ring gear 17 .

The upper ends of these side walls terminate in flanges 45.46 secured to the upper wall 32 by welds or the like.

The circumference of the plate 41 is cut to form an opening 47 (FIG. 2) aligned with the hole 39 formed in the earthen wall, and the pinion 30 is inserted into this opening.

A plurality of circumferentially spaced baffles 48 are connected to the side walls 42,
43 extending radially and fixed within the pan to divide the pan into a plurality of private or lubricating oil holding chambers 49 .

The plate 41 is arranged concentrically between the ring gear and the side wall 36.

The side wall 42 has a plurality of holes 50 spaced apart in the circumferential direction near the ring gear 17 to form each partition chamber 49 into an annular chamber 38.
is connected to.

A fill tube 51 (FIG. 3) is fixed at its lower end to the earth wall and has a cap attached thereto for partially filling chambers 38 and 49 with lubricating oil.

An oil immersion rod assembly 52 is also fixed to the upper wall, and an oil immersion rod 53 for checking the oil level is removably attached to this assembly, and the lower end thereof is arranged to extend into one of the partitions 49. has been done.

Standard drain plug 54 (Figure 3) to facilitate oil changes.
is removably attached to the lower wall.

When the excavator 10 is substantially horizontal, the chambers 38.49 are supplied with lubricating oil through the fill tube 51.

Since the lubricating oil is provided with the communication hole 50, it tends to be at a common liquid level.

Preferably, the chambers 38, 49 are filled with oil so as to cover at least the lower portion of the ring gear 17.

As the slewing pinion 30 rotates and moves around the ring gear, lubricating oil splashes onto the meshing teeth, providing complete and continuous lubrication of the teeth during use.

When the excavator 10 is tilted from a horizontal position, such as when operating on an inclined surface, the compartment 49 acts to maintain a fairly even distribution of lubricating oil around the chamber 38. .

The compartment, which is maintained on the high side primarily because of the holes 50 provided on the outside of the compartment, traps and retains nearly all of the lubricating oil initially contained when the machine is horizontal.

Therefore, only a small amount of oil that was contained on the high side of the chamber 38 between the teeth 24 and the side wall 42 runs to the low side.

Also, the compartment kept on the lower side has sufficient volume to accommodate the oil thus running.

This cooperation between the high and low side compartments is such that the low side of the chamber prevents oil from leaking through the lip seal members 25, 26 when the machine is operating on an inclined surface. A low oil level is maintained.

However, a small amount of oil leakage through the lip seal member 26 for the purpose of lubricating the ball bearing 23 is acceptable.

As is readily apparent from the above description, the present invention provides improvements to gear drive case and lubrication systems.

This case prevents dirt and small amounts from entering the interior and greatly reduces the wear that normally occurs with known mechanisms of this type.

Furthermore, this case contains lubricant that is maintained at a minimum level, yet ensures continuous and adequate lubrication of all parts of the mechanism even during adverse driving conditions, such as driving on mountains.

[Brief explanation of drawings]

Fig. 1 is a side view of a fluid-operated excavator having a closed gear and drive mechanism according to the present invention, and Fig. 2 is a partially cutaway view of Fig. 1 taken along line ■-■ for convenience of explanation. The enlarged top view of the cut sealed gear drive mechanism, FIGS. 3 and 4 are cross-sectional views taken along the lines ■-■ and ■-■ in FIG.
The figure is a partial sectional view taken along the line V-V in FIG. 2. 10... Fluid operated excavator, 11... Upper unit, 12... Movable lower carriage,
13...Swivel bearing, 21...Power transmission mechanism, 29...Swivel shaft, 30...
・Swivel pinion, 31... Case, 32...
...Earth wall, 34...Lower wall, 36...
side wall.

Claims (1)

[Scope of Claims] 1. An upper unit having a support fixed thereto below, a movable lower carriage having a reaction type ring gear fixed thereto, which is arranged concentrically with respect to a vertically arranged central axis, and the support being fixed to the lower carriage. It has a swing bearing rotatably mounted, and a swing pinion mounted on the upper unit and rotatably provided with a vertically arranged swing shaft, and mounted on the swing shaft and arranged to directly mesh with the ring gear. a power transmission mechanism, and a lower annular wall extending radially inwardly toward the central axis proximate the ring gear and the slewing pinion and forming an enclosed and sealed annular chamber. and a plurality of lubricating oil holding chambers arranged inside the annular chamber and divided in the circumferential direction with respect to the central axis and communicating with the annular chamber, An earth-moving machine in which teeth meshing with the pinion are arranged in the annular chamber. 2 said ring gear has internal teeth facing radially inwardly towards said central axis and forms part of said wall means, said wall means being vertically spaced and horizontally disposed; an annular earth wall and a bottom wall, and an annular inner side wall disposed generally perpendicularly, the top wall and the bottom wall extending radially inward from the ring gear toward a central axis; are spaced radially inward from the ring gear and are arranged substantially perpendicularly between the soil wall and the bottom wall, and the lubricating oil holding chamber is arranged within the annular chamber and has continuous outer and inner walls. a plurality of baffle plates extending radially inwardly toward the central axis between the side walls of a generally annular, U-shaped tray having a bottom wall and each spaced apart from the wall means; The tray further has a cutout opening in a part of its circumference for accommodating the swivel pinion, and the annular chamber and the plurality of lubricating oil holding chambers are in communication with each other. An earthmoving machine according to claim 1, achieved by a plurality of holes provided on the outer wall of each of the chambers.