JPS5838045Y2 - Seal structure of earthwork arm - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a second bearing portion between a pair of first bearing portions spaced apart from each other, such as a pivot connection point between a working arm and a packet in a backhoe. This invention relates to a seal structure in a shaft support that is relatively rotatably positioned around a shaft inserted into a shaft.

In this type of structure, there was a problem in which earth and sand entered through the gap between the bearing parts during earthwork work and caused wear and tear on the shaft support.
As shown in Publication No. 2524, a removable spacer is fitted between both bearing parts, and a sealing member having a rectangular cross section and having an axial width wider than the spacer is fixed to the outer circumference of the spacer. There is a known technology for preventing the seal member from deforming beyond a certain level, but in this conventional structure, the seal member is wider than the spacer and has a rectangular shape. While maintaining the contact pressure of the wide seal member against the end surface of the receiving part at a predetermined, almost constant pressure, the spacer, which is narrower than the seal member, ensures the action of the seal member in order to prevent the seal member from being significantly deformed. In order to obtain the narrow width part required for It is difficult for the spacer to sufficiently absorb errors caused by the manufacturing of the stepped notch, and for this reason, by moving the bearing from side to side, a gap is created between the sealing member and the bearing, through which dirt and sand can enter. There have been problems such as pressure loss of the seal member due to thrust I and load caused by relative movement of both bearings.

Although the present invention has a simple shaft support structure, the seal member has sufficient elasticity in the direction of the shaft support axis.
It has sufficient sealing performance regardless of slight changes in the gap width between the bearing parts, absorbs manufacturing errors of the shaft support,
Another object of the present invention is to obtain a sealing structure for an arm for earthworks that prevents the sealing member from being pressed to an extreme degree and has good sealing performance over a long period of time.

The characteristic configuration of the seal structure of the earthwork arm according to the present invention is that a pair of first bearings are pivotally supported on the shaft at an appropriate distance from each other in the axial direction, and
The shaft portion L between the first bearing portions pivots the second bearing portion; In the seal structure, a protective member is provided between the first and second bearing parts so as to cover an outer periphery of a gap formed between opposing end surfaces of the second bearing parts. The mutually opposing end surfaces of the second bearing portions are formed into flat surfaces, and the shaft is inserted into an annular groove-shaped gap formed between these end surfaces and the outer circumferential surface of the pivot shaft. an annular hard spacer that surrounds the periphery of the shaft, and an elastic seal member that is located on the outer peripheral side of the hard spacer and has a V-shaped cross section that is open on the outer side in the radial direction of the shaft, each of which is detachable. Furthermore, the width of the open end portion of the elastic seal member in the axial direction is set to be larger than the width of the hard spacer in the axial direction, and this configuration provides the following effects.

That is, by interposing an elastic sealing member with a V-shaped cross section between the two bearing parts, the sealing member itself has great elasticity, and manufacturing errors in the shaft supporting structure such as shaft length and bearing length can be reduced. In addition, since the opposing end surfaces between both shaft parts are flattened, the manufacturing process of the shaft support is facilitated and production efficiency is improved. Since it has a V-shape with the outer side open, it prevents minute dirt, etc. from entering between the bearing part and the protective member covering the outside of the gap between the two end faces, and the dirt, etc. entering into the shaft side. It has a difficult shape and can ensure good sealing performance, and the hard spacer allows the sealing member to be extremely compressed even if both bearings come into relative proximity due to their movement. In addition, the seal member and the spacer are made removable and fitted independently between both bearing parts, so the seal member can be used as a spacer. Since it expands and contracts without interfering with other parts, good sealing performance can be ensured over a long period of time, and it is also advantageous for their replacement.

Embodiments of the present invention will be described below with reference to the drawings.

The swivel base 2 is attached to the traveling machine base equipped with the crawler traveling device 1 so that it can rotate fully, and the bracket 3 is attached to the swivel base 2 so that it can rotate around the vertical axis 1, and this bracket l-3
Then, a working arm formed by pivotally connecting the boom 4 and the arm 5 to each other so as to be able to swing freely is pivotally connected to the working arm 6, and a packet 7 is pivotally connected to the working arm 6. A hydraulic cylinder 8 is interposed between the boom 4, the boom 4 and the arm 5, and between the arm 5 and the bucket 1 to rotate the swivel base 2 and the working arm 6 and swing the packet 7. This is a backhoe for ground excavation work that can also be used to dig side ditches.

The bracket 3 and boom 4, the boom 4 and arm 5, the arm 5 and packet 7, and the bracket 3 and boom 4,
Hydraulic cylinder 8 for arm 5 and packet 7...
The shaft supports 2 ... which pivotally connect the ... are constructed in almost the same way, and the sealing structure for them will be explained below using the shaft support 9 of the working arm 6 and the packet 7. do.

A pair of first packets are arranged in a row at a distance from each other in the packet 7.
The second bearing part 11 connected to the tip of the working arm 6 is positioned between the bearing parts 10 and 10, and the bearing parts 10
, 10. Insert the shaft 12 into 11 to prevent it from being pulled out, and then attach the shaft support 9.
, so that both bearing parts 10.11 are connected to the shaft 1.
They are configured to rotate relative to each other around the axis 0 of the two.

In the longitudinal direction of the shaft 12, the first. A gap where the end faces of the second bearing portions 10, 10.11 face each other,
That is, in the annular groove-shaped gap formed between the opposing end surface and the outer circumferential surface of the shaft 12, an annular elastic seal member 13 having a V-shaped cross section and an open radially outward side is elastically displaced. It is removably interposed so that both side edges thereof are always in contact with the opposing end surfaces of both bearing parts 10.11, thereby preventing dirt, etc. from entering between both bearing parts 10.11 and the shaft 12 from the outside. It is designed to prevent this.

The two wheel bearing portions 10.11 are located at opposite positions on the shaft 12 side from the sealing member 13, and the width in the axial direction of the shaft 12 is set so that the width of the open end portion of the elastic sealing member 13 in the free state is the width in the axial direction; and the width in the axial direction; Slightly smaller than the axial width of the gap formed between the opposing end surfaces of the second bearing parts 10, 10.11, and sufficient to prevent the elastic seal member 13 from being deformed more than necessary. An annular hard spacer 14 set to a certain degree
is removably interposed therein, and is configured to prevent the second bearing part 11 from moving toward the first bearing part 10 and coming closer than a predetermined width.

A cylindrical protection member 15 is slidably fitted onto the outer periphery of the seal member 13 so as to extend over the outer periphery of both bearing portions 10. The seal member 13 is fixed by punching to prevent other objects from colliding with the seal member 13 from the outside as much as possible.

Since the protection member 15 is fixed by punching, it can be easily disassembled even if the seal member 13 or spacer 14 is damaged.

The present invention is not limited to backhoes, but can be applied to various types of shaft supports for earthwork arms, such as working arms attached to shovel loaders.

[Brief explanation of drawings]

The drawings show an example of the sealing structure of the earthwork arm according to the present invention, and FIG. 1 is an overall side view of the backpaw, and FIG. 2 is a partially cutaway front view of the pivot support. 10...1st bearing part, 10...1st bearing part,
11...Second bearing part, 12...Shaft, 1
3... Seal member, 14... Hard spacer, 15... Protective member.

Claims (1)

[Scope of utility model registration request] A pair of first bearing portions 10.10 are pivotally supported on the shaft 12 at an appropriate distance from each other in the axial direction, and the shaft 12 is pivoted between the first bearing portions 10.10.
The second bearing part 11 is pivotally supported on the parts, and these first bearing parts 11 are
．． The first bearing part 10,10. Second
A sealing structure in which a protection member 15 is provided between the bearing parts 10, 10.11, and the first. Second bearing part 1
0 and 10.11 are formed into flat surfaces on opposite sides, and a groove is formed in an annular groove-shaped gap defined by both end surfaces and the outer circumferential surface of the pivot shaft 12. , an elastic seal member 13 located on the outer peripheral side of an annular hard spacer surrounding the circumferential portion of the shaft 12 and having a V-shaped cross section and open on the outer side in the radial direction of the shaft 12, each of which can be freely attached and detached. The arm for earthwork work is attached to the arm for earthwork work, and further, the width of the open end portion of the elastic seal member 13 in the axial direction is set to be larger than the width of the hard spacer 14 in the axial direction. Seal structure.