JPH04124321U - Bearing structure of pin connections of construction machinery - Google Patents

Abstract

(57) [Summary] (with amendments) [Purpose] In the bearing structure of the pin connection part of construction machinery,
This prevents dirt, sand, etc. from entering the inside of the bearing, prevents the sealing function from deteriorating even if the outermost seal is damaged, and further ensures the lubricating function of the bearing. [Structure] A through hole through which a pin 3 is inserted is provided in both the central swinging side boss 2 and the fixed side bosses 1 arranged on both ends, and non-greasing bushings 5, 5 are provided on both sides inside the through hole of the swinging side boss 2. A lubricating oil reservoir 6 is formed between the two oil-free bushings 5,5, and the pin 3 is supported and lubricated. In addition, a dust seal portion 7 consisting of a plurality of dust seals 71, 72 is provided at the outer end of the non-greasing bushing 5, 5, and a groove portion 21 is provided on the outer peripheral edge of the swinging side boss 2.
An O-ring seal 8 is attached to seal the gap 9 between the stationary side boss 1 and the swing side boss 2. The lubricating oil reservoir 6 is provided with a grease nipple 10 for lubricating.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is a non-lubricated shaft used in pin connections of civil engineering construction machines such as hydraulic excavators. Regarding the bearing structure of the bearing.

0002

[Conventional technology]

Conventionally, oil-free bearings such as oil-impregnated bearings, plastic bearings, and solid lubricated bearings have been used for civil engineering. Attachments for construction machinery, such as hydraulic excavator booms, arms, buckets, etc. It is used for pin connections of similar types, and due to the location where civil engineering construction machinery is used, pins are To prevent dust from entering the gap between the unlubricated bearings in the connection part, In general, a dust seal is fitted on both ends of the non-grease bearing on the outer surface of the non-grease bearing. is installed as a single item, and depending on the swinging part, the outer periphery of the swinging side may be An O-ring is attached to the edge to seal the gap between the opposing fixed end face.

0003 For example, a through hole is provided in the fixed side boss a and the swinging side boss b, and a pin is inserted into the through hole. pin c is connected to fixed side boss a with bolt d, and pin c is connected to fixed side boss a through bolt d. Grease-free bushings e, e through which the pin c passes are arranged on both sides of the through hole b, and the grease-free A grease reservoir f is formed between the bushes e, e, and both outer ends of the non-greasy bushes e, e are formed. A dust seal g is provided as a single unit, and an O-ring is attached to the outer peripheral edge of the swinging side boss b. The seal h is attached to seal the gap i between the fixed side boss a and the swinging side boss b. Ru. Additionally, a grease nipple k is installed to close the grease hole opening into the grease reservoir f. I'm being kicked.

0004

[Problem that the idea aims to solve]

However, in the conventional dust intrusion prevention structure described above, the fixed side boss a and the pin Since there is a risk of dirt entering through the gap j between the However, due to damage to the O-ring h itself, the gap between the sliding surfaces of the fixed side boss a and the swinging side boss b There was a risk that earth and sand could enter through the gaps. In addition, the fixed side boss a and the swinging side boss b may be damaged due to wear caused by sliding between the fixed side boss a and the swinging side boss b. There is a problem that the sealing performance decreases due to an increase in the gap i between the movable side boss b, Gap j between fixed side boss a and fixed side boss a in the axial direction along pin c, and between fixed side boss a and swinging side boss Earth and sand enters from the outer circumferential direction of b and is pushed further into the gap by the rocking movement of the rocking part. This may reduce the sealing performance of the dust seal g, and dirt may enter the inside of the bearing. However, this has the problem of accelerating wear and causing lubricant grease to flow out.

[0005] The purpose of this invention is to ensure the sealing function even if the outermost seal is damaged. This prevents dirt, etc. from entering the bearing and prevents the bearing's lubrication performance from deteriorating. It is an object of the present invention to provide a bearing structure for a pin connection part of a construction machine that can be stopped.

[0006]

[Means to solve the problem]

The bearing structure of the pin connection part of the construction machine of the present invention is based on one member (for example, the swinging side part). A swing side boss is provided at the end of the other member (for example, the fixed side member). A fixed side boss is provided on the side, a swinging side boss is sandwiched between the fixed side boss, and the swinging side boss and A pin that is swingably connected by a pin that passes through a through hole provided in the fixed side boss. In the connecting part, a non-greasing bushing through which a pin passes is fitted into the through hole of the swinging side boss. There are multiple dust particles on the outside of the non-greaseable bushing, that is, on the fixed side boss side, to prevent dust from entering. The seals are arranged in contact with each other, and the sliding surfaces of the swing-side boss and the fixed-side boss face each other. At the side, the swinging side boss and the fixed side boss are attached to both or either one of the swinging side boss and the fixed side boss. Equipped with an O-ring seal that prevents dust from entering the gap between the sliding surface and the fixed side boss. Since it is attached, there is a gap between the fixed side boss and the swinging side boss or between the fixed side boss If earth and sand enters through the gap between the pin and the sliding surface of the non-greased bushing and the pin, By installing multiple dust seals, it is possible to prevent dirt from entering the This can increase the effectiveness of the dust seal and prevent damage to the outer dust seal. It is possible to ensure sufficient sealing function even when This prevents grease from flowing out from the gap between the sliding surface and the seal. ability to be reliably maintained

[0007]

【Example】

The first embodiment of the present invention will be explained with reference to FIG. 1. A fixed side boss 1 and a swinging side boss 2 A through hole is provided in both sides, and non-greasing bushings 5, 5 are arranged on both sides of the through hole of the swinging side boss 2. A pin 3, whose one end is connected to the fixed boss 1 with a bolt 4, is attached to the fixed boss 1. It passes through the through hole and the non-greasing bushings 5, 5, and connects the fixed side boss 1 and the swinging side boss 2. Connected for rotation. A grease (lubricating oil) reservoir 6 is formed between the non-greasable bushings 5, 5, and the non-greasable bushing A plurality of (two in this example) dust seals 71 and 72 are formed at the outer ends of the dust seals 5 and 5. A dust seal portion 7 is provided, and a groove portion is provided on the outer peripheral edge of the swinging side boss 2. 21 is formed, and the O-ring seal 8 is installed in the groove 21 to connect the fixed side boss 1 and the swinging side boss 1. The gap 9 with the base 2 is sealed. Note that the groove portion 21 is not limited to the swinging side boss 2, and may be provided on the fixed side boss 1. Alternatively, it may be provided on both the fixed side boss 1 and the swing side boss 2. Additionally, a grease nipple 10 is provided to close the grease hole opening into the grease reservoir 6. I'm being kicked.

[0008] According to this configuration, the gap 9 between the fixed side boss 1 and the swinging side boss 2 or the fixed side boss If earth and sand enters from the gap 11 between the bushing 1 and the pin 3, the grease-free bushing 5 and the pin 3 The dust seal part 7 prevents dirt from entering the gap between the sliding surfaces. There are two dust seals 71 and 72 between the outer dust seal 71 and inner dust seal 72. A closed space is formed surrounded by the lip provided by 72, and grease is stored in this closed space. The sealing effect can be enhanced by accumulating the dust on the outside. Even if the seal 71 is damaged, the closed space where grease has accumulated and the inside dust will be removed. Seal 72 ensures sufficient sealing function and also provides a non-greasy seal. Grease flows out from the gap between the sliding surface of the bush 5 and the pin 3 through the inner dust seal. 72, the closed space where grease is stored, and the outer dust seal 71. This allows the sealing ability to be maintained reliably.

[0009] To explain the second embodiment with reference to FIG. 2, the dust seal section 7 has two dust seals. 701 and 702, but the dust seal has the same cross-section. 701, 702 are arranged oppositely, i.e. the lip of the outer dust seal 701 Arranged so that 701A and lip 702A of inner dust seal 702 face opposite directions. Because of this, the closed space that holds the grease is enlarged and the grease holding capacity is increased. In addition to strengthening the structure, it is possible to reliably prevent grease from flowing out from the grease reservoir 6. It is possible.

0010 To explain the third embodiment with reference to FIG. 3, the dust seal portion 7 is similar to that of the first embodiment. Dust seals 71, 72 arranged in the same direction as above, and dust seals 71, 72 and no An oil seal 73 is installed between the greasing bush 5 and has an even better sealing effect. It is something to do.

[0011]

[Effect of the idea]

Since the present invention is constructed as described above, it has the following effects. Ru. Sediment is removed from the gap between the fixed side boss and the swinging side boss, or between the fixed side boss and the pin. If dirt enters the gap between the sliding surface of the non-greased bushing and the pin. This is prevented by the dust seal part, and the outer dust seal and inner dust seal The sealing effect can be enhanced by providing a seal, and the outer dust Sufficient sealing function can be ensured even if the seal is damaged. At the same time, it prevents grease from flowing out from the gap between the sliding surface of the grease-free bushing and the pin. Since it is possible to maintain the sealing ability reliably.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a bearing structure for a pin connection portion of a construction machine according to the present invention.

FIG. 2 is an enlarged sectional view of a main part showing a second embodiment of a bearing structure for a pin connection part of a construction machine according to the present invention.

FIG. 3 is an enlarged sectional view of a main part showing a third embodiment of a bearing structure of a pin connection part of a construction machine according to the present invention.

FIG. 4 is a longitudinal sectional view of a bearing structure of a pin connection part of a conventional construction machine.

[Explanation of symbols]

1 Fixed side boss 2 Swing side boss 3 pins 4 bolts 5 Grease-free bushing 6 Grease reservoir 7 Dust seal part 8 O-ring seal

Claims (1)

[Scope of utility model registration request] Claim 1: A swing-side boss is provided at the end of one member, a fixed-side boss is provided at the end of the other member, the swing-side boss is held between the fixed-side bosses, and the swing-side boss is pivoted by a pin. It is a pin connection part that is freely connected, and a non-greasing bushing is fitted into the through hole of the swinging side boss, and a plurality of dust seals are arranged in contact with each other on the outside of the non-greasing bushing. On the opposing sliding surfaces of the movable side boss and the fixed side boss, on both or either of the swing side boss and the fixed side boss, there is a gap between the sliding surface between the swing side boss and the fixed side boss. A bearing structure for a pin connection part of construction machinery, characterized by being equipped with an O-ring seal that prevents dust from entering.