JPS6340647Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention relates to a bearing structure for construction machinery such as a hydraulic excavator.

[Conventional technology]

FIG. 1 is a diagram showing a hydraulic excavator. In the figure, 1 is a boom, 2 is an arm connected to the boom 1, and 3 is a bucket connected to the arm 2.

FIG. 2 is a sectional view showing a bearing structure of a connecting portion between an arm and a bucket of a conventional hydraulic excavator (Japanese Utility Model Publication No. 53-46702). In the figure, 2a is the bearing part of the arm 2, 3a is the bearing part of the bucket bag 3, and 3a is the bearing part of the bucket 3.
1 is a shim, 32 is a retainer, 33 is a lid-shaped body, 40
34 is a plug attached to the lid-shaped body 33, the shim 31, the retainer 32, and the lid-shaped body 33 are attached to the bearing part 3a.
35 is a bush provided on the inner surface of the bearing portion 2a, 36 is a seal provided between the retainer 32 and the bush 35, and 37 is formed by the retainer 32, the lid-like body 33, the bush 35, etc. pin provided in the space, 38 is pin 3
The oil supply hole 39 provided inside the pin 7 is a passage provided in the pin 37, and the passage 39 communicates the outer surface of the pin 37 with the oil supply hole 38.

In this bearing structure, the pin 37 is
a. It can rotate and move freely with respect to the bearing part 3a, and if the plug 40 is removed and grease is supplied into the space where the pin 37 is provided, the grease will flow through the oil supply hole 38 and the passage 39. Te pin 37
Since the pin 37 is supplied between the retainer 32 and the bush 35, the pin 37 and the retainer 32 and the bush 35
Since the sliding resistance between the pin 37 and the pin 37 is small, no large torsional force or axial force is applied to the pin 37.

[Problems to be solved by the invention] However, in such a bearing structure, since the oil supply hole 38 is provided inside the pin 37,
In order to sufficiently increase the strength of the pin 37, it is necessary to increase the diameter of the pin 37, which increases the size of the entire bearing structure and makes machining the pin 37 troublesome.

For this reason, it is conceivable to provide an oil groove on the inner surface of the bush as shown in Japanese Utility Model Application No. 55-140565, but in this case, it is necessary to provide a seal on the outer surface of the bush, making the structure complicated. become,
In addition, the part of the bushing where the seal is installed cannot receive any force, and it is necessary to provide an oil groove on the inner surface of the cylindrical bushing.Moreover, since the bushing is made of wear-resistant material, machining the oil groove is extremely difficult. It is. Also, if the bush moves relative to the pin, no oil pool will form, the grease will no longer flow, and the seal will no longer be supplied with grease, which will shorten the life of the seal and require more frequent lubrication. .

This idea was made to solve the above-mentioned problems.The overall bearing structure does not become large, the pins and bushes are easy to process, the structure is simple, the seal has a long life, The purpose of the present invention is to provide a bearing structure that does not require frequent lubrication.

[Means for solving problems]

In order to achieve this object, in this invention, in a bearing structure in which a male connecting member and a female connecting member are mutually rotatably connected by a pin, first bushes are provided at both ends inside the male connecting member. a second bushing is provided inside the female connecting member, a lid-like body is provided on the female connecting member, and a second bush is provided inside the female connecting member, and a lid-like body is provided in the space formed by the male connecting member, the female connecting member, and the lid-like body. providing the pin, providing a first dust seal between both ends of the male connecting member and the pin, and providing a second dust seal between the male connecting member side end of the female connecting member and the pin; A space is provided between the first bush on the inner surface of the male connecting member, a first groove communicating with the space is provided on the outer surface of the pin, and an oil pool is provided between the pin and the lid-like body. and a second groove communicating with the oil reservoir is provided on the outer surface of the pin.

[Effect]

In this bearing structure, by supplying lubricating oil to the first groove, the space can be filled with lubricating oil, and by supplying lubricating oil to the oil pool, the lubricating oil can flow through the second groove. is supplied between the pin and the female connecting member.

〔Example〕

FIG. 3 is a front sectional view showing the bearing structure according to this invention, and FIG. 4 is a side view thereof. In the figure,
Reference numeral 19 denotes a lid-shaped body attached to the bearing part 3a with bolts 21, 22 denotes a protrusion provided on the lid-shaped body 19, and the protrusion 22 is fitted into the inner surface of the bearing part 3a. 20 is an O-ring provided on the protrusion 22, 9 is a first bushing press-fitted into both ends of the inside of the bearing part 2a, 17 is a second bushing press-fitted into both ends of the inside of the bearing part 3a, 11b is the gap between the bearing part 2a and the bearing part 3a, 11a is the gap 11b
4 is a pin provided in the space formed by the lid-like body 19, bushes 9, bushes 17, etc.; 10 is a pin provided between both ends of the bearing portion 2a and the pin 4; first dust seal,
18 is a second dust seal provided between the bearing 2a side end of the bearing 3a and the pin 4, 11c is a space provided between the bushes 9 on the inner surface of the bearing 2a, and 23 is a lid-shaped body. With the protrusion provided in 19,
The diameter of the protrusion 23 is sufficiently smaller than the diameter of the pin 4. 8 is a first groove provided on the outer surface of the pin 4;
The groove 8 communicates with the space 11c. 24 is an oil reservoir formed between the lid-shaped body 19 and the pin 4;
6 is a second groove provided on the outer surface of the pin 4;
6 communicates with the oil sump 24. Reference numeral 15 denotes an oil supply hole provided in the bearing portion 2a, and the oil supply hole 15 communicates with the groove 8. 26a is a grease nipple mounting hole communicating with the oil supply hole 15, 5a is a grease nipple inserted into the grease nipple mounting hole 26a, 26b is a grease nipple mounting hole provided in the lid-like body 19, and 5b is a grease nipple inserted into the grease nipple mounting hole 26b.

In this bearing structure, the pin 4 is connected to the bearing part 2.
a. It can freely rotate and move with respect to the bearing part 3a, and when grease is supplied from the grease nipple 5b to the oil pool 24, the grease fills the oil pool 24 and is guided to the groove 16, and then When grease is press-fitted, the grease pushes away the lip of the dust seal 18 and overflows into the gap 11b, thereby lubricating the space between the pin 4 and the bush 17. On the other hand, when grease is supplied from the grease nipple 5a, the grease flows into the space 11c. When it is filled with grease and further press-fitted with grease, the grease pushes away the lip of the dust seal 10 and overflows into the gap 11b, which lubricates the space between the pin 4 and the bush 9, reducing the torsional force acting on the pin 4 in the axial direction. Since the force can be made very small, there is no need to increase the strength of the pin 4, and there is no need to provide an oil supply hole inside the pin 4, so there is no need to increase the diameter of the pin 4. The entire structure can be miniaturized, and the pin 4 can be easily processed. Furthermore, earth and sand from the gap 11b,
O-ring 11a and dust seal 1 prevent muddy water from entering.
0 and 18, and the O-ring 20 can also reliably prevent dirt and mud from entering from the mounting surface of the bearing portion 3a and the lid-shaped body 19. Further, a protrusion 2 having a diameter sufficiently smaller than the diameter of the pin 4 is provided on the lid-like body 19.
3, the sliding resistance between the end surface of the pin 4 and the lid-shaped body 19 is small. Furthermore, since there is no need to provide the dust seals 10, 18 on the outer surfaces of the bushes 9, 17, the structure is simple and the entire surfaces of the bushes 9, 17 can receive force. In addition, bushes 9 and 17 made of cylindrical wear-resistant material
Since there is no need to provide grooves on the inner surfaces of the bushes 9 and 17, processing of the bushes 9 and 17 is very easy. Furthermore, since the space 11c can be filled with grease, the dust seal 10 can be reliably supplied with grease, so the life of the dust seal 10 is extended, and there is no need for frequent lubrication.

In the above embodiment, a bearing structure was described in which the male connecting member is the bearing part 2a of the arm 2 and the female connecting member is the bearing part 3a of the bucket 3. However, this invention can be applied to other connecting parts of a hydraulic excavator. It can be applied to the bearing structure of the construction machine and the bearing structure of the connection part of other construction machines. Furthermore, in the above embodiments, grease was used as the lubricating oil, but other lubricating oils may be used.

[Effect of idea]

As explained above, in the bearing structure according to this invention, the pin can freely rotate and move relative to the male connecting member and the female connecting member, and there is a groove between the pin and the female connecting member. Since lubricating oil is supplied, large torsional and axial forces do not act on the pin, and there is no need to provide an oil supply hole inside the pin, so there is no need to increase the diameter of the pin, so the entire bearing structure The pin can be made smaller and the pin can be easily processed. Furthermore, since there is no need to provide the first and second dust seals on the outer surfaces of the first and second bushings, the structure is simple, and the entire surface of the first and second bushings can receive the force. The first part is made of a cylindrical wear-resistant material.
Since there is no need to provide a groove on the inner surface of the second bushing, machining is very easy, and since the space can be filled with lubricating oil, lubricating oil can be reliably supplied to the second dust seal. This increases the life of the second dust seal and eliminates the need for frequent oiling. In this way, the effects of this invention are remarkable.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a hydraulic excavator, Fig. 2 is a sectional view showing a bearing structure of a connecting part between an arm and a bucket of a conventional hydraulic excavator, and Fig. 3 is a front sectional view showing a bearing structure according to this invention. FIG. 4 is also a side view. 2a, 3a... Bearing portion, 4... Pin, 8... First groove, 9... First bushing, 10... First dust seal, 11c... Space, 16... Second
groove, 17... second bushing, 18... second dust seal, 19... lid-like body, 24... oil pool.

Claims (1)

[Scope of utility model registration request] In a bearing structure in which a male connecting member and a female connecting member are mutually rotatably connected by a pin, first bushes are provided at both ends inside the male connecting member,
a second bushing is provided inside the female connecting member;
A lid-like body is provided on the female connecting member, the pin is provided in a space formed by the male connecting member, the female connecting member, and the lid-like body, and both ends of the male connecting member and the pin are provided. A first dust seal is provided between the male connecting member side end of the female connecting member and the pin, and a space is provided between the first bushing on the inner surface of the male connecting member. A first groove communicating with the space is provided on the outer surface of the pin, an oil pool is formed between the pin and the lid, and a first groove communicating with the oil pool is provided on the outer surface of the pin. A bearing structure characterized by having two grooves.