JPH0338485Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to an improvement of a bearing device for a cylinder head that supports a piston rod of a hydraulic cylinder.

(b) Conventional technology As hydraulic cylinders become faster and more pressurized, it is desired to improve the pressure resistance of sealing members and the performance of bearings. For this reason, a bearing structure as shown in Figure 3 is often used. . That is, piston rod 1
is supported by the cylinder head 2 via a bearing 3, seal members 4 and 5, and a dust removal seal 6 arranged on the cylinder head 2 side.
The distance from the outer end of the cylinder head 2 to the outer end of the cylinder head 2 becomes longer, and as a result, the cylinder head axis X and the rod axis Y are bent due to the clearance of each part of the cylinder and the lateral load of the piston rod 1 itself. As shown by the broken line in the third figure, the piston rods 1 and 2 are inclined to each other, causing friction between the piston rod 1 and the inner surface A located at the outer end of the cylinder head 2.

Assuming this case, a bearing material made of a soft material such as bronze is thermally sprayed on the inner surface of the cylinder head to avoid frictional resistance during sliding contact as much as possible.

(c) Problems to be solved by the invention However, when spraying the inner surface A of the cylinder head 2 as described above, it is necessary to roughen this area once, then apply the spraying, and then finish the sprayed surface. Therefore, there are problems in that not only the processing steps are complicated and costs increase accordingly, but also it is difficult to say that appropriate durability can be exhibited.

(d) Means for solving the problem Therefore, in the present invention, instead of thermally spraying the bearing material as described above, the bearing is placed here, and the inner diameter of the outer bearing is made smaller than the inner diameter of the inner bearing. The piston rod is also large in size to easily cope with the above-mentioned inclination and deflection of the piston rod, thereby improving smooth operation and durability.

The gist of the present invention will be explained below based on the embodiments shown in the drawings.

(E) Embodiment Figure 1 is a partially cutaway side view showing an embodiment of the bearing portion of the cylinder head of a hydraulic cylinder equipped with the device of the present invention. The symbol is marked.

The difference between this invention and conventional products is that the cylinder head 2
Instead of spraying the inner surface A of the piston rod 1, a bearing 3' is disposed in this area so that the bearing 3' makes contact when the piston rod 1 is tilted or deflected.

This results in a bearing that is cheaper and more efficient than the case of thermal spraying, but even in this case, the outer bearing 3' and the inner bearing 3, which have the same inner diameter, are used when the cylinder is fully extended, that is, when the piston 10 is When the piston rod is close to the cylinder head 2, there may be a mutual inclination between the axis X of the cylinder head 2 and the axis Y of the piston rod 1 as shown in the fourth figure, or the piston rod may be tilted due to a lateral load as shown in the fifth figure. This results in a deflection of 1.

Therefore, in the present invention, by forming the inner diameter of the bearing 3' to be slightly larger than that of the bearing 3, damage to the piston rod due to the above-mentioned inclination or deflection can be avoided as much as possible.

In FIG. 2, the bearing 3 shown in FIG. 1 is set as a plurality of bearings 3a, 3b, and these bearings 3',
By setting the inner diameters of a and 3b such that 3'>3a>3b, smooth operation similar to that shown in FIG. 1 can be achieved.

(f) Effect In the device of the present invention configured as described above, the bearing is designed to prevent tilting and deflection of the piston rod 1 caused by machining errors of various parts of the cylinder or lateral loads during reciprocating movement of the piston rod 1. 3' is installed instead of thermal spraying, and its inner diameter is 3'＞
3, it is possible to perform smooth operation.

(g) Effects of the invention As described above, according to the invention, the pre-formed bearing 3' is fitted onto the inner surface A portion without the need for the conventional thermal spraying process, so the manufacturing process can be reduced to that extent. In addition to simplifying the design, at least two bearings 3 and 3' are provided in front and behind the sealing member, and the inner diameter of the bearings is set to 3'> 3, so that appropriate sliding contact can be achieved in response to the inclination and deflection of the piston rod. , which helps improve durability and lowers costs, and the practical benefits are quite significant.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view showing one embodiment of a hydraulic cylinder equipped with the bearing device of the present invention, Fig. 2 is a partially cutaway side view showing another embodiment, and Fig. 3 is a partially cutaway side view of a conventional hydraulic cylinder. A partially cutaway side view showing an example, and FIGS. 4 and 5 are explanatory diagrams showing the operating state of a conventional hydraulic cylinder. 1... Piston rod, 2... Cylinder head, 3, 3'... Bearing, 4, 5... Seal member.

Claims (1)

[Scope of utility model registration request] At least two bearings are provided for the cylinder head that slides on the piston rod, and the bearings are arranged in front and behind the sealing member, and the inner diameter of the bearing is larger on the side of the bearing located on the outside. A bearing device for a hydraulic cylinder characterized by: