JPS5858526B2 - Radial Gata Hybrid Radial Gata Hybrid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bearing method in which a general-purpose rolling bearing that rotates under a radial load is used as an in-line hybrid bearing.

In rolling bearings, in which the inner ring rotates when a radial load is applied, if the inner ring is loosely fitted to the shaft, or if it is a tight fit with little interference, the shaft will roll inside the inner ring (this is called creep).

), significant wear occurs on the contact surface between the shaft and the inner ring, and both the shaft and bearing become unusable in a short period of time.

Therefore, in order to prevent this, it is common to use the inner ring with a tight fit on the shaft, but a tight fit is troublesome when assembling a device that is equivalent to a single bearing.

The present invention is clearly advantageous in terms of workability when mounting the inner ring on the shaft with one clearance or when mounting a rolling bearing on the shaft. It is characterized in that it enables a clearance fit to the shaft of the shaft.

However, in all conventional hybrid bearings, the sliding bearing part is specially designed and manufactured, but the present invention does not require the manufacturing of special parts, and uses general-purpose rolling bearings. The present invention is characterized in that an hybrid bearing can be constructed by an extremely simple structure that only requires a sliding bearing to be formed between the inner ring and the shaft.

That is, in the bearing method of the present invention, the inner ring of a general-purpose rolling bearing that rotates under radial load is attached to the shaft with the clearance fit necessary to produce a squeeze film effect, and the inner ring is inserted between the shaft and the inner ring. A sliding bearing is formed between the shaft and the inner ring by forming a lubricating oil film between them based on the squeeze film effect generated by the lubricating oil, thereby converting the general-purpose rolling bearing into an hybrid bearing. It is what you use.

As a result of experiments, a sliding bearing formed by such a rolling bearing and a shaft has a tendency to form a lubricating oil film very easily, and for example, a deep groove ball bearing (inner diameter 3Q mm).

When an inner ring with an outer diameter of 6211 tm and a width of 16 m0 is fitted onto a shaft with a clearance of 10 μ, even if a radial load of 500 kg is applied, the fitting surface is lubricated with No. 140 turbine oil, and a complete lubricating oil film is formed at 300 rpm or higher. It has been confirmed that the inner ring slides smoothly between the shaft and the inner ring.

When the rotational speed is increased, the rotation between the shaft and the inner ring becomes as shown in FIG.

In the same figure, the chain line indicates the case where the shaft and inner ring are attached and do not operate as a sliding bearing, that is, (shaft rotation speed) - (inner ring rotation speed), but the actual measured values shown by the solid line indicate that the inner ring rotates around the axis. This difference is the rotation speed of the sliding bearing.

In this way, when a rolling bearing is used as a no-brid bearing, the rotational speed of the inner ring of the rotary valve of the sliding bearing is reduced, thereby extending the life of the bearing.

Fig. 2 shows an example of an hybrid bearing mechanism to which the present invention is applied, in which the inner ring 2 of a general-purpose ball bearing 1, which rotates under the radial load W, is attached to the shaft 3 with a single gap fit.
In order to send lubricating oil through the inside of the shaft 3 between the sludged inner ring 2 and the shaft 3, a lubrication hole 4 that opens from one end surface of the shaft 3 to the fitting surface of the inner ring 2 is provided, and a lubrication system that performs pressurized lubrication. A joint 6 is provided at the tip of the tube 5 to form a seal with the end of the shaft 3 using an oil seal 7, thereby forming a lubricating oil supply path.

When lubricating the fitting surface between the inner ring 2 and the shaft 3, it is not necessary to supply lubricating oil under pressure.

In other words, as the shaft rotates, the inner ring also rotates accordingly.
As the opposing walls of the shaft and inner ring gradually approach each other due to the action of the radial load, a fluid film is formed between them due to the squeeze film effect, and therefore there is no need to apply pressure to the lubricating oil.

Furthermore, instead of providing an oil supply hole in the shaft, the same effect can be obtained by injecting lubricating oil from the outside onto the fitting surface.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the actual results of rotation between the button shaft and the inner ring according to the present invention, and Fig. 2 is a diagram showing the actual results of the rotation between the button shaft and the inner ring according to the present invention.
FIG. 2 is a sectional view showing an example of an hybrid bearing mechanism. 1... General-purpose ball bearing, 2... Inner ring, 3... Shaft.

Claims (1)

[Claims] 1 Clearance required to create a squeeze film effect in the inner ring of a general-purpose rolling bearing that rotates under radial load.
It is attached to the shaft with a fit, and a lubricant film is formed between the shaft and the inner ring based on the above-mentioned screwdriver effect generated by the lubricant introduced between the shaft and the inner ring, thereby preventing slippage between the shaft and the inner ring. A radial type hybrid bearing method using a general-purpose rolling bearing characterized by forming a bearing.