JPH04157207A - Underwater bearing device - Google Patents

Abstract

PURPOSE:To prevent seizure between a bearing and a shaft due to their swelling by changing the inside diameter of the bearing with no uniformity in its longitudinal direction, and decreasing the area of a part which has a regular gap at the initial time of water immersion to reduce increase in frictional torque. CONSTITUTION:Both the ends of a bearing material 1 such as rubber and phenol fitted in a back shell 2 are made a diameter which is a regular gap at the initial time of water immersion, and its central part is made a diameter where the regular gap + secular swelling amount are taken into consideration. It is thus possible to prevent the shaft from being stuck due to swelling and frictional torque from increasing, providing high reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a bearing device for a machine having a submerged bearing such as a pump, and particularly to a bearing device most suitable for a submerged bearing of a shaft pump.

[Conventional technology]

Rubber bearings, phenolic bearings, etc. have traditionally been used in spindle pumps, and have a proven track record.When these bearings are submerged in water for a long time, they swell and the inner diameter shrinks, causing the inner diameter to shrink due to temperature changes. In severe cases, the engine could cling to the shaft, increasing frictional torque and making it impossible to start.

[Problem to be solved by the invention]

An object of the present invention is to eliminate troubles such as an increase in frictional torque and an inability to start due to the bearing clinging to the shaft due to swelling.

[Means to solve the problem]

In order to achieve the above object, the inner diameter of the bearing is not uniform in the longitudinal direction, but is changed to reduce the area of the part that becomes a regular gap at the initial stage of submergence, thereby reducing the increase in frictional torque.

Further, this initial normal gap portion is provided at the end of the bearing or at the center of the bearing, and the diameter of the other portions is increased to correspond to the amount of swelling, thereby reducing an increase in frictional torque.

In addition, the small diameter part (regular gap part) is made of a material that does not swell in water, the large diameter part is made of a material that swells, and as the swelling progresses over time, the bearing uniformly becomes a regular gap.

Furthermore, by creating grooves in the back shell made of swelling material, creating gaps between bearing members, and drilling multiple holes in the bearing material, we provide relief when swelling occurs and reduce the impact of the reduction in the inner diameter. I made it.

[Effect]

Rubber bearings, phenol bearings, etc. that have been conventionally used as underwater bearings undergo a swelling phenomenon when immersed in water for a long period of time, making it impossible to obtain an appropriate gap.

Therefore, the inner diameter of the submersible bearing is not uniform in the longitudinal direction, but is changed to reduce the area of the part that becomes a normal gap at the initial stage of submergence, and the diameter of other parts is increased by the amount corresponding to the amount of swelling over time. did.

As a result, at the initial stage of submergence, only the regular gear part slides, and as the swelling gradually progresses after submersion, the regular gap part becomes narrower, but since the area is smaller than before, the increase in friction torque is also small. I'm done.

Also, since the surface pressure is high in this part, it wears out quickly and there is less risk of it clinging to the shaft.

Furthermore, since the portion of the diameter corresponding to the normal gear gear + swelling amount at the initial stage of submergence also swells over time, the entire gap becomes the normal gap by the end of the day, making it an ideal bearing.

Also, rather than changing the inner diameter of the bearing, when it swells, it is made so that it can escape to other parts so that the inner diameter does not shrink.

In other words, grooves are provided on the inner diameter of the back shell on the outer periphery of the bearing material so that when it swells, it can escape not only to the inner diameter but also to the outer diameter, or holes are made in the bearing material so that it can escape in this direction to reduce the inner diameter. Reduced the impact.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

FIG. 1 is a sectional view of an underwater bearing device that is an embodiment of the present invention.

The bearing material 1 is made of a material such as rubber or phenol and is fitted into the back shell 2.

The diameter of both ends of the bearing is larger than the diameter of the center part, and is determined as follows.

Both ends of the bearing = diameter that provides the normal gap at the initial stage of submergence (during assembly).

Bearing center = regular gear knob + diameter that takes into account the amount of swelling over time.

That is, the diameter is increased by an amount that takes into account the amount of swelling over time.

Taking rubber and phenol as an example, the swelling amount is 0.1 m to 1.
It was experimentally determined that the swelling would be approximately 90% in about one year at a size of about 0.

Therefore, if the bearing is configured as described above, the initial stage of submergence...
It slides in the regular gap at both ends of the bearing.

Submerged in water for several months...The gap between both ends of the bearing tends to become narrower, but since the contact area becomes smaller, there is a small possibility that wear will be accelerated and the gap will disappear. Furthermore, even if it were to cling to the shaft, the increase in frictional torque would be small because the contact area is small.

Here, the longitudinal length of the regular gap part is 5 of the bearing length.
If the length is between % and 40%, there is a good balance between the amount of swelling and wear, and the shaft is less likely to cling, which is effective.

More than a year has passed...The gap in the center is almost a regular gap, and both ends are also worn, so almost all diameters are regular gaps.

This process eliminates problems such as increased frictional torque and shaft clinging, making it possible to create highly reliable underwater bearings.

In FIG. 2, the relationship between the diameters of the shaft ends and the center portion is changed from that in FIG. 1, and the same effect can be obtained for the same reason.

FIG. 3 is a sectional view of an underwater bearing according to another embodiment of the present invention.

The bearing material 1 is fitted into the back shell 2, and bearing materials 3 are arranged at both ends thereof. The bearing material 3 is made of a material that does not swell in water, such as ceramic or Teflon, and has a diameter that provides a regular gap with the shaft. The bearing material 1 is made of a material that swells, such as rubber or phenol, which has been conventionally used in underwater bearings, and the diameter thereof has been increased in advance to correspond to the amount of swelling.

Therefore, if configured as above, the initial stage of submergence...Sliding in the regular gap portions at both ends of the bearing.After more than a year...The gap in the center becomes almost a regular gap, and almost all diameters become regular gaps. .

Therefore, a highly reliable underwater bearing can be obtained. Further, if the bearing material 3 is selected from a self-lubricating material such as ceramic or Teflon as in the embodiment, it can be used even under dry conditions at startup, and a water-free bearing is also possible.

FIG. 4 is a sectional view of an underwater bearing according to another embodiment of the present invention.

The bearing material 1 is fitted into the back shell 2 in the same manner as in the other embodiments, but the inner diameter of the back shell 2 is circumferentially grooved to create a gap between the bearing material 1 and the bearing material 1. 4 are configured.

Without this gap 4, the configuration would be a conventional underwater bearing, and when the bearing material 1 swells, it is restrained by the back shell 2 and the inner diameter of the bearing is reduced. When the gap 4 is provided as in the present invention,
Since the bearing material 1 can also escape to the outer diameter side, the influence of the reduction in the inner diameter can be reduced.

5 and 6 are based on the same principle, and the influence of the reduction in the inner diameter is reduced by allowing the swelling to escape through the gaps between the bearing members and the plurality of holes, respectively.

According to the present invention, a highly reliable underwater bearing can be provided because there is no shaft clinging due to swelling and no increase in frictional torque.

〔Effect of the invention〕

According to the present invention, there is no hugging of the shaft due to swelling and no increase in frictional torque, so it is possible to provide a highly reliable underwater bearing device.

[Brief explanation of the drawing]

1 to 6 are cross-sectional views of underwater bearings according to different embodiments of the present invention.

Claims (1)

[Claims] 1. An underwater bearing device using a material that swells in water, characterized in that the inner diameter of the bearing varies depending on its position in the longitudinal direction.