JPH07136686A - Aerator - Google Patents

Abstract

PURPOSE:To provide a screw type aerator which does not cause vibration even when the screw shaft of a cantilever bearing is extended and is of easy maintenance. CONSTITUTION:In a screw type aerator in which an aeration screw 3 is attached to the end of a hollow shaft 2 which is rotated by a motor positioned above water, a small damping blade 4 for controlling the vibration of the hollow shaft 2, which is vibrated by the rotation of the screw 3, is installed in the submerged part of the cantilever hollow shaft 2. In this way, the damping effect is produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aeration device for suppressing vibration of a long cantilever type hollow shaft having a screw at its tip without providing a bearing in water.

[0002]

2. Description of the Related Art A conventional screw type aerator is provided with a screw at the tip of a hollow shaft rotated by a motor, and a cantilever type in which the hollow shaft is supported only on the motor side, and a bearing is also provided in water. There are two types of underwater bearing type. Since this cantilever type bearing is arranged on the water, it is convenient for maintenance.

[0003]

However, since the cantilever type bearing vibrates when lengthened, there is a limit to the length and it cannot be made too long. Further, since the submersible bearing type has the neck portion of the screw, the length of the screw shaft can be increased, but there is a drawback in that maintenance is troublesome.

It is an object of the present invention to provide a cantilever type screw type aerator which does not vibrate even if its screw shaft is lengthened and is easy to maintain.

[0005]

The present invention has been made to achieve the above object, and in a screw type aerating device having an aerating screw at the tip of a hollow shaft rotated by a water motor, In order to obtain a vibration damping effect, a cantilever type hollow shaft having the screw is provided with a small damping blade for suppressing the vibration of the hollow shaft vibrated by the rotation of the screw in the portion immersed in the water. What is done is summarized.

[0006]

[Function] The screw type aerator using the water motor is
To avoid flooding of the motor due to fluctuations in water level, a long cantilever bearing is usually used. However, when the screw is immersed in water and rotated, the long hollow shaft oscillates, but by installing a small damping blade for shaft holding at the intermediate position of this long screw shaft, the holding generated as a reaction force from the driving fluid A force or the like acts on the screw, so that resonance does not occur even at a normally calculated resonance point.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A screw shaft support device for an aeration device of the present invention will be described below with reference to the illustrated embodiments. In the figure, 1 is a driving motor which is usually supported on the water surface via a bracket B and the like. A hollow shaft 2 is attached to the motor 1 for driving, and the hollow motor has a required length. An aeration screw 3 is provided at the tip of the shaft. The hollow shaft 2 has a predetermined length so that the screw at the tip is driven at a predetermined water depth position.

Since this long hollow shaft is cantilevered only on the motor side, vibration is generated by the rotation of the screw. Therefore, it is necessary to support at least the middle of the long hollow shaft with a bearing. In consideration of maintainability, it is not preferable to use a submersible bearing, but in order to set the position of the stirring screw deeper in water, it becomes necessary to intermediately support a long drive shaft in some way.

In the present invention, the intermediate support is not rigidly performed by the submerged bearing, but is flexibly performed by utilizing the reaction in water on the centrifugal blade, for example, and the hollow shaft is also used for damping the drive shaft. A small disk-shaped damping blade 4 is provided at an intermediate position in the water.

By providing such a damping blade 4 in the underwater portion of the hollow shaft 2, although the shaft power by the motor is slightly increased, it does not require regular maintenance unlike the underwater bearing.
It is possible to configure a maintenance-free system as a whole.

In an actual OD tank or pond, fibrous dust, algae, etc. may become entangled with the damping blade 4 and cause a problem. However, in this case, for example, when a vibration sensor or the like is provided and the shaft vibration above a certain standard is detected due to the entanglement with the damping blade 4 of fibrous dust or algae,
By automatically rotating the hollow shaft in reverse,
The dust that is entangled in the can be reliably removed, and it can be made substantially maintenance-free.

[0012]

The aeration apparatus of the present invention is provided with an aeration screw at the tip of a hollow shaft rotated by a water motor.
The cantilever type hollow shaft with this screw is provided with a small damping blade in the submerged part, so even if the hollow shaft rotates and vibration occurs Since the vibration is absorbed and the vibration of the hollow shaft is suppressed to obtain the vibration damping effect, there is an advantage that the hollow shaft can be elongated and there is no bearing in the water, so that maintenance can be easily performed.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of an aeration device of the present invention.

[Explanation of symbols]

 1 Motor 2 Hollow shaft 3 Screw 4 Damper

Claims (1)

[Claims] 1. A screw type aerating device having a screw for aeration provided at the tip of a hollow shaft rotated by a water motor, wherein a cantilever type hollow shaft having the screw is provided with a screw at a portion immersed in the water. An aeration device characterized in that a small vibration damping blade for suppressing vibration of a hollow shaft that vibrates due to the rotation of is provided to obtain a vibration damping effect.