JPH02236017A - Bearing of rotating shaft - Google Patents

Abstract

PURPOSE:To obtain stable rotation of a shaft and prolong a bearing's life by a method wherein in a bearing device formed with a layer made of viscous material such as lubricant oil around the bearing, optionally changing the thickness of the viscous layer permits a corresponding attenuation coefficient to be obtained. CONSTITUTION:A slit between a bearing 2 and a frame 3 for supporting a peripheral length variation bearing is filled with viscous material such as lubricant oil thereby constituting a mechanism wherein the vibration of a shaft 1 is attenuated by attenuation force of a viscous layer 4 around the bearing 2. That is, a peripheral length variation power device 8 appropriately operates according to operating conditions such as the number of rotations of the shaft 1 and temperature to rotate a power transmission shaft 9 and change the interval between engaged parts 6 and 7 so as to change the peripheral length of the variable peripheral length shaft supporting frame 3. As a result the thickness gammaof the viscous layer 4 around the bearing 2 changes thereby determining attenuation coefficient accordingly. Thus by changing and adjusting the thickness gammaof the viscous layer, the optimum attenuation coefficient for the operating conditions can be obtained to realize stable rotation of the shaft.

Description

Detailed Description of the Invention (1) Object of the Invention [Field of Application of the Invention] The present invention relates to a bearing device for a rotating shaft that supports the bearing by forming a layer of viscous material such as lubricant or water around the bearing. It is something.

(2) Prior Art [Background of the Invention] When a rotating body rotates at a high speed, rotational energy and centrifugal force increase, so a bearing device that can rotate at a higher speed is required.

When rotating the rotating shaft at high speed, it is necessary to increase the damping force of the bearing device to suppress resonance when the rotational speed is close to the natural frequency of the shaft system. Since the rotating shaft rotates around the center of gravity, it is necessary to reduce the damping force and the load on the bearing in order to eliminate the cause of early bearing failure.

Conventionally, in bearing devices for rotating shafts, a gap is formed between the bearing and the support, and a viscous substance such as lubricant or water is infiltrated into the gap to create a layer, and a damper is created that utilizes the damping force due to the viscosity of this layer. By adding this, vibrations caused by resonance are suppressed.

The damping force due to viscosity is determined by the thickness and viscosity of the layer of the viscous material, so it is difficult to set an appropriate value depending on the magnitude of vibration.Furthermore, when the bearing becomes hot, the viscosity of the viscous material decreases. As a result, the damping force decreases, resulting in severe vibration during operation of the device.

As described above, the operating conditions are not constant, and in order to achieve the optimum vibration state, it is necessary to arbitrarily adjust the damping characteristics of the bearing device in accordance with the operating conditions such as the rotation speed and temperature.

(3) Purpose of the Invention The purpose of the present invention is to provide a bearing device that supports a bearing by forming a layer of viscous material such as lubricant or water around the bearing.
It eliminates the drawbacks of conventional technology and enables faster rotational axes.
Another purpose is to extend the life of the bearing.

(4) Summary of the invention The present invention is a bearing device that supports a bearing by forming a layer of viscous material such as lubricant or water around the bearing, and damps by changing the thickness of the viscous material layer. Focusing on the fact that the coefficient changes, we devised a way to change the layer thickness depending on operating conditions such as rotational speed and bearing temperature.

(5) Embodiments of the Invention The present invention will be explained below with reference to illustrated embodiments. Figure 1 is an example of a journey of the present invention. First, to describe the configuration of its main elements, in the figure, 1 is a shaft connected to a power source (not shown), 2 is a bearing such as a rolling bearing or a sliding bearing, and the bearing 2 is attached to the shaft 1. This supports the shaft without hindering its rotation. Reference numeral 3 is a variable circumferential length bearing support whose circumferential length can be changed by a circumferential length changing power device which will be described later. Reference numeral 4 denotes a layer of viscous material such as lubricant or water, which is formed in the gap between the bearing 2 and the variable circumference bearing support 3. Reference numeral 5 denotes a support base that supports the variable circumference bearing support 3, and is fixed to a fixing member (not shown). Reference numeral 6 denotes an engaging portion that is threadedly engaged with the variable circumferential length bearing support shaft 3 and a variable circumferential length power transmission shaft 9, which will be described later. Reference numeral 7 denotes an engaging portion formed on the variable circumference bearing support 3 for engaging a circumferential length variable power transmission shaft 9, which will be described later, and is connected so that the circumferential length variable power transmission shaft 9 can rotate freely. Reference numeral 8 denotes a circumferential length variable power device which operates as appropriate depending on the operating state of the shaft 1. Reference numeral 9 denotes a circumferential length changing power transmission shaft, which has an engaging portion (B) 7 and stop portions 11a and 1lb formed at the tip thereof to freely rotate and restrain the circumferential length changing power transmitting shaft in the length direction. 6 and screwed together,
The distance between the engaging portions 6 and 7 is changed by rotating the circumferential length changing power transmission shaft. Reference numeral 10 denotes a rotation measuring device for measuring the movement of the circumferential length changing power transmission shaft 9.

Next, the axis 1, which will be described in detail about the operation and effect of the present invention, is as follows:
It is rotated by a power source (not shown), and the gap between the bearing 2 and the variable circumference support 3 is filled with a viscous material such as lubricant or water, and the damping force of the layered viscous material around the bearing 2 Attenuates the vibration of shaft 1.

Here, the circumferential length changing power device 8 operates as appropriate in response to the given operating conditions, rotates the circumferential length changing power transmission shaft 9, and changes the distance between the engaging portion 6 and the engaging portion 7. As a result, the circumferential length of the variable circumferential length bearing support member 3 changes, and the thickness of the viscous material layer between it and the bearing 2 changes. When this circumference is changed, a part of the viscous body is
Moves in and out of the internal viscous reservoir. Further, the rotation of the circumferential length changing power transmission shaft 9 is measured by the rotation measuring device 1o, and the thickness of the layer (Δr in the following equation) can be calculated from this measurement data.

The damping force for suppressing shaft vibration is determined by the product of the damping coefficient and the vibration speed of the shaft. The damping coefficient in the case of a layered viscous material is given by the calculation formula: Cd=k·μ·r·(L/Δr)3. Here, k is a coefficient determined by the shape of the outer circumference of the bearing and the inner diameter of the variable circumference support, μ is the viscosity of the viscous material, r is the radius of the shaft, L is the width of the bearing, and △r is the bearing and bearing support. It is a gap between style and style. Therefore, depending on the operating conditions such as the rotation speed of the supported shaft, etc. and the temperature of the bearing part, the gap △r between the bearing of the above formula and the bearing support part can be changed and adjusted by appropriate means to be optimal for the relevant operating conditions. It is possible to obtain a damping coefficient and realize stable rotation of the shaft.

(6) Modifications and Application Examples of the Invention As a circumferential length changing power device, as shown in FIG. 2, instead of using rotational power, an elastic member such as a piezoelectric element 13 may be used, and several thin plates may be used around the bearing. One configured with members for the purpose of damping such as stacked laminated dampers 12, one configured with a plurality of peripheral length variable power devices with variable circumference bearing support (not shown), and one configured with a plurality of peripheral length variable bearing supports, and The same effect can be obtained even if the circumferential length of the variable bearing support does not change continuously but changes in one step or in multiple steps.

(7) Effects of the Invention As described above, according to the present invention, in a bearing device that supports a shaft by forming a layer of viscous material such as lubricant or water around the bearing, the thickness of the layer of viscous material Since it is possible to arbitrarily change the damping coefficient, it is possible to realize a bearing device that can achieve an optimum vibration state even at high speed rotation and extend the life of the bearing.

[Brief explanation of drawings]

FIG. 1 is a front view showing an embodiment of a bearing device according to the present invention. FIG. 2 is a front view showing a modification of the bearing device according to the present invention. In the figure, 1 is a shaft, 2 is a bearing, 3 is a variable circumference bearing support, 4 is a layer made of viscous material, 5 is a support base,
6 is an engaging part, 7 is an engaging part, 8 is a circumferential length changing power device, 9 is a circumferential length changing power transmission shaft, 10 is a rotation measuring device, lla, ll
b is a stop portion.

Claims (1)

[Claims] 1. A bearing device that supports a rotating shaft by forming a layer of viscous material around the bearing, characterized in that it is equipped with means for changing the thickness of the layer of viscous material. A bearing device for a rotating shaft. 2. The rotating shaft bearing device according to claim 1, comprising a laminated damper in which thin plates are stacked on the outside of the bearing.