JPH04165118A - Damper bearing - Google Patents

Abstract

PURPOSE:To actively control vibration through nonlubricated simple structure by giving vibration to a spring to support a bearing, severally sticking piezo-elec tric ceramics plates to both the sides of the spring to form electrodes on the surfaces of the above plate, and connecting the electrodes to a resistance to form a circuit for converting the vibration into electricity. CONSTITUTION:A plate spring 3 is given vibration through a bearing 2 to support a rotary shaft 1, and piezo-electric ceramics plates 5 are severally stuck to both the faces of a square section-shaped rib 4 composing the spring 3. An electrode is formed on the surface of the plate 5, and as the one side of the plate 5 elongates, its opposite side contracts to make piezo electric effect generate positive and negative voltages in the electrodes on the plate 5 according to the elongation and contraction of the plate 5. Potential difference therefore occurs between the two electrodes to flow electric current through a resistance 6 connected between the electrodes to generate heat in the resistance 6. Thus vibrational energy is converted into electrical energy and then thermal energy to generate damping effect for producing a nonlubricated damper bearing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a damper bearing that supports a rotating shaft and has a high damping effect.

[Conventional technology]

Conventionally, many damper bearings use an oil film to utilize the damping effect due to the squeeze effect. It consists of a bearing, a narrow gap for forming an oil film, and a centering spring that returns the bearing to the center of the gap when it vibrates. The magnitude of this attenuation is largely influenced by the viscosity of the oil and the shape of the narrow gap. Generally, the narrow gap is provided at the outer periphery of the bearing, which increases the external size of the bearing. Furthermore, in order to form an oil film, it is necessary to supply oil, and a seal is also required to prevent this oil from leaking to the outside of the bearing. As a result, the outer shape of the bearing becomes even larger. Note that related bearings of this type include, for example.

The specification of Japanese Patent Application No. 56-6412 is mentioned.

[Problem to be solved by the invention]

Since the above-mentioned conventional technology uses an oil film, it is necessary to take oil into consideration, and due to its structure, there is a problem in that the external size of the bearing becomes large. Also, the magnitude of the damping effect is 1,
It is greatly affected by the viscosity of the oil and the shape of the narrow gap. Therefore, in order to obtain the maximum damping effect, it is necessary to control the viscosity of the oil, the size of the gap, etc., which is complicated.

Further, this damping effect is passive and vibration cannot be actively suppressed.

An object of the present invention is to provide a compact damper bearing that does not use oil.

[Means to solve the problem]

] - In order to achieve this effect, the present invention converts vibration energy into electrical energy using a piezoelectric ceramic plate instead of the damping effect due to the squeeze effect using an oil film.
Furthermore, it was configured to use a resistor to convert heat energy for consumption.

In addition, by applying a voltage to the piezoelectric ceramic, a bend in phase opposite to the bend occurring in the piezoelectric ceramic plate is generated, thereby suppressing vibration.

[Effect]

Vibrations are applied to the springs that support the co-rotating shafts via bearings that support them. This spring has a square cross-section, and piezoelectric ceramic plates are attached to both the front and back sides of the spring. Additionally, electrodes are formed on the surface of each plate, and the plates are connected to resistors to form a circuit.

When the spring bends due to vibration, the piezoelectric ceramic on its surface expands in the in-plane direction on one side and contracts in the in-plane direction on the other side. As a result, due to the piezoelectric effect of piezoelectric ceramics, a voltage is generated in the electrodes of this plate depending on the magnitude of expansion and contraction. At this time, if a positive voltage is generated at the electrode of the expanded plate, a negative voltage is generated at the electrode of the contracted plate. Therefore, a potential difference occurs between the two electrodes, and current flows through the resistor connected between the electrodes, generating heat.

In addition, by connecting a power source instead of a resistor and applying voltage, a bend is generated in the piezoelectric ceramic plate in the opposite way to the above, and the bending is controlled so that it is in the opposite phase to the bending caused by the vibration of the rotating shaft. Suppress vibration.

〔Example〕

Embodiments of the present invention will be described below with reference to FIG.

Fig. 1 shows a vertical cross-sectional view, and its configuration includes a rotating shaft 1, a bearing 2 that supports it, a spring 3 with a square cross section that supports these from a casing, etc., and a spring 3 that is attached to both the front and back sides of this spring. It consists of a piezoelectric ceramic plate 5 and a resistor 6 connected to an electrode on this plate to form a circuit.

In this figure, the casing and the like are omitted and not shown. Furthermore, the mounting position of the resistor 6 merely indicates its presence.

In this embodiment, a non-lubricated rolling bearing is used as the bearing 2 to achieve an oil-based redamper bearing. Rotating axis 1
Vibrations are transmitted to a squirrel-cage spring 3, which was selected from the viewpoint of good axial symmetry, as a spring that supports this, through a bearing 2 that supports the bearing 2. Electrodes are formed on the surface of a piezoelectric ceramic plate 5 attached to both the front and back surfaces of ribs 4 with a square cross section that constitute this spring, and electrodes are formed on the surface of the piezoelectric ceramic plate 5, which is connected to a resistor 6 to form a circuit. When 4 bends due to vibration, the piezoelectric ceramic plate 5 on its surface expands in the in-plane direction on one side and contracts in the in-plane direction on the other side. As a result, due to the piezoelectric effect of piezoelectric ceramics, a voltage is generated in the electrodes of this plate depending on the magnitude of expansion and contraction. At this time, if a positive voltage is generated at the electrode of the expanded plate, a negative voltage is generated at the electrode of the contracted plate. Therefore, a potential difference occurs between the two electrodes, and current flows through the resistor connected between the electrodes, generating heat. In this way, by converting vibration energy into electrical energy and then into thermal energy, vibration energy is consumed and a damping effect is achieved.

According to this embodiment, an oil-free damper bearing can be achieved, and there is an effect that damping can be applied to the rotating shaft system of equipment that does not like oil.

Moreover, it becomes possible to know the vibration frequency from the fluctuation period of the potential difference.

In the embodiment shown in FIG. 3, an auxiliary electrode for vibration frequency measurement is newly provided, and the output from the auxiliary electrode for vibration frequency measurement is transferred to the phase inverter 7 by a phase inverter 7 and an amplifier 8 in place of the resistor 6. By connecting the electrode to the electrode via the amplifier 8, the vibrations occurring in the first part are actively suppressed. Here, power supplies to the phase inverter and amplifier are omitted.

〔Effect of the invention〕

According to the present invention, an oil-free damper bearing can be provided. As a result, it can be used in equipment that would otherwise be impossible due to the use of oil. Additionally, since no oil is used, the entire bearing structure is simplified.

Unlike the conventional passive method, vibration can be actively suppressed.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of one embodiment of the present invention, and FIG. 2 is an explanatory diagram of the spring portion of FIG. 1. FIG. 3 is an explanatory diagram in which only the different parts from FIG. 1 are drawn in another embodiment of the present invention. 1... Rotating shaft, 2... Bearing, 3... Spring, 4...
・Rib, 5... Piezoelectric or ceramic plate, 6... Resistor, 7... Phase inverter, 8... Amplifier.

Claims (1)

[Claims] 1. In a bearing device that supports a rotating shaft, a spring with a rectangular cross section that supports the bearing, a piezoelectric ceramic plate attached to both the front and back sides of the spring, and an electrode formed on the surface connected to an external resistor to control rotation. A damper bearing characterized in that it has a damper structure and a damper.