JPH03292435A - Torsional damper - Google Patents

Abstract

PURPOSE:To maintain constant viscosity even under a high temperature to suppress increase of vibration and to elongate a lifetime of an elastic body such as rubber and charged fluid by controlling viscosity of viscous fluid charged between a plate fixed to a rotation shaft and an inertial ring. CONSTITUTION:An inertial ring 4 is fitted via an elastic body 3 to a plate 2 fixed to a rotation shaft 1, and ER fluid 5 as viscous fluid is charged. An insulating body 6 is interposed between the elastic body 3 and the inertial ring 4. Since the plate 2 and the inertial ring 4 rotate together with the rotation shaft 1, when those are adopted as electrodes, stationary plug members 7, 8 being in contact with those rotary bodies respectively are provided, and the plug members 7, 8 are connected to a control circuit 9, which is connected to a power source 10. Viscosity of the ER fluid 5 is controlled by applying a specified voltage to the ER fluid 5 from the power source 10. With this constitution, constant viscosity can be maintained even under a high temperature, and consequently increase of vibration can be suppressed to elongate a lifetime of an elastic body and vicous fluid.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention provides an inertia ring that is attached to a plate fixed to a rotating shaft such as an engine crankshaft, a vehicle drive shaft, or a propeller shaft through an elastic body. This invention relates to a torsional damper that reduces torsional vibration of a rotating shaft by sealing a viscous fluid into the gap formed between these three parts.

[Conventional technology]

As shown in FIG. 2, a conventional torsional damper filled with fluid is formed between a plate 2 fixed to a rotating shaft 1 and an inertia ring 4 attached via an elastic body 3. A device in which a viscous fluid 100 is sealed in the gap is known. As the viscous fluid to be sealed, silicone oil of about several hundred thousand cSt is used.

[Problem to be solved]

Since the viscosity of conventionally used silicone oils has a large temperature dependence, the viscosity decreases significantly due to thermal effects such as the ambient temperature during use and self-heating of the rubber and silicone oil. If the viscosity decreases significantly, the damping force will decrease and torsional vibration will increase. As the torsional vibration increases, the self-heating of the comb and silicone oil also increases. In this way, a vicious cycle of repeated increases in vibration and heat generation results in a shortened lifespan of the rubber and silicone oil.

Therefore, this invention aims to maintain a constant viscosity even at high temperatures by controlling the viscosity of the viscous fluid that is sealed in it, suppressing the increase in vibration, and prolonging the life of the elastic body such as rubber and the sealed fluid. The purpose is to provide a functional damper.

[Means to solve the problem]

In order to achieve the above object, the present invention uses a fluid whose viscosity can be controlled, such as an ER fluid, as the viscous fluid.

[Effect]

In this invention, when an ER fluid is used as the viscous fluid to be sealed, it is possible to control the viscosity of the sealed ER fluid by applying a voltage to the sealed ER fluid using the plate and the inertia ring as electrodes. Alternatively, it is also possible to enclose a magnetic fluid and control the viscosity of this fluid using magnetic force.

〔Example〕

A preferred embodiment of the present invention will be described below with reference to FIG.

Rotating shaft 1. Plate 21 elastic body 3. The inertia ring 4 has the same structure as the conventional one. ER fluid 5 was sealed as the viscous fluid. Further, an insulator 6 was interposed between the elastic body 3 and the inertia ring 4. Since the plate 2 and the inertia ring 4 rotate together with the rotating shaft 1, when these are used as electrodes,
Stationary plug members 7, 8 are provided in contact with each of the rotating parts, and these plug members 7, 8 are connected to a control circuit 9, which in turn is connected to the power supply 1[). By applying a predetermined voltage to the ER fluid 5 from the power source 10, the viscosity of the ER fluid 5 is controlled.

Note that a sensor (not shown) for sensing the viscosity of the ER fluid 5 is provided, and information from this sensor is detected by the control circuit 9 to control the voltage. As the rotating shaft 1 rotates, the temperature of the ER fluid 5 increases and the viscosity decreases, and by applying a voltage, the viscosity of the ER fluid 5 increases.

In the embodiment shown in FIG. 1, the ER fluid 5 is enclosed as a viscous fluid, but the viscosity may be controlled by magnetic force, such as a magnetic fluid.

〔effect〕

As explained above, according to the present invention, a fluid whose viscosity can be controlled, such as ER fluid, is used as the viscous fluid, so by controlling the viscosity of the enclosed viscous fluid, it is possible to maintain a constant viscosity even at high temperatures. As a result, it becomes possible to suppress the increase in vibration and extend the life of the elastic body and viscous fluid. Furthermore, it becomes possible to easily change various characteristics with the same shape, and it is expected that the development period will be shortened due to common parts.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a preferred embodiment of the present invention, and FIG. 2 is a sectional view showing a conventional example. DESCRIPTION OF SYMBOLS 1... Rotating shaft, 2... Plate, 3... Elastic body, 4... Inertia ring, 5... ER fluid.

Claims (1)

[Claims] 1. In a torsional damper in which an inertia ring is attached to a plate fixed to a rotating shaft via an elastic body, and a viscous fluid is sealed in a gap formed between these three members, ER as the viscous fluid. A torsional damper characterized by using a fluid whose viscosity can be controlled, such as fluid.