SU1719099A1 - Vibration exciter - Google Patents

Abstract

The invention relates to a vibration technique. The purpose of the invention is to increase the efficiency - achieved by performing the unbalance in the form of a hollow cylinder with a load in the form of a fraction. 2 Il.

Description

The invention relates to a vibration technique and can be used to drive vibrations in vibratory machines, for example, in conveyors, feeders, screens, sieves, etc.

An inertial vibrator is known, consisting of a body, body shields in which a rotating shaft is mounted on bearings, on the slots of which are mounted cones covered by imbalance. To ensure that the cones move along the shaft, the vibrator is equipped with a screw with a steering wheel rotating in a nut fixed to the housing. The screw is connected to the thrust and movable wedges, made with the longitudinal grooves for the shaft, interacting with the pressure wedges and the bearing. Between the cones is a spring.

A vibration exciter is known, comprising a housing, a drive shaft and an annular body planted on it with an offset center of gravity about its axis. The ring-shaped body is made of an elastic material that deforms under the action of centrifugal forces. In one side of the ring-shaped body is placed fraction.

However, these exciters are ineffective, as the aging of the elastic material and the constant effect of centrifugal forces emit fraction from the ring-shaped body, which leads to a decrease in the amplitude of oscillations and an increase in the time of activation of the exciter.

Also known is an exciter comprising a drive shaft on which a hollow body, partially filled with liquid, with a float located in it is fixed. The volume of the float is equal to the volume of the unfilled liquid part of the hull. The body is spherical; the float is hollow and partially filled with liquid. Load 6 is placed in the float. The fluid viscosity in the float is lower than the fluid viscosity in the housing.

However, the prototype is characterized by low efficiency, due to the duration of the launch, since at the initial moment the body begins to roar, and the liquid and the float placed in it remain at rest. Due to the frictional forces between the fluid and the inner surface of the body

with

about

3

h

As the fluid begins to spin. Since the inner surface of the housing 3 does not have blades, the process proceeds slowly. The slowdown of the process is also due to the inhibition of the liquid 2 by the float 4, which remains stationary in the initial period. The synchronous velocity of the fluid and the body occurs in 15-18 seconds. When the fluid acquires the speed of rotation of the body, the float begins to move with acceleration. This takes a few more seconds. Thus, the output to the operating mode is 20 seconds or more. This is unacceptable when using such a vibration exciter in a feeder for loading, for example, mine cars, since the car loading process itself lasts about a minute. When the car is rearranged, the vibrating feeder is turned off, i.e., about 20% of the working time is spent on switching off and on the vibration exciter.

The complexity of the design and increased dimensions also reduce the efficiency of the vibration exciter. The complexity of the design due to the presence of liquids placed in housings. The presence of liquids requires increased enclosure sealing. In addition, the complexity lies in the technology of manufacture. First, you need to make a hole in the float, put the load and liquid in it, seal the hole tightly (to prevent leakage of liquid and mixing it with liquid), and then put the assembled float through the hole and pour the liquid into the body. After that, tightly close the hole in the case. Because of the spherical surface and large holes, this is difficult to do. The size of the hole is governed by the size of the load and float.

In addition, the holes must be through, otherwise the lid will serve as an additional unbalance and the launch of the vibration exciter into operation will occur when there is a static moment on the motor shaft. With one hole, balance can be achieved by welding the cover. But welding does not work well with vibration. Cracks appear at the weld sites, depressurization occurs, and liquids are mixed. In the float and the casing, two caps are needed, which, in spherical shapes, require careful adjustment, it becomes necessary to use sealing gaskets. All this complicates the design, increases the cost of the product, and consequently, reduces efficiency. The disturbing force depends on the angular velocity and

kinetostaticheskogo moment. The latter depends on the mass of the unbalance and its distance from the axis of rotation. As the weight of the load increases, the size of the float will increase, and

therefore, the dimensions of the case. Increasing the unbalance distance from the axis of rotation also leads to an increase in size.

The purpose of the invention is to increase efficiency.

0 The goal is achieved by the fact that in a known vibration exciter containing a drive shaft, a hollow body fixed on it and the unbalance placed inside it with a load inside, the unbalance is performed in

5 as a hollow cylinder with a load in the form of a shot and distance rings covering it, the outer surface of which is spherical.

When applying the invention, the time of the output of the exciter on the operating mode is reduced, since it is limited by the time of the complete set of revolutions by the electric motor, i.e. the start-up is 4-5 times faster. This is achieved by the fact that

5, the imbalance with the load inside in the form of a fraction is carried away by the body immediately as soon as the electric motor picks up full revolutions. This is facilitated by distance rings with a spherical outer surface,

0 that cover unbalance.

The absence of liquids in the proposed design reduces the time for unwinding them (liquids) and moving the unbalance to the inner wall of the body, not

5 requires a sealing system, simplifies the design, reduces the size and cost, and generally improves the efficiency of the vibration exciter.

FIG. 1 shows the vibration exciter;

0 in FIG. 2 shows section A-A in FIG. one.

The vibration exciter comprises a drive shaft 1 with a hollow body 2 fixed on it. In the body 2, the unbalance 3 is placed. The unbalance 3 is made in the form of a hollow cylinder 4 in which the weight 5 is placed in the form of a fraction. Cylinder 4 covers distance rings b, the outer surface of which is spherical. At the same time, according to experimental data, the dimensions, for example, may be as follows. The outer diameter of the ring 6 (Fig. 2) is Lk - 3/4 of the inner diameter of the housing 2, the thickness of the ring is not more than 1/10 of the diameter of the cylinder 4. The fraction fills the cylinder by 65-70%.

5 The vibration exciter operates as follows .... A motor (not shown) is turned on, which transmits the torque Va: 1 and the casing 2 fixed on it. Pr1 /; unwinding the case 2 unbalance 3 in

in the form of a cylinder 4 with a weight 5 placed in it in the form of a fraction remains at rest until the electric motor and, therefore, the shaft 1 and the housing 2 gain the full speed of rotation. This is facilitated by distance rings, which have a point contact with the inner surface of the housing 2, which reduces the resistance forces at start-up, i.e., the activation of the vibration exciter occurs almost at idle speed in the absence of a static moment on the housing-shaft. With a full set of revolutions, unbalance 3 is carried away by the housing 2 and, rotating with it, creates an imbalance of the system, i.e., leads to amplitude oscillations. When you turn off the motor deba0

five

Lance 3 for some time (1-2 seconds) continues to move together with housing 2, then sinks to the lower position and slips along the inner surface of the housing until the system is completely stopped. When the motor starts, the cycle repeats.

Claims (1)

Vibro-exciter comprising a drive shaft, a hollow body fixed on it and an imbalance placed inside it with a load inside, so that, in order to increase efficiency, the balance is made in the form of a hollow cylinder with a load in the form of a fraction and of distance rings covering it, whose outer surface is spherical. / / 4 Fie.2 Compiled by I. Proskurin Tehred M. Morgental  J 5 // / s / sis s / / u / s s if / /.  I g /: FIG. one Proofreader T. Paly