JPH0319766A - Dynamic balancer for rotary unit - Google Patents

Abstract

PURPOSE:To enable a balance weight to be moved, even while a rotary unit is in rotation, by providing a plurality of permanent magnets and the balance weight in a rotary ring and arranging a plurality of electromagnets in a position opposed to a permanent magnet in a fixed ring. CONSTITUTION:In the case of rotation-moving a balance weight 16a by 22.5 deg. in the counterclockwise direction, first an excitation current is supplied to electromagnets 17a3, 17a4 through a slip ring. In this way, magnetic force is generated in the electromagnets 17a3, 17a4, but the polarity of this magnetic force is selected in a direction that attractive force acts between the electromagnets and permanent magnets 15a1 to 15a4. Accordingly, each of permanent magnets 15a1 to 15a4 is attracted to each of electromagnets 17a3, 17a4 and moved to an intermediate position of these electromagnets 17a3, 17a4. That is, a rotary ring is rotated by 22.5 deg. in the counterclockwise direction, and also the balance weight 16a is moved by 22.5 deg. in the counterclockwise direction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a dynamic suspension for a rotating body for correcting unbalance during rotation of the rotating body.

[Conventional technology]

For example, it is well known that in grinding work, if the spindle to which the grinding wheel (hereinafter referred to as the grindstone) is attached is well balanced during rotation, the surface roughness of the machined surface can be improved. Therefore, grinding machines are made to have rigidity so that they do not vibrate not only when the main shaft rotates alone, but also when the grindstone is attached. However, whetstones, which are consumable items, are generally not well-balanced, so
The spindle to which the grindstone is attached generates minute vibrations during rotation, making it impossible to improve the surface roughness of the machined surface.

For this reason, a balancer is used to precisely adjust the balance during rotation of the main shaft to which the grindstone is attached.

Such balancers have a method of rotating a grinding wheel to measure the amount of unbalance, then stopping the rotation of the grinding wheel and moving a balance weight, but this method requires time to rotate and stop the grinding wheel. There was a problem. Therefore, in recent years, means have been proposed that allow the balance weight to be moved even while the grindstone is rotating. This means provides a drive source within the balancer body that rotates integrally with the grindstone,
The power is transmitted to the balance weight to move it.

[Problem to be solved by the invention]

By the way, the above-mentioned means for moving the Haranth weight even while the grindstone is rotating is equipped with a drive source, a power transmission mechanism such as a feed screw and gears in the balancer body, so the structure becomes a multi-H structure, and There was a problem that there were many rotating mechanisms and there was a risk of failure.

The purpose of the present invention is to solve the problems of the above-mentioned conventional techniques, to provide a dynamic balancer for a rotating body that can move the balance weight even while the rotating body is rotating, has a simple structure, and is less prone to failure. It is on offer.

[Means to solve the problem]

In order to achieve the second object, the present invention provides a dynamic balancer for a rotating body, which is equipped with a rotatable balance weight within a suspension body that is attached to a rotating shaft and rotates integrally with the suspension body. an attached rotating ring, permanent magnets attached to the rotating ring at predetermined angular intervals, a fixed ring located outside the rotating ring and fixed to the balancer body, and each of the permanent magnets of the fixed ring. The present invention is characterized by the provision of a plurality of electromagnets mounted at opposing positions and current supply means for selectively supplying excitation current to these electromagnets.

[Effect]

When the excitation current is supplied to a specific electromagnet via the current supply means while the halancer main body is rotating, the specific electromagnet is excited. This generates an attractive force against the adjacent permanent magnet, which attracts the permanent magnet and causes the rotating ring to rotate. As the rotary ring rotates, the harness weight attached to it is also moved by the same angle as the rotation angle of the rotary ring.

〔Example〕

Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 is a sectional view of a dynamic balancer for a rotating body according to an embodiment of the present invention, and FIG. 2 is a layout diagram of permanent magnets and electromagnets shown in FIG. 1. In each figure, ■ indicates the main body of the dynamic balancer. Reference numeral 2 denotes a bolt for fixing the main body 1 to, for example, a flange (not shown) of a grindstone. As a result, when the grindstone shaft is rotated, the grindstone, flange, and main body 1 rotate as one. The structure of the main body 1 will be explained below. 3 is a case, 4 is a fixing ring made of an insulating member, and 5 is a fixing ring provided in contact with the outer peripheral surface of the fixing ring 4, also made of an insulating member. Each fixing ring 4, 5 is fixed to the case 3 with bolts 6, 7, respectively. 8 indicates the lid;
It is attached to the fixing ring 5 by bolts 9. lQa
, 10b are ball bearings whose inner rings are fixed to the shaft portion of the case 3 with a predetermined distance maintained by spacers Ila and Ilb. 12a and 12b are rotating rings, and ball bearings lQa and 10, respectively.
It is fixed to the outer ring of b. As a result, rotating ring 1
2a and 12b can freely rotate relative to the case 3.

1.5a+ to 15at+ 15b+ to 15b4 are permanent magnets, which are attached to the rotating rings 12a. 12b. 16a and 16b are rotating rings 12a and 12, respectively.
The balance weight is shown mounted in place in b. 17
A1 to 17a4 are electromagnets fixed to the fixed ring 4 with bolts 18, respectively. The electromagnet 17a1 consists of four electromagnets arranged at 90 degree intervals as shown in FIG. Similarly, electromagnets 17az, 17a3. 17a4 also consists of four electromagnets arranged at 90 degree intervals. Therefore, the electromagnet group attached to the fixed ring 4 consists of 16 electromagnets arranged at intervals of 22.5 degrees. Although not shown, another electromagnet group 17
b+-I7b. has the same structure as the electromagnet groups 17al to 17an, and is provided offset in the axial direction with respect to these as shown in FIG. A permanent magnet 19 is placed between adjacent electromagnets and is attached to the fixed ring 4. The polarity of the surface side of one permanent magnet is determined by the rotation ring 12a. Permanent magnet 15a+ attached to 12b ~
15at, 15b. The polarity is such that an attractive force acts between the permanent magnets 15 and 15b4, and the magnetic force of the permanent magnet 19 is selected to be smaller than the magnetic force when the electromagnet is excited.

20a+~20a4, 20e. 20b+~20bn
For example, slip rings are arranged and fixed on the outer peripheral surface of the fixed ring 5, respectively, and 21 is a brush that comes into sliding contact with each slip ring. Each brush 21 is fixed to a non-rotating part (not shown), for example, a spindle head of a grinding machine. Slip ring 20a
+ is connected to four electromagnets 1.7a via fixed rings 5 and 4. Similarly, slip ring 20a 2-2
0a4 are connected to electromagnets 17a2 to 17+i, respectively, and slip rings 20b and 20b4 are connected to electromagnets 17b+ to 17b4, which are not shown, respectively. In addition, the slip ring 20E connects each electromagnet 11a+ to I
1aa. This is a grounding slip ring common to 17b to 17b4.

Next, the operation of this embodiment will be explained. First, the main body 1 of the dynamic balancer is attached to the rotating body, and the rotating body is rotated.
Measure vibration. Through this measurement, Haransway I-
16a. It becomes clear how far to move 16b in the circumferential direction from its current position (this position is known).

Note that during the above rotation, no current is supplied to each electromagnet, and each of the permanent magnets 15a+ to 15a4 . , 15b+ to 15b4 are located in positions facing the permanent magnets 19 of the fixed ring 4, thereby exerting an attractive force on each other to prevent rotation of the rotating rings 12a, 12b.

Next, referring to FIG. 2, a description will be given of the operation when rotating the balance way eye 6a by 22.5 degrees counterclockwise. First, slip ring 20as, 20
Excitation current is supplied to the electromagnets 17az and 17a4 via a4. This causes electromagnet 17a. , 17a4, but this magnetic force is caused by the permanent magnets 15a, ~15
The polarity is selected in the direction in which an attractive force is exerted between it and a4. Therefore, each permanent magnet 15a . -15a4 are each electromagnet 17a3. These electromagnets 1 are attracted by 17a4
Move to the intermediate position between 7a3 and 17a4. That is, the rotating ring 12a has rotated 6 times 22.5 degrees counterclockwise, and the balance weight 16a has also moved 22.5 degrees counterclockwise.

If the current of each electromagnet is cut off in this state, each permanent magnet 1
5a1 to 15a4 are attracted to the opposing permanent magnets 19,
The rotating ring 12a is prevented from rotating, and the balance weight l. 6a is held stopped at that position.

To move the balance ways 1 to 16a further counterclockwise from this position, electromagnets 17at. 17a, and to move the electromagnets 17a3.17a clockwise. 17az should be excited. In addition, the movement of the balance weight 16b is
This is done in exactly the same way as the movement of a.

In this way, in this embodiment, a permanent magnet and a balance weight are attached to the rotating ring, and an electromagnet is provided in the fixed ring opposite to these permanent magnets, and the rotating ring can be rotated by an arbitrary angle by selectively energizing the electromagnet. Since the balance weight is moved, the balance weight can be moved even while the rotating body is rotating, and the configuration can be simplified. Furthermore, since there are fewer moving parts, the occurrence of failures can be reduced. Furthermore, since a permanent magnet is attached to the fixed ring, the balance way 1 can be maintained in a stopped state in cooperation with the permanent magnet of the rotating ring.

In addition, in the explanation of the above embodiment, an example was explained in which 4 permanent magnets are provided in the rotating ring and 16 electromagnets are provided in the stationary ring, but these numbers can be determined arbitrarily, and if the number is increased, , it is clear that finer adjustment of the haranth weight can be made. Further, the permanent magnet provided in the fixed ring can be inserted into each electromagnet, and in that case, the eight lance weights can be moved by simply energizing one adjacent electromagnet. Furthermore, if means for constantly energizing the required electromagnets to hold the eight run weights is adopted, the permanent magnets provided in the fixed ring can be omitted.

〔Effect of the invention〕

As described above, in the present invention, the rotating ring is provided with a plurality of permanent magnets and a balance weight, and the fixed ring is provided with a plurality of electromagnets at positions facing the permanent magnets, so that even when the rotating body is rotating, The balance weight can be moved, the structure is simple, and there are few moving parts, so the occurrence of breakdowns can be reduced.

[Brief explanation of drawings]

9 10 FIG. 1 is a sectional view of a dynamic balancer according to an embodiment of the present invention,
FIG. 2 is a layout diagram of the permanent magnets and electromagnets shown in FIG. 1. 1... Main body, 3... Case, 4, 5.
...Fixed ring, 10a, 10b...Ball hair ring, 12a12b...Rotating ring, 15a+~15aa, 15b+~15b4, 19...
...Permanent magnet, 16a, 16b...Balance weight, 17a+~17at----+electromagnet,
20a1-20b4. , 20E-...Slip ring, 21...Brush. 1 1

Claims (1)

[Claims] A dynamic balancer for a rotating body, which is equipped with a rotatable balance weight within a balancer body that is attached to a rotating shaft and rotates integrally with the rotating shaft, includes a rotating ring to which the balance weight is attached, and a rotating ring that is attached to the rotating ring at predetermined angular intervals. a fixed ring located outside the rotating ring and fixed to the balancer body; a plurality of electromagnets mounted on the fixed ring at positions facing each of the permanent magnets; A dynamic balancer for a rotating body, characterized in that it is provided with a current supply means for supplying an excitation current.