Rotary drivers

Abstract

Working rotational speed LR, at which the plurality of balancing spherical bodies 20d are released outward in the radial direction to make the plurality of balancing spherical bodies 20d perform balancing actions of rotors 137, 139, is set so as to be lower than the resonance rotational speed CR of the rotors 137, 139. As a result, magnetic force working on the respective balancing spherical bodies 20d is lowered to decrease repulsion between the respective balancing spherical bodies 20d, thus concentrating the plurality of balancing spherical bodies 20d on an unbalancing cancellation position to restrain the generation of impact noise while making a balancing spherical body 20d perform a sufficient balancing action.

Description

technical field [0001] The invention relates to a rotary driving device with an automatic balancing mechanism for eliminating the unbalanced rotation of a rotating body. Background technique [0002] It is generally used in various rotary drive devices such as industrial machinery, home appliances, and microcomputers, and an automatic balance device for eliminating the rotational imbalance of the rotating body including the rotating shaft is often used. For this automatic balancing device, there have been various proposals regarding its structure in the past, for example, the device recorded in Japanese Patent Application Laid-Open No. 10-257710 is as Figure 6 As shown, the automatic balancing mechanism A including the hollow annular casing 3 is installed on the output shaft of the motor part 1, that is, the rotating shaft 2, and a plurality of freely movable parts are stored inside the hollow annular casing 3 of the automatic balancing mechanism A Moving balancing spheres ...

AI Technical Summary

Problems solved by technology

[0005] However, as mentioned above, if the magnetic force of the holding magnet 5 is set too strong, then if Figure 7 As shown in (a) and (b), although the retention of the balance spheres 4 is good during low-speed rotation, when these balance spheres 4 move freely for balancing, especially as shown in Figure 7 As shown in (c) and (d), affected by the strong magnetic force of the above-mentioned holding magnet 5, the balance spheres 4 will repel each other

As a result, the above-mentioned plurality of balancing spheres 4 become in a scattered state and cannot be arranged in a concentrated manner where the unbalance should be moved, so that the above-mentioned sufficient balancing effect may not be obtained sometimes.

[0006] In contrast, as Figure 8 As shown in (a) and (b), if there is no above-mentioned holding magnet 5, although the above-mentioned good balancing effect can also be obtained, very strong and frequent conflicts occur between the balance spheres 4 during low-speed rotation, and these balance spheres The conflicting sound between 4 becomes a big noise problem when the device is in use, which makes the user have a bad sense of use

Such noise problems are Figure 7 and Figure 8 Particularly prominent in vertical installations where the axis of rotation shown is horizontal

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