JPH036138Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a low-speed rotation motor, and specifically relates to a low-speed rotation motor such as a spindle motor for rotating a compact disk.

(Prior Art) Fig. 1 shows a conventional example of this type of motor, in which 1' is a housing, 2' is a magnet as a stator, 3' is a spindle, 4a' is a bush, and 4b' is a Rotor core, 5 is rotor coil,
6' is a support, 7' is a bearing, 8 is a brush, and 9' is a commutator. However, in this type of motor, in order to reduce iron loss such as eddy current loss, it is common to use a laminated core made by laminating an iron core punched from silicon steel plates or permalloy as the rotor core 4b'. According to the authors, the disadvantage was that it required a lot of man-hours to stack and fix the iron core, and the number of parts was large, resulting in high costs. Furthermore, since the rotor core 4b' is assembled by sequentially stacking a large number of cores on the bush 4a', the cores may not be fixed coaxially around the spindle 3', which may cause vibration or rotation of the motor. This has the drawback of causing unevenness and deteriorating the performance of the motor.

(Purpose of the invention) The present invention was proposed in order to eliminate the above-mentioned drawbacks, and its purpose is mainly for low-speed rotating motors with relatively low iron loss, in which the rotor core is integrally made of a highly permeable material. This reduces the number of man-hours required to assemble the rotor core and, in turn, the rotor, making it easier to manufacture and reducing costs, while also preventing performance degradation such as vibration and rotational unevenness that existed in the past. The aim is to provide motors for

(Structure of the idea) The present invention will be explained below with reference to the drawings.

FIG. 2 shows an embodiment of the present invention. In the figure, 1 is a substantially cylindrical housing, and a magnet 2 serving as a stator is attached to a part of the inner peripheral surface of the housing.
A rotor is disposed inside the magnet 2, facing the magnet 2 with an air gap interposed therebetween. Such a rotor has a substantially bottomed cylindrical rotor core 4 fixed near the end of the spindle 3,
A rotor coil 5 is wound around the outer peripheral surface of a rotor core 4 in a cylindrical shape. Here, the present invention is characterized in that the rotor core 4 is integrally formed of a sintered metal with high magnetic permeability. Therefore, the rotor core 4 is integrally formed as a whole from sintered metal such as iron, permalloy, silicon steel, etc., and is not made of a layered iron core as in the past.

A support 6 is fitted to one end of the housing 1 in the axial direction, and a sleeve 6a protruding from the inner surface of the support 6 is inserted into a gap between the rotor core 4 and the spindle 3. Two bearings 7 are interposed between the two bearings. Note that 8 represents a brush and 9 represents a commutator.

Therefore, the present invention is mainly used in spindle motors for compact disks, generally at 500 [rpm].
This is applied to low-speed rotation motors used at the following rotation speeds.In this type of motor, the rate of change in magnetic flux acting on the rotor core 4 due to low-speed rotation is relatively small, so iron loss such as eddy current loss is also relatively small and can be kept within a practically acceptable range. In particular, if the rotor core 4 is integrally constructed of sintered metal, it is more effective in reducing iron loss.

(Effects of the invention) As described above, according to the invention, in a low-speed rotation motor used within an allowable range for practical iron loss, the rotor core is integrally formed of a highly permeable material. rotor processing,
This has the effect of facilitating assembly work and reducing costs by reducing the number of man-hours and parts. At the same time, by making the rotor core integral, it is possible to strictly ensure the coaxiality of the entire rotor, including the rotor core itself and the spindle after rotor assembly.
It has advantages such as being able to provide a high-performance low-speed rotation motor that is free from vibration and uneven rotation.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional example, and FIG. 2 is a sectional view showing an embodiment of the present invention. 1...Housing, 2...Magnet, 3...
Spindle, 4...Rotor core, 5...Rotor coil, 6...Support, 6a...Sleeve, 7...
...Bearing, 8...Brush, 9...Commutator.

Claims (1)

[Claims for Utility Model Registration] Comprising a rotor coil wound around the outer peripheral surface of a cylindrical rotor core, a stator disposed opposite to the rotor coil via an air gap, and a spindle mounted in the center of the rotor core. What is claimed is: 1. A low-speed rotation motor comprising: a rotor core formed integrally with a sintered metal having high magnetic permeability;