TW202123579A - Permanent magnet type spindle motor - Google Patents

Abstract

According to the permanent magnet type spindle motor provided by the invention, a plurality of magnetic groups located in the rotor have a specific space type, so that the magnetic flux is concentrated to achieve the effect of improving the rotating speed, each magnetic group is provided with a first magnet, and the diameter of a tubular rotating shaft of the rotor is mirrored and positioned in the rotating shaft in a mirror shooting axis, and the two holes are formed in the rotating shaft in a penetrating manner, and the two holes are formed in the rotating shaft in a penetrating manner, the rotating shaft is located at the position between the outer ring surface of the rotating shaft and each of the first magnets, respectively, and axially extending through the axial ends of the rotating shaft along the axial direction of the axis of the lens, respectively, close to each of the first magnets.

Description

Permanent magnet spindle motor

The present invention relates to motors, and particularly relates to a permanent magnet spindle motor.

In order to obtain good machining accuracy, it can be applied to the spindle of the machine tool, that is, it needs to have high rotation accuracy, high speed, wide working speed range, high rigidity, low temperature and high reliability, which will affect the spindle Although the factors that have the above characteristics are not single, it is undeniable that the spindle motor, which is the source of the spindle rotation power, certainly has an important position.

Compared with induction motors, permanent magnet motors have a wider speed range (constant power speed ratio, CPSR), better efficiency, and high output torque at low speeds, making the driven spindle more suitable for The machine tool performs high-speed and precise processing, but the torque characteristics of the motor have a great influence on the state of the spindle rotation. For example, the size of the ripple affects the machining tool mark of the machine tool, and the torque affects the degree of whether the machine tool performs heavy cutting , The size of the speed affects the processing efficiency of the machine tool, etc., and the difference caused by the difference in the output characteristics of the motor will be highlighted in the machine tool industry, and it will seriously affect the characteristics of the spindle rotation, even if there are only some differences between the different motors. There are many differences, but in the application of machine tools, some differences will cause major differences.

Therefore, the main purpose of the present invention is to provide a permanent magnet spindle motor that can increase the speed range to increase the working efficiency of the machine tool.

The reason is that, in order to achieve the above-mentioned object, the permanent magnet spindle motor provided by the present invention makes most of the magnetic groups located in the rotor have a specific spatial pattern, so that the magnetic flux is concentrated to achieve the effect of increasing the speed. Among them, each The magnetic assembly has two first magnets respectively, which are mirrored with each other with the diameter of a tubular rotating shaft of the rotor as the mirror axis, and are separately arranged in the rotating shaft. Two magnetic barrier spaces in the shape of holes are penetrated through the rotating shaft. And are respectively located on the part of the rotating shaft between the outer ring surface of the rotating shaft and each of the first magnets, and respectively close to each of the first magnets and extending along the axial direction of the rotating shaft at the farthest distance from the mirror axis Passes through the two axial ends of the rotating shaft.

In each of the magnetic groups, each of the first magnets is elongated in cross section along the radial direction of the rotating shaft, and the long axis and the mirror axis are separated by an acute angle in the direction toward the center of the rotating shaft .

Wherein, each of the magnetic groups further includes a second magnet, which is buried in the rotating shaft between the first magnets.

In each of the magnetic groups, the center of the second magnet corresponds to the mirror axis, and the length is smaller than that of each of the first magnets.

Among them, the ratio of the inner diameter to the outer diameter of the rotating shaft is 0.6:1 to 0.8:1, so that the spindle motor can drive a large-diameter machine tool spindle.

First, referring to Figures 1 to 3, the permanent magnet spindle motor (10) provided in a preferred embodiment of the present invention mainly includes a stator (20) and a rotor (30). ) And most of the magnetic assembly (40).

The stator (20) has a ring-shaped stator body (21), and most of the stator slots (22) are radially recessed on the inner ring surface of the stator body (21) to serve as The space for accommodating the coil winding, in which the coil winding is preferably distributed winding.

The rotor (30) has a rotating shaft (31) and accommodating spaces (32) of the same number as the number of magnetic groups. The rotating shaft (31) is in a straight tube shape, and the inner diameter is 0.6 to 0.8 times the outer diameter, so that the thickness of the tube wall is smaller than the radius of the tube hole. Each accommodating space (32) is in the shape of a single hole, and is arranged along the circumference of the rotating shaft (31), and spaced in sequence and equidistant from each other in a straight line across the two axial directions of the rotating shaft (31). Between the ends, and in the radial direction corresponding to the rotating shaft (31), it presents a bent strip shape.

Each of the magnetic groups (40) has two first magnets (41), a second magnet (42), and two magnetic barrier spaces (43), which make each of the first magnet (41) and the second magnet The magnet (42) is stuffed in the corresponding accommodating space (32), and is buried in the rotating shaft (31). More specifically, in each of the magnetic groups (40), the first magnets (41) are embedded in the mirror mirror each other with the diameter of the rotating shaft (31) as the mirror axis (L1). In the rotating shaft (31), the nearest end (411) of each of the first magnets (41) close to the mirror axis (L1) is separated from each other; the second magnet (42) is located between each of the The first magnets (41) are intermittently embedded in the rotating shaft (31), and the center position of the second magnet (42) is located on the mirror axis (L1); and each of the first magnets (41) ) Corresponds to the long axis (L2) of the elongated shape of the radial section of the rotating shaft (31), and further in the direction toward the center of the rotating shaft (31), separated from the mirror axis (L1) by an acute angle ( α), and make the long axis (L3) of the second magnet (42) corresponding to the elongated shape of the radial section of the rotating shaft (31) perpendicular to the mirror axis (L1), and make the second magnet The length of (42) is less than the length of each of the first magnets (41); each of the magnetic barrier spaces (43) is in the shape of holes, and each of them penetrates the shaft (31) in the axial direction of the shaft (31). Between the two ends in the axial direction, and are respectively close to the farthest end (412) of each of the first magnets (41) away from the mirror axis (L1) in the long axis direction, and are located at the adjacent first magnets (41) and Between the outer circumferential ring surfaces of the rotating shaft (31).

In the above-mentioned component, the rotor (30) extends through the stator (20), and because the outer diameter of the shaft (31) is smaller than the inner diameter of the stator body (21), the rotor (30) is ringed on the outer side of the shaft (31) A ring-shaped air gap space is formed between the surface and the inner ring surface of the stator body (21). At the same time, in the example of this embodiment, the angle range where each magnetic group (40) is located is further The corresponding number of stator slots is 6, even if the number of each stator slot (22) is 6 times the number of the magnetic groups (40), the disclosure of this value is only for illustrative purposes and not as the present invention The limitations, such as changing the above 6 times to 6 times to 10 times, etc., are only simple changes to the present invention.

From the perspective of efficiency, one of the main technical features of the permanent magnet spindle motor (10) is the effect provided by the magnetic barrier spaces (43) on the concentration of magnetic flux. For this reason, please refer to the permanent magnet spindle motor (10) shown in Figure 4A. The magnetic field diagram of the magnetic spindle motor (10) and the magnetic field diagram of the spindle motor for comparison without magnetic barrier space shown in Fig. 4B. From the difference shown in the magnetic field lines, it can be seen that the permanent magnet spindle motor (10) has a concentrated The effect of magnetic flux can provide higher torque and higher speed to meet the needs of the spindle. Moreover, the circle diagram in Figure 5 also shows the permanent magnet spindle motor (10) The working speed range (C1) is also larger than that of the comparison spindle motor (C2) as shown in Figure 4B. It is obvious that the permanent magnet spindle motor disclosed in this case does have improved torque and high-speed applications. The specific effect is in line with the requirements of the main shaft of the machine tool, so that the technology provided by the present invention is particularly suitable for use as a main shaft motor.

In addition, what needs to be explained is that although the magnetic assembly of the foregoing embodiment includes a second magnet in addition to the first magnet, in industrial applications, the second magnet can be omitted. When the magnetic assembly does not have a second magnet, there is no significant difference in the effect that can be achieved with the previous disclosure. However, when the magnetic assembly does not have a second magnet, in order to effectively utilize the limited volume of the shaft, the mutual mirroring can be shortened. The distance between the closest ends of the two first magnets.

(10): Permanent magnet spindle motor (20): Stator (21): Stator body (22): Stator slot (30): Rotor (31): Hinge (32): accommodation space (40): Magnetic group (41): The first magnet (411): Nearest (412): far end (42): The second magnet (43): Magnetic Barrier Space (L1): Mirror axis (L2): The long axis of the first magnet (L3): The long axis of the second magnet (α): The angle between the long axis of the first magnet and the mirror axis (C1): Rotation speed range of this embodiment (C2): Speed range of the control group

Figure 1 is a schematic plan view of a preferred embodiment of the present invention. Figure 2 is a perspective view of the magnet assembly and the rotor in a preferred embodiment of the present invention. Fig. 3 is a partial cross-sectional view taken along the line 3-3 in Fig. 2 in a preferred embodiment of the present invention. Fig. 4A is a diagram of magnetic field lines of a permanent magnet motor for comparison. Fig. 4B is a diagram of magnetic field lines of a comparatively expensive embodiment of the present invention. Fig. 5 is a circle diagram of the present invention and the comparative permanent magnet motor.

(31): Hinge

(32): accommodation space

(41): The first magnet

(411): Nearest

(412): far end

(42): The second magnet

(43): Magnetic Barrier Space

(L1): Mirror axis

(L2): The long axis of the first magnet

(L3): The long axis of the second magnet

(α): The angle between the long axis of the first magnet and the mirror axis

Claims (10)

A permanent magnet spindle motor, including: The stator has a ring-shaped stator body, and most of the stator slots are separately arranged on the inner ring surface of the stator body; A rotor with a tubular rotating shaft coaxially extending through the stator body and making the inner diameter of the rotating shaft larger than half of the outer diameter of the rotating shaft; The majority of the magnetic groups, which are smaller in number than the slots, are arranged in the rotating shaft in sequence along the circumference of the rotating shaft, and each has two first magnets with elongated cross-sections along the radial direction of the rotating shaft. A magnet is embedded in the rotating shaft symmetrically with the diameter of the rotating shaft as the mirror axis, and the long axes of the two first magnets and the mirror axis are separated by an acute angle in the direction toward the center of the rotating shaft , The two hole-shaped magnetic barrier spaces are respectively located on the part of the rotating shaft between the outer ring surface of the rotating shaft and each of the first magnets, and are respectively close to the farthest ends of each of the first magnets from the mirror axis It extends along the axial direction of the rotating shaft and passes through the two axial ends of the rotating shaft. The permanent magnet spindle motor according to claim 1, wherein each of the magnetic groups further includes a second magnet interposed between each of the first magnets. The permanent magnet spindle motor according to claim 2, wherein, in each of the magnetic groups, the center of the second magnet is located on the axial direction of the mirror axis. The permanent magnet spindle motor according to claim 2 or 3, wherein in each of the magnetic groups, two sides of the second magnet are separated from each of the first magnets. The permanent magnet spindle motor according to claim 2 or 3, wherein, in each of the magnetic groups, in the cross-sectional direction along the radial direction of the rotating shaft, the length of the second magnet is less than the length of each of the first magnets . The permanent magnet spindle motor according to claim 1, wherein in each of the magnetic groups, the first magnets are separated from each other. The permanent magnet spindle motor according to 2 or 3, wherein the rotor has the same number of accommodating spaces as each of the magnetic groups, and is separately arranged on the rotating shaft to accommodate each of the magnetic groups. The permanent magnet spindle motor according to claim 7, wherein each of the accommodation spaces is a single hole, which penetrates the shaft. The permanent magnet spindle motor according to claim 1, wherein the inner diameter of the rotating shaft is 0.6 to 0.8 times the outer diameter of the rotating shaft. The permanent magnet spindle motor according to claim 1, wherein the number of the stator slots is 6 to 10 times the number of the magnetic groups.

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