Motor rotor core structure

Abstract

The motor rotor core structure provided by the application mainly has the following technical features: a plurality of spaced-apart through-hole spaces are sequentially arranged on the rotor core of a rotary motor along the circumferential direction of the motor rotary shaft, and when the through-hole spaces obstruct the magnetic circuit in the rotor, a plurality of straight rod-shaped coupling elements made of non-magnetic material are simultaneously arranged in the through-hole spaces. The stacked state of the plurality of silicon steel sheets used to form the rotor core is fixed by the coupling elements, so as to improve the rigidity of the rotor core as a whole and reduce the possibility of deformation or damage of the silicon steel sheets caused by the centrifugal force of high-speed rotation.

Description

Technical Field

[0001] This invention relates to motor technology, and in particular to a motor rotor core structure. Background Technology

[0002] In order to suppress the stress caused by centrifugal force on the rotor of the main shaft motor under high-speed rotation, the US2014167551A1 patent publication uses the shape design of the magnetic barrier hole on the slot side of the rotor magnet. By utilizing the smooth arc shape of the hole wall on the outer diameter side of the magnetic barrier hole, the maximum stress in the narrowest area between this part and the outer diameter surface of the rotor under centrifugal force is reduced. This means that even if the rotor is damaged due to stress concentration under high-speed rotation, it will be confined to the aforementioned narrowest area, thereby preventing it from flying off to the stator side.

[0003] Meanwhile, Case 551A1 also explicitly states that it is not recommended to use through holes through the rotor to provide for the insertion and connection of through bolts, because through holes will become new stress concentration points, which will lead to a reduction in the strength of the rotor; moreover, in terms of spindle motors, the conventional technology of increasing the spindle diameter to improve rigidity and thereby obtain good machining accuracy also leads to a relative reduction in the radial thickness of the rotor elements surrounding the spindle, making it difficult to add the above-mentioned through holes within the limited radial thickness range of the rotor to achieve the purpose of fixing the silicon steel sheets between the iron core with through bolts. Summary of the Invention

[0004] The main objective of this invention is to provide a motor rotor core structure that can improve the structural rigidity of the rotor core, enabling the motor rotor to meet the high-speed rotation requirements of the spindle motor.

[0005] To achieve the above objectives, the main technical feature of the motor rotor core structure provided by the present invention is that, along the circumferential direction centered on the motor rotation axis, a plurality of through-hole-like spaces spaced apart from each other are sequentially provided on the rotor core of the rotating motor. While these through-hole-like spaces form obstacles to the magnetic circuit inside the rotor, they also allow for the passage of a plurality of straight rod-like connecting elements made of non-magnetic materials. The overlapping state of the plurality of silicon steel sheets constituting the core is fixed by these connecting elements, thereby improving the overall rigidity of the core and reducing the possibility of deformation or breakage of the silicon steel sheets caused by the centrifugal force of high-speed rotation.

[0006] Furthermore, the aforementioned plurality of through-hole-shaped spaces each include a through-hole-shaped magnetic barrier space and a through hole adjacent to and connected to the magnetic barrier space, and each of the through-hole-shaped spaces is located on both sides of the magnet slot of the rotor core in the aforementioned circumferential direction. The through-hole-shaped spaces located on both sides of a single magnet slot are mirrored to each other with the diameter of the aforementioned circumference as the mirror axis and are connected to the magnet slot by the magnetic barrier space.

[0007] The magnetic barrier space is a magnetic barrier space with a first side adjacent to and connected to the magnet slot, and a second side adjacent to and connected to the through hole. The inner diameter of the first side of the magnetic barrier space is larger than the inner diameter of the second side. The magnetic barrier space with a constant inner diameter is located on the radial cross-section of the above-mentioned circumference. Its specific shape can be a triangular planar geometry.

[0008] At the same time, the inner diameter of the second side of the magnetic barrier space is also smaller than the inner diameter of the through hole, so that the connecting element inserted in the through hole will not be radially displaced into the magnetic barrier space through the connection between the magnetic barrier space and the through hole, thereby achieving the restraint and positioning effect of the connecting element.

[0009] Furthermore, the inner diameter of the connecting part between the magnetic barrier space and the magnetic slot is smaller than the inner diameter of the first side of the magnetic barrier space, and also smaller than the height of the slot space in the aforementioned circumferential radial direction of the magnetic slot. This ensures that the magnet embedded in the magnetic slot will not be displaced into the magnetic barrier space through the connecting part between the magnetic slot and the magnetic barrier space, thereby providing a restraining and positioning effect for the magnet located in the magnetic slot. Attached Figure Description

[0010] Figure 1 This is a perspective view of a preferred embodiment of the present invention.

[0011] Figure 2 This is a preferred embodiment of the present invention. Figure 1 Sectional view of the 2-2 section line.

[0012] Figure 3 and Figure 4 This is a preferred embodiment of the present invention. Figure 2 A magnified view of the local region K. Detailed Implementation

[0013] First, it should be noted that the motor rotor core structure described below through a preferred embodiment of the present invention is an example of the rotor element of a spindle motor intended for high-speed rotation. However, the parts of the spindle motor that do not impede the disclosure of the technical features of the present invention will not be mentioned in the following description. However, such omitted parts are common knowledge that is known to those skilled in the art before the application of this invention, and their omission does not affect the completeness of the disclosure of the main technical features of the present invention.

[0014] Please see Figure 1 and Figure 2 As shown, the motor rotor core structure 10 provided in a preferred embodiment of the present invention mainly includes an iron core 20, a plurality of perforated magnet slots 30, a plurality of paired magnetic barrier spaces 40, a plurality of through holes 50, and a plurality of connecting elements 60.

[0015] The iron core 20 is a ring-shaped tubular article formed by sequentially and coaxially stacking multiple annular silicon steel sheets. It has an inner diameter annular surface 21 defined by the inner wall of the tubular tube and an outer diameter annular surface 22 defined by the outer wall of the tubular tube. The inner diameter annular surface 21 has a circular cross-sectional shape in the radial direction. The outer diameter annular surface 22 can also have a circular cross-sectional shape in the radial direction, or it can be formed by sequentially and interlacing multiple first arcs 221 and second arcs 222 with different curvatures, as disclosed in this embodiment, with the curvature center of the outer diameter annular surface 22 coaxial with or parallel to the center of the inner diameter annular surface 21.

[0016] Each of the magnet slots 30 is disposed on the iron core along the central axis of the inner diameter annular surface 21 and between the inner diameter annular surface 21 and the outer diameter annular surface 22. This allows the magnets (not shown in the figure) to be accommodated through the hole space of each magnet slot 30, and the magnets are positioned by the hole walls of each magnet slot 30, so that the magnets can be tightly embedded inside the iron core 20. However, the specific shape of these magnet slots 30 is not a technical feature of this invention and will not be described in detail in this specification.

[0017] These magnetic barrier spaces 40 are mirrored to both sides of each magnet slot 30 with the diameter of the inner diameter annular surface 21 as the mirror axis, and are perforated in the iron core 20 along a direction parallel to the axial direction of the inner diameter annular surface 21. They are connected to the adjacent magnet slot 30 by a first side 41.

[0018] These through holes 50 are respectively extended along the axial direction of the inner diameter annular surface 21 and penetrate the iron core 20, and are connected in pairs to a second side 42 of each pair of magnetic barrier spaces 40.

[0019] Please see Figure 4 Each of the connecting elements 60 has a straight rod-shaped body 61 made of a non-magnetic material such as stainless steel or aluminum, which extends through each of the through holes 50 and has both ends of the rod protruding beyond the end faces of the tube shaft of the iron core 20. The two ends (not shown in the figure) are located outside the tube shaft of the iron core 20 and are fixed to the ends of the rod shaft of the rod body 61, thereby applying force to the silicon steel sheets to maintain the overlapping state of the silicon steel sheets. At the same time, due to its non-magnetic physical properties, the hole space of the through holes 50 still maintains its obstructive effect on the magnetic circuit.

[0020] For clarity regarding the spatial configuration of the magnet slots 30, magnetic barrier spaces 40, and through holes 50, please refer to [link / reference needed]. Figure 3As shown, the magnetic barrier space 40 located on one side of the magnet slot 30 is connected to the magnet slot 30 by a portion of the first side 41, and the inner diameter of the connected area 411 is smaller than the inner diameter of the first side 41. At the same time, the connecting channel 421 formed by the partial connection of the second side 42 of the magnetic barrier space 40 to the partial connection of the through hole 50 also has an inner diameter smaller than the inner diameter D of the through hole 50. This inner diameter difference allows the magnet slot 30, the magnetic barrier space 40 and the through hole 50 to communicate with each other while preventing the magnet embedded in the magnet slot 30 and the rod body 61 extending through the through hole 50 from being shifted into the magnetic barrier space 40 through the connected areas 411 or the connecting channel 421.

[0021] In this embodiment, the through holes 50 are circular in radial cross-section, and the cross-sectional shape of the rod body 61 in radial direction is a complementary circle, so that the peripheral walls of the rod body 61 can be correspondingly attached to the hole walls of the through holes 50, thus ensuring a stable fit between the rod body 61 and the through holes 50. In other embodiments, the shape of the through holes can be different from the planar geometry of this embodiment, such as ellipse or polygon.

[0022] In addition, the magnetic barrier spaces 40 are triangular in shape in the radial cross section, with the first side of the triangle defined by the first side 41, the second side defined by the inner hole wall 43 of the magnetic barrier space 40 near the inner diameter annular surface 21, and the third side defined by the outer hole wall 44 of the magnetic barrier space 40 near the outer diameter annular surface 21, and the connecting channel 421 is located within the range of the third side.

[0023] Through the composition of the above components, the motor rotor core structure 10 provides through holes 50 for the insertion of connecting elements 60, thereby achieving a good fixation of the stacked silicon steel sheets, which improves the rigidity of the core. At the same time, since the non-magnetic characteristics of the connecting elements 60 are limited, the magnetic barrier effect formed by the through holes 50 and the magnetic barrier spaces 40 is maintained. Thus, the motor rotor core structure 10 can combine core strength and electromagnetic characteristics, which is a significant improvement compared with the prior art.

[0024] Further, please refer to Figure 3 In order to achieve better mechanical characteristics of the motor rotor core structure 10, this invention further studies the dimensions of the magnetic barrier spaces 40 and the through holes 50. The data shown in Table 1 below are sufficient to prove that this invention has a better safety factor compared to the prior art.

[0025] Table 1

[0026]

[0027] In the above table,

[0028] B is the first included angle, defined as the included angle between the inner wall 43 of the magnetic barrier space and the inner groove surface 31 of the adjacent magnet groove 30 near the inner diameter annular surface 21 in the radial direction of the iron core 20.

[0029] C is the second included angle, defined as the interior angle between the inner wall 43 and the outer wall 44 of the magnetic barrier space in the radial direction of the iron core 20.

[0030] The magnetic barrier spaces 40 and the connected magnet slots 30 satisfy 150°≤B≤190° and 16°≤C≤35°, wherein;

[0031] These through holes 50 satisfy the formula (I) on the right: 1.9% ≤ α ≤ 10.1%.

[0032] In the formula, D is the diameter of the through holes 50, and Ro is the radius of the second arcs 222. The magnetic barrier spaces 40 and the adjacent connected through holes 50 satisfy the following formula (II).

[0033] Formula II: 11.3% ≤ γ ≤ 14.3%.

[0034] In the formula, F is the magnetic barrier width, which is defined as the straight-line distance between the interconnected magnetic barrier spaces 40 and the through holes 50, between the curvature center positions of the first side 41 and the through hole 50; Ro is the radius of the second arcs 222.

[0035] As shown in Table 1 above, the motor rotor core structure 10 can effectively improve its safety factor to over 1.01, and can enhance the rigidity of the core 20 under high-speed rotation, thereby reducing the deformation or damage that may occur under centrifugal force.

[0036] The above description describes the preferred embodiments of the present invention and the technical principles applied thereto. For those skilled in the art, any obvious changes such as equivalent transformations or simple substitutions based on the technical solutions of the present invention, without departing from the spirit and scope of the present invention, shall fall within the protection scope of the present invention.

Claims

1. A motor rotor core structure, characterized in that, Includes: A ring-shaped iron core is formed by sequentially and coaxially stacking multiple ring-shaped silicon steel sheets. It has an inner diameter ring surface and an outer diameter ring surface, and the outer diameter ring surface is formed by multiple first arcs and multiple second arcs of different curvatures, which are sequentially and alternately connected. Multiple magnet slots, spaced apart from each other, are respectively located between the inner and outer diameter annular surfaces of the iron core and extend axially through the iron core parallel to the curvature center of the inner diameter annular surface. Multiple pairs of through holes extend axially through the iron core, parallel to the curvature center of the inner diameter annular surface, and are respectively separated from the two sides of each magnet slot in the radial direction. Multiple pairs of perforated magnetic barrier spaces extend along the axial direction of the curvature center parallel to the inner diameter ring surface of the iron core, respectively penetrating the iron core, and each pair of magnetic barrier spaces is located between the two sides of each magnet slot and the pair of through holes, and is respectively connected to the magnet slot with a first side and to the through hole with a second side. Multiple rod-shaped connecting elements made of non-magnetic material are respectively inserted and fixed in each of the through holes, and apply opposing forces to the two ends of the iron core, which act on the stacked silicon steel sheets. The wall of each through hole rests against the peripheral side surface of each connecting element that extends into its hole space; The inner diameter of each of the first sides is larger than the inner diameter of each of the second sides; The inner diameter of each of the first sides is greater than the inner diameter of the connecting area between each of the first sides and each of the magnet slots; and The inner diameter of the channel connecting the second side to the through hole is smaller than the inner diameter of the through hole.

2. The motor rotor core structure as described in claim 1, characterized in that, These through-holes satisfy the following formula I, and each of these magnetic barrier spaces and each of these adjacent through-holes that are connected to it satisfies the following formula II: Official (I): 1.9% ≤ α ≤ 10.1%; Formula II: 11.3% ≤ γ ≤ 14.3%; where, D is the diameter of these through holes; Ro is the radius of the second arc; F represents the interconnected magnetic barrier spaces and through holes, and is the straight-line distance between the first side and the center of curvature of the through hole.

3. The motor rotor core structure as described in claim 1, characterized in that, Each of the magnetic barrier spaces is triangular in shape, with a first side defined by the first side, a second side defined by an inner hole wall, and a third side defined by an outer hole wall. The positions of the through holes that connect to each of the magnetic barrier spaces are located within the range of the third side.

4. The motor rotor core structure as described in claim 1, characterized in that, In the radial direction of the iron core, the inner angle between the magnetic barrier space near the inner diameter annular surface of the iron core and the outer diameter annular surface of the magnetic barrier space is between 16° and 35°.

5. The motor rotor core structure as described in claim 1, characterized in that, In the radial direction of the iron core, the magnetic barrier space is close to the inner hole wall of the inner diameter ring surface of the iron core, and the adjacent magnet groove is close to the inner groove surface of the inner diameter ring surface. The inner angle between the two is between 150° and 190°.

6. The motor rotor core structure as described in claim 1, characterized in that, Each of the connecting elements includes a straight rod-shaped body extending through the through holes, and two ends located outside the two ends of the iron core along the axial direction, each end being fixedly connected to the rod end of the rod body.

7. The motor rotor core structure as described in claim 1, characterized in that, The radial cross-section of each through hole has a circular planar geometry.

8. The motor rotor core structure as described in claim 1, characterized in that, The radial cross-section of each through hole has an elliptical planar geometry.

9. The motor rotor core structure as described in claim 1, characterized in that, The radial cross-section of each through hole has a polygonal planar geometry.

Images