Skewed slot iron core stacking tool with low magnetic performance loss

Abstract

The utility model relates to a skewed slot iron core stacking tool with low magnetic performance loss. The skewed slot iron core stacking tool comprises a stacking tool and a press machine, the stacking tool comprises a lower pressing plate, a mandrel, an insert, an upper pressing plate, a bolt, a gasket and a nut. The lower end face of the lower pressing plate is a tool supporting acting face. The upper end face of the upper pressing plate is a pressing acting face. A central hole and three screw holes are formed in the lower pressing plate; the outer circular surface of the core shaft is a punching sheet centering mounting surface, and two insert sheets are embedded in two spiral-line-shaped grooves formed in the outer circular surface of the core shaft in an inward and outward extending manner to form a punching sheet circumferential limiting part which is in clearance fit with a slotted hole of an iron core punching sheet; a central hole and three waist-shaped holes are formed in the upper pressing plate; the upper end and the lower end of the mandrel are respectively matched with the center holes in the upper pressing plate and the lower pressing plate in an inserted mode, the lower ends of three bolts are respectively connected with the three threaded holes in the lower pressing plate, the upper ends of the three bolts respectively penetrate through the three kidney-shaped holes, and gaskets and locking nuts are installed, so that the iron core punching sheets which are stacked after being pressed are adhered. The device realizes uniform angle spiral arrangement of the punching sheets along the central generatrix direction, and can reduce the magnetic performance loss of the punching sheets.

Description

Technical Field

[0001] The utility model belongs to the field of motor processing, and in particular relates to a stacking tool for skew slot iron cores with low magnetic performance loss. Background Art

[0002] Compared with the straight slot structure, the stator structure of the skew slot motor has a small tooth harmonic electromotive force, a low waveform distortion rate, and a large torque, so it is used more and more widely. When the stator core of the skew slot motor is stacked, a core shaft with straight grooves is usually used in combination with straight inserts to achieve the effect of tilting the slots after the stator punchings are stacked. In the core obtained in this way, the stator punchings are not arranged in a spiral with a uniform angle along the center busbar direction, but the slots are arranged in a linear non-uniform manner. In addition, the magnetic performance loss is relatively large due to the excessive degree of compression between the punchings during the stacking process. Although this method achieves the tilting of the core along a certain angle, the tooth harmonic electromotive force is significantly reduced. However, due to the non-uniform angle spiral arrangement and the large magnetic performance loss of the punchings, the further improvement of the motor performance is limited. Utility Model Content

[0003] In view of the deficiencies of the prior art, the utility model proposes a low magnetic loss stacking tool for skew slot cores, which can realize spiral arrangement of punching sheets at uniform angles along the central busbar direction and reduce magnetic loss of the punching sheets.

[0004] The above-mentioned purpose of the utility model is achieved through the following technical solutions:

[0005] A stacking tool for low magnetic performance loss of skew slot iron core, comprising a stacking tool and a press; the stacking tool comprises a lower pressure plate, a core shaft, an insert, an upper pressure plate, bolts, gaskets, and nuts; the lower end surface of the lower pressure plate is a tool support surface in contact with the workbench of the press; the upper end of the upper pressure plate is a pressure surface in contact with the pressure head of the press; a center hole is formed on the lower pressure plate, and three screw holes are formed on the lower pressure plate at the periphery of the center hole; the outer circumference of the core shaft is a punching alignment mounting surface that is clearance-matched with the center hole of the iron core punching, and two spiral grooves are formed on the outer circumference of the core shaft, and the spiral angle of the spiral is the same as the inclination angle of the stator iron core; protruding outwards in the two grooves respectively Two elastic inlays are embedded in a manner, and the two inlays constitute a circumferential limiting portion of the punch that cooperates with the slot hole gap of the iron core punch; a center hole is formed on the upper pressure plate, and three waist-shaped holes are formed on the upper pressure plate at the periphery of the center hole; the lower end of the core shaft is inserted and matched with the center hole of the lower pressure plate, and the upper part of the core shaft is inserted and matched with the center hole of the upper pressure plate, and the core punch stacking space is formed between the upper and lower pressure plates, and there are three bolts, and the lower ends of the three bolts are respectively threadedly connected with the three threaded holes on the lower pressure plate, and the upper ends of the three bolts are respectively passed through the three waist-shaped holes on the upper pressure plate, and washers and locking nuts are installed to make the stacked core punches bonded and connected after being pressed down by the set pressure of the press.

[0006] Moreover, the width of the two grooves on the core shaft is 0.2 mm.

[0007] Furthermore, the insert is made of 0.2 mm thick beryllium copper foil.

[0008] The advantages and positive effects of the utility model are:

[0009] 1. Two spiral grooves are set on the surface of the core shaft of the stacking tooling of this device, and protruding inserts are installed in the two grooves. The notches on the punching piece are embedded with the two inserts to limit the circumferential direction of the punching piece, so that the punching piece can be arranged in a spiral with a uniform angle along the center busbar direction.

[0010] 2. The utility model uses a press with a set pressure value to evenly press the upper pressure plate, and then uses bolts and nuts to tighten the upper pressure plate, so as to control the clamping force between the punching sheets and achieve excellent parallelism at both ends of the iron core. The stacking operation has low magnetic performance loss on the punching sheets. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a schematic diagram of the overall structure of the stator core stacking tooling of the skew slot motor of the utility model;

[0012] Figure 2 This is the main view of the mandrel and insert after assembly of the utility model;

[0013] Figure 3This is a top view of the assembled mandrel and insert of the utility model;

[0014] Figure 4 This is a cross-sectional view of the stacking tooling of the skew slot stator core of the utility model. DETAILED DESCRIPTION

[0015] The structure of the present invention will be further described below with reference to the accompanying drawings and through examples. It should be noted that the present examples are descriptive rather than restrictive.

[0016] A stacking tool for low magnetic loss of skewed slot core, see Figures 1-4 , its invention point is: including stacking tooling and press (not shown in the attached drawings), the stacking tooling includes a lower pressing plate 1, a core shaft 2, an insert 3, an upper pressing plate 4, a bolt 5, a gasket 6, and a nut 7. The lower end face of the lower pressing plate is the supporting surface of the tooling, which is supported on the workbench of the press through the supporting surface. The upper end of the upper pressing plate is the pressure surface, which cooperates with the pressing head of the press during the pressing process. A center hole that matches the outer circle of the core shaft 2 is formed in the center of the lower pressing plate 1, which is used to realize the vertical installation of the core shaft on the lower pressing plate; in addition, three screw holes are formed on the periphery of the center hole on the lower pressing plate for connecting and fastening the punch with the bolt 5. The outer circle of the core shaft 2 is slightly smaller than the inner hole of the punch, which can realize the clearance fit between the outer circle of the core shaft and the inner circle of the punch. Two spiral grooves are made on the outer circle of the core shaft 2, and the spiral angle of the spiral is the same as the inclination angle of the stator core; the width of the groove is 0.2mm, and the distance between the relative outer sides of the two grooves is slightly larger than the size of the punching slot. In the present invention, it is preferably larger than the size of the punching slot by 0.05mm. The insert 3 is made of 0.2mm thick beryllium copper foil. Taking advantage of the elastic deformation characteristics of beryllium copper, the two inserts are respectively embedded upright in the two spiral grooves on the core shaft. Through the cooperation of the punching slot and the two inserts, the stator punching is uniformly spirally arranged. A hole that matches the outer circle of the core shaft 2 is made in the center of the upper pressure plate 4. The upper pressure plate is used to press the stacked punching plates; there are three waist-shaped holes on the upper pressure plate, and the three waist-shaped holes respectively match the three screw holes on the lower pressure plate to facilitate the bolt 5 to pass through the upper pressure plate and tighten the nut 7. The bolt 5, gasket 6 and nut 7 are used to tighten the upper and lower pressure plates, so that the punching plates are bonded together.

[0017] The usage of this tool is:

[0018] 1. Insert the mandrel into the center hole of the lower pressure plate;

[0019] 2. Insert the two inserts into the two spiral grooves of the core shaft respectively;

[0020] 3. Apply adhesive evenly on both ends of the required number of punching sheets;

[0021] 4. First, apply adhesive only on the upper end of the bottom punch and install it on the mandrel. Align the notches on the punch with the two inserts on the tooling to achieve square positioning of the punch along the circumference.

[0022] 5. Apply adhesive on both sides of the punching sheets used in the middle and stack them one by one on the mandrel, and align the notches on the punching sheets with the two inserts on the tooling to achieve square positioning of the punching sheets along the circumference;

[0023] 6. Install the top punch onto the mandrel after applying adhesive only on the lower end; align the notches on the punch with the two inserts on the tooling to ensure the punch is positioned squarely along the circumference.

[0024] 7. Tighten the three bolts into the three corresponding screw holes of the lower pressure plate;

[0025] 8. Install the upper pressure plate onto the mandrel;

[0026] 9. Place the stacked mold on the press, adjust the press pressure to 1.0 MPa, and press the upper end of the upper plate to compress the punching sheet;

[0027] 10. Install the washers and nuts onto the bolts, tighten them, and close the press;

[0028] 11. Remove the insert and mandrel;

[0029] 12. Place the tooling into a high-temperature test chamber and heat it to bond the sheets together;

[0030] 13. Remove the tooling from the high temperature test chamber, remove the nuts, and take out the stator core 8.

[0031] In summary, this stacking tooling, when used in conjunction with a press with controllable clamping force, can reduce the magnetic property loss of the punches caused by the stacking operation. Specifically, after stacking a specified number of punches onto the tooling, the upper pressing plate 4 is installed on the mandrel; then the assembled tooling is placed on the press, and the pressure of the press is adjusted according to the size of the punches (pressure range 1.0MPa to 1.5MPa), the press is started, and when the press flattens the upper pressing plate 4, the bolts 5, washers 6, and nuts 7 are tightened.

[0032] The magnetic performance changes of φ36 punching sheets before and after stacking were statistically analyzed using the low magnetic performance loss stacking tool for the skew core. After adopting this operation method, the initial magnetic permeability μ0 and the maximum magnetic permeability μ m The reduction is less than 5%, the remanence B r The reduction is less than 8%, the coercive force H c The increase is less than 4%. The low magnetic loss rate makes the resulting core meet the magnetic performance requirements of most motors.

[0033] Although the embodiments and drawings of the utility model are disclosed for the purpose of illustration, those skilled in the art can understand that various substitutions, changes and modifications are possible without departing from the spirit of the utility model and the appended claims, therefore, the scope of the utility model is not limited to the content disclosed by the embodiments and drawings.

Claims

1. A low magnetic loss stacking tool for skew slot cores, characterized by: It comprises a stacking tool and a press; the stacking tool comprises a lower pressing plate, a core shaft, an insert, an upper pressing plate, bolts, gaskets and nuts; the lower end surface of the lower pressing plate is a tool supporting surface in contact with the workbench of the press; the upper end of the upper pressing plate is a pressure-applying surface in contact with the pressing head of the press; a center hole is formed on the lower pressing plate, and three screw holes are formed on the periphery of the center hole on the lower pressing plate; the outer cylindrical surface of the core shaft is a punching plate centering mounting surface that is clearance-matched with the center hole of the iron core punching plate, and two spiral grooves are formed on the outer cylindrical surface of the core shaft, and the spiral angle of the spiral is the same as the inclination angle of the stator iron core; two springs are respectively embedded in the two grooves in a protruding manner. The two inlays form a circumferential limiting portion of the punch that matches the slot hole gap of the iron core punch; a center hole is formed on the upper pressure plate, and three waist-shaped holes are formed on the periphery of the center hole of the upper pressure plate; the lower end of the core shaft is inserted into the center hole of the lower pressure plate, and the upper part of the core shaft is inserted into the center hole of the upper pressure plate. The core punch stacking space is formed between the upper and lower pressure plates. There are three bolts, and the lower ends of the three bolts are respectively threadedly connected with the three threaded holes on the lower pressure plate, and the upper ends of the three bolts are respectively passed through the three waist-shaped holes on the upper pressure plate, and washers and locking nuts are installed to make the stacked core punches bonded and connected after being pressed down by the set pressure of the press.

2. The low magnetic loss stacking tool for skewed slot cores according to claim 1, characterized in that: The width of the two grooves on the core shaft is 0.2 mm.

3. The low magnetic loss stacking tool for skewed slot cores according to claim 2, characterized in that: The inlay is made of 0.2 mm thick beryllium copper foil.

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