STATOR WITH OPTIMIZED WINDING SPACE

Description

[0001] The present invention relates to a stator with teeth and a winding space optimized in the area of ​​the tooth head. The invention relates equally to split and unsplit stators.

[0002] In the electrical industry, coil winding technology refers to the type and method of winding an electrical conductor (insulated wire or stranded wire) into a coil. The windings of stators or rotors of motors are also called coils. The winding technology significantly determines the properties of electromechanical assemblies containing windings. These properties include insulation strength, quality factor, the required size for a specific power output or magnetic force, and the magnetic stray field. Because energy efficiency requirements are increasing significantly, the demands on the development of components for electromechanical assemblies, such as those found in electric motors, are also growing.

[0003] Electrical machines, such as electric motors and generators, typically consist of a stator and a rotor. In stators, the iron-containing body is often manufactured from sheet metal using a stamping process, meaning the laminations are continuous across the entire circumference. Typically, the yoke, teeth, and tooth tips are also continuous – without any joints. In the axial direction, such stators usually consist of several laminations, which are often bonded, baked, or stamped together using burrs.

[0004] To generate a magnetic field, a coil of winding wire is wound around each tooth. The torque output of a motor increases, among other things, with the current flowing through the windings and the number of turns wound around the teeth. Therefore, a high fill factor is desirable. When winding teeth with tooth tips, a gap must be left between adjacent tooth tips to allow the winding tool to fit, which is the case for needle-wound, undivided stators. Alternatives include flyer-wound and, if applicable, split stators.

[0005] To reduce the cogging torque and waviness inherent in the design of a motor, the teeth often have so-called tooth heads, such as hammer-shaped or T-shaped tooth heads.

[0006] The fill factor mentioned above is the sum of the cross-sectional areas of the inserted copper wires divided by the cross-sectional area between the individual teeth. However, if only very low cogging torque and minimal waviness are permitted for the electric motor, tooth heads are often essential. In such cases, because a certain clearance must be maintained between the tooth heads, only an average copper fill factor can be achieved.

[0007] Electrical machines often require such a high power density that it can only be achieved with a high copper fill factor.

[0008] Exemplary stator teeth and tooth heads are described in DE 102 29 333 A1 and DE 10022071 A1. DE 10 2014 114929 A discloses a permanent magnet synchronous machine using tooth coil technology.

[0009] From JP 2007 288983 a winding tooth for a stator of an electrical machine is known, which has a T-shaped tooth head which is arranged on a tooth neck, wherein an insulating layer is provided along the tooth neck and a respective side surface of the respective projection of the tooth head.

[0010] A technically simple and efficient solution for improving the fill factor of a stator tooth with tooth heads is therefore desirable, particularly in a stator where the respective tooth heads are integrally formed with the corresponding tooth. Furthermore, a winding tooth with a tooth head is known from JP 2006 320167 A, in which an insulation layer arranged along the tooth head provides recesses for a winding wire.

[0011] The present invention is therefore based on the objective of overcoming the aforementioned disadvantages in the prior art and of further developing a stator with teeth having tooth heads in such a way that an optimized winding is achieved.

[0012] This problem is solved by the combination of features according to claim 1.

[0013] According to the invention, the insulation on the winding tooth is designed to provide targeted support for the winding wire, enabling orderly winding. Preferably, a contour is created in the insulation layer extending along the tooth head, which is adapted to the wire diameter and the winding pattern. It is designed such that minimal displacement forces act on the winding wire after the winding process, ensuring that the wire remains in its target position after being laid down.

[0014] According to the invention, a winding tooth of an electric machine stator is provided with a tooth head arranged at a tooth neck, the tooth head having a tooth head end face (at the radially outer end). To reduce motor ripple, the tooth head has two projections extending laterally from the tooth neck. An insulating layer is provided along the tooth neck and the respective lateral region of each projection, and each insulating layer forms a projection in the area of ​​the tooth head that extends laterally from the tooth head. These projections of the insulating layer thus form holding devices for positioning the winding wires in the area of ​​the tooth head. This makes it possible to fill the groove between two adjacent teeth with a better fill factor.

[0015] In a preferred embodiment of the invention, the respective projection of each insulation layer extends essentially in the same lateral direction as the extension direction of the respective projections. It is also advantageous if each projection is located at the outermost lateral end section of the winding tooth, directly adjacent to the respective corner of the winding tooth that forms at the transition from the respective side surface of the projections to the tooth head face. This allows for maximum space utilization for the winding.

[0016] Another preferred measure to ensure that the winding wire remains in its target position after being laid down by the winding tool is to design the contact angle α of the winding wire against the insulation layer to be less than 45°. Alternatively or additionally, a grooved structure adapted to the wire diameter of the winding wire can be incorporated into the insulation layer. It is therefore further advantageous if the insulation layer, at least in the area of ​​the respective projections of the tooth head, has such a corrugated or grooved surface structure for positioning the winding wire, thus enabling orderly winding.

[0017] This can be achieved, for example, by ensuring that the tangent running from the center of the winding tooth's base to the contact surface of the insulation layer in the area of ​​the respective projections is oriented at an angle α to the central winding tooth axis, where α < 45°. However, the point of intersection at the "center of the base" is not fixed. The angle chosen between the two lines is more important.

[0018] Another aspect of the present invention relates to a stator with a stator center on which a plurality of winding teeth extending radially outwards, as described above, are formed, wherein at least one, preferably, but preferably all winding teeth, are wrapped with a winding wire having a winding wire diameter DW both in the region of the tooth neck and in the region of the tooth head.

[0019] In a preferred embodiment of the invention, it is provided that, viewed in the circumferential direction, a utility slot is provided between each two immediately adjacent winding teeth, and the following condition applies to the width of the utility slot: BN ≥ 2.5 ▪ DW , where DW is, as previously stated, the winding wire diameter of the winding wire of the wound stator.

[0020] It is also advantageous if the following ratio applies to the height of the tooth head H ZK in the area of ​​the projections in relation to the height of the lateral tooth H WZ: H ZK ≥ 0.1 ▪ HZ. It goes without saying that the tooth head should never exceed approximately 20% of the tooth's height, so that an optimal range lies between 10% and 20%.

[0021] In a further advantageous embodiment of the invention, it is provided that the projection of the respective insulation layer has a length L a which corresponds to at least 30%, and more advantageously at least 50%, of the winding wire diameter DW of the winding wire.

[0022] It is further advantageous if the filling factor is approximately 18% - 25% larger compared to an identically designed stator with winding teeth of the same arrangement and geometry, but without the presence of an insulating layer in the area of ​​the tooth head.

[0023] Another aspect of the present invention relates to an electric motor comprising a stator as described above.

[0024] Other advantageous embodiments of the invention are characterized in the dependent claims or are described in more detail below together with the description of the preferred embodiment of the invention with reference to the figures.

[0025] It shows: Fig. 1 shows a view of a partial area of ​​a stator with three teeth and Fig. 2 shows a further representation of an embodiment.

[0026] The invention is described below using an exemplary embodiment with reference to the Figure 1 and 2 described in more detail, whereby identical reference symbols in the figures indicate identical structural and / or functional features.

[0027] In the Figure 1 A view of a partial section of a stator 30 with three winding teeth 1 is shown, whereby the two outer winding teeth 1 are only partially visible. Each winding tooth 1 has a tooth neck 3 at the end of which a tooth head 2 is formed in one piece.

[0028] The tooth head 2 is designed as a T-shaped tooth head and has a tooth head face 20 at its radially outer end. The tooth head 2 has two projections 21a, 21b, which extend laterally from the tooth neck 3 in the direction of the respective adjacent tooth head 2 of the adjacent coil tooth 1.

[0029] Furthermore, it can be seen that the groove between two winding teeth 1 is provided with an insulating layer 10a, 10b, which is provided on the surface of the winding teeth 1 along the tooth neck 3 and the respective lateral area of ​​the respective projections 21a, 21b. The winding tooth 1 does not have an insulating layer 10a, 10b in the area of ​​the tooth head face 20. As also shown in the Figure 1 and 2As can be seen, the respective insulation layer 10a, 10b, each provided in the area of ​​the tooth head 2, forms a projection 11a, 11b that extends laterally away from the tooth head 2 and also in the direction of the adjacent tooth head 2 of the neighboring winding tooth 1. The resulting projection of length L a, relative to the upper surface of the insulation layer, represents a positioning device for the winding wire W. The positioning for the ordered winding can be further improved by the fact that the insulation layer 10a, 10b has a wave-shaped recess 14, at least in the area of ​​the tooth head 2, into which the winding wire can dip and is thereby located in a precisely defined position on the winding tooth 1. It is also evident in the two Figure 1 and 2, that the respective projection 11a, 11b is located at the outermost lateral end section of the coil tooth 1 and is directly adjacent to the respective corner Ea, Eb of the coil tooth 1, wherein the corners Ea, Eb define the transition from the respective side surface at the projections 21a, 21b to the tooth head front face 20.

[0030] The usable slot 31 between each pair of immediately adjacent winding teeth 1 has a width BN = 4.5 ▪ DW. For the height of the tooth head H ZK in the area of ​​the projections 21a, 21b in relation to the height of the winding tooth H z, the following applies in this embodiment: H ZK = 0.15 ▪ HZ .

[0031] In the Figure 2 The orientation of the contact surface A is shown for better explanation. A tangent to the contact surface A of the insulation layer 10b is shown. The tangent T runs at an angle of 30° to the radial direction of the winding tooth axis Wa.

[0032] The invention is not limited in its implementation to the preferred embodiments specified above. Rather, a number of variants are conceivable which make use of the solution presented, even in fundamentally different embodiments, as long as they fall within the scope of protection of the invention as defined by the independent claim.

Claims

1. Winding tooth (1) for a stator of an electrical machine having a T-shaped tooth head (2), arranged on a tooth neck (3), having a tooth head front side (20), wherein the tooth head (2) has two projections (21a, 21b) for reducing the motor ripple, which extend laterally away from the tooth neck (3), wherein an insulation layer (10a, 10b) is provided along the tooth neck (3) and a respective lateral surface of the respective projection (21a, 21b) of the tooth head (2), characterized in that the respective insulation layer (10a, 10b) forms a projection (11a, 11b) in the region of each of the projections (21a, 21b) of the tooth head (2), which extends laterally away from the tooth head (2), wherein the respective projection (11a, 11b) of the insulation layer (10a, 10b) is formed at the outermost lateral end section of the winding tooth (1) and directly adjacent to the respective corner (Ea, Eb) of the winding tooth (1), which is located at the transition from the respective lateral surface on the projections (21a, 21b) of the tooth head (2) to the tooth head front side (20), and wherein the insulation layer (10a, 10b) has a corrugated or grooved surface structure for positioning a winding wire (W) at least on the respective lateral surface of the respective projections (21a, 21b) of the tooth head (2).

2. Winding tooth (1) according to Claim 1, characterized in that the respective projection (11a, 11b) of the respective insulation layer (10a, 10b) extends substantially in the same direction as the extension direction of the respective projections (21a, 21b) of the tooth head (2).

3. Winding tooth (1) according to any one of the preceding claims, characterized in that the tangent (T) extending at the contact surface (A) of the insulation layer (10a, 10b) in the area of the respective projections (21a, 21b) of the tooth head (2) extends at an angle α oriented to the radially outwardly extending winding tooth axis (Wa), wherein α < 45°.

4. Stator (30) having a stator center on which a winding tooth (1) or a plurality of radially outwardly extending winding teeth (1) according to any one of Claims 1 to 3 are formed, wherein at least one of the winding teeth (1) is wound both in the area of the tooth neck (3) and in the area of the tooth head (2) using a winding wire (W) having a winding wire diameter Dw.

5. Stator (30) according to Claim 4, characterized in that, viewed in the circumferential direction, there is a useful slot (31) between each two directly adjacent winding teeth (1), wherein the width of the useful slot (31) is BN ≥ 2.5 · Dw.

6. Stator (30) according to either one of preceding Claims 4 or 5, characterized in that the following applies to the height of the tooth head HZK in the area of the projections (21a, 21b) of the tooth head (2) in relation to the height of the winding tooth Hz : HZK ≥ 0.1 · Hz.

7. Stator (30) according to any one of preceding Claims 4 to 6, characterized in that the projection (11a, 11b) of the respective insulation layer (10a, 10b) has a length La which corresponds to at least 30% of the winding wire diameter Dw of the winding wire (W).

8. Electric motor comprising a stator (30) according to any one of Claims 4 to 7.