Stator for an electric motor of a vehicle drive system

Abstract

The present invention relates to a stator (100) for an electric motor of a vehicle drive system, the stator comprising: a stator yoke (110); a plurality of stator teeth (120) which project from an inner side (112) of the stator yoke (110), a receiving space (AR) for at least one coil winding (130) being formed between adjacent stator teeth (120); and at least one closure element (140) for the receiving space (AR); wherein each receiving space (AR) has a first end region (EB1) on the inner side (112) of the stator yoke (110) and a second end region (EB2) opposite the first end region (EB1), wherein at least one flexible projection (114) is formed in the first end region (EB1) and can be brought to bear against a coil winding (130) in the receiving space (AR), and wherein the at least one closure element (140) is arranged in the second end region (EB2).

Description

[0001] 23-3056

[0002] Stator for an electric motor of a vehicle drive

[0003] The present disclosure relates to a stator for an electric motor of a vehicle drive, a drive system for a hybrid or electric vehicle, a hybrid or electric vehicle, and a method for manufacturing a stator for an electric motor of a vehicle drive. The present disclosure relates in particular to fixing coil windings without filler material, such as resin or impregnating material.

[0004] State of the art

[0005] In conventional electric motor production, it is often necessary to use resin or an impregnating material to permanently fix the windings in the stator. This step typically involves inserting the windings into the stator slots, followed by a costly and time-consuming process of filling the remaining space with resin to securely fix the windings. This additional manufacturing step not only increases material costs but also extends production times.

[0006] Disclosure of the invention

[0007] The object of this disclosure is to provide a stator for an electric motor of a vehicle drive, a drive system for a hybrid or electric vehicle, a hybrid or electric vehicle, and a method for manufacturing a stator for an electric motor of a vehicle drive, which enable improved fixation of coil windings. In particular, it is an object of this disclosure to simplify a production process of the stator and / or to reduce material consumption.

[0008] This problem is solved by the subject matter of the independent claims. Advantageous embodiments are specified in the dependent claims. 23-3056

[0009] According to an independent aspect of the present disclosure, a stator for an electric motor of a vehicle drive, in particular of a hybrid or electric vehicle, is specified. The stator comprises: a stator yoke; a plurality of stator teeth projecting from an inner surface of the stator yoke, wherein a receiving space for at least one coil winding is formed between adjacent stator teeth; and at least one closing element for the receiving space; wherein each receiving space has a first end region on the inner surface of the stator yoke and a second end region radially opposite the first end region, wherein at least one flexible projection is formed in the first end region which can be applied to, or is applied to, a coil winding in the receiving space, and wherein the at least one closing element is arranged in the second end region.

[0010] According to the invention, the coil windings are arranged between flexible projections on the stator yoke and a locking element. In particular, when the coil windings are inserted into the receiving space, the flexible projections can be bent by contact with the coil windings, so that the flexible projections press against the coil windings and thus fix the coil windings in the receiving space. This eliminates the need to fill gaps in the receiving space with resin or impregnating material, thus simplifying the stator production process and reducing material consumption.

[0011] The term “axis of rotation”, as used in the context of this disclosure, refers to the axis around which the rotor of the electric motor rotates. The axis of rotation typically runs along the center of the rotor and stator, along the length of the electric motor.

[0012] The term “radial,” as used in the context of this disclosure, refers to a direction perpendicular away from (outward from) or toward (inward from) the axis of rotation. In particular, the radial direction may be the line extending perpendicularly outward from the center of the rotor and / or stator (the axis of rotation) to the edge. 23-3056

[0013] The term “axial”, as used in the context of the present disclosure, refers to a direction along or parallel to the axis of rotation, such as from an upper end of the stator to a lower end of the stator.

[0014] Preferably, the receiving space is a stator groove. A stator groove is an elongated depression or slot that extends along the inner surface of the stator or stator yoke.

[0015] Preferably, the receiving spaces of the stator, in particular the stator slots, are arranged radially on the inside of the stator yoke, evenly distributed along the circumference of the stator yoke.

[0016] Preferably, the coil winding is a bundle of individual windings, which may, for example, be surrounded by an insulating material. In some embodiments, two or more bundles can be inserted into each receiving space, e.g., along the radial direction, such as 3, 4, 5, 6 or more bundles.

[0017] Preferably, the at least one flexible projection is flexible along an axis of rotation of the electric motor. Furthermore, the at least one flexible projection can be essentially inflexible in the direction of rotation of the electric motor. A projection flexible in one direction can adapt to pressure or changes in shape in that direction, while a projection inflexible in another direction does not allow significant deformation in that other direction, even when a force is applied to it.

[0018] Preferably, the at least one flexible projection is plate-shaped. The term "plate-shaped" refers to the form of the flexible projection, which, in its unbent state, has a relatively large extent in two dimensions (length and width), while its thickness (the third dimension) is comparatively very small.

[0019] Preferably, at least one flexible projection is designed as a flap. A flap is shaped similarly to a flap-like projection and has a thin, flexible nature that can be bent relatively easily in a specific direction. 23-3056

[0020] Preferably, the plane formed by the length and width of the flexible projection is essentially parallel to the radial direction in the undistorted state of the flexible projection.

[0021] Preferably, the plane formed by the length and width of the flexible projection is essentially perpendicular to the axis of rotation when the flexible projection is in its undistorted state.

[0022] The term "parallel" refers to an essentially parallel alignment, e.g., of surfaces or axes, whereby a deviation of a few degrees, e.g., up to 5° or even up to 10°, from an exact parallel alignment is still considered an "essentially parallel alignment." Similarly, the term "perpendicular" refers to an essentially perpendicular alignment, e.g., of surfaces or axes, whereby a deviation of a few degrees, e.g., up to 5° or even up to 10°, from an exact perpendicular alignment is still considered an "essentially perpendicular alignment."

[0023] Preferably, the stator yoke and / or the plurality of stator teeth are formed from a rotor lamination stack. A rotor lamination stack is a composite structure consisting of several stacked and interconnected laminations. These laminations are typically made of ferromagnetic material (e.g., stamped) and are typically between 0.2 mm and 0.5 mm thick. The laminations are stacked on top of each other to form a laminated structure and can be joined together by various methods, including riveting, gluing, welding, or mechanical connections such as pressing. A common method is the use of baking varnish, a special adhesive that cures at elevated temperatures and firmly bonds the laminations together.

[0024] Preferably, the at least one flexible projection is formed on at least one lamination of the rotor lamination stack. For example, the at least one flexible projection can be formed during the stamping process, so that only minor modifications to the stator manufacturing process are necessary to realize the embodiments of the present disclosure. 23-3056

[0025] Preferably, at least one first lamination of the rotor lamination stack has at least one flexible projection, and at least one second lamination of the rotor lamination stack does not have a flexible projection. In other words, laminations with projections and laminations without projections can be present in the direction of the axis of rotation (e.g., alternating). In particular, only some of the laminations of the rotor lamination stack can have a projection, such as every tenth lamination.

[0026] Preferably, the at least one locking element can be inserted axially into the second end region of the receiving space. In one example, the at least one locking element can first be inserted into the second end region of the receiving space, and then the at least one coil winding can be inserted into the receiving space. Alternatively, the at least one coil winding can first be inserted into the receiving space, and then the at least one locking element can be inserted into the second end region of the receiving space.

[0027] Preferably, the at least one locking element can be inserted axially into guide grooves or recesses on opposite radial inner surfaces of the receiving space. This allows the at least one locking element to be fixed at least radially and in the direction of rotation.

[0028] Preferably, the at least one locking element is a slotted locking wedge that can be inserted axially into the guide grooves or recesses on the opposite radial inner surfaces of the receiving space. In other words, the at least one locking element can be a separate element. This can be advantageous, for example, in the case of continuous wave winding.

[0029] Alternatively, the at least one locking element can be widened by the multitude of stator teeth, for example by appropriately shaped end sections or stator feet of the multitude of stator teeth. For example, the end sections can have radial projections that fix the at least one coil winding radially and in the direction of rotation.

[0030] Preferably, the stator further comprises insulation in the receiving space between the stator teeth and the at least one coil winding. The insulation can, for example, be a paper, such as grooved paper, which electrically insulates the at least one coil winding from the stator.

[0031] Preferably, no filling material is present in the receiving space, in particular no resin and / or impregnating material.

[0032] According to a further independent aspect of the present disclosure, a drive system for a hybrid or electric vehicle is specified. The drive system comprises at least one electric drive machine with at least one rotor and at least one stator according to the embodiments of the present disclosure.

[0033] According to another independent aspect of the present disclosure, a hybrid or electric vehicle, in particular a motor vehicle, is specified. The hybrid or electric vehicle comprises the drive system according to the embodiments of the present disclosure.

[0034] Depending on the embodiment, the hybrid or electric vehicle can be a pure electric vehicle (BEV) or a plug-in hybrid vehicle (PHEV).

[0035] The term "vehicle" includes cars, trucks, vans, buses, motorhomes, motorcycles, etc., used for the transport of people, goods, etc. In particular, the term includes motor vehicles for passenger transport.

[0036] According to another independent aspect of the present disclosure, a method for manufacturing a stator for an electric motor of a vehicle drive, in particular of a hybrid or electric vehicle, is specified. The method comprises:

[0037] Providing a stator yoke and a plurality of stator teeth projecting from an inner side of the stator yoke, wherein a receiving space for at least one coil winding is formed between adjacent stator teeth, wherein each receiving space has a first end region on the inner side of the stator yoke and a second end region radially opposite the first end region, and wherein at least one flexible projection is formed in the first end region; 23-3056

[0038] Inserting at least one coil winding into the receiving space, such that the at least one flexible projection is deformed and rests against the at least one coil winding; and

[0039] Closing the second end area of ​​the recording space with at least one closing element.

[0040] It should be understood that the step of inserting at least one coil winding into the receiving space can be performed first, followed by the step of closing the second end area, or that the step of closing the second end area can be performed first, followed by the step of inserting at least one coil winding into the receiving space.

[0041] Brief description of the drawings

[0042] Examples of the manifestation of the revelation are shown in the figures and are described in more detail below. They show:

[0043] Figure 1 schematically shows a sectional view of a stator for an electric motor of a vehicle drive according to embodiments of the present disclosure,

[0044] Figure 2 schematically shows another sectional view of the stator of Figure 1, and

[0045] Figure 3 shows a flowchart of a method for manufacturing a stator for an electric motor of a vehicle drive according to embodiments of the present disclosure.

[0046] Implementations of the revelation

[0047] Unless otherwise noted, the same reference symbols are used for identical and equivalent elements in the following.

[0048] Figure 1 schematically shows a sectional view of a stator 100 for an electric motor of a vehicle drive according to embodiments of the present disclosure. Figure 2 schematically shows another sectional view of the stator 100 of Figure 1. 23-3056

[0049] Figure 1 shows the axis of rotation DA of the electric motor and the axial direction ARI, which runs along or parallel to the axis of rotation DA. Figure 2 shows the radial direction RRI, which extends perpendicularly outwards from the center of the stator 100 or the axis of rotation DA to the edge, and the direction of rotation DR of the electric motor.

[0050] The stator 100 comprises a stator yoke 110 and a plurality of stator teeth 120 projecting from an inner surface 112 of the stator yoke 110, wherein a receiving space AR for at least one coil winding 130 is formed between adjacent stator teeth 120.

[0051] The receiving space AR can be a stator groove, i.e., an elongated depression or slot extending along the inner surface of the stator 100 or stator yoke 110. The receiving spaces AR of the stator 100, in particular the stator grooves, can be arranged radially on the inner surface 112 of the stator yoke 110, evenly distributed along the circumference of the stator yoke 110.

[0052] In some embodiments, each coil winding 130 can consist of a bundle of individual windings, which may, for example, be surrounded by an insulating material 132. In some embodiments, two or more bundles can be inserted into each receiving space AR, e.g., along the radial direction RRI, such as 3, 4, 5, 6 or more bundles.

[0053] The recording space AR has a first end area EB1 on the inside 112 of the stator yoke 110 and a second end area EB2, which is opposite the first end area EB1 (radially).

[0054] In the first end region EB1, at least one flexible projection 114 is formed which can be applied or is in contact with a coil winding 130 that is outermost in the radial direction RRI in the receiving space AR.

[0055] In the second end region EB2, at least one locking element 140 is arranged, which closes the receiving space AR. The combination of flexible projection 114 and locking element 140 secures the coil windings 130 in the receiving space AR, without 23-3056

[0056] Filling material, such as resin and / or an impregnating material, would need to be poured into the gaps.

[0057] In some embodiments, the stator 100 further comprises insulation 150 in the receiving space AR between the stator teeth 120 and the at least one coil winding 130. The insulation 150 can, for example, be a paper, such as grooved paper, which electrically insulates the at least one coil winding 130 from the stator 100.

[0058] The at least one flexible projection 144 can be flexible along or in the direction of the axis of rotation DA of the electric motor, as shown in Figure 1. Furthermore, the at least one flexible projection 114 can be essentially inflexible in the direction of rotation DR of the electric motor or perpendicular to the axis of rotation DA of the electric motor. The projection flexible in one direction can adapt to pressure or changes in shape in that direction, while the projection inflexible in another direction does not allow significant deformation in that other direction, even when a force is applied to it.

[0059] Typically, the at least one flexible projection 114 is plate-shaped. The plane formed by the length and width of the flexible projection 114 can be essentially parallel to the radial direction RRI in the unbent state of the flexible projection 114. Furthermore, the plane formed by the length and width of the flexible projection 114 can be essentially perpendicular to the axis of rotation DA in the unbent state of the flexible projection 114.

[0060] In some embodiments, the stator yoke 110 and / or the plurality of stator teeth 120 are formed from a rotor lamination stack. Here, the at least one flexible projection 114 can be formed on at least one lamination of the rotor lamination stack. For example, the at least one flexible projection 114 can be formed in the stamping process, so that only minor modifications to the manufacturing process of the stator 100 are necessary to realize the embodiments of the present disclosure. 23-3056

[0061] In some embodiments, at least one first lamination of the rotor lamination stack has at least one flexible projection, and at least one second lamination of the rotor lamination stack does not have a flexible projection. In other words, laminations with projections and laminations without projections can be present (e.g., alternating) in the direction of the axis of rotation DA. In particular, only some of the laminations of the rotor lamination stack can have a projection, such as every tenth lamination.

[0062] In some embodiments, the at least one locking element 140 can be inserted axially into the second end region EB2 of the receiving space AR. In one example, the at least one locking element 140 can first be inserted into the second end region EB2 of the receiving space AR, and then the at least one coil winding 130 can be inserted into the receiving space AR. Alternatively, the at least one coil winding 130 can first be inserted into the receiving space AR, and then the at least one locking element 140 can be inserted into the second end region EB1 of the receiving space AR.

[0063] The at least one locking element 140 can be inserted axially into guide grooves or recesses 122 on opposite radial inner surfaces of the receiving space AR. This allows the at least one locking element 140 to be fixed radially and in the direction of rotation DR.

[0064] In some embodiments, the at least one locking element 140, as shown in Figures 1 and 2, is a groove locking wedge that can be inserted axially into the guide grooves or recesses 122 on the opposite radial inner surfaces of the receiving space AR. In other words, the at least one locking element 140 can be a separate element. This can be advantageous, for example, in the case of continuous wave winding.

[0065] Alternatively, the at least one locking element can be widened by the plurality of stator teeth, for example by appropriately shaped end sections or stator feet of the plurality of stator teeth (not shown). For example, the end sections can have radial projections that fix the at least one coil winding radially and in the direction of rotation. 23-3056

[0066] Figure 3 shows a flowchart of a method 300 for manufacturing a stator for an electric motor of a vehicle drive according to embodiments of the present disclosure.

[0067] Method 300 comprises, in block 310, providing a stator yoke and a plurality of stator teeth projecting from an inner side of the stator yoke, wherein a receiving space for at least one coil winding is formed between adjacent stator teeth, wherein each receiving space has a first end region on the inner side of the stator yoke and a second end region opposite the first end region (radially), and wherein at least one flexible projection is formed in the first end region; in block 320, inserting the at least one coil winding into the receiving space, such that the at least one flexible projection is deformed and bears against the at least one coil winding; and in block 330, closing the second end region of the receiving space with at least one closing element.

[0068] It should be understood that first step 320 of inserting the at least one coil winding into the receiving space and then step 330 of closing the second end area can take place, or that first step 330 of closing the second end area and then step 320 of inserting the at least one coil winding into the receiving space can take place.

[0069] According to the invention, the coil windings are arranged between flexible projections on the stator yoke and a locking element. In particular, when the coil windings are inserted into the receiving space, the flexible projections can be bent by contact with the coil windings, so that the flexible projections press against the coil windings and thus fix the coil windings in the receiving space. This eliminates the need to fill gaps in the receiving space with resin or impregnating material, thus simplifying the stator production process and reducing material consumption.

[0070] Although the invention has been further illustrated and explained in detail by means of preferred embodiments, the invention is not limited by the disclosed examples and other variations can be derived from them by a person skilled in the art without reference to 23-3056

[0071] to exceed the scope of protection of the invention. It is therefore clear that a multitude of variations exist. It is also clear that the exemplary embodiments mentioned are merely examples and are not to be interpreted in any way as limiting, for example, the scope of protection, the possible applications, or the configuration of the invention. Rather, the preceding description and the description of the figures enable the person skilled in the art to implement the exemplary embodiments in concrete terms. With knowledge of the disclosed inventive concept, the person skilled in the art can make numerous modifications, for example, regarding the function or the arrangement of individual elements mentioned in an exemplary embodiment, without exceeding the scope of protection defined by the claims and their legal equivalents, such as further explanations in the description.

Claims

23-3056 Patent claims 1. Stator (100) for an electric motor of a vehicle drive, comprising: a stator yoke (110); a plurality of stator teeth (120) projecting from an inner side (112) of the stator yoke (110), wherein a receiving space (AR) for at least one coil winding (130) is formed between adjacent stator teeth (120); and at least one closing element (140) for the receiving space (AR); wherein each receiving space (AR) has a first end region (EB1) on the inner side (112) of the stator yoke (110) and a second end region (EB2) opposite the first end region (EB1), wherein at least one flexible projection (114) is formed in the first end region (EB1) which can be applied against a coil winding (130) in the receiving space (AR), and wherein the at least one closing element (140) is arranged in the second end region (EB2).

2. Stator (100) according to claim 1, wherein the at least one flexible projection (114) is flexible along an axis of rotation (DA) of the electric motor, in particular wherein the at least one flexible projection (114) is substantially inflexible in the direction of rotation (DR) of the electric motor.

3. Stator (100) according to claim 1 or 2, wherein the stator yoke (110) and / or the plurality of stator teeth (120) are formed from a rotor lamination stack, and wherein the at least one flexible projection (114) is formed on at least one lamination of the rotor lamination stack.

4. Stator (100) according to claim 3, wherein at least one first lamination of the rotor lamination stack has at least one flexible projection and at least one second lamination of the rotor lamination stack does not have a flexible projection.

5. Stator (100) according to one of claims 1 to 4, wherein the at least one closure element (140) can be inserted axially into the second end region (EB2) of the receiving space (AR), in particular into guide grooves (122) on opposite radial inner sides of the receiving space (AR). 23-3056 6. Stator (100) according to one of claims 1 to 5, further comprising insulation (150) in the receiving space (AR) between the stator teeth (120) and the at least one coil winding (130).

7. Stator (100) according to any one of claims 1 to 6, wherein no filling material is present in the receiving space (AR), in particular no resin and / or impregnation material.

8. Drive system for a hybrid or electric vehicle, comprising at least one electric drive machine with at least one rotor and at least one stator (100) according to one of claims 1 to 7.

9. Hybrid or electric vehicle comprising the drive system according to claim 8.

10. Method (300) for manufacturing a stator (100) for an electric motor of a vehicle drive, comprising: Providing (310) a stator yoke (110) and a plurality of stator teeth (120) projecting from an inner side (112) of the stator yoke (110), wherein a receiving space (AR) for at least one coil winding (130) is formed between adjacent stator teeth (120), wherein each receiving space (AR) has a first end region (EB1) on the inner side (112) of the stator yoke (110) and a second end region (EB2) opposite the first end region (EB1), and wherein at least one flexible projection (114) is formed in the first end region (E1); Inserting (320) the at least one coil winding (130) into the receiving space (AR) such that the at least one flexible projection (114) is deformed and rests against the at least one coil winding (130); and Closing (330) the second end area (EB2) of the receiving space (AR) with at least one closing element (140).

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