Contacting unit for contacting two contact surfaces of an electric motor, electric motor, and vehicle

Abstract

The invention relates to a contacting unit (100) for electrically connecting two planar contact surfaces (210, 220) of an electric motor, the contacting unit comprising: a main body (110) having an upper face and a lower face; and at least one elastically deformable spring element (120) having a proximal end portion (121) which is part of the main body (110) and is provided for contacting a first (210) of the two planar contact surfaces (210, 220), and having a distal end portion (122) which is spaced from the upper face and is provided for contacting a second (220) of the two planar contact surfaces (210, 220), the contacting unit (100) being characterized in that the distal end portion (122) is designed to make point contact with the second planar contact surface (220) when in contact with the second contact surface (220), and / or the proximal end portion (121) has, on the lower face, a bulge that is designed to make at least point contact with the first contact surface (210) when in contact with the first planar contact surface (210).

Description

[0001] it for contacting two contact surfaces of an electric motor

[0002] Electric motor and vehicle

[0003] The invention relates to a contacting unit of two contact surfaces of an electric motor, an electric motor with such a contacting unit and a vehicle with such a contacting unit and / or such an electric motor.

[0004] An electric motor, for example a permanently excited synchronous motor (PSM) of a vehicle, may comprise a stator housing and a rotor arranged in the stator housing. To control the electric motor, an electronics housing with electronics may be arranged on the stator housing, with the electronics providing control.

[0005] A time-varying magnetic field induces a vortex-like electric field around magnetic flux lines in the stator housing. This electric field drives ring-shaped currents through the stator housing, so-called eddy currents. These flow more effectively the higher the frequency of the magnetic field and the conductivity of the stator housing. According to the magnetic field law, the eddy currents generate a magnetic field, the so-called reaction field. Inside the vortex, this field opposes the external magnetic field and weakens it. As the frequency increases, the induction becomes stronger because the change in the magnetic flux becomes greater. Even a small area penetrated by the magnetic field is sufficient to generate sufficient eddy currents. The current density increases towards the edge of the stator housing, as does the magnetic field strength, which is composed of the external field and the reaction field. This process is called current displacement.At a sufficiently high frequency, the current only flows over the outer circumference of the stator housing (skin effect) and an electrodynamic shield is formed.

[0006] Openings in this shield are caused, among other things, by ventilation openings and housing joints without seals, which leads to reduced shielding effectiveness. Since the current induced by the alternating field can no longer flow freely, slot antennas can form. Continuous contact between the stator housing and the electronics housing cannot be guaranteed due to design constraints, resulting in cavities or air resistance between the stator housing and the electronics housing. This air resistance can also lead to the disadvantages described above.

[0007] If a contact unit is arranged between the stator housing and the electronics housing, a contact force can act on the contact unit between the two contact surfaces. Shear forces and other forces can also occur, which can deform or even damage the contact unit.

[0008] It is therefore an object of the present invention to provide a contacting unit, an electric motor, and a vehicle that eliminate and / or at least improve one or more of the aforementioned disadvantages. In particular, it is an object of the present invention to provide a contacting unit that has improved robustness against shear and other forces, such that the contacting unit can be used flexibly.

[0009] According to a first aspect, the object is achieved by a contacting unit for electrically connecting two contact surfaces of an electric motor. The contacting unit comprises a base body with an upper and a lower side. The contacting unit further comprises at least one elastically deformable spring element with a proximal end section enclosed by the base body for contacting a first of the two flat contact surfaces and a distal end section spaced from the upper side for contacting a second of the two flat contact surfaces.The contacting unit is characterized in that the distal end portion is configured to form a point contact with the first contact surface upon contact with the first contact surface, and / or the proximal end portion has a bulge on the underside configured to form at least one point contact with the second contact surface upon contact with the second contact surface. The contacting unit can have two, three, or more spring elements. The features of the at least one spring element described above and below can be implemented as features of the two, three, or more spring elements.

[0010] By forming the point contact by means of the distal end section and / or the point, in particular line, contact of the bulge, a surface pressure can be increased at the same contact force compared to flat end sections between the two contact surfaces and at the same time a contact resistance can be reduced.

[0011] To form the point contact, the distal end section can be rounded at least in sections and / or at least in sections can simulate a rotational ellipsoid, a bowl, a sphere, or a hemisphere. Due to the rounded shape and / or the simulation, point contact can be ensured even if the second contact surface is tilted relative to the distal end section. Consequently, design and / or manufacturing-related deviations can also be taken into account, and the contacting unit can be used universally for these.

[0012] The proximal end portion may be configured to form a line contact with the second contact surface.

[0013] The distal end portion can be a physical end portion, such that the spring element terminates at the distal end portion. The proximal end portion can be a theoretical end of the spring element, such that the spring element is connected to the base body and / or there is no physical proximal end portion.

[0014] To form the point contact, in particular the linear contact, the bulge can be rounded at least in sections and / or at least in sections simulate a solid cylinder or a half cylinder. The bulge can be formed by deforming the base body, in particular in the region of the proximal end section. The deformation can include or be a bulging toward the underside.

[0015] The contact unit can be made of a sheet metal. The sheet metal can have a uniform thickness along the thickness direction and can be deformed to form the contact unit.

[0016] The spring element(s) may be formed by lateral recesses on the first and / or second sides mentioned below.

[0017] The base body can extend from a first end portion to a second end portion along a longitudinal direction, and the base body can have a predetermined thickness along a thickness direction that runs perpendicular to the longitudinal direction. The base body can extend along a width direction that runs orthogonal to the longitudinal direction and the thickness direction, with a predetermined width, wherein in particular the thickness is smaller than the predetermined width.

[0018] The line contact may extend along a contact direction that is parallel to the longitudinal direction

[0019] The spring element can be arcuate, wherein in particular an intermediate section of the spring element connecting the proximal to the distal end section is arcuate and / or rectilinear at least in sections.

[0020] The spring element, hereinafter referred to as the first spring element, can be adjacent to the first side of the base body. Alternatively or additionally, the contacting unit can further comprise at least one second spring element adjacent to the second side of the base body, wherein the base body extends in the width direction from the first side to the second side. The contacting unit can comprise a plurality of first spring elements and / or second spring elements on at least one of the first and second sides.

[0021] The contacting unit may comprise a plurality of first spring elements with two, three or more first spring elements and / or a plurality of second spring elements with two, three or more second spring elements.

[0022] The distal end portion can extend away from the base body. Viewed along a direction from the bottom to the top, the distal end portion of the first and / or second spring element(s) can extend from the top and be spaced from the top. In contrast, the third and / or fourth spring element can extend along the direction from the bottom and be spaced from the bottom, so that in particular the first and second spring elements extend opposite to the third and fourth spring elements. The first and / or second spring elements can extend upwards along the direction, while the third and / or fourth spring elements extend downwards along the direction.

[0023] The distal end portion of the first and / or second spring elements can be arranged between the base body and, in the state of the contacting unit arranged between the two contact surfaces, the contact surface of the two contact surfaces that faces the upper side. In contrast, the distal end portion of the third and / or fourth spring elements can be arranged between the lower side and the other contact surface of the two contact surfaces that faces the lower side.

[0024] The first spring elements can have a predetermined spacing along the first side, in particular along the longitudinal direction. The predetermined spacing can be uniform and / or irregular. The second spring elements can have a predetermined spacing along the second side, in particular along the longitudinal direction. The predetermined spacing can be uniform and / or irregular. When arranging the first spring elements on the first side and the second spring elements on the second side, these can be offset or parallel to one another, viewed along the longitudinal direction.

[0025] The contacting unit can comprise at least a third spring element that has a proximal end portion enclosed by the base body and a distal end portion spaced from the underside. Consequently, the third spring element can be oriented opposite to the first and / or second spring elements when viewed along the direction of thickness. Furthermore, the contacting unit can comprise at least a fourth spring element. Thus, the third and / or fourth spring elements can be formed on the first and / or second side. In the embodiment with the third and / or fourth spring element, the proximal end portion can be formed without the bulge, since contact with the two contact surfaces occurs via the first, second, third and / or fourth spring elements.Features related to the first and second spring elements may be formed as features of the third and fourth spring elements, wherein the first and second spring elements extend upwardly from the top side and the third and fourth spring elements extend downwardly from the bottom side.

[0026] The contacting unit may consist of or comprise an electrically conductive material.

[0027] The contact unit can be formed in one piece. Alternatively or additionally, the base body can be ring-shaped and / or racetrack-shaped.

[0028] The thickness of the base body and a thickness of the spring element and / or the second spring element can be the same.

[0029] The object is achieved according to a second aspect by an electric motor comprising a contacting unit according to the first aspect.

[0030] The electric motor may comprise a stator housing with one of the contact surfaces and an electronics housing with the other of the contact surfaces, wherein the contacting unit is arranged between the first and second contact surfaces and electrically connects them to one another.

[0031] According to a third aspect, the object is achieved by a vehicle comprising a contact unit according to the first aspect and / or an electric motor according to the second aspect. The vehicle may comprise an electric motor.

[0032] Preferred embodiments are explained using the accompanying figures. They show:

[0033] Fig. 1 is a perspective view of an embodiment of a contacting unit;

[0034] Fig.2 is a further perspective view of the embodiment of Fig. 1;

[0035] Fig. 3 shows an embodiment of a contacting unit in an electric motor; and

[0036] Fig. 4 a vehicle with an electric motor and a contact unit

[0037] In the figures, identical or essentially functionally identical or similar elements are designated by the same reference numerals.

[0038] 1 and 2 show perspective views of an embodiment of a contacting unit 100 for contacting two planar contact surfaces 210, 220 of an electric motor 200. The contacting unit 100 comprises a base body 110 with a top and a bottom side. The contacting unit 100 further comprises at least one elastically deformable spring element 120, here three spring elements 120 with a proximal end section 121 enclosed by the base body 110 for contacting a first 210 of the two planar contact surfaces 210, 220 and a distal end section 122 spaced from the top side for contacting a second 220 of the two planar contact surfaces 210, 220. In FIG. 1, the distal end section 122 extends upward.

[0039] As shown in Figs. 1 and 2, the distal end portion 122 is rounded at least in sections and / or at least in sections simulates an ellipsoid of revolution, a bowl, a sphere, or a hemisphere. Consequently, the distal end portion is round when viewed in three-dimensional space. The proximal end portion 121 is also rounded in sections. In particular, the proximal end portion simulates a half-cylinder.

[0040] Fig. 3 shows a side view of the contacting unit 100 between the contact surfaces 210, 220 of the electric motor 200. As shown in Fig. 3, the distal end portion 121, due to its rounded shape, is designed to form a point contact with the second contact surface 220 upon contact with the second flat contact surface 220. Furthermore, the proximal end portion 220, due to its semi-cylindrical shape, forms a bulge on the underside, which is designed to form at least one point contact, in particular here a line contact, with the first contact surface 210 upon contact with the first flat contact surface 210.Due to the rounded shapes of the proximal and distal end sections 121, 122, the contact surface 210, 220 between the end sections 121, 122 and the contact surfaces 210, 220 is reduced and, with the same contact force, a significantly higher surface pressure is achieved, which results in a lower contact resistance.

[0041] As further shown in Figs. 1 and 2, the contacting unit 100 can be formed by deforming and processing a sheet metal, in particular with a predetermined sheet thickness. Furthermore, Figs. 1 and 2 show that the bulge is formed by bulging the base body 110 in the region of the proximal end section 110 toward the underside. Consequently, the contacting unit 100 can be easily manufactured.

[0042] Fig. 3 further shows the contacting unit 100 in the electric motor 200, wherein the contacting unit 100 electrically connects the first and second contact surfaces 210, 220. Due to structural reasons, the two contact surfaces 210, 220 are not electrically connected to one another without the contacting unit 100, which, as described above, is disadvantageous. Furthermore, the distance between the two contact surfaces 210, 220 can vary, necessitating an adaptable contacting unit 100. Fig. 3 shows a contact force F pressing the distal end portions 122 of the spring elements 120 downward. This contact force F deforms the spring elements 120 from an original state into a deformed state. In the deformed state, the spring elements 120 exert a downward force on the proximal end portion 121 so that it is brought into contact with the lower contact surface 220.The point and line contact provides a high surface pressure.

[0043] Figure 3 further shows that the contact surfaces 210, 220 are flat in the region of the contacting unit 100. In other words, the contact surfaces 210, 220 extend along two planes in the region of the contacting unit, which are particularly parallel to one another. Even if the planes are not parallel, a point or line contact can be provided.

[0044] Fig. 4 shows a vehicle 300 with an electric motor 200, wherein the two contact surfaces 210, 220 of the electric motor 200 are electrically connected to one another by means of the contacting unit 100.

[0045] Reference symbol

[0046] 100 contact unit

[0047] 110 basic bodies

[0048] 120 spring element

[0049] 121 proximal end section

[0050] 122 distal end section

[0051] 200 electric motor

[0052] 210 contact surface

[0053] 220 contact area

[0054] F contact force

[0055] 300 vehicle io

Claims

Patent claims 1 . Contacting unit (100) for electrically connecting two flat contact surfaces (210, 220) of an electric motor (200), comprising: a base body (110) with an upper side and a lower side;at least one elastically deformable spring element (120) with a proximal end section (121) enclosed by the base body (110) for contacting a first (210) of the two planar contact surfaces (210, 220) and a distal end section (122) spaced from the upper side for contacting a second (220) of the two planar contact surfaces (210, 220), wherein the contacting unit (100) is characterized in that the distal end section (122) is designed to form a point contact with the second contact surface (220) upon contact with the second planar contact surface (220), and / or the proximal end section (121) has a bulge on the underside which is designed to form at least one point contact with the first contact surface (210) upon contact with the first planar contact surface (210); 2. Contacting unit (100) according to claim 1, wherein the distal end portion (122) is rounded at least in sections to form the point contact and / or at least in sections simulates an ellipsoid of revolution, a shell, a sphere or a hemisphere.

3. Contacting unit (100) according to claim 1 or 2, wherein the proximal end portion (121) is designed to form a line contact with the second contact surface (220).

4. Contacting unit (100) according to one of the preceding claims, wherein the bulge for forming the point contact, in particular the line contact, is rounded at least in sections and / or at least in sections simulates a solid cylinder or a half cylinder.

5. Contacting unit (100) according to one of the preceding claims, wherein the base body (110) extends from a first end section to a second end section along a longitudinal direction and the base body has a predetermined thickness along a thickness direction which runs perpendicular to the longitudinal direction, wherein the base body (110) extends along a width direction which runs orthogonal to the longitudinal direction and to the thickness direction with a predetermined width, wherein in particular the predetermined thickness is smaller than the predetermined width.

6. Contacting unit (100) according to claim 5, wherein the line contact extends along a contact direction that is parallel to the longitudinal direction.

7. Contacting unit (100) according to one of the preceding claims, wherein the spring element (120) is arcuate, wherein in particular an intermediate section of the spring element (120) connecting the proximal to the distal end section (121, 122) is arcuate at least in sections.

8. Contacting unit (100) according to one of the preceding claims, wherein the spring element (120) is adjacent to a first side of the base body (110), and / or wherein the contacting unit (100) further comprises at least one second spring element (120) which is adjacent to a second side of the base body (110), wherein the base body (100) extends in the width direction from the first side to the second side.

9. Contacting unit (100) according to one of the preceding claims, wherein the contacting unit (100) is formed in one piece, and / or wherein the base body (100) is ring-shaped and / or racetrack-shaped.

10. Contacting unit (100) according to one of the preceding claims, wherein the thickness of the base body (110) and a thickness of the spring element (120) are the same.

11. Electric motor (200) comprising a contacting unit (100) according to one of the preceding claims.

12. Electric motor (200) according to claim 11, wherein the electric motor (200) comprises a stator housing with the first contact surface (210, 220) and an electronics housing with the second contact surface (210, 220), wherein the contacting unit (100) is arranged between the first and second contact surfaces (210, 220) and electrically connects them to one another.

13. Vehicle (300) comprising a contacting unit (100) according to one of claims 1 to 10 and / or an electric motor (200) according to claim 11 or 12.

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