Electric machine with a connecting element for connecting a winding of a stator to a printed circuit board having at least two insulation displacement contacts

Abstract

The invention relates to an electric motor, comprising a rotor and a stator, wherein the winding is formed by a winding wire having a winding wire end (5), wherein the winding wire end (5) is electrically contacted with the printed circuit board (3) at the end face via a connecting element (1), wherein each of the connecting elements (1) has at least two insulation displacement contacts (4), wherein a winding wire end (5) of the stator winding is received in each insulation displacement contact, wherein each connecting element (1) has a separate electrical connection with the printed circuit board (3), wherein the connecting element (1) has a base body (8), wherein in the assembled state, the bottom face of the base body is in contact with the printed circuit board (3), wherein each of the at least two insulation displacement contacts (4) has a clamping groove (7) which is perpendicular to the bottom face of the base body (8), wherein the clamping groove (7) is formed by spaced-apart legs (11, 12, 13) extending from the base body (8), wherein at least two of the legs (11, 12) are of elastic design.

Description

[0001] The invention relates to an electric machine having a connecting element for electrically connecting a winding of a stator to a printed circuit board, having the features according to the invention.

[0002] The electric motor comprises a rotor connected to the motor shaft and rotatably mounted in a housing. The rotor is provided with permanent magnets. The stator is arranged in or around the rotor and carries a plurality of windings on an iron core. When properly controlled, the windings generate a magnetic field that drives the rotor in rotation. The windings are usually wound in three phases and are correspondingly provided with three electrical connections, by means of which the windings can be connected to a control unit (ECU). For this purpose, the windings are usually contacted with a printed circuit board, on which the control unit is arranged. The contact is made by means of soldered and brazed connections or by means of insulation displacement contacts (IDC).

[0003] The object of the present invention is to provide a connecting element for electrically connecting a winding of a stator to a printed circuit board which allows contacting which is as simple as possible and has a long service life.

[0004] This object is achieved by an electric machine having a connecting element and having the features according to the invention.

[0005] Thus, the electric motor has a rotor and a stator, the rotor being mounted in a rotatable manner about a rotation axis, the stator having a stator core and a coil wound on the stator core, the winding being formed by a winding wire having winding wire ends, and the winding wire ends being in electrical contact with a printed circuit board at an end face via connecting elements. Each connecting element has at least two insulation displacement contacts, in each of which a single winding wire end of the stator winding is received. Each connecting element has a single electrical connection to the printed circuit board. The connecting element combines the winding wire ends into one electrical connection to the circuit board, thereby making it possible to save space and reduce the number of electrical connections. The insulation displacement connector enables long-term contacting of the winding wire. The electrical connection is preferably a solder connection or a single press-fit contact.

[0006] The connecting element also has a base body, the bottom side of which contacts the printed circuit board in the assembled state, and at least two insulation displacement contacts each have a clamping groove oriented perpendicularly to the bottom side of the base body. The winding wire end can thus be inserted particularly easily into the groove. The grooves are preferably arranged parallel to each other.

[0007] The clamping slot is formed by spaced legs extending from the base, at least two of the legs being resilient.

[0008] In one embodiment, the two clamping slots are formed by three legs, the middle leg being part of the two insulation displacement contacts. The middle leg is preferably rigidly formed. However, it is also possible to provide that each insulation displacement contact has two legs, and that all legs are spaced apart from each other.

[0009] It is advantageous if a winding wire end accommodated in at least two insulation displacement contacts of a connecting element is assigned to one motor phase. Since no insulation is required between the contacts, the wire diameter of the winding wire can be increased, thereby increasing the current carrying capacity of the motor per phase. Preferably, only two insulation displacement contacts are provided per connecting element.

[0010] Two preferred embodiments of the present invention are described in more detail below in conjunction with the accompanying drawings. Similar or similarly functioning components are indicated by the same reference numerals in the drawings. They show:

[0011] Figure 1 : A longitudinal section through a connecting element with two insulation displacement contacts, and

[0012] Figure 2 : Longitudinal section through another connecting element with two insulation displacement contacts.

[0013] Figure 1 and Figure 2 The connecting elements 1 shown in the drawings have in common that they comprise a single press-fit contact 2 for making electrical contact with a printed circuit board 3 and two insulation displacement contacts 4 for respectively receiving an end 5 of a winding wire 6 of a stator of an electric machine.

[0014] The insulation displacement contact (IDC) 4 has a clamping groove 7. The sharp contact in the clamping groove 7 cuts the insulation of the winding wire end 5, and realizes the electrical contact of the core of the winding wire 6.

[0015] Since only one press-fit contact 2 is provided, this results in a more compact design than using two separate connecting elements, each with one press-fit contact. Each clamping groove 7 accommodates only one winding wire end 5. This has the advantage that a defined gap geometry exists before the winding wire end 5 is pressed in. Furthermore, this results in better contact reliability, which remains even after aging and vibration loads of the connecting element 1.

[0016] The two ends 5 that are in contact in one connecting element 1 are associated with one phase of the motor. Since no insulation is required between the contacts, the wire diameter of the winding wire can be increased, thereby increasing the current carrying capacity of each phase of the motor.

[0017] like Figure 1As shown, the connecting element 1 preferably has a flat base body 8 with two opposite end faces 9, 10. The first end face 10 rests on the printed circuit board 3 with a large area in the state attached to the printed circuit board 3. The press-fit contact 2 is formed on this first end face 10. Two insulation displacement contacts 4 are arranged on the second end face 9, each of which is formed by two legs 11, 12 extending away from the base body 8. A clamping groove 7 is arranged between each two legs 11, 12. The legs 11, 12 are arranged spaced apart from each other. The clamping groove 7 is arranged approximately perpendicular to the surface of the printed circuit board 3 and the first end face 10 of the base body 8. In each case, one wire 6 is inserted into one insulation displacement contact 4 or clamping groove 7. The insertion direction is schematically indicated by an arrow 13. The legs 11, 12 are preferably elastic in order to allow permanent and stable pressing of the winding wire 6 in the clamping groove 7. The clamping groove 7 has a sharp contact area on the inside of the surface of the leg, which strips the winding wire 6 when the winding wire 6 is pressed in and passed through. The clamping groove 7 has an insertion and pressing chamfer 14.

[0018] Figure 2 Another embodiment is shown. Figure 1 Compared to the embodiment of the present invention, only three spaced-apart legs 11, 12, 13 are provided on the second end face 9 of the base body 8. The two insulation displacement contacts 4 share the middle leg 13. The middle leg 13 is rigidly designed, located between the two outer legs 11, 12 and thus forming two clamping grooves 7. In order to enable the winding wire end to be permanently pressed into the clamping groove 7, the two outer legs 11, 12 are of elastic design. The clamping groove 7 also has an insertion and pressing chamfer 14.

[0019] In a further embodiment, depending on the application, a connecting element with more than two insulation displacement contacts may also be provided.

[0020] Often, the connecting elements may not have press-fit contacts but may be soldered directly to the printed circuit board.

[0021] The winding wire is preferably formed from enameled copper wire.

Claims

1. An electric machine comprising a rotor and a stator, wherein the rotor is mounted rotatably about a rotation axis, the stator comprises a stator core and a coil wound on the stator core, the winding being formed by a winding wire having winding wire ends (5), and wherein: The winding wire end (5) is electrically contacted with the printed circuit board (3) at the end face through the connecting element (1), wherein the connecting elements (1) each have at least two insulation displacement contacts (4), in each insulation displacement contact the winding wire end (5) of the stator winding is received, and each connecting element (1) has a separate electrical connection with the printed circuit board (3), characterized in that the connecting element (1) has a base (8), in the assembled state, the bottom face of the base (8) is in contact with the printed circuit board (3), the opposite side ends of the base (8) include a recessed arc-shaped cavity below the at least two insulation displacement contacts (4), and the at least two insulation displacement contacts (4) each have a clamping groove (7), the clamping groove (7) is perpendicular to the bottom face of the base (8), and the clamping groove (7) is formed by spaced legs (11, 12, 13) extending from the base (8), and at least two legs (11, 12) are of elastic design; Each of the connecting elements (1) is defined by a respective one-piece monolithic component.

2. The motor according to claim 1, characterized in that The electrical connection is a soldered connection or a single press-fit contact (2).

3. The motor according to claim 1 or 2, characterized in that: The two clamping grooves (7) are formed by three legs (11, 12, 13), the middle leg (13) being part of the two insulation displacement contacts (4).

4. The motor according to claim 3, characterized in that The middle leg (13) is rigid.

5. The electric machine according to any one of the preceding claims, characterized in that The winding wire ends (5) accommodated in the at least two insulation displacement contacts (4) of the connecting element (1) are assigned to a motor phase.

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