ELECTRIC MOTOR AND SWITCHING UNIT THEREFOR

Abstract

An electric motor has a switching unit with a number of contact wires and an annular frame part. The contact wires are arranged to form an interconnect ring for the coil ends of a stator winding and the ends of the wires being connected by insulation displacement contacts. Each of the contacts have two insulation displacement limbs for connecting at least two of the wire ends, the limbs being spaced apart, thus forming an insulation displacement slot therebetween. The frame part of the switching unit has a number of plug-in pockets for receiving the insulation displacement contacts, the number corresponding to the number of insulation displacement contacts.

Claims

1. An electric motor, comprising: a switching unit having a number of contact wires, an annular frame part, and insulation-displacement contacts; said contact wires disposed to form an interconnection ring for coil ends of a stator winding, said contact wires having wire ends connected to said insulation-displacement contacts; each of said insulation-displacement contacts having two insulation-displacement limbs for connecting at least two of said wire ends and said two insulation-displacement limbs are spaced apart from one another so as to form an insulation-displacement slot; and said annular frame part of said switching unit having a number of insertion pockets, corresponding to a number of said insulation-displacement contacts, for receiving said insulation-displacement contacts.

2. The electric motor according to claim 1, wherein said insertion pockets of said annular frame part each have a slot formed therein which is in alignment with said insulation-displacement slot of one of said insulation-displacement contacts which is inserted into said insertion pockets.

3. The electric motor according to claim 1, wherein: each of said insulation-displacement contacts has at least one limb-side blade edge; and said insulation-displacement slot and/or said insulation-displacement limbs of at least one said insulation-displacement contacts is configured such that at least two of said wire ends, which are introduced into said insulation-displacement slot one behind the other in a slot longitudinal direction and which are guided along said at least one limb-side blade edge there, are in reliable clamping contact.

4. The electric motor according to claim 1, wherein said insulation-displacement slot of at least one of said insulation-displacement contacts has, in a slot longitudinal direction, a first slot region, a limb free end-side slot opening formed therein and adjoining said first slot region, and a second slot region which adjoins said first slot region and is widened.

5. The electric motor according to claim 4, wherein said insulation-displacement slot of at least one of said insulation-displacement contacts has a recess contour, which forms a predetermined bending point for one of said insulation-displacement limbs, in a slot end region which is averted from said limb free end-side slot opening in the slot longitudinal direction.

6. The electric motor according to claim 5, wherein said recess contour, which serves as said predetermined bending point, forms an abutment contour, which narrows said insulation-displacement slot, as a stop for at least one of said wire ends.

7. The electric motor according to claim 1, wherein at least one of said insulation-displacement limbs of said insulation-displacement contacts has, on an outside of said one insulation-displacement limb, at least one raised joining contour.

8. The electric motor according to claim 1, wherein the electric motor is a brushless radiator fan motor of a motor vehicle.

9. The electric motor according to claim 4, wherein said second slot region is widened in a shape of a diamond or a rhombus.

10. The electric motor according to claim 5, wherein said recess contour is a circularly shaped recess contour.

11. A switching unit for an electric motor, comprising: a number of contact wires for interconnecting coils of a stator winding; and a number of phase connections which are formed by a corresponding number of insulation-displacement contacts or contain said insulation-displacement contacts.

12. The switching unit according to claim 11, further comprising a frame part with a number of insertion pockets corresponding to a number of said insulation-displacement contacts and for receiving said insulation-displacement contacts.

13. An insulation-displacement contact for connecting at least two wires or wire ends of a switching unit, comprising: two insulation-displacement limbs being spaced apart from one another so as to form an insulation-displacement slot.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0029] FIGS. 1A and 1B are diagrammatic, perspective views of an insulation-displacement contact with an insulation-displacement slot which is flanked by two insulation-displacement limbs, without or with a joining contour arranged on the outside of a limb of a slot opening, according to the invention;

[0030] FIG. 2 is a front view of one of the insulation-displacement limbs of an insulation-displacement contact with a circular recess in the limb transition region, which circular recess produces a predetermined bending point;

[0031] FIG. 3 is a perspective view of an interconnection ring with a plurality of contact wires which are arranged in a circle and three insulation-displacement contacts which are arranged equidistantly;

[0032] FIG. 4 is a perspective view, according to FIG. 3, of a switching unit with an interconnection ring of the kind and with an annular frame element;

[0033] FIG. 5 is a perspective view of the switching unit according to FIG. 4 without the interconnection ring and with a view of an insertion pocket without an insulation-displacement contact inserted;

[0034] FIG. 6 is a perspective view, according to FIG. 5, of one embodiment of the switching unit with closed coil cassettes;

[0035] FIG. 7 is a perspective view of a stator with the switching unit fitted;

[0036] FIG. 8 is a perspective view of the stator with the switching unit fitted and the rotor and also the electronics system (printed circuit board) of an electric motor, the electronics system being connected to the insulation-displacement contacts; and

[0037] FIG. 9 is a perspective view of the electric motor as a radiator fan motor for motor vehicle, including the switching unit and the electronics system.

DETAILED DESCRIPTION OF THE INVENTION

[0038] Referring now to the figures of the drawings in detail and first, particularly to FIG. 1A and 1B thereof, there is shown an insulation-displacement contact 1, simply called contact in the text which follows, with an insulation-displacement slot, simply called slot 2 in the text which follows, which is flanked by two insulation-displacement limbs, simply called limbs 3 in the text which follows, of the insulation-displacement contact 1, that is to say is located or formed between the two limbs 3. The contact 1 is preferably a stamped part. The limbs 3 of the contact 1 merge with a contact head 5 which is preferably provided with a passage opening (passage bore) 4. Joining contours 6 (grooves, pegs) are integrally formed or stamped into the outside of the limbs 3.

[0039] The slot 2 has a slot opening 7 in the region of the free ends of the limbs 3. A first, comparatively short insulation-displacement contour 9 adjoins the slot in the slot longitudinal direction 8. The insulation-displacement contour merges with a widened region 10 in the slot longitudinal direction 8. Said widened region is preferably diamond-shaped. A further, comparatively long insulation-displacement region, but at least a clamping region 11, adjoins the region 10 in turn. The insulation-displacement region ends at the ends which are situated opposite the limb free ends, that is to say at the transition region 12 of the limbs 3.

[0040] On account of these contact geometries, reliable contact connection of not only one wire, but rather of two or more wires, is possible. The wires are introduced or pressed into the slot 2 one after the other in the slot longitudinal direction 8 and in the process (azimuthally) cut on the circumference. In this case, the cut depth is greater than or equal to the thickness of an insulation (insulating sheathing) of the or each wire. To this end, the mutually facing limb edges of the limbs 3 are designed in the manner of blades as blade edges 13 in the region of the slot 2. The reduction in diameter of the first wire which is cut in the slot 2 is, for example, approximately 22%, while the reduction in diameter of the further wire which is cut in the slot 2 is, for example, approximately 16%, based on a copper wire with a diameter of, for example, 1.12 mm and a wire insulation of, for example, 0.003 mm, that is to say a total wire diameter of approximately 1.15 mm to 1.16 mm.

[0041] In the embodiment illustrated in FIG. 2 of the insulation-displacement contact 1, of which only the left-hand side insulation-displacement limb 3 is illustrated, the diamond-shaped region 10 has, on the side facing the slot opening 7, a tapering, comparatively pronounced cutting contour 10a. A recess contour 12a, which is round in the exemplary embodiment, is provided in or at the transition region 12 of the limbs 3. This leads to an at least slight reduction in the limb width b of the limbs 3 in comparison to the limb width of the insulation-displacement contacts 1 according to FIGS. 1A and 1B without a recess contour of this kind in the transition region 12.

[0042] This recess contour 12a defines a predetermined bending point 12b for the limbs 3 when the limbs bend outward as the wires or wire ends denoted 20 are introduced into the insulation-displacement slot 2 of the contact 1. In addition, the recess contour 12a forms an abutment edge 12c, for example in the form of a sector-like protrusion, which narrows the insulation-displacement slot 2 as a slot-internal stop for the wire ends 20.

[0043] FIG. 3 shows an interconnection ring 18 with a plurality of contact wires 19 which are arranged in a circle and three insulation-displacement contacts 1 which are arranged equidistantly and with each of which two wires or wire ends 20 make insulation-displacement contact.

[0044] FIG. 4 shows a switching unit 21 with an interconnection ring 18 of this kind. The switching unit 21 has an annular frame body (frame part) 22, preferably composed of plastic. The frame body in turn has, in the region of the respective insulation-displacement contact 1, a receiving pocket (insertion/joining pocket) 23 for receiving the insulation-displacement contact 1.

[0045] FIG. 5 shows the switching unit 21 or the frame part 22 according to FIG. 4 with two insulation-displacement contacts 1 inserted into the associated insertion pockets 23, while the insertion pocket 23 shown in the foreground of the figure is shown without an insulation-displacement contact 1. The slots 25 which are introduced into the insertion pockets 23 and are in turn provided with a slot opening 24 at the end side are in alignment with the slot 2 of the respective insulation-displacement contact 1. In this case, the respective frame-side slot opening 24 is located on that slot side which is situated opposite the slot opening 7 of the insulation-displacement contact 1, that is to say on the introduction or insertion side of the respective insertion pockets 23.

[0046] As shown in FIGS. 3 and 4, the wire ends 20 with which contact is made run normally to the slot plane spanned by the slot 2.

[0047] FIG. 6 shows a further embodiment of the switching unit with complete, closed coil cassettes 26 which are integrally formed on the frame part 22 of the switching unit 21. In the assembled state of the stator 27, shown in FIG. 7, of an electric motor 28, the coil cassettes receive the stator teeth of the stator and the individual coils of the stator winding are or will be wound around the coil cassette, in a manner not illustrated in any detail.

[0048] FIG. 8 shows the stator 27, provided with the switching unit 21, according to FIG. 7, including the rotor 29 and motor shaft 30 and also including the electronics system (printed circuit board) 31 and the contact-connections between the electronics system and the insulation-displacement contacts 1 by the contact heads 5 of the insulation-displacement contacts. The contact heads are inserted into, for example crimped lug-like, insertion pockets 32 of contacts (flat contacts), which are produced as stamped and bent parts from flat wire, or contact sections 33 and in the process form the phase connections for three-phase current supply to the stator or motor winding.

[0049] FIG. 9 shows the fitted or assembled electric motor 28 as a radiator fan motor for a motor vehicle, including the stator 27, switching unit 21 and fan impeller 34.

[0050] The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention: [0051] 1 Insulation-displacement contact [0052] 2 Insulation-displacement slot [0053] 3 Insulation-displacement limb [0054] 4 Passage opening/bore [0055] 5 Contact head [0056] 6 Joining contour [0057] 7 Slot opening [0058] 8 Slot longitudinal direction [0059] 9 Insulation-displacement contour [0060] 10 Region [0061] 11 Insulation-displacement region [0062] 12 Transition region [0063] 12a Recess contour [0064] 12b Predetermined bending point [0065] 12c Abutment edge/stop [0066] 13 Blade edge [0067] 18 Interconnection ring [0068] 19 Contact wire [0069] 20 Wire/wire end [0070] 21 Switching unit [0071] 22 Frame part/body [0072] 23 Receiving/insertion/joining pocket [0073] 24 Slot opening [0074] 25 Slot [0075] 26 Coil cassette [0076] 27 Stator [0077] 28 Electric motor [0078] 29 Rotor [0079] 30 Motor shaft [0080] 31 Electronics system/printed circuit board [0081] 32 Insertion pocket [0082] 33 Contact/contact section [0083] 34 Fan impeller