BUS BAR AND METHOD FOR CONTACTING AN ELECTRIC MOTOR

Abstract

A bus bar (1) and a method for contacting an electric motor, addresses the problem of specifying a solution with which a simple, reliable and secure contacting of the electric motor is achieved. This problem is resolved at the device side thereby that on the first end (3) of the bus bar (1) a hole (5) is disposed that is undersized in comparison to the diameter of the feed-through contact (6). A method is provided wherein a bus bar (1) is provided which, on a first end (3) of the bus bar (1), comprises a hole (5) that is undersized compared to the diameter of the feed-through contact (6) and that the contacting of a feed-through contact (6) of an electric motor with the hole (5) of the provided bus bar (1) takes place in one operating step by press-fitting a stator (12) connected with the feed-through contacts (6).

Claims

1.-10. (canceled)

11. A bus bar for contacting a feed-through contact of an electric motor, wherein the bus bar has a first end and a second end, wherein on the first end of the bus bar a hole is disposed that is undersized compared to the diameter of the feed-through contact.

12. A bus bar as in claim 11, wherein at the hole a flange encompassing the hole is disposed.

13. A bus bar as in claim 11, wherein the hole is round, oval, n-gonal or has the form of a cloverleaf.

14. A bus bar as in one of claims 11, wherein the second end of the bus bar is disposed bent at an angle of 30, 45 or 90.

15. A bus bar as in one of claims 11, wherein the second end of the bus bar is disposed connected to conductor tracks of a circuit board.

16. A method for contacting a feed-through contact of an electric motor, wherein a bus bar is connected electrically conducting with the feed-through contact, wherein a bus bar is provided which at a first end of the bus bar comprises a hole being undersized in comparison to the diameter of the feed-through contact and that the contacting of a feed-through contact of an electric motor with the hole of the provided bus bar is carried out in an operation step comprising the press-fitting of a stator connected with the feed-through contact.

17. A method as in claim 16, wherein the bus bar is provided with a flange encompassing the hole.

18. A method as in claim 16, wherein the bus bar is provided with a curvature or a bend for the purpose of tolerance compensation.

19. A method as in one of claims 16, wherein the bus bar is provided with a second end bent at an angle of 30, 45 or 90.

20. A method as in one of claims 16, wherein the bus bar is contacted with its first end across the feed-through contact with a stator winding of a motor and with its second end with a conductor track of a circuit board, wherein on the circuit board the components required for activating the motor are disposed that provide an inverter circuit.

21. A method as in claim 17, wherein the bus bar is contacted with its first end across the feed-through contact with a stator winding of a motor and with its second end with a conductor track of a circuit board, wherein on the circuit board the components required for activating the motor are disposed that provide an inverter circuit.

22. A method as in claim 18, wherein the bus bar is contacted with its first end across the feed-through contact with a stator winding of a motor and with its second end with a conductor track of a circuit board, wherein on the circuit board the components required for activating the motor are disposed that provide an inverter circuit.

23. A method as in claim 17, wherein the bus bar is provided with a curvature or a bend for the purpose of tolerance compensation.

24. A method according to 17, wherein the bus bar is provided with a second end bent at an angle of 30, 45 or 90.

25. A method according to 18, wherein the bus bar is provided with a second end bent at an angle of 30, 45 or 90.

26. A bus bar as in one of claims 12, wherein the second end of the bus bar is disposed bent at an angle of 30, 45 or 90.

27. A bus bar as in one of claims 13, wherein the second end of the bus bar is disposed bent at an angle of 30, 45 or 90.

28. A bus bar as in one of claims 12, wherein the second end of the bus bar is disposed connected to conductor tracks of a circuit board.

29. A bus bar as in one of claims 13, wherein the second end of the bus bar is disposed connected to conductor tracks of a circuit board.

30. A bus bar as in one of claims 14, wherein the second end of the bus bar is disposed connected to conductor tracks of a circuit board.

Description

[0045] Further details, characteristics and advantages of embodiments of the invention are evident in the following description of embodiment examples with reference to the associated drawing. Therein depict:

[0046] FIG. 1 a prior art unit, comprised of three bus bars with press-fit spring contact sleeves, provided for contacting a motor,

[0047] FIG. 2 an alternative prior art unit having three bus bars for contacting an electric motor, each with integrated spring contact sleeves,

[0048] FIG. 3 an embodiment of a bus bar according to the invention,

[0049] FIG. 4 an alternative embodiment of a bus bar according to the invention,

[0050] FIG. 5 a sectional representation through a feed-through contact with a pressed-on bus bar,

[0051] FIG. 6 a device for carrying out the method for contacting an electric motor with the bus bars according to the invention, in a first state,

[0052] FIG. 7 the device for carrying out the method for contacting an electric motor with the bus bars according to the invention, in a second state, and

[0053] FIG. 8 a perspective representation of a motor housing with feed-through contacts and pressed-on bus bars.

[0054] In FIG. 1 is depicted a unit intended for contacting a motor, comprised of three bus bars 1 each with press-fit spring contact sleeves 2 of prior art. Each of the three prior art bus bars 1 comprises at a first end 3 a spring contact sleeve 2 attached electrically conductive to the bus bar 1. These spring contact sleeves 2 can be connected with the bus bar 1 for example by welding, soldering or bolting.

[0055] At the particular second end 4 each of the bus bars 1 has an end which is suitable, for example for connecting with a, not shown, circuit board 10. Such electrically conductive connection can be established, for example, by soldering or bolting.

[0056] The three bus bars 1 are disposed in a common receiver or a housing which insulates the bus bars 1 against each other. The spring contact sleeves 2 of the bus bars 1 are slid onto the feed-through contacts 6 of a motor and in this way connect a circuit board 10 controlling the motor with the feed-through contacts 6, which are contacted, for example, with a stator having several stator windings. To the motor, consequently, a control voltage or a control current can be supplied.

[0057] In FIG. 2 an alternative prior art unit having three bus bars 1 for contacting an electric motor is shown, each including integrated spring contact sleeves 2. In this implementation the spring contact sleeves 2 are integrated at a first end 3 of the bus bar 1 in a special receiver and connected with the bus bars 1.

[0058] However, the implementations shown in FIGS. 1 and 2 have the disadvantage that the lines or bus bars to be contacted with a feed-through contact 6 must each be equipped with a spring contact sleeve 2 or a spring contact element at a first end 3, which makes these solutions complex and expensive.

[0059] In FIG. 3 a first embodiment of a bus bar 1 according to the invention is depicted. It is provided to punch the bus bar 1 out of, for example, a conductive metal sheet of appropriate thickness or strength and to provide it at its first end 3 with a hole 5. In a later press-fit process this hole 5 serves for receiving a, not shown, feed-through contact 6. One or several of these feed-through contacts 6 having a circular cross section are placed according to prior art in corresponding bores in housing 8 of a motor in order to establish an electrical connection between stator windings located in the motor and an activating unit.

[0060] The second end 4 of bus bar 1 can optionally be angled and/or developed into a contact which is electrically connected with the control unit activating the motor.

[0061] The hole 5 in the bus bar 1 can be, for example, round or oval. Independently of the precise form of hole 5, it is developed such that the hole 5 is undersized with respect to the feed-through contact 6. The hole 5 consequently has an inner diameter that is less than the outer diameter of the feed-through contact 6 to be contacted.

[0062] It is in this way possible to attain a secure connection between bus bar 1 and the feed-through contact 6 when, during a press-fit process, the bus bar 1 is slid or pressed onto the contact 6.

[0063] The bus bar 1 depicted in FIG. 3 has in the proximity of the hole 5 a formed-out margin or flange 7, such as is known, for example, from the field of flange forming. Through the out-forming of this flange 7 the area of the contact face forming between the bus bar 1 according to the invention and a feed-through contact 6 is enlarged and therewith the transfer resistance between the bus bar 1 and the feed-through contact 6 is decreased.

[0064] Such flange 7 can, for example, also be developed about the hole 5 using a means for flanging or a similar means. In the dimensioning of flange 5 is provided that the inner diameter of the developing hole 5 with flange 7 has the above described undersize.

[0065] For shaping the form of the hole 5 other suitable shapes, such as a triangular or an n-gonal or a cloverleaf structure can be utilized. An example of an implementation of hole 5 in the form of a cloverleaf is depicted in FIG. 4.

[0066] FIG. 5 is a sectional representation in which the bus bar 1 has been pressed with a flange 7, formed out on the first end 3 in the proximity of the hole 5, onto a feed-through contact 6 and in this way has been connected mechanically stable and electrically conducting with the feed-through contact 6. Evident is the feed-through contact 6, disposed in a bore introduced in a motor housing 8, which is electrically insulated against the motor housing by means of an insulation sleeve 9.

[0067] The second end 4 of the bus bar 1 is bent at an angle of, for example, 90 and is thus angular or angled. This angular end of bus bar 1 can be conducted through an opening provided for this purpose in the circuit board 10 and be soldered to a conductor track of the circuit board 10, for example, on the side of the circuit board 10 facing away from a motor housing 8. The circuit board 10 is only shown symbolically and can receive the components or structural elements, that may be associated with an inverter, necessary for activating the motor,

[0068] FIG. 6 shows a device for carrying out the method for contacting an electric motor (press-fit process) with the bus bars 1 according to the invention in a first state. This state corresponds to the start of the press-fit process in which the required parts have been provided and brought into their corresponding positions.

[0069] To prepare the process a holder plate 11 is supplied. This holder plate 11 comprises, for example, indentations for receiving the bus bars 1 required for the contacting. These indentations have the task of holding the emplaced bus bars 1 in place while the press-fit process is in process. Alternative means for fixing the bus bars 1 on the holder plate 11 are feasible.

[0070] The holder plate 11 has, for example, counterbores whose position agrees with the holes 5 of the emplaced bus bars 1. With respect to their particular diameter, these counterbores are larger than the diameter of the feed-through contact 6 to be press-fit into hole 5 of the bus bar 1 and enable thus a press-fit process without the feed-through contact 6 coming into contact with the holder plate 11.

[0071] FIG. 6 shows the case in which a three-phase electric motor is to be contacted with three feed-through contacts 6. The holder plate 11 consequently has three indentations suitable for receiving three bus bars 1, into which the three bus bars 1 have been placed. FIG. 6 shows only a basic depiction to explain the press-fit process and does not precisely show the precise course of the emplaced bus bars 1. However, clearly shown are the three downwardly angled second ends of the three bus bars 1 as well as the three first ends 3 with their holes 5.

[0072] Before the start of the press-fit process a hermetically closable motor housing 8 or an appropriate part of a motor housing 8 is also provided which includes the bores for receiving the feed-through contacts 6. Into these bores, which are conical in shape, the insulation sleeves 9 are emplaced or have already been secured in place.

[0073] As shown in FIG. 6 a stator 12 to be installed in the motor housing 8 is also provided, which has already been preassembled with the feed-through contacts 6 to be press-fit into the bus bars 1. The stator 12 in the depicted three-phase motor is already preassembled with three feed-through contacts 6.

[0074] At the start of the press-fit process the bus bars 1 are placed into the holder plate 11 at the positions provided therefor. The motor housing 8, or the appropriate part of a motor housing 8, is subsequently aligned above the holder plate 11 and placed onto the holder plate 11. The alignment is carried out such that the conical bores for receiving the feed-through contacts 6 and worked into the motor housing 8 are positioned perpendicularly above the holes 5 of the bus bars 1.

[0075] Stator 12 is furthermore disposed with its preassembled feed-through contacts 6 by means of a, not shown, retaining fixture above the motor housing 8 and aligned such that it can be slid into the motor housing 8. In addition, the alignment of stator 12 takes place such that the feed-through contacts 6 in the subsequent press-fit process will reach the holes 5 of the bus bars 1. The holes 5 are thus located in the imaginary extension of the feed-through contacts 6.

[0076] The retaining fixture is formed such that it can simultaneously exert forces 13 onto the points indicated by arrow tips. Through an external force 13 acting onto the retaining fixture and its transmission into these points, the stator 12 and the feed-through contacts 6 are shifted into the direction of the holder plate 11 and in this way sunk or pressed into the motor housing 8.

[0077] While the stator 12 with the preassembled feed-through contacts 6 is, for example, continuously pressed into the motor housing 8, the distance between the feed-through contacts 6 and the corresponding bores in motor housing 8 continuously decreases further until the feed-through contacts 6 merge into the bores as well as into the insulation sleeves 9 disposed in the bores.

[0078] In the further course of the press-fit process the feed-through contacts 6 reach the holes 5 of the associated bus bars 1 and are pressed into these prefabricated holes 5. Due to the undersize of the holes 5, the feed-through contacts 6 are contacted with the bus bars 1 by means of cold welding.

[0079] When the retaining fixture has reached its end position, the press-fit process is completed and the stator 12 has been pressed into the motor housing 8 and the feed-through contacts 6 as well have also been pressed into the holes 5 of the bus bars 1. The completed press-fit process, in which the retaining fixture has reached its end position, is depicted in FIG. 7.

[0080] The generated unit comprised of motor housing 8, feed-through contacts 6 and bus bars 1 is removed from the holder plate 11. Therewith the press-fit process is completed and an electrically conducting connection has been established between the bus bars 1, the feed-through contacts 6 and the windings of stator 12. Subsequently a circuit board 10, for example, can additionally be applied and soldered to the second ends 4 of bus bars 1.

[0081] FIG. 8 shows a perspective representation of a motor housing 8 with feed-through contacts 6 and pressed-on bus bars 1. In the depiction three bus bars 1 are disposed insulated against the motor housing 8 in corresponding channels provided in motor housing 8. Each of the bus bars 1 has at its first ends 3 in the proximity of the hole 5 a flange 7 and is depicted as already pressed onto the associated feed-through contact 6. The particular second ends 4 of bus bars 1 are bent at right angles and terminate next to one another in the upper left of FIG. 8. It is intended to contact the second ends 4, prepared and disposed in this manner, with a circuit board 10, not shown. As can be seen in FIG. 8, the form of the bus bar can deviate from a straight course and be adapted to structural requirements.

LIST OF REFERENCE NUMBERS

[0082] 1, 1 Bus bar

[0083] 2 Spring contact sleeve

[0084] 3 First end

[0085] 4 Second end

[0086] 5 Hole

[0087] 6 Feed-through contact

[0088] 7 Flange/Margin

[0089] 8 Motor housing

[0090] 9 Insulation sleeve

[0091] 10 Circuit board

[0092] 11 Holder plate

[0093] 12 Stator

[0094] 13 Force (F)