CN210898831U

CN210898831U - DC commutator motor

Info

Publication number: CN210898831U
Application number: CN201920645119.2U
Authority: CN
Inventors: 利博尔·库德拉
Original assignee: Brano AS
Current assignee: Brano AS
Priority date: 2018-05-07
Filing date: 2019-05-07
Publication date: 2020-06-30
Anticipated expiration: 2029-05-07
Also published as: DE202019102493U1; CZ309732B6; CZ2018216A3

Abstract

A DC commutator motor is provided with a shield device having a PCB on an opposite surface on a commutator side of the motor. The shielding device comprises three supporting layers of the printed circuit board, one above the other and separated by an insulating layer. The upper support layer facing the commutator-side front face of the motor is provided with an LC filter. The LC filter is conductively connected with its output terminals to electrical terminals of the motor. The middle supporting layer is provided with two adjacent middle conducting plates which are insulated from each other, and the middle conducting plates are provided with holes. The lower support layer is provided with a lower conductive plate, and the lower conductive plate is provided with a hole. In the hole of the intermediate conductive plate, a sleeve is mounted in an electrically conductive manner, the sleeve passing through the opening of the lower conductive plate with one end electrically insulated and being connected to the input terminal of the LC filter of the upper supporting layer with the second end thereof. The lower conductive plate is peripherally connected to the conductive housing of the motor by a conductive peripheral shield.

Description

DC commutator motor

Technical Field

The present invention relates to a DC commutator motor, in particular for a motor vehicle, which is encapsulated in a conductive housing surrounding the periphery of the motor, the output shaft passing through this conductive housing in the front of the motor, and which is provided with a shielding device with a PCB in the opposite face of the motor.

Background

The DC commutator motor emits electromagnetic interference that is emitted by the motor commutator. Electromagnetic interference is an undesirable phenomenon that manufacturers attempt to minimize. The allowed interference limit is determined by national regulations or set by the manufacturer himself for a specific application in the car.

For DC commutator motors, it is difficult to meet the required interference limits. The electrical suppression is achieved by including commonly known components such as bipolar or feed-through capacitors, chokes or shields of the electrical equipment housing with additional conductors and ground. So-called LC filters are known for interference suppression, which comprise connected coils and capacitors. These filters are connected to the inside of the motor or the outside of the motor housing. They are used wherever different frequency response characteristics of the filter in the pass band and the stop band are required.

CN201584861 discloses an EMC filter with a printed circuit board soldered to the motor. The EMC filter includes a circuit board provided with an EMC filter board, and the circuit board is soldered to one end of a motor output shaft, an opening is arranged on the printed circuit board, the motor output shaft is guided through the opening, and a power opening into which a motor power terminal is inserted is also arranged on the circuit board. A conductive copper layer is disposed around the power opening in the board. The EMC filter and the soldering method are simple, low in manufacturing cost, and high in filtering efficiency.

There are numerous methods and devices for electromagnetic interference suppression of electric motors. The disadvantages of the prior art solutions are that the printed circuit board is too large, the efficiency is not sufficient, the frequency response characteristics of the filter are not sufficient, or the layout is not suitable so that the DC commutator motor cannot be used in the auxiliary and operating equipment of the motor vehicle.

SUMMERY OF THE UTILITY MODEL

The object of the invention is to minimize electromagnetic interference in a small DC commutator motor for controlling or driving various auxiliary devices installed in a motor vehicle. It is an object of the invention to be able to use a DC commutator motor in an apparatus to which strict EMC restrictions are imposed and which would otherwise have to use a more expensive brushless motor. The closest goal is to suppress electromagnetic interference of a DC commutator motor used in a car seat positioning mechanism.

The DC commutator motor according to the present invention substantially eliminates the disadvantages of the prior art and achieves the objects of the present invention. The DC commutator motor is for a motor vehicle, is enclosed in a conductive housing arranged around the outer periphery of the motor, and an output shaft passes through the conductive housing at the front face of the motor, and is provided with a shield device having a PCB on the opposite face on the commutator side of the motor. The shielding device comprises three supporting layers of the printed circuit board, one above the other and separated by an insulating layer, wherein: an upper support layer facing the commutator-side opposite surface of the motor is provided with an LC filter conductively connected with an electric terminal of the motor by an output terminal thereof; the middle supporting layer is provided with two adjacent middle conducting plates which are insulated with each other, and the middle conducting plates are provided with holes; the lower support layer is provided with a lower conductive plate, and the lower conductive plate is provided with a hole; a sleeve is mounted in a conductive manner in the hole of the intermediate conductive plate, the sleeve passing through the opening of the lower conductive plate with one end thereof electrically insulated, and being connected to the input terminal of the LC filter of the upper support layer with a second end thereof; and said lower conductive plate is peripherally connected to said conductive housing of said motor by a conductive peripheral shield.

A preferred embodiment of the DC commutator motor according to the present invention is as follows.

The LC filter is disposed on the upper support layer on a side facing the opposite face of the commutator side of the motor.

The end of the sleeve that passes through the hole in the lower conductive plate is connected to the power line of the motor.

The LC filter includes two induction coils whose output terminals connected to the electric terminals of the motor are connected in parallel via capacitors and in parallel via capacitors arranged in series, and whose input terminals connected to the power line through the bushing are connected through capacitors arranged in series, conductors between the capacitors and conductors between the capacitors being connected to a ground terminal of the motor and a ground conductor of a vehicle electric network.

According to the utility model discloses a DC commutator motor is equipped with multilayer PCB shield assembly, this multilayer PCB shield assembly have the space combination of LC wave filter, feed-through capacitor (feed-through capacitor) and shield cover. According to the utility model discloses a DC commutator motor has the shielding device who suppresses radiation interference and the interference propagation on the circuit both. According to the utility model discloses a DC commutator motor shield has been proven to be high efficiency in the EMC laboratory.

The advantage of the DC commutator motor according to the invention is in particular that the electromagnetic interference is reduced to a lower level that meets the required interference limits.

Drawings

A DC commutator motor according to the invention is shown in the drawing, in which

Figure 1 is a side view of an electric motor with a screening arrangement,

figure 2 is an arrangement of layers of a shielding device,

figure 3 shows the arrangement of the upper layers of the printed circuit board,

figure 4 shows the arrangement of the intermediate layers of the printed circuit board,

FIG. 5 shows an arrangement of lower layers of a printed circuit board, an

Fig. 6 shows the LC filter connection.

List of reference numerals

1 motor 2 surrounding 3 front face

4 output shaft 5 facing surface 6 commutator side

7 electrical terminal 8 electrical terminal 9 ground terminal

10 housing 11 support layer on shielding device 12

13 insulating layer 14 intermediate support layer 15 insulating layer

16 lower supporting layer 17 shielding case 18 LC filter

21 power line 22 power line 23 ground conductor

26 coil L1 input 27 coil L2 input 28 coil L1 output

29 coil L2 output 31 conductive plate 32 conductive plate

33 conductive plate 31a hole 32a hole

33a hole 33b hole 36 hole

37 conductive sleeve 38 conductive sleeve L1 coil

L2 coil C1 capacitor C2 capacitor

C3 capacitor C4 capacitor C5 capacitor

Detailed Description

According to fig. 1, a DC commutator motor 1 is provided around its outer periphery 2 with an electrically conductive housing 10, which electrically conductive housing 10 merges smoothly with the front face 3 of the motor, with an output shaft 4 protruding from the front face 3. A shield device 11 is provided on the opposing face 5 opposite to the commutator side 6 of the motor 1, and on the side of the shield device 11 facing the opposing face 5 of the commutator side 6 of the motor 1, an LC filter 18 is arranged in the form of a printed circuit board from which the coils L1, L2 are exposed. The LC filter 18 is connected with its output terminals to the

electrical terminals

7, 8 of the motor 1. On the opposite side from the opposite face 5 of the electric motor 1, the input terminals of the LC filter 18 protrude from the shielding 11, being connected to the

power lines

21, 22 of the vehicle electric network. The shielding 11 is provided with a conductive shield 17 along the periphery, which conductive shield 17 connects the shielding 11 with the conductive housing 10 of the motor 1.

Fig. 2 shows the arrangement of the

support layers

12, 14, 16 of the printed circuit board and the insulating layers 13, 15 of the shielding means. An insulating layer 13 is arranged between the upper support layer 12 and the middle support layer 14, and an insulating layer 15 is arranged between the middle support layer 14 and the lower support layer 16.

According to fig. 3, the upper support layer 12 on the side of the opposite face 5 (according to fig. 1) of the commutator side 6 of the motor 1 is provided with a PCB forming an LC filter. The LC filter comprises two induction coils L1, L2. One output of the induction coil L1 is connected to the electrical output 7 of the motor through a flat output and to one side of the capacitor C3, while the second output is connected to one side of the capacitor C2. One output of the induction coil L2 is connected to the electrical terminal 8 of the motor through a flat output and to the other side of the capacitor C2, while the second output is connected to one side of the capacitor C4. The input of the induction coil L1 is connected to the power supply line 21 and to one side of the capacitor C5 through a flat connector. The input of the induction coil L2 is connected to the power supply line 22 and to one side of the capacitor C6 by a flat connector. The other sides of the capacitors C3, C4 and the capacitors C5, C6 are connected to each other, while the other sides of the capacitors C3, C4, C5, C6 are conductively connected to the ground conductor 23 of the vehicle electrical network.

Referring to fig. 4, the middle support layer 14 is provided with two

conductive plates

31, 32, the

conductive plates

31, 32 being spaced apart so that they do not contact each other or are insulated from each other. The

conductive plates

31, 32 are substantially at a level with each other. In the

conductive plates

31, 32, holes 31a, 32a arranged parallel to each other are established, each hole being located in one of the

conductive plates

31, 32. In the holes 31a, 32a of the

conductive plates

31, 32,

bushings

37, 38 are mounted in a conductive manner.

Fig. 5 shows the lower support layer 16 on which the conductive plate 33 is disposed. The conductive plate 33 has two circular holes 33a, 33b through which the

conductive sleeves

37, 38 freely pass. The

conductive sleeves

37, 38 are made of copper and have a cylindrical shape. In the inner space of the cylindrical

conductive sleeves

37, 38,

power lines

21, 22 of the vehicle electric power network are placed, the

power lines

21, 22 being conductively connected with the inner surfaces of the

sleeves

37, 38. The ends of the

bushings

37, 38 pass through holes 33a, 33b in the bottom conductive plate 33 and are connected to the

power lines

21, 22 of the motor 1. The

conductive sleeves

37, 38 pass through holes 33a, 33b in the conductive plate 33 with sufficient clearance to avoid short circuits. In the conductive plate 33, a hole 36 for the ground conductor 23 of the vehicle electrical system is further formed, the ground conductor 23 being conductively connected to the conductive plate 33. The lower support layer 16 is joined by means of a conductive glue on its periphery to a conductive shield 17 (not shown), which conductive shield 17 is arranged around the periphery of the conductive housing 10 of the electric motor, as shown in fig. 1.

According to fig. 6, the LC filter 18 is arranged on the upper support layer 12 (according to fig. 3) and comprises two induction coils L1, L2, the

output terminals

28, 29 of the induction coils L1, L2 being connected to the

electric terminals

7, 8 of the electric motor, the input terminals 26, 27 being connected to the

electric power lines

21, 22 by means of conductive bushings 37, 38 (according to fig. 5). The output terminals of the induction coils L1, L2 are connected together in parallel by conduction through a capacitor C2 and through capacitors C3, C4 arranged in series. The input terminals 26, 27 of the induction coils L1, L2 are connected to each other via capacitors C5, C6 arranged in series. The conduction between the capacitors C3, C4 and the conduction between the capacitors C5, C6 are connected to each other by a lead wire 24, which lead wire 24 is connected to the ground terminal 9 of the electric motor 1 by the lead wire 25 and is connected to the ground conductor 23 of the vehicle electric network.

According to fig. 5, the

bushings

37, 38 pass with one end through the electrically insulating holes 33a, 33b in the lower conductive plate 33, while according to fig. 6, the second ends of the

bushings

37, 38 are connected to the input terminals 26, 27 of the induction coil of the LC filter of the upper support layer 12. In the support layers 12, 14, 16, axially symmetrical holes are provided for the ground conductors 23 to pass through.

The printed circuit board also acts as a feed-through capacitor. The motor output lines are connected to the vehicle electrical network via an LC filter and feed-through capacitors. The vehicle ground is connected to the shield. In order to minimize interference, the LC filter, the multilayer PCB having the function of a feed-through capacitor, and the shield case connecting the lower conductive plate 33 to the conductive housing 10 along its periphery are combined together in the smallest possible installation space on the commutator side of the motor. The shield case closes a space above the output line of the motor. The cover is made of copper foil using a conductive adhesive. The copper foil forms a continuous conductive connection of the housing of the motor to the lower layers of the multilayer printed circuit board. The printed circuit board is soldered with the individual components, the coil and the capacitor. The

conductive plates

31, 32 arranged on the middle support layer 14 and the conductive plate 33 arranged on the lower support layer 16 are made of copper. The printed circuit board is configured to act as a feed-through capacitor to prevent high frequency interference. The feed-through capacitor is formed between support layers 16, 14 of the printed circuit board, wherein an insulating layer 15 forms the dielectric of the capacitor. The arrangement of

conductive plates

31, 32, 33 comprises two feed-through capacitors. The properties of the capacitor depend on the distance of the layers, the shape of the pattern constituting the capacitor plates, and the kind of material in the insulating layer.

Claims

1. A DC commutator motor, in particular for a motor vehicle, which is encapsulated in an electrically conductive housing (10) arranged around the outer circumference (2) of the motor (1) and through which conductive housing (10) an output shaft (4) passes at the front face (3) of the motor (1), and which is provided with a shielding device (11) with a PCB on the opposite face (5) on the commutator side (6) of the motor (1),

it is characterized in that

The shielding device (11) comprises three support layers (12, 14, 16) of the printed circuit board, one above the other and separated by insulating layers (13, 15), wherein

-an upper support layer (12) facing the opposite face (5) of the commutator side (6) of the electric motor (1) is provided with an LC filter (18), which LC filter (18) is conductively connected with its output terminals (28, 29) to the electric terminals (7, 8) of the electric motor,

-the intermediate support layer (14) is provided with two adjacent, mutually insulated intermediate conductive plates (31, 32) provided with holes (31a, 32a),

-the lower support layer (16) is provided with a lower conductive plate (33), said lower conductive plate (33) being provided with holes (33a, 33b),

-in the holes (31a, 32a) of the intermediate conductive plates (31, 32), bushings (37, 38) are mounted in an electrically conductive manner, the bushings (37, 38) being electrically insulated with one end thereof through openings (33a, 33b) of the lower conductive plate (33) and being connected with a second end thereof to input terminals (26, 27) of the LC filter of the upper support layer (12), and

-the lower conductive plate (33) is connected peripherally to the conductive housing (10) of the electric motor (1) by means of a conductive peripheral shield (17).

2. The DC commutator motor of claim 1, wherein the DC commutator motor

The LC filter (18) is arranged on the upper support layer (12) on the side facing the opposite face (5) of the commutator side (6) of the electric motor (1).

3. The DC commutator motor according to claim 1 or 2, wherein the DC commutator motor is characterized

The ends of the bushings (37, 38) that pass through the holes (33a, 33b) in the lower conductive plate (33) are connected to power lines (21, 22) of the motor (1).

4. The DC commutator motor of claim 3, wherein the DC commutator motor

The LC filter (18) comprises two induction coils (L1, L2), the output terminals (28, 29) of the two induction coils (L1, L2) connected with the electrical terminals (7, 8) of the electric motor being connected in parallel via a capacitor (C2) and in parallel via a series-arranged capacitor (C3, C4), and the input terminals (26, 27) of the induction coils (L1, L2) connected to the power lines (21, 22) through the bushings (37, 38) being connected through a series-arranged capacitor (C5, C6), the conductors between the capacitors (C3, C4) and between the capacitors (C5, C6) being connected to a ground terminal (9) of the electric motor (1) and to a ground conductor (23) of a vehicle electrical network.