DE102004037912A1 - Electric motor with suppression - Google Patents

Abstract

An electric motor is proposed in which an X2Y capacitor (2), which is installed inside the motor housing (1) for guiding the electric motor, is provided, in which a first Y capacitor (C¶y1¶) is connected between a first contact line (5a ) and ground (G) is connected, a second Y-capacitor (C¶y1¶) between a second contact line (5b) and ground (G) is connected, and an X-capacitor (C¶x¶) between the first contact line (5a) and the second contact line (5b) is connected. The proposed electric motor opens up a replacement of all conventional suppression or filter components in an electric motor, since the X2Y capacitor (2) is arranged close to the source of interference and shielded by the motor housing (1) RF-friendly.

Description

The The invention relates to an electric motor, in particular a commutator motor, the two to his brushes premier Having contact lines.

State of technology

at All electronic systems or components pass requirements the EMC (electro-magnetic compatibility) with regard to immunity to interference and spark suppression. This has the consequence that in all used for electrical Components usually already in the planning phase EMC measures be developed and integrated accordingly. Through these measures should be guaranteed be that the electrical components in a defined electromagnetic Environment without mutual interference work. The EMC is thus an essential quality feature in product planning.

A possibility the filtering a commutator motor is to connect inductors in series to the armature. Enough If this is not the case, capacitors will also be connected between the anchor terminals or their supply lines and serving as a mass housing. Limit these acting as a choke inductors and capacitors the main ones disorders Today commutator motors, which by the brush fire during the commutation process arise. Are enough such suppression measures not out, can with additional Filtering or shielding the components further improvements be achieved.

Around the high suppression requirements need to be fair in the corresponding motors usually several capacitors and chokes, if necessary with ferrite elements, are used. This conventional solutions have a correspondingly high space requirement. It also increases especially the price of individual suppression elements considerably with the engine size.

One way to reduce space requirements, at the same time reduce costs, and also to improve the performance and the quality of filtering, has been offering for some years, the X2Y capacitor, as in the 5 and 6 is shown. The X2Y capacitor 2 who in 5 is schematically shown on the left in a perspective view and is shown schematically on the right in a plan view with designation of its four connections, makes for a relatively simple suppression technique three Kondenstoren advantage, as in the in 6 shown circuit diagram is shown. In this suppression technique, two Y capacitors C _y1 , C _y2 , each derived from a contact line of the motor, used to derive common mode noise to ground, with an X-capacitor C _{x is connected} to suppress differential interference across both contact lines. That is, the X2Y capacitor 2 has two contact terminals A, B and at least one ground terminal G, wherein a Y capacitor C _y1 between a contact terminal A and ground G, a second Y capacitor C _y2 between a second contact _terminal B and ground G and an X-capacitor C _x are connected between the two contact terminals A, B. This is a single X2Y capacitor 2 able to simultaneously suppress both common mode and differential interference.

Advantages of invention

Of the Electric motor according to the invention is characterized by a within the motor housing in this built-in X2Y capacitor for filtering of the electric motor, in which a first Y-capacitor between a first contact line and ground is connected, a second Y-capacitor between a second contact line and ground is connected, and an X capacitor between the first contact line and the second contact line is switched.

Of the Electric motor according to the invention combines the X2Y capacitor so with an electric motor that the X2Y capacitor built into its motor housing and thus integrated into the electric motor. This allows the usual suppressor or filter components are replaced, the contacting of the X2Y capacitor by its arrangement within the motor housing so can be optimized that a maximum suppression is guaranteed, because the quality of suppression is mainly through one as possible large-scale ground connection and determines an RF-compliant shield of the X2Y capacitor. These two factors are due to the arrangement of the X2Y capacitor inside the motor housing, which serves as a mass, particularly easy to implement, since this both a large-scale ground connection allowed, as well as an RF-compatible shielding offers. Next exists when installed in the motor housing X2Y capacitor for filtering the advantage of being a short distance from the brushes, i.e. to the main interference source the electric motor can be arranged, resulting in a better suppression results than in a remote to the brushes outside the motor housing selected arrangement.

The electric motor according to the invention preferably has a contact plate adapted to the motor housing and inserted therein for receiving the X2Y capacitor. By such a contact plate can be used in this X2Y capacitor can be easily placed and contacted during assembly of the electric motor, with a connection with high quality can be achieved, ie, the best possible contact of the serving as a mass motor housing and the contact lines to the brushes.

in this connection the contact plate is preferably adapted to the motor housing, that it is full surface on the inner lateral surface of the motor housing is applied. Further preferably, the contact sheet is alternatively or additionally via a Pins on the brush holder of the Electric motor pressed to the motor housing so that one possible Good ground connection and a stable installation of the X2Y capacitor takes place. Further alternatively or additionally the contact plate is preferably via a spring mechanism to the motor housing depressed and / or the contact plate is positively connected to the motor housing, to reach the ground connection. The contact plate is preferably designed so that the ground connection can be made as large as possible. Further alternatively or additionally the contact plate preferably designed so that of this recorded X2Y capacitor symmetrical to the brushes the electric motor sits when the contact plate inserted into the motor housing is. By such an arrangement, it follows that both contact terminals of the X2Y capacitor have an equal distance from the brushes of the electric motor, the main sources of interference are, why a better filtering is done.

Of the X2Y capacitor is preferably in the electric motor according to the invention soldered to the contact plate and / or connected by means of an insulation displacement connection with the contact plate and / or connected by means of a clamping connection with the contact plate, resulting in easy assembly with high quality contacting can be done.

drawing

Further Advantages of the invention will become apparent from the following description.

In The drawings is an embodiment of the invention shown by way of example. The drawings, the description and the claims contain numerous features in combination or as a preferred embodiment of the invention. The person skilled in the art will appreciate the features expediently also consider individually and / or to meaningful further combination sum up.

It demonstrate:

1 an advantageous embodiment of an electric motor according to the invention in a partial sectional view;

2 this in 1 shown preferred embodiment of an electric motor according to the invention in a perspective partial view;

3 perspective front and rear views of the in the in the 1 and 2 used electric motor used contact plate with recorded X2Y capacitor;

4 the installation of the in 3 shown contact sheet in the in the 1 and 2 shown electric motor;

5 Schematic diagrams of an X2Y capacitor; and

6 a circuit diagram of an X2Y capacitor.

description of the embodiment

1 shows a partial sectional view of the in the motor housing 1 built-in X2Y capacitor 2 , where this inside the motor housing 1 symmetrical to the brushes 6a . 6b of the commutator motor is arranged. The X2Y capacitor 2 is from a contact plate 3 held so that its contact terminals A, B to contact lines 5a . 5b abut the brushes 6a . 6b provide energy. Next lies the contact plate 3 on the motor housing 1 and thereby connects the two ground terminals G1, G2 of the X2Y capacitor, with which this at the contact plate 3 is attached, with the mass serving as the motor housing 1 , The contact sheet 3 is from the brush holder 4 to the motor housing 1 pressed, in this preferred embodiment in particular by a pin 4a , the angled pressure surfaces 3a . 3b of the contact sheet 3 in a recess 1a of the motor housing, as it is in the 2 and 4 is shown.

A preferred embodiment of the contact sheet used is in 3 shown. The contact plate receiving the X2Y capacitor is preferably a copper sheet onto which the X2Y capacitor 2 is soldered and which a large-area contact with the motor or pole housing 1 allowed. Alternatively or additionally, the X2Y capacitor can be connected to the contact plate by means of an insulation displacement connection or a similar clamping connection 3 get connected. The geometry of the contact sheet 3 is chosen according to the size of the X 2 Y-capacitor 2 a simple contact allows and also optimally to the inside of the motor housing 1 adapts. The X2Y capacitor 2 is attached so that it is symmetrical to the brushes 6a . 6b sits, causing the contact lines 5a . 5b between the X2Y capacitor 2 and the brushes 6a . 6b are equal. In another brush arrangement, the position of the X2Y capacitor can be adjusted accordingly.

The contact sheet 3 also has two angled contact surfaces 3a . 3b on what about it via a corresponding pin 4a on the brush holder 4 to the motor housing 1 is pressed, as it is in 4 is shown. The pin 4a and other pins of the brush holder 4 serve at the same time as a fixation of the brush holder 4 in the motor housing 1 , Another fit ensures that the contact plate 3 over the entire surface of the inner circumferential surface of the motor housing 1 as it is in the 1 and 2 is shown. If this fit alone is not sufficient, it is also possible to connect the contact plate with the motor housing in a form-fitting manner or in addition to press it radially by way of a spring mechanism. The motor housing 1 serves as shielding of the X2Y capacitor at the same time 2 ,

In the 1 . 2 and 4 is an axial lead out of the contact leads 5a . 5b shown. When radially from the motor housing 1 guided contact lines can be achieved by shorter selected distances to the brushes a further interference suppression.

In summary, it should be noted that according to the invention a large-area ground connection of the X2Y capacitor 2 to the motor housing 1 over a contact plate 3 which is about a pin 4a on the brush holder 4 to the motor housing 1 is pressed. Replaces the X2Y capacitor all conventional suppressor or filter components in an electric motor, so there is a significant cost savings. Such a replacement is possible if the preferred embodiments, such as large ground connection, shielding by arrangement within the motor housing, symmetrical arrangement of the contact lines, shortest possible contact lines and a good conductive mass connection are considered.

Claims (8)

Electric motor, characterized by an inside of the motor housing ( 1 ) into this built-in X2Y capacitor ( 2 ) for suppression of the electric motor, in which a first Y-capacitor (C _y1 ) between a first contact line ( 5a ) and ground (G) is connected, a second Y-capacitor (C _y2 ) between a second contact line ( 5b ) and ground (G) is connected, and an X-capacitor (C _x ) between the first contact line ( 5a ) and the second contact line ( 5b ) is switched. Electric motor according to claim 1, characterized by a to the motor housing ( 1 ) adapted and used in this contact plate ( 3 ) for receiving the X2Y capacitor ( 2 ). Electric motor according to claim 2, characterized in that the contact plate ( 3 ) to the motor housing ( 1 ) is adapted so that it is completely on the inner circumferential surface of the motor housing ( 1 ) is present. Electric motor according to claim 2 or 3, characterized in that the contact plate ( 3 ) via a pin ( 4a ) on the brush carrier ( 4 ) of the electric motor to the motor housing ( 1 ) is pressed. Electric motor according to one of claims 2 to 4, characterized in that the contact plate ( 3 ) in a form-fitting manner with the motor housing ( 1 ) connected is. Electric motor according to one of claims 2 to 4, characterized in that the contact plate ( 3 ) via a spring mechanism to the motor housing ( 1 ) is pressed. Electric motor according to one of claims 2 to 6, characterized in that the contact plate ( 3 ) is designed such that the X2Y capacitor ( 2 ) symmetrical to the brushes ( 6a . 6b ) of the electric motor sits when the contact plate ( 3 ) in the motor housing ( 1 ) is used. Electric motor according to one of claims 2 to 7, characterized in that the X2Y capacitor ( 2 ) to the contact plate ( 3 ) is soldered and / or by means of an insulation displacement connection with the contact plate ( 3 ) is connected and / or by means of a clamping connection with the contact plate ( 3 ) connected is.