JP2002517973A - Motors for automotive accessories - Google Patents

Abstract

(57) Abstract: The present invention relates to an electric motor whose operation state can be adjusted, particularly for ventilation of a passenger compartment of a motor vehicle, heating, or a forced ventilation device of an air conditioner. The motor includes a stator with an exposed outer surface (4). The motor is powered via a module that includes resistors (R1, R2, R3) for changing its operating state. According to the invention, these resistors consist of a resistive layer (6) arranged on the outer surface (4) of the stator according to a suitable band pattern. The outer surface (4) of the stator includes a plurality of metal contacts (C1, C2, C3, C4) arranged in a resistance layer for forming at the terminals of the resistors (R1, R2, R3).

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to an electric motor with adjustable operating conditions, in particular for automotive equipment, especially for forced ventilation of ventilation, heating or air-conditioning installations.

[0002] A forced ventilation device of the type described above usually comprises an electric motor for rotating a turbine for sending an airflow in the cabin of a motor vehicle. The electric motor of the forced ventilation device includes a rotor and a stator having an exposed wall surrounding the rotor.

[0003] The electric motor is generally powered via a speed change module of the forced ventilation system including at least one electrical resistance. In practice, such a module includes a plurality of series resistors, each terminal connected to a contact electrode (plot). One terminal of the motor is usually connected to the last electrode of the connection, and the other terminal is connected to ground. Next, connection means are provided which are coupled to the operating state control components of the motor, and one of said electrodes is generally connected to a power supply means for transmitting a DC voltage.

A disadvantage of the known motors incorporated in modules of the type described above is that, in the event of a fault, they are overheated by the Joule effect resulting from the large amount of current circulating in the resistance of the module, thereby deteriorating the module, Means that the motor itself deteriorates. In order to solve this problem, especially when applied to a forced-ventilation device, the resistor is formed as a resistance layer disposed on an insulating substrate (generally made of ceramic) to form the module, and at least one resistor is formed. Each of the arrangement patterns is connected to a contact electrode. In practice, this module is interposed in the air duct through which the air flow passes to cool the resistance.

[0005] However, the external dimensions of motors of this type equipped with such modules are large and in many cases conflict with the demands of modern motor vehicles. The present invention has been made to solve such a problem, and the present invention provides a cylindrical exterior in which a resistor of a module is directly installed on an outer surface or an inner surface of a stator, and the stator is closed at least at one end by a flange. Is proposed.

In accordance with the present invention, a module includes at least one resistor configured as a thin resistive layer of a selected dimension, the resistor according to a selected band pattern.
It is arranged on at least a part of the outer surface or inner surface of the stator.

According to another useful feature of the invention, the surface of the stator has at least two metal contacts arranged on both sides of the pattern, these contacts forming the terminals of the resistor. . The contacts are further connected to contact electrodes of the type described above, one of these contacts being connected to one terminal of the motor. Thus, when applied to the above described forced ventilation system, the fluid passing through the outer surface of the stator releases the heat generated by the resistive layer due to the Joule effect.

[0008] It is advantageous if the surface of the stator has a third metal contact which is connected to the other terminal of the motor without contacting the resistive layer. In that case, the contact is configured to be connected to the ground. Thus, an equivalent circuit configuration is: a first terminal is connected to a first contact, a second terminal is connected to a second contact, and the second contact is also preferably connected via a fuse. At least one electrical resistor connected to one of the electrical terminals of the electric motor, the other electrical terminal being connected to a third contact, the third contact being preferably connected to ground. An electric motor; and a power supply, preferably a DC voltage, connected to one of the first and second contacts.

According to another advantageous feature of the invention, the outer surface of the stator further supports a separator layer and preferably a protective layer, these layers being between the resistive layer and the outer surface of the stator. , The resistive layer and the metal contact. These layers are made of an insulating material having a thermal expansion coefficient substantially similar to that of the resistance layer.The resistance layer and the stator portion where the resistance layer is arranged are made of different materials having similar thermal expansion coefficients. Be composed.

[0010] Other features and advantages of the present invention will become apparent upon reading the following detailed description and upon reference to the accompanying drawings. The description and accompanying drawings set forth the features of the present invention. They also serve to promote an understanding of the invention, rather than to define the invention itself. FIG. 1 shows an electric motor according to the invention in a forced-ventilation device for ventilation, heating or air-conditioning equipment in a passenger compartment of a motor vehicle. This motor is substantially cylindrical.

The rotating shaft 1 rotates around a cylindrical axis XX. The rotating shaft 1 is held by fastening elements 2a, 2b arranged at both ends of the motor body. A rotor 3 is connected to the rotating shaft 1. The stator has an outer surface 4 surrounding the rotor 3 and having an axis which is substantially cylindrical and substantially coincides with the axis of rotation XX.

The rotating shaft 1 of the electric motor drives a turbine (not shown) provided below in FIG. 1, and its rotation generates an air flow, and a part of the air flow (arrow F) is It flows outside the outer surface 4. In an embodiment, the turbine creates an intake airflow that circulates downward in a substantially vertical direction. In some cases, the electric motor may output from both ends of the shaft. An electric motor M of this type (FIG. 2a) is normally connected to the connection interface A2, preferably via a protective fuse P2 (eg a resistor with a positive temperature coefficient, a bimetallic or hot-melt protective means). A first terminal is included. The second terminal of the motor is connected via a connection interface A2 to a terminal B5, which is generally connected to ground.

The first terminal of the electric motor is connected to the output of the operating state change module 10 of the electric motor M via the connection interface A2. This module 10 according to the prior art as shown in FIG. 2a includes a unique connection interface A1 as well as an additional protective fuse P1. The module 10 in the example described comprises three series-connected resistors R1, R2, R3, the resistor R3 being connected to the fuse P1, which is connected to the fuse P2 of the motor block via the connection interfaces A1 and A2. It is connected.

The common terminal of the resistors R1 and R2 is connected to a connection terminal B2, while another terminal of the resistor R1 is connected to a different terminal B1. The common terminal of the resistors R2 and R3 is connected to the terminal B3, while another terminal of the resistor R3 is connected to the terminal B4. Terminal B5 is connected to ground.

In this case, an external connection means (not shown) is provided to connect the voltage supply source V (12 V) to the terminal B1, B2, B3 or B4. Such a connection means can be formed, for example, as a conductor pad which can occupy a plurality of positions for connecting the power supply means to one of these terminals.

Thus, the voltage U at the terminals of the motor M changes according to the terminal to which it is connected. In general, the resistors that need to be considered are: When the terminal B1 is connected, R1 + R2 + R3. When the terminal B2 is connected, R2 + R3. When the terminal B3 is connected, R3. When the terminal B4 is connected, it can be ignored. A conventional motor in a forced-ventilation device combined with a module of the type shown in FIG. 2a thus has two different connection interfaces, as well as two
Includes protective fuses. According to the invention, the electrical resistance of the module 10 is configured as a resistive layer that is silk-screen printed directly on the outer surface of the stator. The motor according to the invention therefore comprises only a single connection interface (A) and a single protective fuse P.

The resistance layer has an expansion coefficient close to that of the stator body and is preferably made of a selected weak resistance material. For example, the selected material for the resistive layer could be 35XX ceramic sold by DuPont, USA, and the stator could be stainless steel.

In the embodiment, the resistance layer 6 is silk-screen printed according to a pattern shown by a broken line in FIG. Advantageously, the resistance layer 6 is insulated from the outer surface 4 of the stator by a layer made of insulating material 7 (FIG. 3). This insulating separator layer 7 can be made of, for example, an insulating varnish with a serial number 3506 sold by DuPont. The metal contacts C1, C2, C3, C4 (FIG. 1) cover the resistive layer 6 at one point, at selected spacings in the pattern, and are made of a material whose expansion coefficient is similar to that of the resistance layer. It is configured. Actually, the contacts C1, C2, C3, C4, C5
Is made of, for example, a silver paste with a serial number 7760 sold by DuPont. The contacts define three series resistors R1, R2, R3, two each.

[0019] Between the metal contacts C1 and C2, the pattern of the resistive layer forms a first track R1 of a selected width and height. This track is defined by a material band having a resistivity ρ, a width L1, and a peripheral length l1. Thus, the resistance R1 is determined by the following equation.

(Equation 1) Here, e is the thickness of the resistance layer disposed on the stator surface 4.

The first track is open and the contacts C2, C3 couple to a second track that overlaps and defines the first track of the resistor R1. The second track has a width L
1. Defined by a material band having a width L2 and a peripheral length l2 different from the peripheral length l1, the resistance R2 of which is given by:

(Equation 2)

Further, a third track is coupled to the second track near metal contact C3. The resistance R3 is as follows.

(Equation 3)

In the embodiment, the pattern of the resistance layer is continuous, and the three tracks correspond to the contact C2.
, C3. Each track is substantially rectangular and each corner is defined by a band of resistive layer of different width between the tracks.

According to the pattern shown in FIG. 1, the bandwidth of the resistive layer decreases from track to track as it moves away from the third central track of resistor R3. These band widths L
1, L2, L3 are selected such that L1 <L2 <L3, and thus: R1>R2> R3

The track is substantially symmetric with respect to an axis parallel to the rotation axis XX of the rotation axis 1. FIG.
Shows that the width and height of each track increase with distance from the third track, and therefore the perimeters l1, l of the first, second and third tracks
2, 13

(Equation 4) Becomes Thereby, the difference between R1, R2, and R3 can be further increased (R1> R
2> R3).

In the embodiment, the three tracks are made of the same material having a substantially constant resistivity. Furthermore, the resistance layer has a constant thickness e. Therefore, by adjusting the length li and the band width Li of the periphery of the track, the values R1, R2, and R3 can be adapted to obtain a desired resistance value. The metal contact C5 is arranged on the stator surface, in particular on the insulating layer 7, without contacting the resistance layer 6. The metal contact C5 is configured to connect to a terminal B5 that is connected to ground. Furthermore, the contacts C1, C2, C3, C4 are connected to terminals B1 of the type described above.
, B2, B3, B4. A protective layer 9, preferably made of an insulating material, comprises a resistance layer 6 and contacts C1, C2, C3.
, C4.

As described above, the electric motor according to the present invention has the silk-screen printed resistance on the outer wall of the stator 4. Therefore, it is much more compact than the structure of a conventional motor. Moreover, when applied to a forced ventilation device, a part of the airflow (arrow F) generated by the rotation of the turbine passes through the resistors R1, R2, and R3. When a voltage is applied to the motor, the heat generated by these resistances due to the Joule effect is dissipated by a portion of such airflow.

Of course, the invention is not limited to the above-described embodiments, which are given by way of example only, but can be extended to other variants. For example, the number of resistors (three in the embodiment) can be changed according to the intended use. Therefore, different numbers of metal contacts and tracks are provided. The above rectangular shape of the truck is given as an example. In alternative embodiments, these shapes may be different shapes, for example, elliptical or circular. In general, the shape of the pattern itself defining the tracks to be overlaid can be further different.

In the above example, each track is made of the same resistance material. However, these tracks can be made of different materials with different resistivity ρ1, ρ2, ρ3, which can further widen the difference between the resistors R1, R2, R3. The track is formed of a layer having a constant thickness e. However, these tracks can also be provided in layers of different thicknesses e1, e2, e3 in order to more precisely obtain the desired resistance value.

The surface of the stator is cylindrical in the example described above. However, it may be a stator having a flat surface or any external surface. Further, the resistors R1, R2, R3 may be provided on the inner surface of the stator. Finally, the above-mentioned motors, by way of example, can rotate the turbine of the forced-ventilation system in the ventilation, heating or air-conditioning installations of a vehicle compartment. However, the present invention can be applied to any other electric motor in which the operation state can be adjusted.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing an embodiment of a motor according to the present invention for a forced ventilation device for ventilation, heating, or air conditioning equipment of a motor vehicle.

2A is a diagram showing an electric circuit in a conventional motor module, and FIG. 2B is a diagram showing an electric circuit in a motor module according to the present invention.

FIG. 3 is a sectional view of a pattern of a resistance layer disposed on an outer wall of a stator of the electric motor according to the present invention.

[Explanation of symbols]

 4 Outer surface 6 Resistive layer 7 Separator layer 9 Protective layer 14 Inner surface

Claims (16)

[Claims] An electric motor with adjustable operating conditions for an automotive accessory, comprising a rotor (3) surrounded by a stator having an exposed outer surface (4) and an unexposed inner surface (14). Power is supplied via a motor operating state change module comprising at least one electrical resistance (R1), said resistance (R1) being configured as a resistance layer (6) of a selected dimension (L);
An electric motor, which is arranged on at least a part of the outer surface (41) of the stator or substantially a part of the unexposed inner surface (14) according to a selected band pattern. 2. The surface of the stator includes at least one first and second metal contacts (C1, C4) disposed on a resistive layer, the contacts being disposed on opposite sides of the pattern, 2. The electric motor according to claim 1, wherein two electric terminals of the resistor are formed. 3. The electric motor according to claim 2, wherein the second contact (C4) is connected to one of the electric terminals of the electric motor. 4. The outer surface (4) of the stator further comprises a third metal contact (C5) connected to the other terminal of the motor without contacting the resistive layer. An electric motor according to claim 1. 5. The electric motor according to claim 4, wherein the third metal contact is further connected to ground. 6. The second contact (C4) is connected via a protection fuse (P).
The electric motor according to claim 4, wherein the electric motor is connected to one of terminals of the electric motor. 7. A resistive layer (6) comprising two additional metal contacts disposed between said first and second contacts (C1, C4) at a selected spacing on the pattern. (C2, C3), and the contacts have two resistors, two resistors (R1,
The electric motor according to any one of claims 1 to 6, wherein R2, R3) are defined in series. 8. The contacts (C1,..., C4) each have a variable width (L
The electric motor according to claim 7, wherein two bands of the pattern (i) are defined. 9. The contacts each have two bands of a pattern of variable length (li).
The electric motor according to claim 7, wherein the electric motor is defined individually. 10. The pattern comprising a plurality of open tracks joined to each other and overlapping each other, and a metal contact (C2, C3) is disposed at each junction of the two tracks. The electric motor according to any one of claims 7 to 9, wherein: 11. Each of the band widths (Li) of the resistive layer of the track is equal to the overlapping track (Li).
The electric motor according to claim 10, wherein the width of the electric motor decreases from R3) to a non-overlapping track (R1). 12. The electric motor according to claim 1, wherein the stator portion and the resistance layer are made of individual materials having similar thermal expansion coefficients. 13. A separator layer (7) arranged between said resistance layer (6) and the outer surface (4) of the stator and made of an insulating material having a coefficient of thermal expansion similar to that of the resistance layer. The electric motor according to claim 12, comprising: 14. A protective layer (9) arranged on the resistive layer and the metal contact, the protective layer comprising an insulating material having a coefficient of thermal expansion similar to that of the resistive layer. An electric motor according to claim 1. 15. An air flow (F) can be generated by rotationally driving a turbine of a forced ventilation device of a ventilation or heating or air conditioning system of a vehicle compartment, and the air flow (F).
Motor according to any of the preceding claims, characterized in that at least part of the motor passes through the outer surface (4) of the stator. 16. The electric motor according to claim 1, wherein a DC voltage is supplied.