CN108141104B

CN108141104B - Direct drive for a windscreen wiper

Info

Publication number: CN108141104B
Application number: CN201680063423.5A
Authority: CN
Inventors: S.科勒; M.迪特里希; C.阿克; P.博尔茨
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2015-10-27
Filing date: 2016-09-21
Publication date: 2022-07-01
Anticipated expiration: 2036-09-21
Also published as: WO2017071883A1; CN108141104A; EP3369160A1; DE102015220900A1

Abstract

The invention relates to a wiper direct drive (10) for a wiper device (12) of a motor vehicle, having an EC motor (20) and a helical gear mechanism (22), wherein the EC motor (20) is arranged in a motor housing (14) and the helical gear mechanism (22) is arranged in a gear housing (16), and wherein the helical gear mechanism (22) has a helical gear which has an output journal (30) for fastening a wiper arm (32) of the wiper device (12) and can be driven in rotation by the EC motor (20), the EC motor (20) having a rotor shaft which is provided at least in sections with a worm and is mounted in a rotationally movable manner in a first and a second bearing position, the first and second bearing locations are arranged within the transmission housing (16) on either side of the worm.

Description

Direct drive for a windscreen wiper

Technical Field

The invention relates to a wiper direct drive for a wiper device of a motor vehicle, having an EC motor and a helical gear, wherein the EC motor is arranged in a motor housing and the helical gear is arranged in a gear housing, and wherein the helical gear has a helical gear which has an output journal for fixing a wiper arm of the wiper device and can be driven in rotation by the EC motor.

Background

A wiper direct drive for a wiper of a wiper system of a motor vehicle having a brushless or electronically commutated dc motor is known from us 6,944,906B 2. In the further course of this description, such brushless or electronically commutated direct-current motors are continuously referred to by the abbreviation EC motor (electronically commutated motor).

In the case of such previously known wiper direct drives, the rotor shaft is mounted at least partially in a motor housing associated with the EC motor, and the EC motor itself is designed as an external rotor motor. Furthermore, the rotational speed and torque of the EC motor necessary for operation are adapted by means of the planetary gear set, which is complex to construct.

Disclosure of Invention

The invention relates to a wiper direct drive for a wiper device of a motor vehicle, having an EC motor and a helical gear, wherein the EC motor is arranged in a motor housing and the helical gear is arranged in a gear housing, and wherein the helical gear has a helical gear which has an output journal for fixing a wiper arm of the wiper device and can be driven in rotation by the EC motor. The EC motor has a rotor shaft which is provided at least in sections with a worm and is mounted in a rotationally displaceable manner in a first and a second bearing position which are arranged in a gear housing on both sides of the worm.

A particularly compact design of the wiper direct drive is thus obtained with a simultaneous flexurally rigid and stable mounting of the rotor shaft of the EC motor with respect to the helical gear. Furthermore, by the precise, bilateral support of the worm in the gear housing, the noise generation during operation and the gear wear are reduced. Furthermore, the use of an EC motor results in low maintenance and low-noise operation of the wiper direct drive. In addition, brush sparking of the respective commutator is dispensed with in EC motors in comparison with commutator motors, which leads to an improvement in the electromagnetic compatibility of the wiper direct drive. The commutator is in particular a separate noise source, which is omitted in the EC motor.

Preferably, the rotor shaft has a free end section facing away from the worm, on which the lamination stack provided with permanent magnets is arranged in a rotationally fixed manner, wherein the worm engages with the helical gear, and wherein the lamination stack provided with permanent magnets is coaxially surrounded by a stator with stator windings accommodated in the motor housing.

The removal of the waste heat released in the coil winding into the motor housing and thus the heat balance of the wiper direct drive (W ä rmehaushalt) is thereby significantly improved in comparison with the use of commutator motors.

Preferably, the first bearing position is closer to the motor housing than the second bearing position, and the first bearing position is configured as a fixed bearing and the second bearing position is configured as a floating bearing.

This makes it possible to realize a so-called fixed-floating bearing and to avoid mechanical stresses in the wiper direct drive due to thermal expansion effects. Furthermore, it is possible to dispense with the use of a support bearing or other necessary third bearing point in the region of the free end section of the rotor shaft facing away from the worm.

In a first embodiment, the circuit board is arranged together with the control electronics in the motor housing, wherein the circuit board extends perpendicularly and at a predetermined distance axially spaced apart from the free end section of the rotor shaft.

Thus, an improved heat dissipation of the control electronics may be achieved. The control electronics here comprise logic electronics for internal process control and power electronics for direct control of the stator windings.

Preferably, the circuit board is provided with a rotor position sensor which interacts with a permanent magnet positioned on the free end section of the rotor shaft for rotor position detection.

Thus, an electronic and thus wear-free commutation of the EC motor can be achieved.

Preferably, the control electronics have an output position sensor for detecting the current rotational position of the output journal.

As a result of the resulting purely electronic coupling, a precise spatial coordination of at least two wiper blades, which are in each case driven by means of the wiper direct drive according to the invention, can be achieved, in particular for collision avoidance. Furthermore, a limitation of the wiping area which is swept over by at least one wiper blade which is set in motion by means of a wiper direct drive can be achieved. The resolution capability and measurement accuracy of the output position sensor may be varied as necessary for different rotational angle ranges of the output shaft.

Preferably, the circuit board is connected to a tab-like carrier which passes through an opening in the gear housing and has a free end which is positioned in the region of the helical gear, wherein the output position sensor is arranged on the free end and a ring magnet is provided on the helical gear for interaction with the output position sensor.

The respective current rotational position of the output journal can thus be detected in a simple manner.

Preferably, the motor housing has a first housing part for accommodating the EC motor and a second housing part for the control electronics.

Thus, cooling of the EC motor and the control electronics independently of each other can be achieved.

According to a further embodiment, a plug body made of plastic material is arranged at least in some regions between the first and second housing parts for thermal and electrical isolation, wherein the plug body carries the control electronics and forms a connection plug.

Due to the multiple functionality of the third housing part, which is designed at the same time as a plug body, a structurally particularly simple design results.

Preferably, the motor housing and the gear housing are made of metal, wherein the motor housing is designed for cooling the control electronics and the gear housing is designed for cooling the EC motor.

Thus, an improved cooling of the control electronics and the EC motor, in particular the stator, can be achieved with regard thereto. The motor housing can be embodied, for example, as an aluminum cast cover, an aluminum sheet cover, a steel cover or a sheet cover, and the gear housing can be embodied, for example, in the form of a solid aluminum casting.

In a second embodiment, a circuit board and control electronics are arranged in the transmission housing between the helical gear and a bearing section of the output journal, which bearing section is formed on the transmission housing, wherein the output journal is at least partially surrounded by the circuit board and the circuit board is oriented substantially parallel to the helical gear.

This makes it possible to achieve a reduction in the installation space of the control electronics on the circuit board and an optimization of the heat dissipation. The control electronics in turn comprise logic electronics and power electronics.

Preferably, an annular permanent magnet is arranged on the rotor shaft in the region of the first bearing position, and the circuit board has a rotor position sensor which interacts with the permanent magnet for rotor position detection.

Thereby, an electronic commutation of the EC motor can be achieved.

In this way, a reliable spatial coordination of the driving of, for example, at least two wiper blades by means of the wiper direct drive according to the invention can be achieved. Furthermore, the wiping area of the respective wiper blade can be limited.

Preferably, the gear housing has a plastic gear cover and a connecting plug, which is connected to the circuit board in an electrically conductive manner, in particular by means of a cut-and-clamp connection.

The wiper direct drive can thus be integrated easily in a plug-in manner into the electrical on-board power supply system of the motor vehicle.

Preferably, the gear housing is made of metal, in particular an aluminum casting, and the motor housing is made of metal, in particular an aluminum casting or a deep-drawn sheet metal housing.

Thus, an improved cooling of the control electronics and the EC motor, in particular the stator, can be achieved with regard thereto.

Drawings

In the following description the invention is explained in more detail by means of embodiments shown in the drawings. Identical or identically acting components are provided with the same reference numerals and are each described only once. Wherein:

figure 1 shows a side view of a first embodiment of a wiper direct drive,

figure 2 shows a top view of a longitudinal section of the wiper direct drive along the section line II-II in figure 1,

figure 3 shows a top view of a longitudinal section of the wiper direct drive along the section line III-III of figure 2,

figure 4 shows a plan view of a second embodiment of a wiper direct drive,

fig. 5 shows a plan view of a longitudinal section of the wiper direct drive of fig. 4, an

FIG. 6 shows a cross section of the wiper direct drive along section line VI-VI of FIG. 5.

Detailed Description

Fig. 1 shows a wiper direct drive 10 for a wiper system 12 of a motor vehicle, which has a preferably substantially cylindrical motor housing 14, to which a gear mechanism housing 16 is preferably connected in the axial direction. According to one embodiment, a brushless or electronically commutated direct-current motor, i.e., an EC motor 20, is located in the motor housing 14, and a helical gear mechanism 22 for speed adaptation or for torque increase is accommodated in the transmission housing 16. The EC motor 20 drives the helical gear mechanism 22 in a rotating manner, wherein the helical gear mechanism 22 itself serves to drive, in particular in an oscillating-pivoting manner, an output journal 30 on which a wiper arm 32 of the wiper system 12 of the motor vehicle is fastened (festsetzen).

Fig. 2 shows the wiper direct drive 10 from fig. 1, the EC motor 20 of which is preferably designed rotationally symmetrically to the longitudinal center axis 18 and has a substantially cylindrical rotor shaft 24 which is provided at least in regions with a worm 26. The worm 26 is in constant engagement with a helical gear 28 and together with it forms a helical gear mechanism 22 for driving an output journal 30.

According to one embodiment, the rotor shaft 24 is rotatably mounted in the transmission housing 16 on both sides of the worm 26 in a first and a

second bearing position

40, 42. The first bearing location 40 is diagrammatically closer to the motor housing 14 in the axial direction than the second bearing location 42, wherein the first bearing location 40 is preferably designed as a fixed bearing 44 and the second bearing location 42 pointing away from the motor housing 14 is designed as a floating bearing 46, so that a fixed-floating bearing of the rotor shaft 24 is ensured. The two axially spaced bearing points 40, 42 are preferably designed as rolling bearings, in particular ball bearings.

A lamination stack 54 equipped with permanent magnets 52 is preferably arranged in a torsion-proof manner on the free end section 50 of the rotor shaft 24 pointing away from the worm 26 and forms an exemplary inner rotor together with the rotor shaft 24. In the case of an annular gap, which is not shown for the sake of greater clarity of the drawing, the substantially cylindrical lamination stack 54 is preferably surrounded coaxially in a known manner by an approximately hollow cylindrical stator 60 having stator windings 62, wherein the stator 60 is configured as an outer stator by way of example. The stator winding 62 includes a plurality of coils, which are not shown for the sake of clarity of the drawing, and which are electrically connected to each other in a suitable manner to construct the stator winding 62.

The motor housing 14 comprises a first housing part 70, preferably for accommodating the EC motor 20, and a second housing part 72 for a circuit board 74 having control electronics 76, wherein a plug body 78 having a connection plug 80 configured in an integrated manner thereon or a user plug for electrically integrating the wiper direct drive 10 into the vehicle electrical system of the motor vehicle is arranged at least in some regions between the first housing part 70 and the second housing part 72. The circuit board 74, which is for example approximately circular, is preferably arranged vertically and at a preferably as small as possible axial distance 82 from the free end section 50 of the rotor shaft 24 for reasons of installation space within the second housing part 72 of the motor housing 14.

According to one specific embodiment, the circuit board 74 has, in particular, an electronic rotor position sensor 84, which interacts with a permanent magnet 86 positioned on the free end section 50 of the rotor shaft 24 for rotor position detection, in order to thus be able to carry out the desired electronic commutation of the EC motor 20. The electrical signal of the rotor position sensor 84 is detected, amplified, evaluated by means of logic electronics 88 or control electronics, preferably of digital design, and is supplied to power electronics 90, in particular in the form of a so-called B6 bridge, for direct electronic control of the stator winding 62. The electrical connection between the coils of the stator winding 62 and the circuit board 74 is here realized, for example, by means of a terminal plate 92, wherein the electrical contact between the stator winding 62 and the terminal plate 92 or the circuit board 74 can be realized, for example, by means of a cut-and-clamped connection and/or a soldered connection.

The co-operation of the transmission housing 16 with the first housing part 70 preferably contributes to an optimized dissipation of the lost heat (W ä rmeabfuhr) released by the EC motor 20, and for this purpose is preferably made of a metallic material, in particular in the form of an aluminum casting. The motor housing 14, which is likewise preferably made of a metallic material, can be, for example, a solid aluminum casting or a deep-drawn sheet metal housing, wherein the two

housing parts

70, 72 of the motor housing 14 are designed to reduce the temperature or cool the electronics 74 as efficiently as possible.

In particular, the preferably cup-shaped recess 100 of the annular cover surface 102 of the second housing part 72, which recess is directed in the direction of the EC motor, contributes to the cooling substantially circumferentially, since the circular base surface 104 of the recess 100 ideally lies over the entire surface of the power electronics 90. In order to further optimize the heat transfer, a heat-conducting element 106, in particular a heat-conducting paste, a heat-conducting pad or the like, optionally combined with a heat sink, can be arranged between the power electronics 90 and the bottom 104 of the recess 100, said element increasing the heat-conducting capacity, in particular good heat-conducting capacity, and compensating for slight surface irregularities or roughness.

Furthermore, the two

housing parts

70, 72 of the motor housing 14 are thermally isolated from one another in a very efficient manner by the plug body 78, which is also embodied as a component of the motor housing 14, so that the waste heat of the EC motor 20 is dissipated essentially only by the first housing part 70 connected to the transmission housing 16 to the environment outside the wiper direct drive 10 and does not contribute to the heating of the second housing part 72, which is primarily responsible for cooling the control electronics. Furthermore, the rearward arrangement of the circuit board 74 allows a very simple and rapid assembly of the wiper direct drive 10. Due to the metallic design of the majority of the motor housing 14 connected to the brushless EC motor 20, a high electromagnetic compatibility of the wiper direct drive 10 is also achieved.

Fig. 3 shows the wiper direct drive 10 of fig. 2 with the transmission housing 16 and the motor housing 14 connected thereto in the axial direction with the longitudinal center axis 18, which is itself constructed with two

housing parts

70, 72 and a plug body 78 arranged therebetween. The helical gear 28 is accommodated in the transmission housing 16 so as to be rotatable together with an output journal 30 formed thereon. A tub-shaped recess 100 with a rounded bottom surface 104 is located in a rearward facing cover surface 102 of the second housing part 72 of the motor housing 14. The circuit board 74, together with the power electronics 90 located thereon in particular, is arranged in the second housing part 72, wherein, in the case of a preferred intermediate connection of the thermally conductive element 106, the bottom 104 of the cylindrical recess 100 of the second housing part 72 ideally rests in a full-surface manner on the power electronics 90.

The circuit board 74 for actuating and/or adjusting the EC motor concealed here is preferably electrically conductively connected to the tab-like or tongue-like carrier 112 by means of a (plug) connector 110 or a pin strip with a plurality of angled (press-in) pins 124 indicated in dashed lines, for example in the manner of a cut-and-clamp connection. A carrier 112, which is preferably arranged approximately perpendicular to the circuit board 74, extends in a manner approximately parallel to the longitudinal center axis 18, is guided through an opening 114 in the gear housing 16 until it engages in its interior 116. The carrier 112, which is directed away from the second housing part 72 or the printed circuit board 74, has a free end 118 in the region of the helical gear 28, on which end an output position sensor 120 is arranged, which, by interacting with a ring magnet 122 arranged on the helical gear 28, serves to detect a respective current absolute rotational position or rotational angle of the output shaft 30 in a contactless manner.

The ring magnet 122 is preferably fixed to the helical gear 28 away from the helical gear 28 or in a direction towards the output shaft 30. The ring magnet 122 has a suitable number of pole piece segments to enable absolute rotational position measurement, where resolution capability may vary depending on the respective rotational position or angle of rotation.

By means of the output position sensor 120 and the ring magnet 122, in particular, the wiping area of a wiper arm which is moved on the glass of a motor vehicle by means of a wiper direct drive can be set with high accuracy. Furthermore, the movement processes of the at least two wiper arms, which are moved in each case by means of separate wiper direct drives, can be coordinated in relation to one another in order to exclude collisions.

In order to establish the necessary electrical connection between the output position sensor 120 and the connector 110 and thus the circuit board 74 with the control electronics 76, the carrier 112 preferably has a circuit board 126 which is formed with a preferably all-sided encapsulation 128 made of an electrically insulating material, in particular a thermoplastic. The actual electrical contacting of the output position sensor 120 and the connector 110 with the circuit board 126 is effected, for example, by means of a soldered connection, a cut-and-clamp connection or a screw connection. Instead of the circuit board 126, metal wires or stranded wires embedded in the envelope 128 may also be provided.

Fig. 4 shows a wiper direct drive 200 for a wiper device 202 of a motor vehicle, which preferably has a substantially cylindrical motor housing 204 and a gear housing 206. An EC motor 210, which is designed rotationally symmetrically to the longitudinal center axis 208, is preferably in turn integrated into the motor housing 204, and a helical gear drive 212 is accommodated in the gear housing 206 for adapting the rotational speed and the torque.

The helical gear mechanism 212 is directly driven by means of the EC motor 210, wherein the helical gear mechanism 212 itself serves to drive an output journal 220, which is preferably conical and longitudinally slotted on the end face and on which a wiper arm 222 of the wiper system 202 of the motor vehicle is arranged in a rotationally fixed manner. The helical gear 212 comprises a worm 216, which is formed essentially at the end on the rotor shaft 214 of the EC motor 210 and which engages permanently with a helical gear 218.

The transmission housing 206 preferably has a plastic transmission cover 230 on the underside. A truncated cone-shaped bearing section 234 for rotatably mounting the output journal 220 is formed on the gear housing 206, which is preferably made of a metallic material, while an electrical connection plug 236 or a user plug for connecting the wiper direct drive into the vehicle electrical system of the motor vehicle is preferably formed integrally on the plastic gear cover 230.

The transmission housing 206 may be made, for example, in the form of an aluminum casting. The motor housing 204 is preferably embodied as a deep-drawn, metallic, plate-type component, while the plastic transmission cover 230 is preferably produced by injection molding from a thermoplastic and, if appropriate, fiber-reinforced plastic.

Fig. 5 shows the wiper direct drive 200 of fig. 4, corresponding to the first specific embodiment, wherein, according to one specific embodiment, the rotor shaft 214 of the EC motor 210 accommodated in the motor housing 204 is in turn rotatably mounted in the gear housing 206 on both sides of the worm 216 in a first and a

second bearing position

240, 242. The first bearing position 240 is preferably reconfigured as a fixed bearing 244 to achieve a fixed-floating-support of the rotor shaft 214, and the second bearing position 242, which points away from the motor housing 204, is a floating bearing 246.

A lamination stack 254, which is provided with a plurality of permanent magnets 252 and is coaxially surrounded by a stator 262 having stator windings 264, is preferably arranged in a rotationally fixed manner on a free end section 250 of the rotor shaft 214, which is directed away from the worm 216. The electrical connection of the individual coils of the stator winding 264, which are not shown here for the sake of greater clarity of the drawing, is preferably effected via a connecting plate 266.

Lamination stack 254 and rotor shaft 214 again illustratively configure an inner rotor, and stator 262 again configures an outer stator.

In order to detect the current rotor position or the respective rotational position of the rotor shaft 24, an annular permanent magnet 270 is preferably arranged on the rotor shaft in the region of the first bearing point 240 in a rotationally fixed manner, which permanent magnet interacts with a rotor position sensor (see in particular fig. 6), not visible here, of a circuit board, which is likewise covered here, in order to accommodate the control electronics. Furthermore, the mechanical-electrical design of the helical gear mechanism 216, which is composed of the worm 216 and the helical gear 218, including the EC motor 210 required for its drive, substantially follows the technical implementation of the first embodiment of the wiper direct drive 10 from fig. 1 to 3, so that, in order to avoid repetitions of the contents, reference is made here, in particular, to the description of fig. 2. The electrical connection of the connection plug 236 formed on the plastic actuator cover 230 to a circuit board with control electronics, which is likewise not visible here, is effected here only by way of example by means of known cutting-clamping connections 238.

Fig. 6 shows the wiper direct drive 200 of fig. 5, the EC motor 210 of which is arranged in the motor housing 204 and the helical gear mechanism 212, which is formed together with the helical gear 218 and the worm 216, of which is accommodated in a metal part of the gear mechanism housing 206, which is closed on the underside by a plastic gear mechanism cover 230. The rotor shaft 214 of the EC motor 210 is rotatably supported within the transmission housing 206 in bearing

locations

240, 242 located axially on either side of the screw 216. The rotor position detection of the EC motor 210 is carried out by means of an annular permanent magnet 270 arranged on the rotor shaft 214 in the axial vicinity of the first bearing point 240, which permanent magnet interacts in a contactless manner with a rotor position sensor 272.

As a significant difference from the first embodiment of the wiper direct drive 10 of fig. 1 to 3, in the second embodiment of the wiper direct drive 200 shown here, the circuit board 280 together with the control electronics 282 is positioned between the helical gear 218 and the bearing section 234 formed on the metallic transmission housing 206, wherein the output journal 220 in the transmission housing 206 is at least partially surrounded by the circuit board 280, and the circuit board 280 extends in a parallel, spaced-apart manner relative to the helical gear 218 or relative to the longitudinal center axis 208 of the EC motor 210. Due to this special spatial arrangement of the circuit board 280 in the gear mechanism housing 206, an optimum cooling or cooling of the control electronics 282, in particular of the B6 bridge, for the direct actuation of the power electronics 284 of the EC motor 210 can be ensured in particular by the metallic bearing section 234 of the metallic gear mechanism housing 206. This simultaneously results in a simple and fast installation of the wiper direct drive 200.

An output position sensor 290 for detecting the respective current absolute rotational position of the helical gear 218 is preferably also located on the circuit board 280. The signal of the output position sensor 290 is preferably detected by means of a logic electronics 286, which is a further component of the control electronics 282, amplified, evaluated and further conducted to the power electronics 284 for the purpose of controlling the latter. For this purpose, the helical gear 218 has a permanent magnet with a suitable number of pole piece segments. The electrically conductive connection of the coils, not shown, of the stator winding 264 of the EC motor 210 to the control electronics 282 is effected, for example, by means of a multipolar connector 292 in the known cutting-clamping technique, wherein the connector 292 is preferably inserted through a tunnel-like or channel-like opening 294 in the transmission housing 206 as far as into the motor housing 204.

The connector 292 preferably has insulation 296, preferably on all sides, for reliable electrical insulation of the electrical conductors guided in the connector 292 with respect to the surrounding metallic transmission housing 206. In order to further optimize the cooling or cooling of the control electronics 282, a thermally conductive element 298, in particular a thermally conductive paste or pad, can be arranged between the power electronics 284 and the bearing section 234 of the transmission housing 206.

Claims

1. Wiper direct drive (10, 200) for a wiper device (12, 202) of a motor vehicle, having an EC motor (20, 210) and a helical gear mechanism (22, 212), wherein the EC motor (20, 210) is arranged in a motor housing (14, 204) and the helical gear mechanism (22, 212) is arranged in a gear housing (16, 206), and wherein the helical gear mechanism (22, 212) has a helical gear (28, 218) which has an output journal (30, 220) for fixing a wiper arm (32, 222) of the wiper device (12, 202) and can be driven in rotation by the EC motor (20, 210), characterized in that the EC motor (20, 210) has a rotor shaft (24, a, 214) The rotor shaft is provided at least in sections with a worm (26, 216) and is mounted in a rotationally movable manner in a first and a second bearing position (40, 42, 240, 242) which are arranged on both sides of the worm (26, 216) in the space formed by the transmission housing (16, 206), wherein the motor housing (14) comprises a first housing part (70), a second housing part (72) and a plug body (78) arranged therebetween, and wherein the first housing part (70) is designed in one piece with the transmission housing (16, 206), and wherein the plug body (78) has a connection plug (80) designed in an integrated manner thereon for electrically integrating the wiper direct drive (10) into an on-board electrical system of a motor vehicle, wherein, a pot-shaped recess (100) having a circular base surface (104) is located in a rear cover surface (102) of a second housing part (72) of the motor housing (14).

2. Wiper direct drive according to claim 1, characterized in that the rotor shaft (24, 214) has a free end section (50, 250) facing away from the worm (26, 216), on which a lamination stack (54, 254) provided with permanent magnets (52, 252) is arranged in a rotationally fixed manner, wherein the worm (26, 216) engages with the helical gear (28, 218), and wherein the lamination stack (54, 254) provided with permanent magnets (52, 252) is coaxially surrounded by a stator (60, 262) with stator windings (62, 264) accommodated in the motor housing (14, 204).

3. Wiper direct drive according to claim 1 or 2, characterized in that the first bearing location (40, 240) is closer to the motor housing (14, 204) than the second bearing location (42, 242), and in that the first bearing location (40, 240) is configured as a fixed bearing (44, 244) and the second bearing location (42, 242) is configured as a floating bearing (46, 246).

4. Wiper direct drive according to claim 2, characterized in that a circuit board (74) is arranged in the motor housing (14) together with control electronics (76), wherein the circuit board (74) extends perpendicularly and at a predefined distance (82) axially spaced apart from the free end section (50) of the rotor shaft (24).

5. Wiper direct drive according to claim 4, characterized in that the circuit board (74) is provided with a rotor position sensor (84) which interacts with a permanent magnet (86) positioned on the free end section (50) of the rotor shaft (24) for rotor position detection.

6. Wiper direct drive according to claim 4, characterized in that the control electronics (76) have an output position sensor (120) for detecting the current rotational position of the output journal (30).

7. Wiper direct drive according to claim 6, characterized in that the circuit board (74) is connected to a web-like carrier (112) which passes through an opening (114) in the transmission housing (16) and has a free end (118) which is positioned in the region of the helical gear (28), wherein the output position sensor (120) is arranged on the free end (118) and a ring magnet (122) is provided on the helical gear (28) for interacting with the output position sensor (120).

8. The wiper direct drive according to claim 4, characterized in that the motor housing (14) has a first housing part (70) for accommodating the EC motor (20) and a second housing part (72) for the control electronics (76).

9. The wiper direct drive according to claim 8, characterized in that a plug body (78) made of a plastic material is provided at least in places between the first and second housing parts (70, 72) for thermal and electrical insulation, wherein the plug body (78) carries the control electronics (76) and forms a connection plug (80).

10. Wiper direct drive according to claim 4, characterized in that the motor housing (14) and the gear housing (16) are of metal, wherein the motor housing (14) is designed for cooling the control electronics (76) and the gear housing (16) is designed for cooling the EC motor (20).

11. Wiper direct drive according to claim 1 or 2, characterized in that a circuit board (280) and control electronics (282) between the helical gear (218) and a bearing section (234) of the output journal (220) which is constructed on the transmission housing (206) are arranged within the transmission housing (206), wherein the output journal (220) is at least partially surrounded by the circuit board (280) and the circuit board (280) is oriented substantially parallel to the helical gear (218).

12. Wiper direct drive according to claim 11, characterized in that an annular permanent magnet (270) is arranged on the rotor shaft (214) in the region of the first bearing location (240), and in that the circuit board (280) has a rotor position sensor (272) which interacts with the permanent magnet (270) for rotor position detection.

13. Wiper direct drive according to claim 11, characterized in that the control electronics (282) have an output position sensor (290) for detecting the current rotational position of the output journal (220).

14. Wiper direct drive according to claim 13, characterized in that the gear housing (206) has a plastic gear cover (230) and a connection plug (236) which is connected in an electrically conductive manner to the circuit board (280) by means of a cut-and-clamped connection (238).

15. The wiper direct drive according to claim 14, characterized in that the gear housing (16, 206) consists of metal and is constructed in the manner of an aluminum casting, and the motor housing (14, 204) consists of metal and is constructed in the manner of an aluminum casting or a deep-drawn plate housing.