Windscreen wiper drive of a windscreen wiper device of a rail vehicle

Disclosed embodiments relate to a windscreen wiper drive of a windscreen wiper device of a rail vehicle. The drive includes at least one electric motor, a gear, the input shaft of which being connected to an output shaft of the electric motor, wherein an output shaft of the gear is provided for driving at least one windscreen wiper arm of a windscreen wiper, which arm swings back and forth with the output shaft, a rotation angle sensor unit, which detects a rotation of at least one element of the windscreen wiper drive, and a mechanical rotation angle limitation, which mechanically limits a rotational movement of at least one element of the windscreen wiper drive. The electric motor is formed by a disc motor and the gear is formed by a planetary gear.

PRIORITY CLAIM

This patent application is a U.S. National Phase of International Patent Application No. PCT/EP2016/000821, filed May 18, 2016, which claims priority to German Patent Application No. 10 2015 006 356.1, filed May 19, 2015, the disclosures of which are incorporated herein by reference in their entirety.

FIELD

Disclosed embodiments provide a windshield wiper drive that exhibits high dynamics and exhibits a high torque while being of simultaneously small structural size.

SUMMARY

Disclosed embodiments are based on a windshield wiper drive of a windshield wiper apparatus of a rail vehicle.

DETAILED DESCRIPTION

A rail vehicle is to be understood to mean a track-bound vehicle such as a locomotive, a rail motor set, a rail motor coach, a streetcar, a subway vehicle, a wagon such as a passenger train and/or freight car, in particular a high-speed rail vehicle.

It is provided according to the invention that the electric motor is formed by a disk motor, and the gearing may be formed by a planetary gearing.

A disk motor of the type generally exhibits a high torque while being of small structural length. Owing to the construction of a disk motor, the latter exhibits high dynamics, which are predestined for rapid wiping movements. Owing to the generally ironless rotor, no or only little brush sparking occurs. As a result, brush wear may also be reduced to a minimum.

Furthermore, planetary gearings generally exhibit high efficiency, are of compact construction, and exhibit little or no play.

Such an embodiment also in particular satisfies the high requirements for use on rail vehicles with regard to EMC, IP class, vibration resistance and ambient temperature.

Furthermore, in addition to use of the windshield wiper drive for a windshield wiper with only a main arm, use for a windshield wiper with a main arm and a secondary or parallel wiper arm may also be possible. Altogether, a long service life may be achieved as a result of the omission of the lever mechanism and the associated axial forces on the disk motor.

The disk motor particularly may have an ironless, disk-shaped rotor, which may be composed of an insulating material and on one or both sides of which there are arranged conductor tracks, at least one motor cover, which forms a stator and on which there are arranged permanent magnets which are situated opposite the conductor tracks, and a commutator. The commutator has for example brush holders and carbon brushes guided therein.

The output shaft of the disk motor may be formed by a rotor shaft which bears the rotor.

In one refinement, the disk motor forms a structural unit together with the planetary gearing. This may be realized for example by virtue of the disk motor and the planetary gearing having a common housing, or by virtue of a separate housing of the disk motor being flange-mounted directly onto a separate housing of the planetary gearing. This yields a modular and scalable construction of the windshield wiper drive.

In particular, the output shaft of the disk motor may be directly connected to the input shaft of the planetary gearing, or a gearwheel of the planetary gearing may be arranged directly on the output shaft of the disk motor. This yields a compact construction of the windshield wiper drive.

The output shaft of the planetary gearing particularly may have a receptacle for the direct mounting of the windshield wiper arm of the windshield wiper. In particular, no further mechanical transmission or coupling elements are provided between the output shaft of the planetary gearing and the windshield wiper arm.

This yields a rigid drive train of the windshield wiper drive, because the rotor of the disk motor introduces its rotational movement directly into the planetary gearing, which transmits the rotational movement, for example with a speed reduction, to its output shaft, to which the windshield wiper arm of the windshield wiper may be then directly connected.

The rotational angle sensor device may have at least one contactless rotational angle sensor for detecting the actual position of the windshield wiper arm. The actual position of the windshield wiper arm can then be used for control or regulation of the position of the windshield wiper arm in the context of a setpoint-actual alignment. It is also thereby possible for not only the end positions of the windshield wiper arm but also any desired intermediate position to be set or adjusted to.

Owing to the potentially analogue signal of the for example contactless rotational angle sensor, reliable information regarding the present position of the windshield wiper shaft or of the windshield wiper arm may be available at all times.

In one refinement, the rotational angle sensor device has at least one contactless magnetic field sensor which may be coupled to the output shaft of the planetary gearing or to a rotary element which may be coupled to the output shaft.

Here, in particular, a permanent magnet of the contactless rotational angle sensor may be connected rotationally conjointly to a shaft of the windshield wiper drive. The rotational angle sensor may for example be arranged within a housing of the disk motor or of the structural unit composed of disk motor and planetary gearing, and may detect the rotational angle of the rotor shaft of the disk motor. This embodiment may be preferred for example if the windshield wiper drive has only a single output shaft in the form of a main arm shaft.

Alternatively, the windshield wiper drive may have, at the output side, a main arm shaft, which may be driven in rotation by the output shaft of the planetary gearing, and a secondary or parallel arm shaft, which may be driven in rotation by rotation of the main arm shaft, wherein the main arm shaft may be designed for the fastening of a main arm and the secondary or parallel arm shaft may be designed for the fastening of a secondary or parallel arm of the windshield wiper. In such a case, the rotational angle sensor may be arranged and designed to detect the rotational angle of the secondary or parallel arm shaft of the windshield wiper drive.

The mechanical rotational angle delimiter may have a projection, which may be driven by a shaft of the windshield wiper drive, and a static delimiting element, which has a recess into which the projection projects, wherein delimiting surfaces of the recess constitute stop surfaces for the projection. In particular, the mechanical rotational angle delimiter may be designed to be adjustable, that is to say such that delimiting surfaces or mechanical stops of the rotational angle delimiter are adjustable or variable in terms of their position. It would alternatively also be possible for the delimiting surfaces or mechanical stops to be fixedly predefined.

Here, the projection may be arranged on the main arm shaft of the windshield wiper drive and formed for example as a projecting lug on a clamping ring, which may be fastened on the main arm shaft or on the secondary arm or parallel arm shaft.

Optionally, an electrical or electronic control device may be provided for controlling the disk motor in a manner dependent on signals of the rotational angle sensor device. In one refinement, the electrical or electronic control device may be designed for 4-quadrant operation of the disk motor. Flexible setting of the wiper arm position is thus possible.

The planetary gearing may be designed to reduce the rotational speed of the disk motor, whereby the already high torque of the disk motor may be further increased.

The invention also relates to a windshield wiper apparatus comprising a windshield wiper drive as described above, and to a rail vehicle having a windshield wiper apparatus of the type.

In accordance with a disclosed embodiment of an electric disk motor1shown inFIG. 1is used in each case as a single drive in an embodiments of windshield wiper drives2shown inFIGS. 2 and 3.

The disk motor1, which may operate in accordance with the principle of a unipolar machine, may have an ironless, disk-shaped rotor4composed of an insulating material, on which there are arranged, for example on both sides, conductor tracks composed for example of copper foil. The rotor4may be arranged rotationally conjointly on a rotor shaft6, which may be mounted rotatably in the motor covers8,10, wherein one end of the rotor shaft6, which thus forms an output shaft of the disk motor1, projects through a central opening of a motor cover8. On the motor covers8,10that form a stator, there are arranged permanent magnets12which are situated in each case opposite the conductor tracks of the rotor4, and which have for example a circular cross section. The permanent magnets12may be conventional permanent magnets or else may be neodymium magnets. The latter exhibit a stronger magnetic field and thus a higher torque in the presence of an unchanged rotor current. Furthermore, a commutator14may be provided which has brush holders and carbon brushes16guided therein. The rotor4accordingly rotates in a homogeneous permanent magnetic field, wherein the motor voltage may be applied to the carbon brushes16via a feed line20connected to electrical terminals, and the motor voltage may be supplied via the commutator14directly to the rotor4. The magnetic return path for the disk motor1may be then formed by the motor covers8,10. A disk motor1of the type has a small extent as viewed in the direction of its rotor axis and can therefore be of very shallow construction.

The disk motor1may be controlled by an electronic control device18shown inFIGS. 2 and 3, which for this purpose may be connected via the feed line20to the disk motor1. The control device18may be designed in particular for 4-quadrant operation of the disk motor1.

FIG. 2shows a partial longitudinal section through a windshield wiper drive2according to an embodiment of the invention. The windshield wiper drive2has, in addition to the disk motor1shown inFIG. 1, a planetary gearing22which may be installed together with the disk motor in a structural unit. Here, it is for example the case that a housing24of the disk motor1, comprising the two motor covers8,10, and a housing26of the planetary gearing22are flange-mounted on one another axially, that is to say as viewed in the direction of the rotor shaft6of the disk motor1. The end of the rotor shaft6may be connected rotationally conjointly to an input shaft of the planetary gearing22, wherein the connection may be not visible here. It is alternatively also possible for a gearwheel of the planetary gearing22to be arranged directly on the output shaft or rotor shaft6, projecting out of the housing24, of the disk motor1. An output shaft28of the planetary gearing22projects through a passage opening30of a supporting wall32, to the first side surface34of which the structural unit composed of disk motor1and planetary gearing22is also fastened. The output shaft28of the planetary gearing thus also extends axially beyond the second side surface36, pointing away from the first side surface34, of the supporting wall32, and the output shaft, with its axial elongation, forms a main arm shaft of the windshield wiper drive2. The main arm shaft28may be at least radially mounted not only in the planetary gearing22but also, on the opposite side of the supporting wall32, by means of a bearing flange38which may be fixed in this case for example to the second side surface36. At the free end of the main arm shaft28there may be formed a receptacle for a main arm of the windshield wiper, for example in the form of a surface for a clamping action. Consequently, the drive train for the main arm shaft28may be composed only of the rotor shaft6, the input shaft of the planetary gearing22, the respective gear pairings within the planetary gearing22, and the output shaft28of the planetary gearing, which simultaneously forms the main arm shaft28. Owing to the small number of components, the drive train may be highly rigid, which also gives rise to high dynamics of the windshield wiper drive2. The supporting wall32may be part of any structure in the region of a windshield of the rail vehicle. Whereas the second side surface36of the supporting wall32points outward, that is to say into the surroundings, the first side surface34points inward.

Parallel to the main arm shaft28, there may be provided a secondary or parallel arm shaft40for a secondary or parallel arm of the windshield wiper. The secondary or parallel arm shaft40may be axially and radially mounted in a further bearing flange42, which may be fixed for example to the second side surface36of the supporting wall32. The secondary or parallel arm shaft40has, on its free end, a receptacle for the secondary or parallel arm of the windshield wiper, for example likewise in the form of a surface for a clamping action. The secondary or parallel arm shaft40itself does not have a drive, and is in a known manner driven in rotation indirectly by the main arm shaft28via the windshield wiper fastened to the main arm shaft28and to the secondary or parallel arm shaft40. In an alternative embodiment, a secondary or parallel arm shaft40may also be dispensed with. Then, the windshield wiper has only a main arm, and the windshield wiper drive2has only a main arm shaft28, to which the main arm may be fastened and by which the main arm may be driven in rotation. The back-and-forth movement of the windshield wiper initiated by the actuation of the disk motor1then occurs in a plane perpendicular to the main arm shaft28or to the secondary or parallel arm shaft40.

The windshield wiper drive2furthermore has a rotational angle sensor device44, which in this case may be formed for example by a contactless rotational angle sensor in the form of a magnetic field sensor. A rotor of the magnetic field sensor may be in this case arranged for example on the end of the rotor shaft6of the disk motor1, for example in the form of a permanent magnet. A stator of the magnetic field sensor44, for example in the form of an electrical coil, may be for example fastened to the motor cover10which serves for the mounting of the end of the rotor shaft6. As a result of rotation of the rotor shaft6, the magnetic field changes, which may be detected by evaluation electronics integrated in the magnetic field sensor, wherein a corresponding electrical signal may be then transmitted via a signal line (not shown here) to the electronic control device18. The electrical signal then represents the angular position of the rotor shaft6, which can be converted, by means of the known speed reduction ratio of the planetary gearing22, into the angular position of the main arm shaft28, and thus the present actual rotational position of the windshield wiper can be determined. Then, the electronic control device18, to which for example a value for a setpoint rotational position, setpoint rotational end position and/or a setpoint rotational speed of the windshield wiper input by means of an operating device may be available, can adapt the actual rotational position of the windshield wiper or an actual rotational speed of the windshield wiper to the setpoint values. Instead of such regulation, it is however also possible for merely control of the disk motor1with regard to the attainment of particular rotational positions, rotational end positions and/or rotational speeds to be provided without regulation, wherein feedback of the corresponding actual values provided by means of the rotational angle sensor device44may be expedient in this case too.

The disclosed embodiment shown inFIG. 2may have a mechanical rotational angle delimiter46for the main arm shaft28, for the purposes of restricting the angle range through which the windshield wiper moves to a maximum possible angle range, even in the event that the electronic control device18fails, for example. The rotational angle delimiter46is in this case arranged for example on that side of the supporting wall32which is averted from the structural unit composed of disk motor1and planetary gearing22.

The mechanical rotational angle delimiter46, as may be used in the embodiment ofFIG. 2, may be designed analogously to the rotational angle delimiter used in the embodiment ofFIG. 3, such that, for the purposes of explanation, reference may also be made here toFIG. 4, which shows the rotational angle delimiter46of the exemplary embodiment ofFIG. 3in cross section.

Here, the rotational angle delimiter46has a projection48which may be driven by the main arm shaft28, for example in the form of an axially projecting lug, which may be arranged radially offset with respect to the central axis of the main arm shaft, of a clamping ring which may be clamped on the main arm shaft. Furthermore, the rotational angle delimiter has a static delimiting element50with a recess52into which the projection48projects, wherein delimiting surfaces54of the recess52constitute stop surfaces for the projection48.

Here, the static delimiting element50may be formed for example by a holed plate fixed directly or indirectly to the supporting wall, in which holed plate there may be formed a circular-sector-shaped hole52which may be arranged offset from the central axis of the main arm shaft28and into which the lug48projects axially in relation to the central axis of the main arm shaft28. The lug48itself is in this case likewise of circular-sector-shaped form such that it can bear flush against lateral delimiting surfaces54of the hole52. The holed plate50may be detachably fastened to the supporting wall32in order that it can be exchanged for a different holed plate with changed hole dimensions and delimiting surfaces in order to change the angular area covered by the windshield wiper. In this respect, the mechanical rotational angle delimiter46may be duly predefined here, but is nevertheless adjustable through exchange of the holed plate50.

It would alternatively also be possible for the mechanical rotational angle delimiter46to be of adjustable form in the sense that the delimiting surfaces54or mechanical stops of the rotational angle delimiter are adjustable or variable in terms of their position, without parts having to be exchanged for this purpose.

Owing to the rotational angle detection on the rotor shaft6of the disk motor1and the thus somewhat larger axial extent, the embodiment illustrated inFIG. 2may be suitable in particular for installation in rail vehicles, in the case of which the installation depth for the windshield wiper drive may be less restricted than in the case of, for example, LRVs (streetcars).

In the further embodiment of a windshield wiper drive2shown inFIG. 3, components and assemblies which are identical and of identical action in relation to the embodiment shown inFIG. 2are denoted by the same reference designations. By contrast to the embodiment ofFIG. 2, a central electrical connector56for the windshield wiper drive2can be seen in the embodiment ofFIG. 3, which connector may be connected via a line58to the disk motor1. Furthermore, the rotational angle sensor device44may, in this case too, be arranged for example in the form of a contactless magnetic field sensor in this case not on the rotor shaft6but on the secondary or parallel arm shaft40. More specifically, a rotor of the magnetic field sensor44, for example in the form of a permanent magnet60, rotates with the secondary or parallel arm shaft40, whereas the associated stator may be arranged in a static sensor housing62. It is self-evident that, in this case, too, the magnetic field sensor44may be connected via a signal line (not shown here) to the central electrical connector56. The central electrical connector56has for example a part of an electrical plug connection in the form of a socket, to which there may be then connected a plug of a feed line20which may be connected to the electronic controller18. Thus, the rotational position of the secondary or parallel arm shaft40may be signaled to the electronic control device18by the magnetic field sensor44.

Furthermore, the rotational angle delimiter46is in this case arranged for example on the first side surface34, which faces toward the structural unit composed of disk motor1and planetary gearing22, of the supporting wall32. Also, the two bearing flanges38,42for the main arm shaft28and the secondary arm shaft40respectively are fixed to the first side surface34of the supporting wall32so as to project through passage bores. Furthermore, the main arm shaft28has a central bore64which serves as a washing water feed for washing water which may be applied to the windshield from a dispensing device for example in the form of nozzles. Finally, the structural unit composed of disk motor1and planetary gearing22may be fastened to a housing66, which in turn may be fixed to the first side surface34of the supporting wall32. The rotational angle delimiter46and the rotational angle sensor44are also accommodated in the housing66.

The embodiment illustrated inFIG. 3in, owing to its small axial extent owing to the rotational angle detection on the secondary or parallel arm shaft40, suitable in particular for installation in rail vehicles in which the installation depth for the windshield wiper drive may be restricted, such as for example EMU (Electrical Multiple Unit) or DMU (Diesel Multiple Unit) vehicles.

The proposed windshield wiper drive2for rail vehicles, as may be fastened to the supporting wall32as a unit which can be mounted and dismounted there as a whole, may be thus composed substantially of the disk motor1, the planetary gearing22, the rotational angle sensor device44and the mechanical rotational angle delimiter46. The planetary gearing22may be mounted directly on the disk motor1and may form a structural unit together with the latter. The electronic control device18is in this case may not a constituent part of the windshield wiper drive2, though could likewise be a part thereof.

In applications for use on streetcars (LRV) or other low-speed vehicles, the planetary gearing22may have a lengthened output shaft28onto which the windshield wiper arm can be directly mounted.

The rotational angle sensor device44may be distinguished by an optionally analog output signal which may be directly related to the present rotational position of the windshield wiper arm or the position of the output shaft28of the planetary gear set. As an output signal, a standard current signal of 4-20 mA may be used, because this may be distinguished by very high EMC resistance.

The windshield wiper drive2may be suitable both for segment wiper arms and for parallel wiper arms and permits a wiping angle of for example between approximately 30° and 180°.

The scope of the invention also encompasses embodiments which comprise any desired combination of features of the embodiments described here.

The invention relates to a windshield wiper drive of a windshield wiper apparatus of a rail vehicle, having at least one electric motor, a gearing, the input shaft of which may be connected to an output shaft of the motor, wherein an output shaft of the gearing may be provided for driving at least one windshield wiper arm, which pivots back and forth with the output shaft, of a windshield wiper, a rotational angle sensor device which detects a rotation of at least one element of the windshield wiper drive, and a mechanical rotational angle delimiter which mechanically limits a rotational movement of at least one element of the windshield wiper drive.

Furthermore, the invention also relates to a windshield wiper apparatus of a rail vehicle comprising at least one windshield wiper drive, and to a rail vehicle having a windshield wiper apparatus.

A windshield wiper drive of the type is known from DE 10 2012 023 638 A1. In the document, in the embodiment ofFIGS. 7 to 9, a motor (not shown in any more detail) drives a worm shaft of a worm gearing, the worm gear of which serves as output shaft, which drives a windshield wiper arm of a windshield wiper. The rotational angle sensor device may be in the form of a contact sensor means and has, on the one hand, contact pins arranged on a gearing case and, on the other hand, a conductor structure arranged on the worm gear, along which conductor structure the contact pins slide during a rotation of the worm gear. The mechanical rotational angle delimiter has an arcuate movement section radially offset from the central axis of the worm gear, which arcuate movement section performs an arcuate movement when the worm gear rotates. The movement section can, during a rotation of the worm gear, move within a slide hole of a lever, wherein ends of the slide hole form stops for the movement section such that the movement section abuts against the stop of the slide hole when the worm gear may be rotated beyond an angle range of 270 degrees.

LIST OF REFERENCE DESIGNATIONS