Motor assembly for a wiping device

Abstract

Motor assembly for a wiper device. The invention relates to a motor assembly (1) for a wiper device (2; 25) of a vehicle, this assembly comprising: a first electric motor (5) arranged to provide a first mechanical torque, a second electric motor (6) arranged to provide a second mechanical torque, a mechanical transmission device (7) linked to the first and second motors and configured to deliver a cumulative output torque to drive the wiper device, this cumulative output torque being a sum of the torques supplied by the two motors, a mechanical compensation device (32) configured to compensate for any mechanical desynchronization between the first and second motors and transmitted to the mechanical transmission device. Figure for the abstract: Fig. 1

Description

Title of the invention: Motor assembly for a wiping device

[0001] The invention relates to the field of motors for a wiping device for a vehicle, in particular land, air or sea. The invention applies in particular to motor vehicles, in particular buses and trucks, or even private vehicles.

[0002] Patent application WO 2021018496 discloses an electric motor for a wiping device of a motor vehicle, comprising a stator and a rotor, the stator comprising a plurality of electromagnetic excitation coils. The motor is arranged to rotate a motor shaft about an axis of rotation. The motor also comprises a reduction mechanism with a worm screw on the motor shaft and a toothed wheel shaped to be meshed.

[0003] The invention aims in particular to propose a new motor assembly which is capable of providing greater torques, by using two electric motors of more modest electrical powers, instead of a high-power motor.

[0004] This is advantageous because it is possible to use existing motors for lower power and torque applications, and to combine them together for applications that require higher power and torque. Thus, it can be avoided to provide specific high-power motors for this type of application. In addition, the use of two lower-power motors is better from a thermal point of view because less heating occurs compared to one more powerful motor.

[0005] In such a motor assembly with two electric motors provided with two cranks, motors which are intended to rotate in a synchronized manner, problems may arise with desynchronization of the electric motors in their rotation, which may put mechanical stress on the mechanical transmission device. This may result in blocking the rotation of the two motors, which is, of course, to be avoided. Similarly, when a mechanical connection between these two motors has certain dimensional dispersions, or when the cranks of the motors have different lengths, the mechanical transmission device may become blocked because synchronized rotation of the motors is no longer possible. The rotation of one of the motors cannot be synchronized with that of the other motor because of defects in dimensions and separation distance between the cranks.

[0006] The invention aims in particular to overcome these problems.

[0007] The invention thus proposes a motor assembly for a vehicle wiping device, this assembly comprising: - a first electric motor arranged to provide a first torque mechanical, - a second electric motor arranged to provide a second mechanical torque, - a mechanical transmission device linked to the first and second motors and configured to deliver a cumulative output torque to drive the wiping device, this cumulative output torque being a sum of the torques supplied by the two motors, - a mechanical compensation device configured to compensate for any mechanical desynchronization between the first and second motors and passed on to the mechanical transmission device.

[0008] The accumulation of torques designates a sum of the torques to be achieved which, however, can be affected by losses such as friction within the transmission device.

[0009] Generally speaking, the mechanical compensation device according to the invention makes it possible, despite desynchronization or phase shift of the two motors, to ensure that the mechanical transmission device continues to transmit torque and allows the sweeper arm to continue to operate. Desynchronization can have several causes such as desynchronization of the electric motors in their rotation or dimensional dispersions in the dimensions of the different kinematic parts.

[0010] By "compensation" is therefore meant the compensation of variances in the kinematic geometry of the steering gear, during the operation of the wiping device.

[0011] According to one aspect of the invention, each of the first and second electric motors comprises a crank rotatably connected to an output shaft of the associated motor, and the mechanical transmission device is connected to the cranks.

[0012] According to one aspect of the invention, the mechanical compensation device is produced within the mechanical transmission device.

[0013] According to one aspect of the invention, the mechanical compensation device comprises a mechanical connecting member, belonging to the mechanical transmission device, which connects in rotation the cranks of the first and second electric motors, this mechanical connecting member having two connecting ends for each crank, the distance between these two connecting ends being variable to ensure mechanical compensation.

[0014] The fact that the mechanical transmission device can deform, due in particular to the capacity of the mechanical connecting member to shorten or lengthen, allows this mechanical transmission device to compensate for a desynchronization or a phase shift, either transient or permanent, of the two motors and / or dimensional defects on the cranks, or on their mutual spacing. The invention ensures, in a way, the presence of a clearance thanks to the deformability of the mechanical transmission device, clearance which makes it possible to compensate for a desynchronization. Thus the invention makes functional motor assemblies which have dimensional defects or desynchronization in the rotation of the motors. The invention is particularly advantageous when using continuous type motors, which perform a complete 360° rotation because these motors can become desynchronized / out of phase to the point of causing a blockage of the mechanical transmission device. In addition, the mechanical compensation device uses a kinematic component (namely the mechanical connecting member) of the mechanical transmission device to carry out the compensation, which makes it possible to pool the torque transmission and compensation functions. This makes it possible to avoid additional parts, in large numbers.

[0015] According to one aspect of the invention, the mechanical connecting member is deformable, in particular by traction, compression and / or bending, for example which can be curved.

[0016] According to one aspect of the invention, the mechanical connecting member is made from plastic material.

[0017] According to one aspect of the invention, the mechanical connecting member has a rod shape made of deformable material allowing this rod to flex to ensure compensation.

[0018] According to one aspect of the invention, the mechanical connecting member has V-shaped articulated branches which can move towards each other during deformation.

[0019] According to one aspect of the invention, the mechanical connecting member comprises a piston, for example a spring-loaded or hydraulic type.

[0020] According to one aspect of the invention, the mechanical connecting member comprises two rigid bars connected to each other by a spring member so that these bars can move towards each other or away from each other.

[0021] According to one aspect of the invention, the mechanical compensation device comprises at least one flexible attachment configured to assemble, with play, the mechanical transmission device to a load-bearing part of a vehicle, so that this mechanical transmission device can deform and ensure compensation. The load-bearing part may be, for example, a part of the bodywork, the chassis, or a sub-chassis, of the vehicle.

[0022] According to one aspect of the invention, the flexible fixing comprises a pin housed, with play, in an oblong orifice, in particular with the interposition of an elastic material such as rubber, between this pin and the orifice.

[0023] According to one aspect of the invention, the first and second electric motors are of the continuous motor type, which rotate only in one direction.

[0024] Alternatively, these motors are of the reversible type, which can rotate re- reversible in both directions of rotation.

[0025] According to one aspect of the invention, the motor is of the brushless type (or “brushless motor” in English).

[0026] According to one aspect of the invention, the motor comprises a reducer (also called a "gearbox" in English) associated with the output shaft, this reducer being coupled to the electrical compartment so as to transform the rotation of the rotor of the electrical compartment into rotation of the output shaft.

[0027] This reducer may comprise, in a manner known per se, a worm screw for transmitting the rotation of the rotor shaft into rotation of the output shaft. Other gear parts may be used in this reducer, for example described in patent application WO 2021018496.

[0028] According to one aspect of the invention, the first and second motors are identical, and are arranged to provide identical torques.

[0029] Thus the cumulative output torque is twice the torque of each motor.

[0030] Alternatively, the first and second motors are different, and in particular are arranged to provide pairs of different values.

[0031] According to one aspect of the invention, each stator comprises coils capable of being passed through by an electric current to operate the motor.

[0032] According to one aspect of the invention, the first and second motors are different in that the number of turns forming the coils differs from one motor to the other.

[0033] According to one aspect of the invention, the transmission device further comprises at least one connecting rod linked, at one of its ends, with freedom of pivoting or ball joint, to one of the engine cranks.

[0034] According to one aspect of the invention, this connecting rod is connected with a freedom of pivoting or ball joint, at the other of its ends, to a crank driving the wiper arm of the wiping device to drive a wiper arm of this wiping device.

[0035] According to one aspect of the invention, this end of the crank driving the sweep arm corresponds to a fixed axis of rotation of the sweep arm.

[0036] The connecting rod and the two cranks connected to it thus form three sides of a parallelogram.

[0037] In an exemplary implementation of the invention, the wiping device comprises two wiper arms and the transmission device comprises two connecting rods, each being connected, at its two ends, respectively to a motor crank and a crank driving the wiper arm.

[0038] According to one aspect of the invention, the connecting rods are connected to the ends of the connecting member or rod so that these connecting rods are arranged on either side of the connecting member or rod.

[0039] In another example of implementation of the invention, the wiping device comprises a single sweep arm and the transmission device comprises a connecting rod linked, at one of its ends, to a motor crank and, at the other of its ends, a crank driving the sweep arm.

[0040] According to one aspect of the invention, the crank of one of the motors is connected to the connecting member or rod but not to the connecting rod which is connected to the crank driving the sweep arm.

[0041] Thus this engine transmits its torque to the connecting rod via this connecting rod so that this connecting rod can develop the cumulative output torque.

[0042] The two motors are thus used to provide a combined torque which is used to drive the single sweeper arm.

[0043] The invention also relates to an assembly comprising a motor assembly as described above and a wiping device provided with at least one wiper arm secured to a windscreen wiper blade, this wiping device being actuable by this motor assembly.

[0044] Other characteristics and advantages of the invention will emerge on reading the description which follows, with reference to the appended figures, which illustrate:

[0045] [Fig.l] is a schematic view of the engine assembly according to an exemplary embodiment of the invention;

[0046] [Fig.2] is a schematic view of the motor assembly of [Fig.l], highlighting the phenomenon of desynchronization;

[0047] [Fig. 3] is a schematic view of a mechanical connecting member of the engine assembly of [Fig. 1], in the deformed state;

[0048] [Fig.4] is a schematic view of another example of a mechanical connecting member according to the invention;

[0049] [Fig.5] is a schematic view of another example of a mechanical connecting member according to the invention;

[0050] [Fig.6] is a schematic view of another example of a mechanical connecting member according to the invention;

[0051] [Fig.7] is a schematic view of an engine assembly according to another exemplary embodiment of the invention;

[0052] [Fig.8] is a schematic view of an engine assembly according to yet another exemplary embodiment of the invention.

[0053] [Fig.l] shows an assembly 100 comprising a motor assembly 1 and a wiping device 2 provided with two wiper arms 3 each secured to a windscreen wiper blade (not shown).

[0054] The wiping device 2 can be actuated by this motor assembly 1 as described below.

[0055] This engine assembly 1 comprises: - a first electric motor 5 arranged to provide a first mechanical torque, - a second electric motor 6 arranged to provide a second mechanical torque, - a mechanical transmission device 7 coupled to the first and second motors 5 and 6, and arranged to be actuated simultaneously by these motors 5 and 6 so that this transmission device 7 can deliver a cumulative output torque to drive the wiping device 2, this cumulative output torque being a sum of the torques supplied by the two motors 5 and 6.

[0056] The invention is used in applications which require a large torque to operate large wiping devices, for example for bus or truck applications. In such applications, the windshield to be cleaned has large dimensions, requiring the use of large wiper blades.

[0057] The two motors 5 and 6 with more modest electric powers replace a high-power motor.

[0058] This is advantageous because it is possible to use existing motors for lower power and torque applications, and to combine them together for applications that require higher power and torque.

[0059] Each motor 5 and 6, here of the continuous type, comprises a rotating output shaft 8, respectively 9, arranged to provide the mechanical torque.

[0060] The first electric motor 5, called the main electric motor, comprises a compartment or housing 10 receiving the electromagnetic part of the motor 5, and an electronic control unit (not shown).

[0061] The first electric motor 5 is optionally provided with a position sensor, here a Hall effect sensor, arranged to locate the angular output position of the first electric motor 5.

[0062] The second electric motor 6, called secondary electric motor or follower motor, is devoid of control electronics.

[0063] Each motor 5 and 6 comprises a compartment 10 housing a rotor and a stator, not visible.

[0064] Each motor 5 and 6 further comprises a reducer 11 (also called a “gearbox” in English) engaged with the output shaft 8 and 9.

[0065] This reducer 11 may comprise, in a manner known per se, a worm screw for transmitting the rotation of the rotor shaft into rotation of the output shaft.

[0066] Each motor 5 and 6 comprises a crank 14, respectively 15, linked in rotation at one of its ends to the output shaft 8, respectively 9, of the associated motor.

[0067] A connecting member 16, in the form of a rod, is connected with a freedom of pi vote or ball joint, at each of its ends, to the cranks 14 and 15 of the motors so as to secure them.

[0068] Thus each crank 14 and 15 is connected, at one of its ends, to the output shaft 8 and 9 of the motor and, at the other end, to the connecting member 16.

[0069] Thus the connecting member 16 is movable, in a normal operating situation, while remaining generally parallel to itself.

[0070] The transmission device 7 comprises two connecting rods 17 and 18, each being connected, at its two ends, respectively to a motor crank 14 and 15 and a crank driving the sweep arm respectively 19 and 20.

[0071] The connecting rods 17 and 18 are connected to the ends of the connecting member 16 so that these connecting rods 17 and 18 are arranged on either side of the connecting member 16.

[0072] Each engine crank 14 and 15 has one end which is connected to both the respective connecting rod 17 and 18 and the connecting member 16, by two double ball joints.

[0073] Motors 5 and 6 are placed between the brush arms 3.

[0074] Each crank 19, 20 driving the wiper arm comprises an end 21 linked in rotation to the wiper arm 3 of the wiping device 2.

[0075] This end 21 of the crank 19, 20 driving the sweep arm corresponds to a fixed axis of rotation of the sweep arm 3.

[0076] The connecting rod 17, respectively 18, and the two cranks 14 and 19, respectively 15 and 20, which are connected to it thus form three sides of a parallelogram.

[0077] The connecting member 16 has two double ball joint connecting ends 24, both to one of the engine cranks 14 and 15 and the connecting rod 17.

[0078] The connecting rods 17 and 18 and the connecting member 16 are, in normal operating conditions, aligned.

[0079] However, problems may arise with the electric motors 5 and 6 becoming desynchronized in their rotation, as explained above.

[0080] In this case, as illustrated in [Fig.2], the connecting rods 17 and 18 and the connecting member 16 may be in a configuration in which these elements are misaligned. The cranks 14 and 15 are then desynchronized in their respective rotations.

[0081] In the example described, the connecting member 16 forms a mechanical compensation device 32 according to the invention, configured to compensate for a mechanical desynchronization between the first and second motors 5 and 6 and passed on to the mechanical transmission device 7.

[0082] This mechanical compensation device 32 makes it possible, despite a desynchronization or a phase shift of the two motors 5 and 6, to ensure that the mechanical transmission device 7 continues to transmit torque and allows the sweeper arms 3 to continue to operate.

[0083] The mechanical connecting member 16 has two connecting ends 24 for each crank 14, 15, the distance between these two connecting ends 24 being variable to ensure mechanical compensation.

[0084] In the example of Figures 1 and 2, the mechanical connecting member 16 is deformable, by compression and bending. [Fig. 3] illustrates this mechanical connecting member 16 in a curved configuration, which makes it possible to shorten the distance between the two connecting ends 24 while maintaining its compensation effectiveness.

[0085] The mechanical connecting member 16 has a rod shape made of deformable material allowing this rod to flex to ensure compensation.

[0086] In another exemplary embodiment of the invention illustrated in [Fig.4], the mechanical connecting member 161 has a succession of branches 161a articulated in a V shape which can move towards each other during deformation, in a manner similar to that of an accordion.

[0087] In another exemplary embodiment of the invention illustrated in [Fig.5], the mechanical connecting member 162 has three branches 162a articulated in an L shape which can deform.

[0088] In another exemplary embodiment of the invention illustrated in [Fig. 6], the mechanical connecting member 163 comprises two rigid bars 167 connected to each other by a spring member 168 so that these bars 167 can move towards each other or away from each other.

[0089] In another exemplary embodiment of the invention illustrated in [Fig.7], the mechanical compensation device comprises at least one flexible attachment 170 configured to assemble, with play, the mechanical transmission device 7 to a load-bearing part 171 of a vehicle, so that this mechanical transmission device 7 can deform and ensure compensation.

[0090] The load-bearing part may be, for example, the body of the vehicle, or its chassis or sub-chassis.

[0091] The flexible attachment 170 comprises a pin 172 housed, with play, in an oblong orifice 173, with the interposition of an elastic material 174 such as rubber, between this pin 172 and the orifice 173.

[0092] A connecting element 175 of two external rods 176 can be provided, with a configuration similar to that of the mechanical connecting member 16. This allows greater flexibility of the assembly for better compensation.

[0093] A single flexible attachment 170 may be provided or, alternatively, two flexible attachments 170 each associated with an electric motor.

[0094] [Fig. 8] shows another example of implementation of the invention, in which the wiping device 25 comprises a single wiper arm 26 and the transmission device 27 comprises a connecting rod 28 connected, at one of its ends, to a motor crank 15 and, at the other of its ends, a crank driving the sweep arm 20.

[0095] The engine crank 14 is connected to the connecting rod 29 but not to the connecting rod 28 which is connected to the sweep arm crank 20.

[0096] Thus this engine 5 transmits its torque to the connecting rod 28 via this connecting rod 29 so that this connecting rod 28 can develop the cumulative output torque.

[0097] The two motors 5 and 6 are thus used to provide a cumulative torque which is used to drive the single sweeper arm 26.

[0098] The two motors 5 and 6 are both arranged on one side of the connecting rod 28 and the sweep arm 26 on the other side of this connecting rod 28.

[0099] Motors 5 and 6 are oriented in the same direction.

[0100] In the example described, the connecting rod 29 defines a mechanical compensation device according to the invention, making it possible to absorb deformations caused by desynchronizations which may occur between the motors 5 and 6. The connecting rod 29 can be produced according to one of the forms described with reference to FIGS. 3 to 6.

[0101] Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without departing from the scope of the invention. In particular, the different characteristics, forms, variants and embodiments of the invention can be associated with each other in various combinations to the extent that they are not incompatible or mutually exclusive.

Claims

Claims

1. Motor assembly (1) for a wiping device (2; 25) of a vehicle, this assembly comprising: - a first electric motor (5) arranged to provide a first mechanical torque, - a second electric motor (6) arranged to provide a second mechanical torque, - a mechanical transmission device (7) linked to the first and second motors and configured to deliver a cumulative output torque to drive the wiping device, this cumulative output torque being a sum of the torques provided by the two motors, - a mechanical compensation device (32) configured to compensate for any mechanical desynchronization between the first and second motors and passed on to the mechanical transmission device.

2. An assembly according to the preceding claim, wherein each of the first and second electric motors comprises a crank (14; 15) rotatably connected to an output shaft of the associated motor, and the mechanical transmission device (7) is connected to the cranks.

3. Assembly according to the preceding claim, in which the mechanical compensation device (32) is produced within the mechanical transmission device (7).

4. Assembly according to the preceding claim, in which the mechanical compensation device (7) comprises a mechanical connecting member (16), belonging to the mechanical transmission device (7), which connects in rotation the cranks of the first and second electric motors, this mechanical connecting member having two connecting ends for each crank, the distance between these two connecting ends (24) being variable to ensure mechanical compensation.

5. Assembly according to the preceding claim, in which the mechanical connecting member (32) is deformable, in particular by traction, compression and / or bending.

6. Assembly according to the preceding claim, in which the mechanical connecting member (161) has branches (161a) articulated in a V being able to approach each other during deformation.

7. Assembly according to the preceding claim, in which the mechanical connecting member comprises two rigid bars (167) connected to each other by a spring member (168) so that these bars can move towards each other or away from each other.

8. Assembly according to one of the preceding claims, in which the mechanical compensation device comprises at least one flexible fixing (170) configured to assemble, with play, the mechanical transmission device (7) to a load-bearing part of a vehicle, so that this mechanical transmission device can deform and ensure compensation.

9. Assembly according to the preceding claim, in which the flexible fixing comprises a pin (172) housed, with play, in an oblong orifice (173), in particular with the interposition of an elastic material (174) such as rubber, between this pin and the orifice.

10. Assembly according to one of the preceding claims, in which the first and second electric motors (5, 6) are of the continuous motor type.

Images