Summary
– History of the wiper motor
– Operation of a wiper motor
– Technical data
– In case of a breakdown…
– Windshield wiper motor: where to get supplies?
The wiper system in a vehicle is an essential element of safety and comfort. In this system, the central part that operates the wiper blade mechanism is the electric motor.
Let’s see how it works in the rest of this post.
History of the wiper motor
Some key dates:
Beginning of the 20th century (1900): the first appearance of a windshield wiper system, the first patent date. The windshield wiper is then operated manually.
– 1951: The electric motor is introduced to operate the wiper system.
– 1963: Adaptation of an intermittent operation system.
– Nowadays: electronics has made it possible to adopt automatic wiping and other innovations such as motor rotation reversal, eliminating the complex mechanical system for operating the wiper arms.
How a wiper motor works
Let’s take a brief look at the construction and operation of a wiper motor.
There are two parts:
– The electric motor is composed of an armature (rotating part), permanent magnet inductors fixed on the casing, and three brushes on the armature commutator.
– The mechanism of transmission of the motor rotation: it consists of a worm screw at the end of the armature, which transmits the movement to a large pinion to reduce the speed of rotation (this pinion has on its face several concentric tracks for electrical connections connected to contacts fixed on the housing).
The wiper motor runs either at:
– Low speed: the supply current passes through two opposed brushes (one positive and one ground brush). The force of the inductors’ magnetic field acts on the armature winding to be maximum. This slows down the speed of the motor.
– High speed: The supply current flows through the ground brush and the third brush, offset from the diameter axis by 45°. The inductors’ magnetic field strength will be less: the rotation speed of the motor will be higher.
Technical data
These values are given as an indication and may vary depending on the engine.
|
Power supply |
12 volts |
|
Power |
35 watts |
|
Motor speed (high) |
3000 rpm (35 rpm after gearbox) |
|
Motor speed (low) |
2000 rpm (50 rpm after gearbox) |
|
Power consumption |
6 amps |
|
Induced resistance |
0,5 ohms |
|
Output torque |
4 N.m |
|
Force on wiper arm (for 1 arm of 600mm) |
7 N |
In case of a breakdown…
No more windshield wiping? Here are the checks to be made:
– Determine if the problem is with the wiper linkage (the linkage assembly) or the engine. To do this, listen to see if the motor is active when you operate it.
After checking the fuses, if not, access the motor after removing the arms and protective grilles (if applicable).
– If it is dismantled, you must carry out the following checks:
◦ Mechanical part: check the tracks’ condition (oxidized or cut), clean them or solder them with tin. Clean and lubricate the gears (broken teeth, water in the housing, etc.).
◦ Electric motor: dismantle carefully (pay attention to the brushes and springs), check the general condition (presence of water, dirt, condition of brushes, inductors). Clean the inside of the motor if it is not damaged and grease the bearings.
Wiper motor: where can I get supplies?
Sometimes you cannot disassemble the motor, or the damage is irreparable. In this case, it will have to be replaced:
At the dealer: with the vehicle’s serial number, he will undoubtedly provide you with the right model (average price: $100).
– At an automotive supplier or on an Internet site: the cost here will be lower (20 to 40%), but be careful with ordering errors (for security, with the vehicle information, specify the brand of your windshield wiper and its type if you have dismantled it).
You will pay 40 to 60% less for second-hand parts, but you will have to present your engine for authentication.
Attention: breakdowns are often recurrent on the same vehicle model; for this type of part, you may encounter the same problem with a used part!
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