Space technologies gave the production, and then the home craftsman a great tool - a screwdriver. Most recently, it was used only in space. Today in many garages and home workshops screwdriver is an indispensable tool. It helps to turn a lot of screws and screws in the assembly of furniture, in the repair of equipment and housing. But there is nothing eternal. The time comes when the screwdriver begins to break.
A screwdriver is needed in the household to quickly assemble or repair furniture.
What malfunctions can be fixed at home? How to recognize these problems? To answer this question, you need at least a brief acquaintance with the internal structure of this tool. The main protrusion is the power button. It is designed to turn on the device and to adjust the speed and direction of rotation of the working body - cartridge.
In fig. 1 digit “1” is indicated directly by the switch, digit “2” is the reverse device. The regulation of speed occurs with the help of an electronic device based on a transistor ("3"). The speed of rotation of the cartridge depends on the force of pressing the power button. The reverse is activated by changing the current polarity at the terminals. In the screwdriver, single-phase motors of the collector type, operating from DC, are usually used (in the image, the motor is indicated by the number “4”). The engine consists of a body, magnets, anchors and brushes.
Figure 1. The device screwdriver.
Rotation from the engine is transmitted to the gearbox (figure "5"). It converts high revolutions of the engine into lower ones on the shaft, on which the cartridge with working bits is mounted. The gearbox can be used as a classic, as in all well-known drills, and planetary. The classic gearbox has practically not been used in recent years, so it makes no sense to dwell on it. The structure of the planetary gear reducer includes:
- ring gear;
- sun gear, mounted directly on the motor shaft;
- 2-3 drove.
Next comes the force regulator, which most often has 16 positions. Each of them provides a certain force on the screw or on the screw, so as not to damage the material that they fasten.
And the last element in this series of components and parts is the cartridge.
In case of any malfunction of the tool it is necessary to disassemble the screwdriver. You can do this in the service workshop, but most problems can be fixed at home.Back to table of contents
Reasons for disassembling the tool
Detailed scheme of the screwdriver.
Malfunctions that require disassembly may be in the electrical and mechanical parts of the screwdriver. Symptoms of electrical faults include the following:
- the tool does not turn on;
- does not switch the reverse;
- turns are not regulated.
If the tool does not turn on, you need to check the battery. If the readings of the multimeter are very small, you should try to charge the battery pack. Charging does not help - it is a sign of battery failure. In this case, the unit is opened with battery cells. At each of them, the voltage is checked, which should be in the range of 0.9-1.0 V. All places of the rations are checked. If necessary, replace the elements. If the battery pack is working, you need to carefully disassemble the screwdriver itself. To do this, remove the screws on the perimeter with a screwdriver. They are usually about 9 pieces. The halves of the case are separated very carefully.
The device gear planetary gear.
After disassembling the case, the start button and wires suitable for it are checked. Again need a multimeter. The device will indicate the location of the fault. When removing the start button, you do not need to hurry. Otherwise, some small parts inside the case of the button, can fly out and fly around the room. The same can happen when disassembling the case of the reverse mechanism.
When the engine is running at maximum speed, the system of their adjustment is faulty. The reason may be hiding in the button itself. Maybe the fault of the transistor, which is somewhere near the button. When the button and all circuits up to the electric motor are in good condition, the brushes, the motor windings, and the armature may be faulty.Back to table of contents
Mechanical faults screwdriver also have their symptoms:
- the instrument makes sounds that were not heard before;
- strong vibration of the cartridge and the entire instrument;
- screwdriver jammed during operation.
For different screws you need to choose a suitable nozzle for the screwdriver.
In case of extraneous sounds, it is necessary to disassemble the housing and carefully inspect the bearings and bushings inside it. When they fail, you need to buy new ones and replace them. In case of more complex malfunctions, the gear shaft may be bent, gears may wear out and satellites' pins break. In all cases, defective parts are replaced, lubricated, inspected and the screwdriver body is assembled with mounting screws.
The screwdriver is disassembled, not only for repair, but also for prevention. Disassembling the case does not present any difficulties and does not require a special tool. During operation, dust is stuffed into the case, which poses a certain threat to the integrity and operability of the instrument. Therefore, during preventive disassembly, you need to clean the insides from dust and inspect parts for wear. Most often wear out and require replacement of graphite brushes.Back to table of contents
General rules for disassembly and assembly of the screwdriver
- Disassembly of the body.
- Disassembly of the magnetic holder.
- Disassembly of the electric motor.
- Disassembly of the start button and the stator.
- Disassembly of the cartridge.
To disassemble the screwdriver body, you only need to unscrew the screws with a cross-head screwdriver.
To disassemble the body of the screwdriver, it is enough to unscrew the self-tapping screws using an RH-1 crosshead screwdriver. Disassembling the magnetic holder is quite simple. It is necessary to remove the bearing, spring and coupling half. For disassembly of the engine rotor is removed from the stator. This should be done carefully so as not to damage their windings. It is necessary to take into account such a thing: a bearing with a manifold, a fan and a gearbox are mounted on the rotor. The stator is completely removed from the housing along with the brush holders and the start button.
To remove and disassemble the cartridge, you need to determine the method of its attachment. This may be a thread or a Morse taper. With the threaded method, the cartridge is threaded onto the threads applied to the end of the shaft. To remove it, you need to unscrew the screw having a left-hand thread, with which the cartridge is additionally attached to the shaft end. This screw is inside the cartridge. In the chuck, you need to hold the hex key 10 mm and turn on the drill so that the remaining free end of the key hits the hard surface with a force. Further the cartridge usually turns away quite easily. The Morse taper is a centuries-old method of fastening with a cone applied to the end of the shaft and to the inside of the cartridge. When combined, there is a solid mount. To remove such a cartridge is not very strong blows with a hammer on the body of the cartridge.
After maintenance, repair and replacement of some parts, the assembly is performed in the reverse order.Back to table of contents
How to disassemble the battery?
- Remove the screws at the bottom of the box.
- Open the box.
- Check and reject items.
- Replace and reassemble.
The mounting screws on the bottom of the case can be from 4 to 6. Most often they turn away with a Phillips screwdriver. Screws may have different lengths. This should be considered in order not to confuse them during assembly.
The case is found on some models is not collapsible. In this case, it should be carefully examined and find the line along which the factory gluing passed. You need to take a strong knife and insert it into this groove with a slight stagger from side to side. The hull should break to the top and bottom. It does not matter if it happens past the groove. Everything can be stuck with a tube of good superglue. In the upper part of the case, several battery cells will open to the eye. Each of them measures the voltage, which should not differ much from the nominal one. If the difference exceeds 10%, this battery requires replacement.
After culling it will be left to buy new items and solder them according to the scheme with ordinary soldering accessories. After that, the new battery needs to be charged without the final closing of the lid, allowed to stand for a day, again measure the voltage on each element. If one of them does not hold the voltage, it should be replaced again. After successful completion of work, you need to glue the halves of the case with superglue. When gluing, do not allow the glue to fall on the individual elements of the battery.
The screwdriver is available in the workshop or in the garage of many home craftsmen. This is a very convenient and useful tool. But sometimes it has to be disassembled for preventive cleaning, for repairing a screwdriver button, for replacing its various parts.
All these works can be done at home without a special expensive tool.
The main thing in this case - do not rush.