How to replace the bearings on a Bosch GWS 5-115 angle grinder
How to disassemble an angle grinder and dismantle bearings. Step by step steps
Having disassembled this device, you can replace broken bearings, re-lubricate all parts, dismantle damaged brushes and mount new ones..
In order to separate the rotor and stator bodies, preliminary removal of the handle body in the machine is required. This is done so that you can remove the carbon brushes. They hold the rotary manifold.
The second step will be to unscrew the four screws that secure both the rotor and stator housings..
Take out the gearbox together with the starter, start disassembling it. The gearbox also contains screws that need to be removed. There are four of them in total. This procedure will require some effort from you, since the factory assembly involves the use of a sealant..
Angle grinders of different models have different types of gears. Low power models use spur gears. With a power of over a thousand watts – the use of helical gears.
When you remove the gear cover, it will be possible to remove the assembly in which the helical gear is located. To remove it, use a press or a puller.
To do this, you will have to use special thin tubes. For this reason, using the puller will be inconvenient..
Before removing the gear, it is necessary to check the backlash in the gear connection. Also check if all teeth are intact. And the contact spot is checked.
If you have identified such signs in a bearing that is located on the spindle shaft:
- when you scroll it, you hear a characteristic noise;
- noticed the appearance of backlash;
- no lubrication.
If all these signs are present, it is necessary to replace the old part with a new one. For this, the bearing must be removed. How to do it?
First of all, remove the gear along with the retaining ring. Then you can easily remove the worn out element. When you remove the rotor shaft assembly, the bearing may remain in the gearbox, inside the housing. In this case, use a hammer, on top of a soft guide.
To remove the drive gear in an angle grinder, do this:
- clamp the rotor, unscrew the nut with an open-end wrench;
- the washer is removed;
- now pull out the gear itself.
After checking the appearance of the gear, decide if you need to replace this part. Keep in mind that you need to change both gears at the same time..
Low power angle grinders are equipped with a needle bearing, which serves as a thrust bearing.
Dismantle this part only when it is completely destroyed. There is a proven way to pull out a destroyed clip.
1.Choose a larger tap diameter than the inner diameter of the cage.
2.Put and secure it in the screwdriver chuck. Gradually, at low speed, screw into the cage. When the tap hits the housing bottom in the gearbox, the clip will rise.
The rotor shaft has two more bearings in addition to the needle bearings. To detach them from the rotor, I would recommend using a puller.
The bearing attached to the manifold is easy to remove. The impeller is also equipped with a bearing, which will take a little more time and skill to remove. Both bearings are covered for protection with special rubber caps.
To remove and replace these parts, the nuts are unscrewed, the spur gear is removed, as well as the plastic protection. Now you can freely remove the bearing from the rotor shaft using a puller.
If there is no puller in the toolbox, there is one method, take note of it. Remove the bearing with a vise along with two metal strips, and a hammer, on which a special metal adapter.
Replacing the bearing of an angle grinder at home
From this article you can learn how to independently replace the bearing of an angle grinder.
A very common household tool is an angle grinder, technically it is correctly called an angle grinder. Sometimes there are breakdowns as a result of excessive loading, or parts fail due to long-term operation.
Tools required to repair and replace defective parts
For a high-quality and effective repair of an angle grinder, you will need the simplest tools that almost every zealous owner has..
The presence of a screwdriver will greatly facilitate the disassembly of the angle grinder. But, in its absence, you can easily get by with just various screwdrivers. It is desirable that they have a ratchet mechanism.
To unscrew the nut that attaches the helical drive gear, you will need a wrench called an open-end wrench..
To dismantle the bearing, you cannot do without a special puller.
Perform diagnostics of the electrical component of the device being repaired using a tester. There is also a special device that detects a short circuit of the turns. This device is very convenient, since you can diagnose a breakdown in the stator or rotor without having to remove the assembly..
Be sure to stock up on a grinder diagram. Knowledge of the location of the main components will greatly facilitate the disassembly of the mechanism, repair, or replacement of unusable parts..
Gearbox bearing replacement angle grinder
How to disassemble an angle grinder and replace the bearing yourself?
It is quite possible to do this at home without contacting service centers or repair shops. Just follow my recommendations that will be given in this article..
Most often, work with an angle grinder takes place in a fairly dusty environment. Dust is often the cause of various malfunctions. When this tool breaks down, it is always not enough for chores. So you don’t have to delay the repair.
Assembling the tool with new details
After disassembling the tool, the necessary replacement of all destroyed parts, we will put it back together. Make sure you have all tools, lubricants, clean rags for final touches on hand.
The first step is to assemble the rotor. It is necessary to press in the bearings, install the impeller. Before doing this, carefully lubricate the bearings. Using a wooden guide, press them onto the top of the shaft..
Cover the collector bearing with a rubber guard. This is the same diagram of how to assemble a rotor shaft..
Next, we assemble the gearbox back. We begin this process by installing the gearbox on the rotor shaft housing. When the shaft is already inside the housing, push the drive gear onto it, then the washer and fixing nut.
Now install the gear housing with the shaft inside it into the stator housing. It is necessary to press down on both housings after the manifold bearing is already in its seat. Next, check if the rotor rotates easily on bearings.
The final step is to place the lid where it was. Check how the spindle shaft turns. If you have determined that the rotation is easy even from the movement of your hands, you can start tightening the screws. They fix the cover to the body. Before doing this, lubricate all screws with a sealant..
What are the reasons for the failure of an angle grinder
The angle grinder has a mechanism that carries the greatest load – the rotor. It is also called an anchor. The damage to it is very different. These are temperature loads, and electromagnetic, and, of course, mechanical problems..
As a result, do not be surprised that the angle grinder does not work precisely because of a rotor malfunction. The armature winding overheats and burns out, this will cause a short circuit. So many owners of this tool often carry out all the repair work on their own..
A worn manifold will increase the vibration of parts such as brushes. They burn, as a result of which the mechanism sparks strongly. The main function of such brushes is to transfer current to the collector..
The bearings in the rotor often wear out. If you do not make timely diagnostics and maintenance of bearings, they are completely destroyed. If during operation of an angle grinder you hear a noise that was not previously there, be sure to check the condition of the bearings..
The stator is a stationary component in an electric motor, there is a winding on it. The angle grinder rarely breaks down directly from the stator.
The gearbox is responsible for the rotation of the gear. It needs to be cleaned and lubricated in time..
Most often, brushes are changed in a grinding machine, because the basis of their manufacture is graphite. Replacing these parts is easy.
Disassembly of the angle grinder for prevention
I would recommend disassembling your sander not only for repair and replacement of worn parts, but also for regular maintenance. This will significantly extend the life of the electrical device. Any mechanism works longer and better if it is properly maintained. The angle grinder is no exception..
Disassemble the tool as described in this article. Only now you are doing this not for repairs, but in order to thoroughly clean and lubricate such a necessary tool in the household..
The most ideal option for cleaning is the use of compressed air and blowing nozzles in compressors. You will have to take into account that the angle grinder is cooled through a distance in the middle of the armature and stator.
Excessive construction dust, various particles on the engine. All this needs to be cleaned from time to time.
And if the angle grinder has already been disassembled for prophylaxis, apply fresh lubricant to the parts, as described earlier.
As you can see, maintenance and repair of an angle grinder is not that difficult.!
Gearbox bearing replacement angle grinder
The bearing units of the angle grinder take on heavy loads during work. This is due to the rather frequent failure of the angle grinder due to wear or destruction of bearings. You can remove the defective one and replace it with a new one, if you have the appropriate knowledge and a suitable tool..
- Recommendations
- How to remove
- How to remove / remove the needle bearing in an angle grinder
- How to change
Angle grinder easy to change bearings part-1
- Bosch
- Makita
- Interskol
- Hitachi
- Sparky
Hitachi
At first glance, some designs of bearing assemblies exclude the replacement of the bearing itself, which is included in such an assembly. However, the author of the following video found a way to do this in one of the Hitachi models and thereby save a decent amount of money in the proposed way..
To fix the bearing assembly, a wood crown was inserted into the drill, into the inner surface of which one of its outer diameters tightly sits. When the drill is running, using a sharp object, the plastic material is removed to the size of the outer ring of the bearing. Thus, nothing prevents you from removing the bearing with a hammer and an extension..
Further, when assembling a new bearing, a ring is inserted instead of the worn out plastic (in the video it is most likely made of caprolon or other similar material). Since the ring in the video has a wall thickness that does not allow assembling the gear according to technical requirements, using a chisel, its inner diameter is finalized to the required dimensions.
Interskol
Some designs of bearing assemblies are made without the use of interference fits. So, for example, in the next video, the ball bearing of the Interskol model gearbox housing cover is assembled into a support structure using a washer fastened with threaded connections. For better adhesion to the plane of the body, the surface of the washer is covered with an adhesive.
How to change
Regardless of the model of the angle grinder, the method of replacing bearings is not much different from each other. Adjustment of the repair technology is associated with the design features that each brand has.
How to remove / remove the needle bearing in an angle grinder
It is not difficult to press in a new needle bearing, but removal requires the use of an original puller. In the following video, the author describes the manufacture of such a device and shows its practical action..
The stripper is an expanding collet with beads at the ends of the movable petals. The collet dimensions are made on a lathe, and the central hole is drilled for a rod that spreads the petals. The stripper is inserted inside the bearing and the collars, after the rod moves along the hole, rise up and abut with the lateral surface against the end of the ring. With the help of not very impressive, but reliable levers from the reinforcement with sharpened edges, resting on an inserted washer, the bearing can be removed from the housing.
Important: a needle bearing has a significantly longer service life than a sleeve bearing. However, during operation, the spindle shaft wears out, which also needs to be replaced. In the video described, the author found a replacement option. However, in most cases this can create additional problems..
Makita
One of the Makita models describes the process of replacing bearings without the use of special tools, using any available means at hand. Hardwood blocks are used as base surfaces, which take on the load when performing various technological operations with the use of force..
As accessories, suitable thickness metal sheets and end heads are used (you can use pipes that are suitable for the size) when knocking out the bearings. The shaft centering holes serve as a base for a sharpened rod (in the video this is a modified old screwdriver), with which the shaft itself is released. The only tool in industrial production is a snap ring puller, although without it you can figure out how to remove them using improvised means.
How to remove
In the next video on the Interskol model angle grinder, there is a large spindle play. The author describes in detail how to remove the sleeve bearing sleeve. For this, a tap with a diameter for threading in the inner sleeve is installed in the screwdriver. Next, the tap performs a mechanical operation to cut the thread and after meeting it with an emphasis on the gearbox housing, the bushing will rise along the cutting part of the tap until it is completely out of the bore.
The author does not recommend making the option with pressing out parts fitted with a large interference with pullers in order to preserve their integrity. It is advisable to perform such an operation on pressing equipment..
The plain bearing can be easily replaced with a needle bearing. The main thing is to choose it in accordance with the outer and inner diameter of the sleeve. The following describes how to carry out repair work with an angle grinder, in the design of which a needle bearing is used..
How to change
Regardless of the model of the angle grinder, the method of replacing bearings is not much different from each other. Adjustment of the repair technology is associated with the design features that each brand has.
The following recommendations will help you to successfully complete repair work on bearing assemblies..
- It is necessary to know the design of the operated angle grinder. Study the technical documentation supplied with your angle grinder. Knowledge of the location of units and parts will help to correctly disassemble and assemble the angle grinder during repair.
- The availability of the necessary tools for this will help to perform work on replacing bearings. This tool is not complicated and is almost always available in the arsenal of home craftsmen: screwdrivers, wrenches, hammers, a set of pullers or other manual devices (vise, extensions, drifts of various designs) for fixing and removing bearings.
- When repairing an angle grinder, there is a certain order of work. You should adhere to it, taking into account some differences associated with the features of a particular model..
- Replace bearings if there is even a slight runout of the shaft, since a destroyed bearing can completely destroy the entire power tool.
- Make sure that the power tool is unplugged before carrying out repair work..
Open bearing for Hammer angle grinder. Photo 220V
The tool used must be in good condition:
- the structural elements of the pullers (legs, rods, stops, screw devices) comply with the technical documentation;
- screwdrivers have smooth side edges, a straight rod is securely fixed in the handle;
- the jaws of the wrenches are parallel, do not have cracks or nicks;
- the hammers are securely mounted on the handles.
Compliance with these recommendations will allow you to correctly and safely disassemble the angle grinder, replace defective bearings, re-lubricate all parts and assemble the angle grinder for its further operation..
Slant Tooth Gears
The reason that the device stopped working normally, namely, stopped drilling and chiseling, may lie in worn teeth on the rotor shaft.
If this happens, the teeth will also be worn out on the intermediate helical gear..
This problem occurs when the tool is jammed or the clutch is not working properly. Breakage is eliminated by replacing the intermediate gear and the engine rotor.
The main malfunctions of the punch and their external signs
All unit faults can be divided into 2 groups: mechanical and electrical.
Sparky
In the next video, one of the models of the Sparky angle grinder is out of order. To determine the cause of the malfunction, the author made a complete disassembly of the angle grinder with washing and cleaning of all parts. We did not dwell on the disassembly process in detail in this video. This technological operation can be viewed in the article under the link “How to disassemble a gearbox”.
After analyzing the condition of assemblies and parts, it turned out that the cause of the malfunction of the angle grinder was the front rotor bearing. It was easily replaced with a new one, which was inserted into the gearbox housing without interference and fixed with a washer using threaded screws. The service life of the Sparky angle grinder from the video is 15 years, therefore, the appearance of other defects is not excluded and the author correctly concludes that the purchase of a new angle grinder.
How to remove a bearing from an armature of a power tool: a few practical tips
Now, many home craftsmen, non-professional craftsmen, have a whole arsenal of power tools that help to cope with household non-repair and construction tasks. Rotary hammers, jigsaws, angle grinders, drills – they greatly simplify and do not speed up work. But it happens that the power tool burns out. You should not rush not to send it to the trash heap because of this. Due to intensive operation, the parts wear out, respectively, the equipment is not capable of operating in normal mode. If you know how to remove a bearing from the anchor of a power tool, it is natural to extend the life of your own “helper”. Timely replacement of non-lubricating parts allows you to operate the device for a longer time.
The main task of the power tool motor. it is rotation. The anchor is the fundamental part of the device that forces the working mechanism to turn. The service life of the part depends on the power, not the speed, in addition to the activity of the equipment implementation. Bearings are needed to reduce the friction during the movement of parts. Specifically, they provide smooth rotation and do not enhance the running mechanism of the power tool. If you look at the bearings at the wrong time to lubricate, their service life increases significantly.
How to change brushes for an Interskol perforator
Makita
One of the Makita models describes the process of replacing bearings without the use of special tools, using any available means at hand. Hardwood blocks are used as base surfaces, which take on the load when performing various technological operations with the use of force..
As accessories, suitable thickness metal sheets and end heads are used (you can use pipes that are suitable for the size) when knocking out bearings. The shaft centering holes serve as a base for a sharpened rod (in the video this is a modified old screwdriver), with which the shaft itself is released. The only tool in industrial production is a snap ring puller, although without it you can figure out how to remove them using improvised means.
How to disassemble an angle grinder
We will analyze the main purpose of the angle grinder, the rules of how to disassemble the gearbox of the angle grinder, the rules of operation and methods of disassembling the tool. Let’s pay attention to some of the nuances and important points..
angle grinder – a tool that is designed for grinding, cutting various materials. This is an indispensable equipment for some types of construction and repair work. Therefore, it is necessary to have such a tool at home, it will always come in handy..
How do you disassemble an angle grinder? Consider the main details that make up the device. With this information, you will be able to accurately and quickly disassemble and assemble the instrument. This is especially important if the angle grinder suddenly breaks down or some spare parts need to be replaced. In this case, the skill of quick disassembly will come in handy.
The parts that make up the angle grinder
Let’s try to understand what elements the tool consists of:
- Reducer housing;
- Carbon brushes;
- Lever;
- Soft start system;
- Ball bearings;
- Electric motor;
- Switch angle grinder.
Now we will try to determine the most common tool malfunctions and the causes of breakdowns. The cause of premature wear of spare parts is the careless and improper use of the product..
- Failure to comply with safety regulations;
- Violation of recommendations for use;
- Storage of the tool in an improper form or place;
- Using non-original consumables.
Most Common Causes of Angle Grinder Breakdowns
In order to one fine moment when parsing the instrument not to be alone with the question “So I removed all the parts, and which one was junk?”, You must first outline what may be the cause of malfunctions.
If the instrument malfunctions, it may sparkle or twitch. This may be due to some insulation failure or wear of other types of spare parts. Also, this situation happens when replacing brushes..
Sometimes buyers complain about a loud popping sound when plugged into a power outlet. This may indicate a closure.
If you hear a crunchy sound when turned on, the cause of the malfunction is in the bearings of the instrument..
In rare cases, there is some tapping when you press the on key. This indicates a malfunction of the gearbox..
Sometimes, the instrument may not turn on at all. Then you need to make sure the disk is spinning, if it goes but tight, this indicates a problem with the gearbox. If the disc scrolls without problems, then it is worth checking the main motor of the device or brush.
Provided that the tool gets very hot, you first need to understand which part is hotter. If the area where the motor is located heats up, then the reason lies in the incorrect operation of the brushes. If heating occurs near the gearbox, dry lubricant is the cause..
If the angle grinder does not pick up speed and speed when rotating, the cause is in the operation of the engine. In this case, it is recommended to check that the control board is working.
Step-by-step analysis of the angle grinder
The parsing is as follows:
- Remove the nut located on the working disk;
- To remove the outer shell, unscrew the bolts that secure it;
- We separate the gearbox from the housing of the angle grinder;
- Separating the top and back of the case;
- We take out the electrical cord, having previously unscrewed the bolts. In some models, you may find that the back of the case cannot be disassembled in parts, in which case it must be removed completely;
- Take out the wires extending from the engine;
- Next, you need to remove the brushes;
- Disconnect the top of the gearbox from the tool body. Also try to get the anchor carefully;
- It is necessary to remove the air intake from the tool;
- Note that there are two large bolts inside the housing that secure the stator. You need to unscrew them;
- Next to the bolts, you will find two rings that are securely attached to the stator. You will have to move them a little;
- The next step is to remove the stator. Taking a wooden mallet very carefully, you need to knock on the sides of the case, thereby you will ensure that the part comes out quietly;
- The next step is the procedure for disconnecting the gearbox bolts, they are located next to the casing;
- Remove the gearbox from the tool.
Following this diagram, in order to assemble the tool you need to assemble the parts in reverse order. Step by step you will be able to assemble the angle grinder on your own, without outside help, quickly enough. How to remove a part such as an anchor from an angle grinder? To do this, you need to unscrew the nut from the existing housing.
How to remove a bearing from the armature in order to check its performance?
The condition of the bearing on the motor of the power tool must be given due attention. When it wears out above the permissible limit, overheating occurs, and the motor starts to run noisily. If the bearing is not removed from the armature in time, then the stationary and moving parts will begin to touch each other when it rotates when it is running. And this, in turn, threatens with serious damage to the electric motor. This will require replacement of the rotor or armature. Checking the bearings is pretty straightforward. To do this, you need to install the motor on a solid surface, put your hand on top of it and rotate the shaft. The rotor must move freely and not jam. If you hear scratching noises or feel uneven rotation, this will be the first call to the fact that it is necessary to remove the bearing from the anchor and fix the malfunction..
Any bearing has backlash, that is, clearances. Their presence is quite acceptable, however, it is important that the indicators do not go beyond the permissible limits. Check for backlash:
- radial, or longitudinal. To do this, put the engine on a solid surface and try to tilt the shaft in different directions with your hand. The amount of offset depends on the size of the part. For household power tools, deviations should be barely noticeable;
- axial. The check in this case is simpler. It is necessary to take the shaft with your hand and pull or push the rotor in the opposite direction. In household appliance motors, deviations should not exceed 3 mm. The closer this figure is to zero, the better..
If during the disassembly of the electric motor you notice traces of friction of parts, it means that the bearings have worn out. It is necessary to immediately remove the bearing from the armature and replace the spare parts. This will allow you to avoid negative consequences in the form of engine breakdown or complete failure of the tool..
How to remove a bearing from an armature of a power tool: a few practical tips
Today, many DIYers and professional craftsmen have a whole arsenal of power tools that help them cope with domestic and repair and construction tasks. Rotary hammers, jigsaws, angle grinders, drills – all of them greatly simplify and speed up work. However, it happens that the power tool breaks down. Do not rush and send it to the trash because of this. Due to intensive use, the parts wear out, and therefore the equipment cannot work in normal mode. If you know how to remove the bearing from the anchor of the power tool, you can extend the life of your “helper”. Timely replacement and lubrication of parts allows you to operate the device for a longer time.
The main task of the motor of the power tool. it is rotation. The anchor is that important part of the device that makes the working mechanism rotate. The service life of the part depends on the power and speed, as well as the activity of the equipment use. Bearings are needed to reduce friction while moving parts. They provide smooth rotation and improve the running mechanism of the power tool. If the bearings are monitored and lubricated in a timely manner, their service life increases several times..
How to remove the bearing from the anchor angle grinder?
Today, home and professional craftsmen use several methods to solve this problem. If it becomes necessary to remove the bearing from the armature of an angle grinder or other tool, this can be done using the following devices:
- Strippers. These are special devices that allow you to easily and safely remove bearings of different sizes from the anchor of an angle grinder. The use of pullers practically does not require the use of physical force, even if the bearing is tightly seated. The centering mechanism ensures the simultaneous installation of the device’s grippers. It can be used in any position. Before removing the bearing, you need to clean the armature shaft of the angle grinder from old grease, chips, sand, so that nothing interferes with removing the part. The centering mechanism allows the puller to position itself precisely. If the bearing is intact, and the dismantling process is carried out for inspection, it should be pulled out by the inner ring so as not to damage it. For large anchor shafts, an angle grinder use a massive puller with three or four gripping arms, and for small ones, devices with replaceable plates or straps are suitable..
- Hammers, chisels, wrenches and other tools at hand. In this case, in order to remove the bearing from the anchor of the angle grinder, it is heated with gas, squeezed in a vice, grinded, chopped and many other operations are performed. These methods, of course, can be effective, but there is a great risk that the part’s seat will be mechanically damaged. And often the bearing itself after such manipulations without a puller will be unsuitable for further use. In addition, the performer may be injured due to pieces of clip hitting the face, eyes or head, which fly apart after impacts..
As practice shows, pullers are more effective in this situation. They allow you to quickly, easily and without much risk remove the bearing from the armature of the power tool and inspect parts or replace them. If you have to periodically carry out such operations, you should acquire such a useful device. The use of improvised devices is permissible only if you have experience in repairing power tools and an urgent replacement of a part is required.
Features of pressing the bearing onto the engine armature
After you have successfully removed the bearing from the anchor, it is necessary to carry out a number of necessary manipulations before assembling the equipment. If you are installing new parts, it is necessary that they match exactly in width, as well as inner and outer diameters, with the old bearings. It is important that no dirt or dust gets inside the product during installation, because this can lead to corrosion, chips and all kinds of damage. The bearing is mounted on the anchor using a metal pipe, which must first be lubricated. During the pressing process, it is important to ensure that there are no distortions. You should also observe the following nuances:
- lubricate the bearings with a special thick substance. It can be moisture resistant;
- only ½ (for equipment with rotation up to 300 rpm) or 1/3 (for faster tools) of the bearing chamber is filled with grease. You should not put more substance, because all the excess will still be squeezed out during rotation.
Sometimes the process of fitting the bearing onto the armature is simplified if it is preheated in boiling oil. However, you need to be very careful in this case and make sure that the part does not heat up above 100 ° C..