What amount of lubricant should be used when replacing the angle grinder in the gearbox
If the amount of grease in the bearings is controlled by flowing it out from the reverse side, then a certain amount of grease is packed into the angle grinder. Excess grease will leak out during operation. And a small amount of it will not ensure high-quality operation of the gearbox.
Leave as much lubricant in the gearbox as needed to cover the gear teeth.
Apply enough grease as a guide so that it occupies slightly less than half the volume of the gearbox cavity.
Correct grease filling process in angle grinders
Packing grease into the units of an angle grinder has its own rules. You need to know not only the order of its application, but also how much, and where to lay it.
The procedure for applying grease to the grinder gearbox
The new grease is thoroughly mixed before application and applied in a thin layer. The bearings are lubricated by packing. If the grease is in a plastic tube, then the neck of the tube is pressed against the side bearing cage and squeezed out until it flows out of the back side.
The choice of lubricant for the grinder or the better to lubricate the gearbox
Angle grinders (angle grinders), popularly called grinders, are widespread among lovers of tinkering. With their help, the home craftsman can not only perform grinding work, but also cut metal, plastic, stone. Angle grinders are produced by various manufacturers, including domestic.
The angle grinder is a reliable tool that can work, with proper operation and timely replacement of lubricants and carbon brushes, for a long time.
Correctly selected grinder grease not only extends tool life, but also improves performance.
Knowing the rules for choosing a lubricant for a grinder or making it with your own hands, you can perform maintenance without contacting service services.
Grease for bearings LBM
Three bearings are installed in the design of the angle grinder. Two bearings are mounted on the rotor of the tool, one bearing is mounted on the shaft of the driven helical gear of a larger diameter.
In angle grinders, bearings are used that are already filled with grease. But from improper operation, overheating of the tool, grease flows out.
How to choose the right grease for grinder bearings?
Bearing grease must meet the following requirements:
- increase sliding;
- reduce friction between component parts of parts;
- evenly distribute heat and act as a coolant;
- prevent the occurrence of corrosion;
- protect from dirt and dust getting inside;
- work in the required temperature range up to 150C;
The operating conditions of the bearings of an electric motor differ from the operating conditions of the gearbox bearing, not only because of the temperature requirements, but also because of the operating modes, load modes, frequency and speed of rotation.
The grease for the bearings of the electric motor must have protective properties that prevent the ingress of dirt, dust and moisture on the bearing parts.
The Russian market offers a wide range of foreign greases designed for bearings operating in different conditions. But their cost makes us look for cheaper, not inferior in quality, domestic lubricants.
Among domestic lubricants, we recommend paying attention to the Tsiatim-221, VNIINP-246 (GOST 18852-73), VNIINP-235 lubricants.
Well proven lithium greases.
Possessing high water-repellent properties, they have a wide temperature range. The role of the thickener in them is played by organic and inorganic substances. For sealed bearings, it is best to use CIATIM-203, VNIINP-242 greases.
Of the pigment greases for electric motor bearings, blue grease VNIIMP-246 and dark purple ointment VNIINP-235 have become widespread. The first grease is less common than the second one due to its high price.
In today’s Russian market, domestic manufacturers of lubricants are represented in a wide range of products.
Lubricants recommended by foreign tool manufacturers
Foreign tool manufacturers, including angle grinders, recommend specially developed ointments as lubricants for grinders.
One of the most widespread foreign lubricants is a grease marked MoS2 NLGI 2 ISOL-XBCHB 2 DIN 51825-KPF 2 K-20.
- MoS2. indicates the filler material, in this case molybdenum;
- NLGI2. indicates the second viscosity grade;
- ISOL-XBCHB 2. belonging to ISO standards;
- DIN 51825-KPF 2 K-20. the grease is made according to German DIN standards;
- The numbers 51825 mean that the grease is type K.
Lubricants produced with such characteristics are quite expensive. There are imported, less expensive lubricants on the Russian market.
Each tool manufacturer, be it Bosch, Makita, Hitachi, DeWalt, Metabo, RedVerg, Interskol, E256, LEPSE, recommends its own lubricants. This is the manufacturer’s policy. They insist that when performing maintenance, the lubricants specified in the instructions are used. over, non-observance of these recommendations does not allow performing warranty repairs.
Makita grease for the Makita lumbar gearbox is available in tubes. Its high cost is commensurate with the high quality and long service life.
Lubricants of domestic manufacturers for bearings and gearboxes of grinders
With the rise in for foreign lubricants, lubricants of domestic manufacturers have become especially in demand.
Russian lubricant manufacturers have learned to produce high-quality lubricants suitable for any tool.
Lubricants have been developed for reducers of grinders, perforators, drills.
The most popular products are Nanotech Metal Plak Electra. The range of lubricants produced by this company allows you to select the lubricant required for each unit
The main characteristics of a lubricant for angle grinders
In angle grinders, the main unit that is subjected to the greatest loads during operation is a gearbox consisting of helical gears.
The torque generated by the grinder’s rotor is transmitted from the rotor to the working tool through a small helical gear to a large helical gear. Correctly selected gear lubricant significantly reduces frictional force and heating temperature.
The grinder uses bearings that also require periodic lubrication. This especially applies to the spindle bearing of the large helical gear.
A lubricant that meets not only the listed requirements, but also environmentally friendly is suitable.
Lubricants for an angle grinder must have certain characteristics and must be of the required consistency in terms of properties.
Lubricant for the angle grinder gearbox must have:
- viscosity no more than 800 Pa s;
- dropping point not less than 120 ° С;
- ultimate strength not less than 120 Pa.
Lubricant for angle grinders should not have mechanical impurities, be resistant to corrosion, adhere firmly to lubricated parts, not melt at high temperatures, prevent the formation of scoring at the contact points of parts and, of course, have water-repellent properties.
In an angle grinder of any company, two types of plain bearings are used: bearings for an electric motor and support bearings for a gearbox.
The selection of grease for the bearings of an electric motor is different from the selection of grease for the gearbox bearing. It’s all about different working conditions.
What is the lubricant in the grinder gearbox
Technical device of an angle grinder
The LBM design consists of the following elements:
- Metal or plastic enclosures;
- Reducer and its housing made of aluminum alloys;
- Wheel for adjusting the number of rotations;
- Start buttons;
- Lock buttons for quick change of attachments;
- Clamping nut of the working circle;
- Protective cover of the disc and handle with a variable position on the body;
- Electric cables.
Works performed by angle grinder
The grinder instantly gained immense popularity. Since, before its appearance, certain types of work required a significant application of both physical efforts and several tools in their type of purpose for performing one type of operation.
Being, in essence, a universal device for cutting products and materials of various hardness groups, as well as rough abrasive and grinding processing, an angle grinder easily performs the following types of operations:
- Cutting of ferrous and non-ferrous metals;
- Sawing of reinforced concrete, natural and artificial stone, ceramics and other materials of this group;
- By replacing the saw attachment with the corresponding disc, the grinder can cut wood products and lumber from tree species of different structure.
Also angle grinder is used for the following works after sawing:
- Removing scale and paint from metal and wood surfaces;
- Removal of burrs resulting from sawing materials;
- Fine grinding and finishing of surfaces and hard-to-reach places.
Getting high-quality lubrication with your own hands
If you want to use a good lubricant composition of the angle grinder gearbox, but there is no possibility of acquiring it, then you should make it yourself on the basis of the CV joint grease. Do not forget that the material used must have good adhesion.
The composition must adhere firmly to the rubbing elements. The composition for CV joints is characterized by increased adhesion and the ability to work at high temperature loads.
For the manufacture of the mixture, the composition for the SHRUS and the MC-20 oil are taken to enhance the required viscosity and density. Using a homemade mixer, the composition is mixed with a small supply of oil (drop by drop).
And you can also get material from a mixture of Tsiatim-221 and TAD-17 lubricants. The main component is Tsiatim.
Grease for the gearbox of the Makita grinder (Bosch)
For the reason that the grinder is a high-speed, powerful and very hot tool in operating mode, the question of what kind of lubricant to use for the grinder’s gearbox is very important. Immediately we want to highlight the types of lubricants, the use of which for the gearbox (bearings and gears) of the angle grinder is not recommended by specialists. It:
Silicone, pigment and lithium greases and derivatives based on them, both domestically and imported, have proven their worth.
When choosing which lubricant to lubricate the grinder gearbox, it is worth listening to the opinion of professionals in their repair or simply long-term users of this tool. Although their opinions will be far from unambiguous.
So, widely known among motorists, CV joints are equally persistently recommended and rejected by specialists. over, both parties make quite convincing arguments for and against the use of CV joints.
We can say with confidence that the lubricant for the gearbox of an angle grinder must meet the following requirements:
- Be heat resistant and do not leak out of the gearbox as it heats up;
- Increase sliding;
- Reduce the force of friction between touching, moving parts of parts;
- Evenly redistribute the heat load while simultaneously performing cooling functions;
- Protect metal parts from corrosion, penetration of dirt and dust into the mechanism.
As expected, tool manufacturers advise using only their own, native spare parts, consumable parts (brushes) and lubricants.
So, according to the specialists of the Bosch company, the lubricant for the gearbox of the Bosch grinder should be produced by this particular brand. over, it can be successfully used for lubrication of angle grinders and other manufacturers. With which the representatives of Makita, Hitachi, and so on completely disagree. No doubt, branded lubricants are of very high quality and meet all the stated parameters. If not for one but.
The cost of a can of Makita or Bosch grease (really branded, not a Chinese counterfeit) is comparable to a grinder of average Asian production, which, of course, is very expensive. Naturally, the service life of the device directly depends on what kind of lubricant is in the grinder’s gearbox. But in the modern lubricant market, you can pick up a more affordable lubricant and, no less important, not inferior in quality to foreign counterparts.
Grinder lubricant so that the work goes like clockwork
Advice! Experts do not recommend using materials such as solid oil and lithol.
When deciding how to lubricate the grinder, pay special attention to materials based on silicone or silicone oil. These lubricants are excellent for tools that operate at a range of speeds from slow to high speeds and under any load. They are highly resistant to oxidation, protect against corrosion, and are easily combined with plastics and elastomers. The composition contains exclusively silicone and a lithium thickener, which makes them environmentally friendly. The consistency is maintained at temperatures from 50 to 190 degrees Celsius.
One of the most important elements of the grinder is the gearbox. When the tool is in operation, it heats up a lot, because it is behind it that the gears rotate, which leads to strong heating. It is for these reasons that the gearbox casing is made of metal, because it removes heat quickly enough. But the casing alone is not enough to cope with the high temperatures, and proper lubrication plays a huge role.
Each specialist, when asked how to lubricate the grinder’s gearbox, will answer that it is best to use a special lubricant for angle grinders. It is specially designed for the job and the environment in which this tool is used. This grease has a specific blue color. A good, high-quality grease for the grinder gearbox has the following markings: MoS2 NLGI 2 ISOL-XBCHB 2 DIN 51825-KPF 2 K-20. Marking means:
- MoS2. molybdenum disulfide acts as an additive;
- NLGI 2. second viscosity grade;
- ISOL-XBCHB 2. compliance with ISO standards;
- DIN 51825-KPF 2 K-20 is the most important point, it means that the grease complies with German DIN standards.
- 51825 indicates that the material corresponds to a type K grease.
The price for such a mixture is very high, but there is a cheaper grease with similar qualities: KPF 2 K-20, where:
- K. designed for sliding bearings;
- P. with extreme pressure additives;
- F. with solid filler;
- 2. consistency complies with NLGI;
- K. maximum operating temperature 120 degrees Celsius;
- 20. minimum operating temperature.
Note! The use of special lubricants for angle grinders will give the maximum guarantee of reliable operation.
Particular attention should be paid to lubricating the grinders that are under warranty. It is not recommended to do this on your own; you should entrust this work to specialized workshops. There will be used high-quality and original materials with the correct dosage. At home, you can apply the mixture incorrectly, which will negatively affect the durability of the tool.
Advice! It is recommended to take to specialized services not only grinders for warranty, but also those that have already passed the warranty period.
Various lithols and greases for lubricating gears and bearings are strictly prohibited. In addition, opening the case on warranty tools will be a reason for refusing to service, and the use of “unauthorized” lubricant is generally a gross violation of the rules for using the grinder. The only exceptions are external nodes, which, according to the instructions, must be regularly processed.
Boston Gear | 700 Series Gearbox Lubrication
Popular brands of lubricants
Foreign-made gear lubricants are much more expensive than domestic ones. The Bosch brand is widely known from foreign countries. It is used to lubricate tools of the same brand, as well as other models of grinders. The coating has good performance.
From domestic manufacturers, the products of the Nanotech company are known under the name Metal Plak Electra. Lubricants of this brand are used for many components of an electric tool.
Operating the grinder without a lubricant coating will first lead to minor malfunctions in operation, and then to the failure of the tool. Lubricated gearboxes will extend tool life and increase productivity. What kind of lubricant is suitable for the existing device, the master himself decides.
What amount of lubricant should be used when replacing the angle grinder in the gearbox
The amount of lubricant put into the gearbox must be such that the oblique teeth of the gears are completely covered by it. An excess will cause it to be squeezed out from under the cover, and an insufficient amount will not ensure the correct operation of the gearbox.
It is best to be guided by the quantity that was set at the factory by the manufacturer of the angle grinder, but remember that the lubricant can dry out, while decreasing in volume.
In this regard, it is better to put a little more and check the correct distribution of the lubricant after turning on the grinder. In general, the amount of lubricant is usually about 30-50% of the full capacity of the gearbox.
When to change the lubricant in the grinder
The frequency of changing the lubricant depends on how often and under what load the tool is used. Typically, this interval is about a year. In case of intensive use with frequent overheating, the replacement frequency is reduced to six months, sometimes more often.
To carry out maintenance, you will need to disassemble the angle grinder by unscrewing 4 screws on its cover.
After removing the cover, you can see two bevel helical gears: a large and a small gear. The small gear is anchored and drives the large gear. The large one, in turn, is seated on a secondary shaft, to which a cutting or grinding disc is attached.
Correct grease filling process in angle grinders
After the choice of lubricant for the grinder is made, they proceed directly to the maintenance of the tool. The correct process for servicing a grinder consists of several steps. First you need to open the gearbox, then remove the old lubricant, apply a new one, check the correct application. Removing the old grease is necessary for the reason that mixing with new grease will not allow it to work correctly and the entire maintenance procedure will not bring any result.
Correct stuffing of grease in angle grinder
The procedure for applying grease to the grinder gearbox
Before applying a new grease, it must be thoroughly mixed and made sure that there are no lumps or foreign objects in it. Apply a thin layer of lubricant to the gears, making sure that it completely covers the teeth. It is more convenient to fill the grease inside the bearings with a syringe. Then the grease intended for the angle grinder is hammered into the gearbox housing. This is necessary for the reason that during operation it can fly off the gears and with a small amount of it, the gears will run “dry”.
How to properly remove old grease in a grinder
The disassembled grinder gearbox must be well cleaned of the old lubricant. It no longer fulfills its functions, plus solid particles have already accumulated in it, resulting from wear of moving parts. Mixing with new, old lubricant also significantly degrades its performance. Therefore, the gearbox and gears must be thoroughly cleaned.
Removing old grease from the gearbox
Remove old grease with a rag, paper towel, or just a rag. The removed parts can also be washed in gasoline or thinner. The washed parts must be thoroughly dried before assembly. Residual solvent or gasoline will mix with the new grease and change its consistency, which again will worsen its performance.
Characteristics and features of greases for grinders
When servicing any hand tool with moving parts, a lubricant is used that has the following characteristics and features:
- It should not contain solid particles that can cause chipping of the moving parts of the mechanism.
- The temperature at which the lubricant becomes liquid must be over 120 degrees.
- The oil should not absorb moisture, should form a strong film that protects parts from corrosion.
- And also, most importantly, the oil must be of such a viscosity that it has the ability to hold onto moving parts.
The consistency or viscosity of greases is classified according to the NLGI (National Lubricating Grease Institute), and in certain cases it is necessary to use an oil of a certain density. The viscosity of the oil is selected depending on the speed of the gearbox, the higher it is, the more liquid the oil should be. So, depending on the tool, the viscosity is selected:
- Drills, hammer drills, jigsaws, where the gearbox has a low rotation speed. NLGI-2 grease which is soft.
- Lightweight rotary hammers and impact drills. NLGI-1 grade, very soft in consistency.
- LBM, circular saws, brushcutters. NLGI-0 grade, semi-liquid in consistency.
- Heavy rock drills, jackhammers. NLGI-00 class, liquid in consistency.
Grease for the grinder gearbox
The guarantee of a long life of any hand tool consists in its correct periodic maintenance. Of course, you can give it to special service centers for maintenance and diagnostics, but, as they say, “If you want to do well, do it yourself.” Therefore, it is worth figuring out how to independently service such a popular tool among home craftsmen as an angle grinder or a grinder, in common people.
The moving parts of angle grinders are most susceptible to wear. These are the bearings of the armature, gears, as well as the gears themselves, which are in the gearbox. The lubricant (or lubricant) put in by the manufacturer ages over time, its properties are lost, all this leads to greater wear of the gears in the gearbox and, as a consequence, to increased vibration and the appearance of extraneous noise during operation. Periodic maintenance and replacement of the lubricant in the LBM gearbox must be carried out at least once a year.
Lubricant for the LBM gearbox
Almost all global tool manufacturers require the use of their recommended “in-house” lubricant, sold under its brand. In principle, this is correct. The grease used for the grinder’s gearbox, in this case, is tested at the factory, it guarantees a long-term and correct operation of the angle grinder. However, there are some drawbacks, which are the high price of lubricant from these brands.
Types of Lubrication and the Classifications and Properties of Different Lubricants
Lubricant for open gear LBM
In addition to original oils, there are many lubricants produced by third-party manufacturers on the market, so the question of how exactly to lubricate the grinder’s gearbox is not acute.
The products of Haskey, Castrol, Liqui Moly and others have shown themselves well for adding to the grinder gearbox.
Russian manufacturers also keep up with foreign ones and offer their products. Thus, the lubrication of the bevel gearbox LBM from Nanotech is very popular. Of course, such a lubricant for the gearbox is not original and recommended by the manufacturer, therefore, if it is used, the subsequent warranty repair may simply be refused.
What kind of lubricant to choose
- the use of expensive special lubricants for gearboxes from well-known brands;
- the use of universal compounds suitable for any power tool;
- gear lubrication with lithol or grease;
- use of self-made lubricant.
Application of special materials is the optimal solution. When choosing a lubricant for a gearbox, it is recommended to give preference to formulations produced under the same brand as the grinder itself. For example, if the machine is of the AEG brand, then the lubricant must be bought of the same brand.
When using specialized products, the service life of angle grinders is significantly increased, since the manufacturer takes into account all the features and nuances of operating its own equipment. The disadvantage of using branded materials is their high cost, which can affect the family budget.
Most craftsmen use budget grinders or Chinese-made tools. For such machines, specialized lubricants have not been developed by the manufacturer and are unlikely to ever appear. However, this technique also requires maintenance. How to proceed in this case?
Specialists and service technicians recommend purchasing any budget non-branded composition designed specifically for gearboxes. You can also use the grease used for CV joints. the hinge of front-wheel drive vehicles operated under significant loads.
The most unfavorable solution is the use of lithol or solid oil, since both of these materials are not designed for lubrication of friction units heated to high temperatures.
Some owners of grinders use only these compounds, which is why their machines cannot last for the period of operation declared by the manufacturer. In an effort to profit from the here and now, they do not factor in future spending on a new tool or replacement of expensive parts.
Old grease removal phase
Removing used grease is the first step in gearbox maintenance. It is necessary to remove the old layer for several reasons:
- the spent lubricant is not able to perform its functions;
- it contains small particles formed during the wear of the rubbing elements;
- old grease will mix with new grease, because of this, the unit will not work correctly, replacement will not bring any results.
Removal of waste is carried out using disposable paper towels, rags or a piece of tissue at hand. The removed parts of the gearbox should be thoroughly washed in thinner or gasoline, and dried before installation.
Residues from cleaning materials can also mix with the new grease and change its consistency, resulting in performance degradation.
What, how and when to lubricate angle grinders
Grease for the grinder gearbox: period of use, the main stages of replacement. Application technology, recommended amount. Selection criteria and options, self-made lubricant.
In angle grinders (angle grinders), commonly called grinders, the main load falls on the gear reducer that changes the axis of rotation.
Care is required throughout the entire period of operation, since the mechanism needs to reduce friction between its interacting parts, timely maintenance.
The use of grease for the grinder gearbox allows not only to minimize the destructive frictional effect, but also helps to cool the tool.
How much grease is required to replace
Therefore, it is better to first put in a little more material than required and make sure that the lubricant is evenly distributed after the gears of the reducer are activated. The generally accepted norm is filling with lubricant about 40% of the volume of the gearbox.
Bearing grease phase
How to properly lubricate angle grinders
When you need to change the lubricant in the angle grinder
The term of the next lubricant change depends on the loads and the intensity of the use of angle grinders. Usually it is equal to 12 months. With everyday use of a grinder with frequent overheating, the frequency of change is significantly reduced, at least to six months.
To make sure it is necessary to add a new amount of grease, the gearbox must be disassembled by unscrewing the screws on its cover. Inside there is a pair of helical gears.
The small one is placed on the anchor and is used to drive the large one located on the secondary shaft. A grinding or cutting disc is attached to this shaft.
During operation, the lubricant, when the gearbox moves, scatters along the walls of the housing, drying out over time and forming large lumps. The material used for a long time overheats, becomes liquid and flows out of the case.
Inside the Gearbox: How to Grease a Gearbox
Therefore, its volume in the gearbox decreases. If there is only a thin layer of lubricant on the gears, add lubricant.
Grinder grease must be changed if there are dried lumps on the inner walls of the gearboxes or if there is insufficient quantity.
Gearbox lubrication stage
The gearbox must be filled with such a volume of grease that it completely covers the gears.
Control of the sufficiency of lubrication for the angle grinder gearbox is carried out by turning on the grinder for a short time. If, within 3-5 minutes of operation, the node temperature has increased and lubricant is leaking out, part of its volume must be removed. To do this, the gearbox is disassembled again, the excess is removed with a rag or rag.
When checking, the opposite situation can be observed, when noise appears when the angle grinder is turned on. This means that there is not enough lubricant and it needs to be added.
When using a grinder, a periodic check of the adequacy of lubrication of the gearbox elements, the quality of the available lubricant is required.
To carry out routine inspections, it is necessary to unscrew the bolts tightening the cover and visually inspect every detail. If slightly dry or completely dry areas are observed, a complete replacement of the lubricant is recommended.