In detail: do-it-yourself repair of the gearbox of a concrete mixer truck from a real master for the site my.housecope.com.
Repair of a concrete mixer is an important question that sooner or later arises before every builder or owner of this tool. Unfortunately, the breakdown of concrete mixers is a common phenomenon, and there are many reasons for this. First, enormous loads are placed on this device. Secondly, often the owners themselves do not pay proper attention to the instrument, they misuse and store it. It is also fraught with negative consequences, which often require repair work. Before getting down to business on your own, you need to study all the information, stock up on the necessary tools.
It is possible to repair a concrete mixer with your own hands only if you have experience in such work. Have a home appliances fix? Did you bring a car or a moped back to life? Then feel free to start repairing the concrete mixer. If you have never done something like this before, do not know how to hold a screwdriver in your hands and do not have at least an elementary set of tools at home, it is better to turn to professionals for help. Otherwise, there is a risk of losing your concrete mixer altogether.
In order to independently repair the unit, you will need a list of tools (of course, depending on the breakdown, the set may change). Among the main ones are pullers (three-blade and for bearings), a vice, pliers, a hammer, of course - screwdrivers, a chisel. Also, you can not do without a set of keys - gas, wrench, adjustable. Prepare your knife, tester, and caliper ahead of time.
There are many reasons why concrete mixer repairs may be necessary. It happens:
Video (click to play).
when the unit loads more than the established rates;
the drum is untimely cleaned (this must be done after each use);
improperly and in improper storage of the tool.
A special place is occupied by the repair of consumable items - belts, drive gears, shutdown buttons.
Wear of parts, improper storage and operation are the most common causes of breakdowns in concrete mixers. But the replacement of support bearings and gear rims occurs much less often, all because their service life is much longer than the above parts.
Let's consider the main reasons for the breakdown of the main parts of the concrete mixer.
Gears. As a rule, a quick breakdown indicates improper operation. Many owners consider it necessary to periodically lubricate the rims and gears, supposedly this reduces the load on the motor. And they are completely wrong! In this case, the load only increases. When working on the teeth, cement / sand clings, this increases friction and quickly abrades the metal.
Reducer. It wears out quickly due to poor cooling, overload. In this case, the part only needs to be replaced. There is even a chance that you will have to change the entire unit.
Gear ring. Significant mechanical stress is imposed on it. The material of this part is plastic or cast iron. More often cast iron parts become unusable (this is due to the low quality of casting). Therefore, it is better to install a plastic crown initially.
Shutdown buttons. Often the reason for the breakdown lies in them. This is expressed as follows: by pressing the button, the unit (motor) supposedly starts to start, but after a couple of minutes it stops working, stopping. In this case, it is important to replace the button with another, the main condition is that it must have the appropriate number of contacts.
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The buttons in concrete mixers are magnetic actuators, not just an on / off design. This ensures the safety of work, because in the event of a sudden power outage, the machine will stop, and when turned on, it will not start unexpectedly, thereby harming someone.
If the button has become unusable, slowly remove the cover (by unscrewing the screws that hold it), the button itself. View the detail, if necessary, strip the contacts. Also disassemble the button by cleaning it inside.
Sometimes it can happen that the motor works, but the container does not (no rotation occurs). In this case, the cause may be in the belts. Remove the protective cover from the drive and assess the situation. Most often, the strap just slips off - in this case, you need to put it in place. Sometimes, even if the belt is intact and not broken, it may not be suitable for further use. This means that you cannot do without buying a new one. To put it, loosen the bolts that attach the motor (there are two of them), put the belt. Start with a shallow pulley (near the motor), gradually moving to a large one. It is advisable to use someone's help - it is very difficult to cope on your own, because you need to delay the engine and immediately tighten the bolts. Actions take place simultaneously.
Before replacing the gear and rims, you need to try to rehabilitate them - thoroughly lubricate with lithol. Turn the bowl upside down. Turn on the concrete mixer and spread the crowns with a spatula.
If the gear slips over the teeth of the crown, it's time to change it. The gear consists of 12 teeth and a hole (diameter 14 mm) - for the shaft. Unscrew the fixing bolt (a key for 10 will help), remove the washer and pull out the gear. Be careful not to lose the key (it is small, located in the gear). Put the key on the new gear and put it back in place by doing the steps in reverse order.
This work, unlike those described, is more painstaking and will require skill and time. First, remove the motor box, which is on the concrete mixer, the belt - this way you will get to the pulley. It is made of plastic. Therefore, it is quite logical that over time, the pulley hole will round and it will not be able to rotate the shaft.
The pulley is attached to the corkscrew ring on the back of the box. This means that you cannot do without a complete analysis of the design.
There is also a "plus" in this - you will fully appreciate the condition of the bearings. If there are distortions and jams, they will also have to be changed. Then it remains only to collect everything and return the concrete mixer to its previous state.
In principle, as you can see, it is not so difficult to make repairs. But still it is better that the concrete mixer does not break. You can postpone the breakdown time by adhering to simple tips, with the help of which you can not think about repair for a long time:
always clean the mixer after use, especially make sure that dust from cement and mortar does not get into the mechanism and engine;
do not overload the tool, do not try to make more concrete at a time than is allowed by the instructions;
try to keep the concrete mixer in the form in which you purchased it - in this case, you can use the guarantee of repair, which will be made by specialists.
The video clearly shows how to repair the gearbox of a concrete mixer on your own. You will learn how to restore the flared gearbox shaft, install the bearing, circlip and collar, install the flange in the bearing, assemble and install the repaired barrel reducer on the auto mixer.
We recommend that you contact a specialized service to avoid possible additional breakdowns during self-repair of the concrete truck gearbox. This will save you time and money!
You can find all the necessary spare parts for the repair of a concrete mixer truck here:
Repair service for concrete mixer trucks:
Video Repair of the gearbox of a concrete mixer truck of the TekhMash channel
This article will focus on repairing the SBR-132A concrete mixer with your own hands.
In general, I want to say that the concrete mixer is quite reliable. Has already withstood two "self-weight" foundations, and this is more than 100 m 3 of concrete, plus plinths for these houses, floors and so on in little detail. They make it in Russia, in the city of Lebedyan. Personally, I bought it at this particular plant. Immediately in reserve I bought a pair of belts, a plastic driven pulley and a drive sprocket.
Breakage manifests itself by turning off the concrete mixer when the button is released. Simply put, we press the green button - the mixer turns. Letting go - it, the infection, stops. This is not such a big sadness, and the simplest breakdown, but also the most frequent. The fact is that this is not really a button, but a KJD17 magnetic starter. The thing is very convenient, unlike a simple switch, and is made for the sake of our safety with you. When the light is turned off, the starter button will open, and when the light is suddenly turned on, it (the stirrer) will not start up suddenly and will not hurt the poor builder, who at that time took it into his head to stick his finger between the gears. That is, it is a simple "foolproof". Treating the sore is quite simple.
We remove the cover on which the button hangs.
I have it in gray, screwed on with four self-tapping screws. for a Phillips screwdriver. Just the top of engineering. Developers. Try unscrewing these 4 screws in the field. This is a concrete mixer, and picking out concrete from these “crosses” on self-tapping screws is a dubious pleasure. Thousands of users remember you in not the best words. If only they put the imbus there with rubber plugs or something. In general, the first couple of times you can unscrew it with a screwdriver, and then only with pliers with swearing pliers.
Okay, unscrewed. Carefully remove the cover and see that 5 wires go to the starter from the inside.
Disconnect them carefully. We unscrew the button (it is also on two self-tapping screws).
Now this button must be disassembled in order to clean the contacts that are inside. With a thin screwdriver, press on the two latches that are located at the top and bottom of the button. We remove the front part. We see a small “penny” with a leg. The leg is slightly bent, so the “penny” must be placed as it stood, otherwise it will not work. We remove the "penny". On the back side, you will most likely see a small black carbon deposit. Because of this carbon deposits, in fact, the mixer does not work as it should. We clean everything with meeeeee sandpaper. We look at the core, which is in contact with this "penny", we clean it too. Putting it all in reverse order. We are glad to the new working day!
I would like to draw your attention to the fact that the KJD17 magnetic starter is 5-pin. The fifth contact goes to the emergency thermostat of the engine and at a certain elevated temperature cuts off the power from the engine.
The motor works, tries, hums merrily (obviously without any signs of tearing and nibbling), but the agitator does not turn. Fixing!
The belt is a consumable item, just like in a car. The SBR-132A is equipped with a 5PJ 610 (five-strand belt 610 mm long). With its replacement, everything is simple. We remove the protective cover, disconnect the contacts from the starter so that it does not interfere. We slightly loosen the two bolts that are on the back side and secure the motor. Lift the motor up a little with our hands and remove the belt. This is if it is still there))) Usually, if it buzzes and does not twist, then the mixer has removed or tore the belt for you, and you do not need to remove anything. He puts on without much effort, at first it clings to a small pulley that is on the motor. Then it is pulled over the top. Then you need to tighten the belt. It is better to do this with a friend. A friend presses on the box, and you tighten those two bolts that you loosened before removing the belt.
The concrete mixer works, turns, and in order to extend the life of the drive gear and crowns, you need to get used to the fact that all these things need to be thickly greased with lithol before starting the shift. Turn the bowl over with the neck down, turn on the stirrer and use a spatula to spread the lithol on the crowns. The agitator hums quite, humming and thereby showing that it is good now))))
Jokes as a joke, and sooner or later the gear will turn into this:
It will begin to slip along the teeth of the crown and deliver a lot of not very pleasant impressions. It's time to change it! I don’t know where to buy, I buy it directly from the plant in Lebedyan, since it is not far from us. The gear has 12 teeth and an internal shaft hole of 14 mm in diameter.
Replacement! With a certain skill, it is not necessary to remove the bowl, it is enough to unscrew the fixing bolt with a 10 key,
remove the washer and pull out the gear. Carefully! There is a small key there, so you must not lose it. In the photo above, everything is so easy and accessible, because the pear is removed, and if you are lazy to remove the pear, then you need to be smart and use all the work of fine motor skills of the fingers in order to fish it out from there. But it's real! Checked! 4 times already.
The pulley is made of plastic. The shaft that this pulley slides on is round and milled to one side. So, the whole trouble is that when the hole on the pulley becomes completely round, it turns freely on the shaft. Accordingly, the motor turns, the pulley turns, but the shaft does not ((((
It would seem, why change it, this pulley? He removed the cover from the motor box, as when replacing a belt, removed the belt and removed the pulley. It seems to hang out, but it doesn’t come off, even though you crack. But the point is this: the pulley on the back of the box is fastened with a retaining ring, so it makes little sense to make efforts to remove it without removing the box with the motor. Therefore, we unscrew the two nuts and remove the two bolts that hold the box to the frame. The box will be removed together with the pulley and a bare shaft will remain. Now it remains to unclench and remove the retaining ring. The pulley will fall out by itself. It is completely unclear why it is impossible to make a pulley not of metal, but out of the corner of my ear I heard that modern SBR-132 has already begun to make metal. But these are rumors.
If you have already removed the entire box and saw the shaft, then it is worth nothing to check it for bearing wear. Turn the shaft with your fingers, make a few turns, if everything is fine, then change the pulley and put everything back together, if something sticks and the shaft turns unevenly, congratulations))) you got to replace the bearings. We read the next paragraph.
The feeling that the agitator has become old and there is no longer that former agility in it. It seems to be spinning quickly, but it does not start the first time. When it sticks, the engine no longer buzzes merrily, but rather a strained hum. In general, there is a feeling that you need to buy a new mixer, but everything is not so tragic. It's all to blame for a pair of bearings that stand on a shaft on which a pulley is attached on one side, and a gear on the other. Here he is, our hero! And two old men who have outlived their own)))
This is bearing 203, or according to the international classification 6203. It costs like two loaves of sliced bread, so repairs are not very expensive. We remove the box with the motor, as in the case of replacing the pulley. We remove the concrete mixer pear. I will tell you how to remove it in the next paragraph. Remove the drive gear (see above). And we are left alone with this situation.
From the side of the gear, squeeze the retaining ring and remove it. Since I do not have a suitable puller, the shaft had to be knocked out with brute force. To prevent the frame from springing, I had to use a high-tech device called “board sawn to size”))) It looks something like this:
Unfortunately, I don't remember the size. In general, carefully, but strongly, substituting a piece of wood on the shaft so as not to bend it, we knock out the shaft together with the bearings.
In the end, we have a shaft in our hands, on which two bearings hang, a bushing between it the size of an outer bearing race and a small spacer sleeve. If there is a tool, then further manipulations are not difficult at all. If not, buy - it will come in handy more than once!
We put the puller on the side where the gear was (the key, I hope, has already been pulled out) and press on the shaft, pulling out the bearings.
We change the bearings to new ones, lubricate the shaft with lithol and also put on new bearings with a puller. Or you can pick up a tube for the diameter of the shaft, and carefully hammer them into place, knocking strictly on the inner race of the bearing.
Then we assemble everything in the reverse order, not forgetting about all the spare parts, and enjoy the work of the concrete mixer.
Also, nothing complicated, you need a gas wrench, open-end for 13 and our old friend - a three-legged puller.
We unscrew the lock nut with a gas wrench, and then the pear fastening nut.
With a 13 key, unscrew the locking bolt on the side. Pear didn't fall out?)) It's not scary! We install a three-legged puller and calmly squeeze out the shaft.
At some point, the pear will fall out. There will be shims on the shaft, try not to get them confused.
That's all! If you have any questions, ask in the comments. Not all photos, as the repair progresses I will try to add more photos for clarity! Good construction, everyone!
