How To Remove The Impeller From A Chainsaw

26th February 2021

2.1 Species

They are divided into types according to their structure. There are 3 types:

Closed pump impeller

open. They are a single wheel with blades carved on it. Since the wheel is open, sand, clay and other dirt will not clog it. Pumps with such impellers are used for pumping dirty water. Of the minuses, a large loss of energy from the engine and low head can be noted;
closed They are 2 discs between which there are blades. Due to the complexity of the design, the electric pump will often clog up, however, if you pump clean water, it will be the most efficient device among all centrifugal pumps;
semi-closed: Combine properties of both closed and open types. The similarity with the latter is that the design has one impeller, and the length of the blades is borrowed from the closed type. In pumps with a semi-closed impeller, the role of the second wheel, as in the closed type, is played by the pump wall. This type of impeller provides good performance and the ability to pump slightly contaminated water. So to speak, the golden mean between open and closed type.

2.2 Types of fastening

Energy from the engine to the impeller is transmitted through a special shaft that is attached to the center of the impeller. For good operation of the pumping station, the attachment point must be reliable and durable. It should not turn. There are 4 different types of fastening:

cone;
cylinder;
cruciform;
hexagon.

The cone is designed for easy wheel change. Used in conjunction with a plastic impeller. Since the mount allows for easy replacement of the impeller, it is not very secure. And if the pumping station operates with a high density liquid, a large amount of efficiency will be lost. But for pumps with water, this is the ideal mounting choice.

Hexagonal impeller mount

The main advantage of the cylinder is the precise position of the impeller on the shaft. In order to prevent the impeller from turning, the mount is supplemented with special projections. Cylinder mounts are used in submersible pumps.

The cruciform mount is the stiffest of all. The presence of four lugs firmly fixes the impeller to the shaft. A pump with such a mount is used for pumping liquids with a high density.

The hexagon is also a rigid mount, but not the same as the cruciform one. Its advantage is the rather light impeller attachment and, at the same time, the absence of turning. Together with the open impeller it will be the ideal solution in a pump for pumping dirty water.
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1 Main functions

The impeller of a water pump, or impeller, is the main component of a water-running device. It uses the energy received from the engine, acts on the water and moves it. As the impeller rotates, the centrifugal force also acts on the water and overflows it. Because of such a device for moving water with an impeller, they are called centrifugal. Most of these devices today are electrical.

Surface pump impeller

2.3 Why change?

The impeller is the main element that is constantly damaged by the action of water. At the same time, it is the main working part of the pump. For ease of use, it is possible to replace the impeller. There are many companies on the market that make spare parts for pumping stations for various purposes.

If you are looking for a water pump, consider Kama. It produces closed impellers for cylindrical mounting. They are made of light alloy steel and have an ideal balance of performance and power. These impellers are intended for submersible circulation pumps.
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2 What is it made of?

The impeller material directly affects pump performance. Differences in weight and strength determine the purpose of the electric pump. weight consumes more engine power, but the device can handle higher density fluids. Lighter weight is more economical, however, and the power decreases from this. Also, the price of the pump depends on the type of material. Also, metal elements can corrode.

Now the following materials are used to make this part:

steel. Strong material, hardly corroded. The steel part weighs in the region of 150 grams. The choice of this material is a compromise between performance and energy consumption;
aluminum. Expensive material, but lightweight and durable. Corrosion resistant. Since it is lightweight, performance is low. But it is stronger and more durable than plastic;
plastic. The cheapest, but also the lightest material. Apparatus with such a detail will be the most productive, but not capable of pouring anything heavier than water. The material is not as durable as all others, and the impeller will have to be changed frequently;
cast iron. Heaviest material. Used in models for high density liquids. Easy to manufacture, but not too long service life due to corrosion.

The choice of material should be based on the purpose for which the device is being purchased. If for a simple transfer of water. take plastic, if for vegetable oil or any other liquid of high density, then cast iron or steel. Aluminum is not profitable because of its price.
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How to choose and replace a pump impeller?

Since ancient times, people needed to pump water. And they came up with pumps. The principle of operation was simple. the mechanism scooped up water at one end and poured it into the other. Times changed, mechanisms improved, but this principle of water pumps remained.

In the modern world, electric pumps are now used, and a part that is similar in function to an ancient device is now called an impeller.

3 Replacement instructions

In order to change the impeller, you must first remove it. To do this, unscrew the front of the engine. There you will see an impeller. The wheel can be held by special bolts so that it does not fly off. If there are any, unscrew them. After that it will be possible to remove the impeller.

It so happens that a spare part does not lend itself to simple action, sits too tightly and cannot be removed. The question is how to remove the wheel from the pump? To do this, you need to heat it up (if it is not plastic). A blowtorch is perfect. After heating, remove the impeller using a screwdriver, without touching it with your hands.

Replacing the pump impeller

After that, you can put a new impeller. Make sure that it fits in the type of attachment and in diameter. Be careful not to damage the blades when installing. This will negatively affect the subsequent operation of the pump.

Situations when it is necessary to change the impeller occur quite rarely. once every few years. But if it breaks down, replacing it yourself will save you money on repairs from the master.

The impeller, or impeller, of a water pump is the main component of today’s electric pumps. There are different impellers for different purposes of the device. The right material and impeller type is the key to productivity and success. In the event of a breakdown, the impeller can be easily replaced by yourself. This will save time and money for repairs by the master.
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A little about the rules for operating the node

Regardless of the manufacturer’s brand (Stihl, Husqvarna, Partner, Patriot, Makita), chainsaws are divided into household, semi-professional and professional. The difference, however, is not the quality of the assembly or the fabrication of the components, but the class of tasks performed, the performance and the continuous power of the drive. This predetermines the choice of the material of the leading sprocket for the chainsaw, its design and the design of the saw chain.

The performance of the tool will be determined by the way the chain-sprocket pair is operated. In most cases, users use one of two options:

The chain is operated until the teeth are completely worn out, and then both the saw blade and the sprocket are replaced at the same time;
Periodic replacement of chains with different pitch, and each will require a different drive sprocket.

The choice of option is often determined by the owner’s attitude to his instrument. If it’s all the same what to cut (wood or steel staples, screws, etc. stuck in it), then you can stop at the first option. The chain, however, will have to be adjusted periodically, thereby reducing the performance of the chainsaw.

It is strongly not recommended to leave the old chain with a new sprocket and vice versa. When the saw blade is worn out, the probability that the tooth pitch will not match is almost one hundred percent. Therefore, at the initial moment of starting, both components of the chain drive will be subjected to significant dynamic loads. As a result, either the chain will stretch prematurely, “adjusting” to the sprocket, or upon impact, one of the teeth on the drive sprocket will burst.

In addition, it is worth focusing on the operation of the bearing assembly of the drive sprocket shaft. When the saw is operating at working speed, only the crankshaft rotates. But all chainsaws periodically operate at idle speed when the bearing rotates. With a lack of lubrication, the wear of the seat occurs, and. as a result. additional beating of the teeth of the still fully functional chain transmission.

It follows from this that when replacing the chain and the drive sprocket for a chainsaw, it is a good idea to replace the bearing at the same time.

Features of replacing the star for chainsaws of different brands

When replacing or repairing a chainsaw, the design features of the model should be taken into account. The specifics of servicing the coupling drum of popular manufacturers:

Stihl (Stihl). The models of this brand have one-piece and collapsible types of sprockets. To unwind the clutch, you will need a 19 head and a knob. It should be noted that the thread is left-handed, and a reflective plate is installed behind the clutch (a consumable, often breaks when diagnosing a drum).
Partner (Partner). The peculiarity of this brand is that when replacing the sprocket it is recommended to change the bearing. If you ignore this step, after a scheduled repair there is a risk of chain malfunction, changing the pitch with active sawing.
Husqvarna (Husqvarna). Many Husqvarna models use an interchangeable sprocket. This simplifies scheduled replacement and repairs. When disassembling the tool, you will need a 13 wrench to fix the shaft from the impeller side.
Carver (Carver). Unlike other manufacturers, there are no specific design features of the clutch. Depending on the brand, the star can be solid or collapsible.

SWJ802E. How To Replace Install Chain Saw Chain | Sun Joe Pole Saw

It is recommended that you carefully read the instructions before starting the scheduled repairs. It indicates the important design features of the saw, the frequency of replacing consumables.

Types of stars

Depending on the class of the chainsaw, all the stars are divided into two groups. professional and household. The first type of parts have increased wear resistance, are made of strong metal alloys that are not subject to corrosion and mechanical damage. Households often require replacement and scheduled repairs; with active use of the tool, diagnostics are recommended every six months. By design features, the following types of asterisks can be distinguished:

National teams. The removable ring can be easily unscrewed from the drum axis, which makes it easy to check and replace this part. Almost all European models of chainsaws are equipped with such stars.
Whole. They consist of a hub and a stationary crown (the number of teeth may be different, you need to carefully read the instructions for the chainsaw). Due to the factory pressing, the crown cannot be removed separately from the hub, therefore, in case of a breakdown, the entire clutch drum must be disassembled. Such a mechanism is usually found on Chinese models.

If you plan to service your chainsaw on your own, it is recommended to purchase a tool with a professional type of drive sprocket. It should be collapsible, which reduces the cost of repair and maintenance of the tool.

How to remove a sprocket from a mcculloch chainsaw

Many owners of gasoline chainsaws after a device breakdown are concerned about how to remove a chainsaw sprocket.

The design of the chainsaw device is a classic mechanism that is driven by an internal combustion engine. The design of the unit uses one of the simplest single-cylinder two-stroke carburetor engines that run on gasoline. The simplicity of the engine and the design of the chainsaw as a whole is the key to the trouble-free and reliable operation of the device in harsh operating conditions. Chainsaw operation does not require a large amount of knowledge and skills from the operator. The only condition for long-term and uninterrupted use of the device is the implementation of regular technical inspection and maintenance of the device. In the process of working with the device, it is required to regularly replace the wearing parts. To reduce tool wear, control the lubrication quality of the saw chain, its tension, the degree of chain wear and the degree of wear of the drive sprocket.

Before repairing a chainsaw, you should study its design. To replace one of the main structural elements of the device. the drive sprocket. it is required to study the mechanism of the unit’s clutch.

How to unscrew?

It is easy to remove and replace this part yourself. Work technology:

Secure the piston in the saw cylinder. First, remove the protective cover on the body, the air filter and unscrew the spark plug. Install a special piston stopper in the hole formed. instead, you can use a dense nylon cord or wire up to 15 cm long.If the piston interferes, you can slightly turn the sprocket or move the chain clockwise.
Unscrew the bolts on the cover that secures the tire, remove the protective cover. Loosen the chain tension or remove the saw attachment. At the same time, you can clean from dust, dirt and sawdust.
Depending on the model, the sprocket acts as an element of the clutch drum or be built in separately. In the second option, remove this part, replace it with a new one. The one-piece construction is difficult to repair. it is required to disassemble the unit. To do this, unscrew the coupling clockwise, remove the drum. Check structural parts for wear and deformation.
Figure 4. Replacing the star with a new one

If the sprocket is an element of the clutch drum, then the entire part will have to be changed. When replacing, you should pay attention to the conformity of the model. it must be similar to the factory one.

Algorithm for replacing the clutch drum

When replacing the clutch drum, only a strictly defined type of structural element of the device should be used for installation. When replacing the drum, the bearings of the structural element should be changed simultaneously.

To carry out repair work, you should purchase a special repair kit, which includes a drive sprocket and a bearing. After purchasing the repair kit, you should prepare the materials and tools required for the repair. The main tools that will be required during the repair are the following:

universal wrench that comes with the chainsaw;
piston stopper, can be made of plastic or metal;
special puller of the centrifugal mechanism or clutch drum.

The work procedure consists of several stages. Each stage has its own characteristics, depending on the design features of the chainsaw, but the scheme and sequence of work is the same for any model of the unit.

How to assemble?

The assembly of the coupling mechanism should be carried out in the reverse order. First, install the sprocket on the needle bearing, then put on the drum, washer, gasket and the clutch itself. Tighten counterclockwise, lightly fix the piston.

If your chainsaw has an oil drive spring, it can be built into the drive sprocket. In most models, the correct position of this element is marked with a special color or notch. To get to the desired position, turn the sprocket until it clicks.

The last step in the assembly is to install the guide bar. During this process, it is required to release the handbrake and then check that the chain teeth fit into the corresponding grooves. After installation, mount the chainsaw chain until it is operational. Finally, remove the stopper, screw in the spark plug and replace the filter. The final step of the repair is to secure the protective cover of the case.

The device of a leading star on a chainsaw

Almost all models of modern chainsaws use a centrifugal clutch system. The specificity of this mechanism is that when the maximum number of revolutions of the gasoline engine is reached, the clutch drum starts automatically, transferring the rotation to the drive sprocket. This reduces stress on the base parts of the tool, extending life and maximizing productivity.

Figure 1. Diagram of the drive sprocket

The clutch drum, where the sprocket is located, can be located on the inside or outside of the chainsaw body. There is always a cover on top to protect the moving mechanisms from dirt, sawdust and dust. The clutch itself is a metal disc in the clutch drum. The entire mechanism is attached to the engine crankshaft by bolts with springs, along the edges of which there are friction linings. When the engine rpm exceeds a certain value, centrifugal force is generated, exerting strong pressure on the inside of the drum. After that, the sprocket starts up. the rotation of the chain saw begins.

Important! It is the sprocket that drives the chainsaw chain. All parts of this mechanism are closely interconnected, a breakdown of the headset leads to a malfunction of the instrument.

The main reasons for replacing the drive sprocket

The universal wrench is the main tool that will be required when replacing the sprocket.

The most common reasons that force the tool to be repaired associated with the replacement of the drive sprocket are:

jamming of the chain due to the occurrence of defects during the operation of the unit;
high wear of the sprocket as a result of long-term operation of the unit.

With regular use of the device, increased wear of the drive sprocket occurs as a result of the application of increased loads on it in the process of sawing wood. There are two ways to operate the device:

using one saw chain;
using several saw chains alternately.

When using the first method of operation, the chain is operated until it is completely worn out. This method has several disadvantages. The main one is the problem of monitoring wear during intensive operation of the unit.

When using two or more chains in the process, it is possible to achieve uniform wear of the chains and sprocket, which makes it possible to extend the period of operation of the device before carrying out repairs, which consists in replacing the sprocket. In addition to the wear of the sprocket, one should not forget about the bearing that is installed in the sprocket. This structural element works at any engine speed. When replacing a sprocket, change the bearing at the same time.

The clutch complete with the sprocket must be replaced in time. If the repair work is not carried out in a timely manner during operation, the tool experiences increased vibration, which leads to an increase in the wear of the bearings installed in the internal combustion engine on the crankshaft axles. The maximum depth of wear of the sprocket teeth should not exceed 0.5 mm. The sprocket has twice the lifespan of a single chain, so two chains should be used during operation. After the chains have reached the end of their life, replace the chains and the drive sprocket at the same time.

Algorithm for replacing the clutch drum

Regular technical inspection is necessary for the smooth use of the chainsaw.

To carry out repair work, a special repair kit should be purchased, which includes a drive sprocket and a bearing. After purchasing the repair kit, prepare the materials and tools required for the repair. The main tools that will be required during the repair are the following:

universal wrench that comes with the chainsaw;
piston stopper, can be made of plastic or metal;
special puller of the centrifugal mechanism or clutch drum.

Unit clutch design

Chainsaws are units that are equipped with drive sprockets, which are a single complex with a clutch basket.

The clutch engages automatically, depending on the number of engine revolutions.

A centrifugal clutch is installed on the units, which works in automatic mode, depending on the number of engine revolutions.

When the engine of the unit is idling or at low speeds, the elements of the clutch basket, which have friction linings, have a certain level of freedom in the radial direction. The presence of freedom of movement leads to the fact that under the action of the springs, the elements are attracted to the center of the rotation shaft and do not transfer the rotational motion to the sprocket drum. With an increase in the engine speed of the apparatus, the centrifugal force exceeds the force of the springs, which leads to the displacement of elements with friction linings. These elements are pressed against the inner walls of the drum under the action of centrifugal force. Due to this contact, the rotational movement is transmitted to the drum and the sprocket, which drives the saw chain of the tool. The chain saw sprocket can be located either outside the tool, or under a special cover that protects the mechanism from damage, and the operator of the device from injury.

The main advantage of this type of clutch is that when the saw chain jams, the elements with friction linings slip, which protects the internal combustion engine from serious damage.

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How to remove and replace an asterisk from a chainsaw?

Many owners of gasoline chainsaws after a device breakdown are concerned about how to remove a chainsaw sprocket.

When replacing the sprocket, all work must be carried out carefully and with care.

The sequence of repair work

At the first stage, the saw headset is dismantled, the guide bar cover is removed. After removing the cover, the guide bar and saw chain are dismantled. The fastening nuts are unscrewed using the universal wrench, which is included in the delivery set of the unit.

After removing the saw chain and guide bar, the air filter is removed. Then the spark plug is removed. In place of the dismantled spark plug, a pre-prepared engine piston stopper is installed. The stopper allows you to fix the position of the piston in the cylinder and prevent the crankshaft from turning. Remove the clutch using a special puller installed in the socket of the universal key. All actions should be carried out clockwise.

After removing the clutch, an approach to the internal parts of the device opens, that is, after removing the clutch, you can remove the sprocket.

After removing the clutch drum, depending on its type, the crown and sprocket are inspected and checked. Depending on the design of this unit, the worn out structural elements are replaced. When carrying out repairs, special attention should be paid to the springs of the centrifugal mechanism and its cams. If wear is found, replace them.

If the components do not cause any complaints, all structural elements are installed on the chainsaw in the reverse order. First of all, unscrew the piston stopper and pull out the starter cord, after which the piston stopper is installed in place. This complex sequence of operations makes it possible to clamp the centrifugal mechanism onto the crankshaft of the unit. The clutch is installed in place and clamped using the universal wrench supplied with the chainsaw. Clamping with a key should be done counterclockwise.

The last stage of the repair work is the installation of the remaining structural elements of the device.

When replacing the sprocket, all work must be carried out carefully and with care. All repair work must be carried out using special tools, otherwise the centrifugal mechanism or the saw chain may be damaged.

Sources:

http://vahatehnika.com/other/kak-snyat-zvezdochku-s-benzopily-mcculloch.html
http://masterinstrumenta.ru/pily/kak-snyat-zvezdochku-s-benzopily.html

Chainsaws chainsaw, impeller, remove