Do-it-yourself plunger pump repair

In detail: do-it-yourself plunger pump repair from a real master for the site my.housecope.com.

Almost all high pressure hydraulic systems are equipped with plunger pumps. High pressure plunger pumps have all the qualities that are considered when choosing pumps for such systems, such as: reliability, ease of product design and efficiency.

The high-pressure plunger pump serves as a mechanism or drive for other mechanisms in special machines. Hydraulic pumps are widespread and are responsible for the normal and coordinated operation of the vehicle. The plunger pump is used in a wide range of industries.

Plunger, translated from English, means to dive or dive, so these devices are used for hydraulic machines.

Plunger pump for bentonite P80

A plunger is a volumetric rock pump with a simple action, which is equipped with a working body made in the form of a plunger.

In turn, the plunger is a part of various types of pumps associated with hydraulics and multi-stage gas compressors.

In terms of execution, specifics of operation and structure, a plunger-type pump is similar to a piston unit. The presence of a special piston, in the form of a plunger, is the main distinguishing feature of plungers from pistons. Due to the creation of high pressure in the system plunger pumps are not used in everyday life.

High-pressure plants have found their main application in the chemical and oil refining industries. The use of such devices makes it possible to mix the components of solutions with high accuracy in the proportions necessary for the process, which is very convenient in production processes. The design features of these pumps are inherent in differences, and therefore plunger devices are divided into:

Video (click to play).

Due to certain specifics of work, the plunger pump unit is made wear-resistant, sealed, durable and ensures continuous and reliable operation of the plunger.

These units are high-performance devices with high efficiency, which is up to 90%. According to the properties of design features, plunger devices are classified into types:

vertical;
horizontal;
manual;
auto;
multi-plunger;
multi-cylinder;
with sealed cylinders.

Plunger pump HAWK 610003

Plunger pumps have a number of advantages over analogues, which are clearly distinguished:

the lubrication system is thoroughly developed and has good access for the consumer;
due to the design, it is possible to change the parameters and characteristics for the customer;
have a clear and simple control of the device, as well as easy to install;
it is possible to increase or decrease the working pressure in the hydraulic system by changing the number of piston groups.

In the chemical industry for the manufacture of chemicals that do not chemically react with metal.
In the chemical industry for well drilling and transportation and subsequent processing of petroleum products.
In the energy sector for the manufacture of electric drives for steam generators.
For hydraulically driven equipment in mechanical engineering.
In public utilities to perform repair work related to hydraulic communications.
In reverse osmosis machines for the food industry.
High pressure plunger pump for water is used for car washes.

The design of the plunger pump is simple and consists of valves and a piping system.The spring helps the plunger valve work by creating a systematic pressure. When working with high pressure, there is a possibility of skips. To avoid such nuances, the high-pressure plunger pump for water has a complete tightness of the units of the unit.

High-pressure plunger water pumps and devices in this category are reciprocating and powered by a camshaft.

During such a movement, the plunger (aka piston) is driven by a roller pusher. According to its structural arrangement, the plunger moves to the right side, which causes a decrease in the working pressure, which gradually becomes less than the liquid pressure in the suction pipe.

The internal structure of the plunger dosing pump

The suction valve opens due to the pressure difference, after which the working chamber is filled with liquid. At the next revolution of the shaft, the plunger moves to the left and the pressure in the chamber becomes greater than in the discharge pipeline. In this regard, the discharge valve opens and the liquid is squeezed out of the chamber into the pressure pipeline. This whole cycle is repeated constantly for the entire time of operation of the unit.

Some plunger pumps may differ in design from each other, but their principle of operation will remain unchanged.

For example, a diesel engine booster pump does not have discharge valves. This important role for pumping and pressure is created by nozzle valves.

In axial-radial pumps, these functions are performed by rotating blocks in the working chambers. Axial-radial installations are designed so that the pumping of liquid occurs when these blocks rotate. The absence of valves increases the cost of such installations, but this makes it possible to increase their reliability and use in aviation.
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Science and industry are developing and based on practice, scientific research, analysis of the design features of pumps, etc., small-sized unified three-plunger pumps were designed and introduced into production.

The triple plunger pump is the fourth generation pump of the NPG type. These devices differ from previous generations in the diameter of the main element (plunger), hydraulic box and the properties of the valve units of the system. Such systems for increased pressure usually have a basic package:

pressure sensors, alarms and pressure gauges;
safety valve;
shut-off or stop valves;
filter for water purification;
gear oil pump;
liquid cooling system;
safety valve.

If the place to be installed the plunger unit will be stationary, it would be advisable to choose a flat surface for it. This solution allows for scheduled inspection, emergency repairs and equipment maintenance. Surfaces must be rigid and prepared for high vibrations from the installation.

High pressure plunger pump

To ensure a continuous and normal supply to the pump for water, it is necessary to use high-quality flexible hoses, which avoids unnecessary stress on all key parts of the equipment. It is not recommended to connect pipelines with rigid properties to the outlet drain.

The drive shaft and crankshaft should be one after the other in a straight line, without making sure of this, it is forbidden to start the hydraulic system into operation. If this condition is not met, the transmission belt will not perform all its functionality and the entire mechanism may fail. The pump shaft must rotate freely, easily by hand. It is also necessary to choose the rotation of the electric drive of the pump correctly in order to avoid back pressure.
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Most often, they undertake to make a do-it-yourself high-pressure hand pump for car washes. For this, plunger pumps are used, for which the drive is used from an electric motor (electric pump). Engine power must meet the required parameters and the rated power must be at least 75% of the desired value. Often used in the form of a pump pump.

If the traffic at the car wash is not high, you can use an electric motor rated for 220V. For safe operation and to reduce discrepancies in the coincidence of the motor and pump shafts when they are connected, it is recommended to choose soft couplings. The liquid container is selected based on a sufficient volume of water.

It must be connected to a make-up water source and equipped with a filter element to prevent unwanted foreign objects from entering the pump system.

The filter element can be made of stainless mesh with a fine pitch. An important piece of equipment is a capacity regulator or check valve. It prevents the system from being overloaded and does not create back pressure back into the water supply.

Homemade high pressure pump

To install all this equipment, you will need a solid frame. For its convenient movement, wheels of the required diameter are installed, a strong stop for stability and a handle for easy fixing. For reliability and high performance, it is necessary to use reinforced rubber hoses, which are designed for high pressure.

The main element of such equipment is a gun with a nozzle. It is not advisable to make it with your own hands due to technical difficulties. This part is best purchased in the store. It must be remembered that all work carried out on high pressure pumps must be carried out using a clean liquid. Foreign bodies entering the system will cause damage to most of the equipment.

Hydraulic systems have found application in many areas of industry. Important in the performance of their functions are hydraulic pumps that ensure the efficient operation of the system. They come in different types and purposes, which explains the differences in the principles of operation of the mechanisms.

In addition to the main function, which is expressed in the supply of the necessary fluid under a certain pressure, the hydraulic pump can serve as a drive for other devices. One of the most common is the so-called plunger pump. It is a single-acting, efficiency-improving apparatus, the main part of which is designed in the form of a plunger.

The term "plunger" refers to a piston in a hydraulic system that reciprocates. Its appearance is distinguished by a cylindrical shape, characterized by a length that significantly exceeds the diameter.

Plungers are used in hydraulic machines, pumps and diesel engines. The seal, an integral part of the displacer, is located on the cylinder itself, as a result of which, when the latter moves, it moves along the surface of the plunger. This detail distinguishes the plunger from a conventional piston and explains the advantage of the former when working under high pressure conditions. The main indicator of the efficiency of the plunger is the volume of liquid displaced by it, it depends on the length of its stroke. The displacer operation is adjusted due to the last factor. Such mechanisms are usually used for pumping a large volume of liquid medium.
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In order to understand the principle of operation of this apparatus, first you need to explain what a plunger pump is. This is a unit, the use of which is due to the need to supply a certain liquid (mixture) under the influence of high pressure.The reciprocating movement of the plunger, directed to the right, causes a decrease in pressure in the displacer location chamber, which leads to the opening of the suction valve and further filling of the chamber with the required liquid.

The chamber in which the plunger is located is a closed space, which, if necessary, is connected to the pipeline using valves. There are only three types of them: suction, discharge and safety.

The next step in the operation of the plunger is to move it to the left, as a result of which the pressure in the special chamber increases, thereby opening the discharge valve through which water or other mixtures enter the pipeline. The principle of operation lies in the fact that in both the first and second cases there is a difference in pressure, due to which the system works clearly and without disturbance. During operation, energy is transferred to the fluid to overcome inertia, resistance and static height in the pipeline. The most popular three-plunger pumps. The increased interest in them is due to their merits and the almost complete absence of shortcomings.

Scheme of operation of a plunger pair

You can make a piston pump for pumping water in your own garden plot with your own hands. To do this, you will need two valves that will not allow liquid to flow out spontaneously, a pin, which is the main part of the mechanism, and a housing. The body can be made from a pipe. Pipe length not less than 60 cm, pipe diameter not less than 8 mm. Your own piston pump will not cost much, but in terms of technical characteristics it will be inferior to industrially produced models.
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Axial plunger pumps can be classified according to three main features:

manual;
mechanical, more efficient to use than a manual water pump.

single;
double, characterized by the presence of several working chambers;
differential, related to double-acting pumps and having two chambers. As a result, it pumps the liquid more evenly.

By type of pumped liquid:

High pressure plunger pumps have found their application in many areas. These include:

Axial plunger pump device

Building;
Metallurgy;
Oil industry;
Chemical industry;
Water purification;
food industry;
Water supply (water pump);
Energy;
Mechanical engineering (internal combustion engines);
Car wash.

It should be noted that, depending on the application, various configurations of the plunger pump are possible. For example, those models that are used in the oil industry do not provide injection valves. Their functions are performed by valves in the nozzles. This circumstance improves the reliability of the plunger.
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The high pressure axial plunger pump has many advantages. These include:

The rhythmic operation of the mechanism, which is provided by pressure and discharge valves on both sides of a special chamber;
Simplicity, as a result of which it is not difficult to make a high-pressure plunger pump with your own hands and install it;
Power;
long-term operation;
Modular design, thanks to which, if necessary, it is possible to order the manufacture of a plunger pump with individual characteristics, for example, for a car wash;
Compliance with international standards;
A wide range of pumping products, with different temperatures and consistency.
The compactness of axial plunger units saves the working surface;
The ability to adjust the speed of rotation, this keeps the situation under control;
Possibility of changing the working volume of the device;
High performance.

In addition to the advantages, the use of axial plunger structures also has disadvantages.They occur during intensive work and are expressed in the appearance of pulsations and vibrations. Their negative impact can be prevented by attaching additional devices to the high-pressure pump with your own hands. They can become working plungers. For example, a three-plunger pump does not allow vibrations.

Plunger pump HAWK 610003

Improper operation of the device threatens with frequent breakdowns, which will be difficult to fix. Therefore, if you do not have such experience, you should not install or repair plunger pumps yourself. Time will be wasted and quality may suffer.
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The service life of the device depends on the correct use of the device, therefore it is necessary to know all the nuances of the installation and use of axial plunger pumps.

Operation of the unit without lubrication is prohibited, as this reduces its performance.
The device assumes rotation only forward, otherwise observe the oil level prescribed by the instructions in this regard.
The installation of the unit must be carried out on a horizontal surface, without slope and unevenness.
In humid, hot climates, the pump must not be used without ventilation. Otherwise, it will fail prematurely.
It is necessary to prevent freezing or damage to the pump during the cold season. It is strictly forbidden to start the device with frozen water inside.

In any case, before starting work with a plunger pump, studying the instructions is mandatory and it is not recommended to neglect this rule.
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Piston pumps and axial plunger pumps are quite similar, but there are still slight differences in their design. First of all, this concerns the shape of the piston, and secondly, its location. The plunger does not touch the walls of the working cabin, which cannot be said about the piston in other models. Plunger units are quite possible to operate in the field, it became possible due to their size. Such high pressure water pumps are much more popular than others.Axial plunger pumps and electric pumps are used everywhere. They work effectively in any production and at home. Manufacturers are constantly improving quality by upgrading technology, innovating and producing economical models.The high pressure fuel pump is an essential part of every diesel engine. Because of this mechanism, the fuel becomes not just a liquid, but a fuel-air mixture. The operation of the pump is also affected by such a part as a plunger pair. She is responsible for the supply of fuel and its distribution.There are two main parts in the design of this element - a plunger and a bushing.The plunger consists of a small cylindrical piston. When the pump is running, the plunger moves inside the sleeve. Performing up and down movements, the plunger sucks in fuel, and then it is injected alternately into the nozzles of the working cylinders, where it ignites under high pressure in the atomized state. The plunger pair of the injection pump has several holes on the bushing through which diesel fuel enters for subsequent injection.In other words, the main purpose of the plunger pair is to accurately measure the fuel, in order to then supply it to the engine cylinders. Also, this element helps the pump supply fuel at the right time with the right pressure. In order for everything to be carried out without failures, it is necessary that the plunger pair meet all the requirements. Therefore, a plunger pair, the price of which is not so small, must be produced on high-tech equipment; it is unrealistic to make it at home.Plunger pair of injection pump - a complex element, it must be operated with caution and constantly comply with the necessary requirements. In order for the device to work smoothly and efficiently, only high quality fuel should be used.Since the quality of fuel at our gas stations leaves much to be desired, the restoration of plunger pairs is a very popular service.Low-quality fuel contains a large number of chemical elements, which significantly reduces the durability of the plunger pair. The most negative effect is produced by water, which enters the fuel as condensate. If there is a lot of water between the sleeve and the plunger, then the lubricating film violates its integrity and the part continues to work without lubrication. This can deform the part so much that restoring the plungers simply won't help. It remains only to buy a plunger pair in the store and try to refuel only with high-quality fuel.There are several signs that a part is defective. One of them is the failure of the motor to start, especially when the motor is warmed up. You can also find out if the injection pump plunger pair is working normally while the engine is running. You have to pay attention to the quality of his work. If the plunger pair is faulty, then the motor loses power, and it works with uncharacteristic sounds. In addition, the engine may run rough and unstable. If at least one symptom was noticed, then it is necessary to make a diagnosis.It should be noted that special equipment is used for diagnostics. Therefore, it is very difficult to say at home whether the plunger pair is faulty or not. In the service station, professionals can accurately tell about the malfunction and the method of solving this is adjustment or complete replacement. During the repair, special equipment is needed to restore the tightness of the bushing and plunger.Now we should tell you how to replace the plunger pair. First you need to go to the store, pick up and buy a plunger pair that will fit a single engine. It is necessary to disassemble everything that is removed around the fuel pump. This is necessary in order to remove the old plunger pair without problems and nothing interferes. Then you need to remove the front cover of the engine, unscrew the nut securing the drive gear, and then unscrew all the pipes and remove the fuel pump. All parts that are in the dirt, at the same time must be cleaned. Only after that, you can begin to disassemble the fuel pump, unscrew the plunger pair itself, but only do this with extreme caution and in a specially prepared place with a set of necessary tools.It is necessary to carefully drain the fuel from it, dismantle the old plunger pair, check the condition of the remaining parts, namely the cam washer, rollers, booster pump, etc. After that, it is necessary to twist the fittings with valves and the engine muffler from the old pair to a new one. Then you can assemble everything in the reverse order, after thoroughly washing the plunger pair with diesel fuel from conservation before installation.To adjust the amount of fuel that is injected, there is a special cut-off edge on the plunger. When the plunger moves upwards, it first closes the exit hole, and through this edge the hole opens slightly. The cutting of this edge is made in a spiral, so that when the plunger is turned, the time to cutoff changes. In order for the plunger to turn and make translational movements, it rests on the cam washer and engages with its pin. When the washer rotates, it also rotates the plunger, and the cams run into the rollers and push it. The plunger is adjusted using shims of various thicknesses. The most important thing is not to forget that a plunger pair, the price of which is quite large, is a very fragile and complex part, so you need to handle it very carefully.The operation of a diesel engine is four cycles, during which a combustible mixture of fuel and air is formed. Ignition does not occur due to a spark, but due to high pressure, so the compression ratio of diesel engines is always increased.Cummins Inc.is one of the world's leading manufacturers of diesel engines and generators. The engines of this company are very different: power varies from 30 to 3600 horsepower, and engine sizes from 1.5 to 90 liters.There is no more complex and responsible unit in a diesel engine than the fuel injection system, more precisely, its main part - the high pressure fuel pump. Many mating parts, highly loaded units, the presence of a precision dosing system make the repair of high-pressure fuel pumps a difficult task even in service conditions. It is all the more difficult to repair the high pressure fuel pump of a diesel engine with your own hands.In automotive technology, almost everything is repaired, except, perhaps, individual oil seals and cuffs, the repair of which is impossible without special materials. The complexity of setting up, diagnosing and repairing high-pressure fuel pumps requires the employee to have skills in working with precision mechanics.It is simply impossible to set up according to factory parameters, without a special diagnostic stand for repairing high-pressure fuel pumps. During the diagnostic study of the injection pump, it is necessary to check:

cyclic supply of the high-pressure pump, in the entire range of revolutions of the high-pressure fuel pump shaft, at start-up, and after cutting off the fuel supply;

stability of the developed pressure;

Uniform supply of injected high pressure fuel pump to the fuel injector.

Even having access to a diagnostic stand, and having studied the issue of repairing a high-pressure fuel pump using numerous videos, it is very difficult to qualitatively check and evaluate its work.In heavy diesel engines, plunger, in-line injection pumps are used. Such devices are more difficult to maintain and repair, since they require special equipment for disassembling it, so we will not consider such high-pressure fuel pumps and their repair.In a passenger diesel engine, a distribution-type injection pump is almost always used. Unlike in-line, in a distribution pump, the force on the plunger is transmitted using a profiled cam. The design of the injection pump turned out to be more compact, but it is hardly easier to expect to repair it on the knee.The Bosh VP44 injection pump is considered the most famous and affordable. Often, the need to repair the insides of the pump arises when:

poor traction and incomplete combustion of fuel even under ideal conditions - in the absence of load and a thoroughly warmed-up engine;

sudden failure and stop of the diesel engine under load, as they say, "death on takeoff." Usually the scanner in such cases diagnoses the code P1630 and P1651.

the appearance of a leakage of diesel fuel in the area of \u200b\u200bthe gland of the seal of the central shaft of the high-pressure fuel pump.

Therefore, we will limit ourselves to the issue of repairing high-pressure fuel pumps with our own hands by replacing seals and eliminating scuffing of the working surfaces of parts.Before disassembling the injection pump drive shaft seal, try to move it in the radial direction. If play is felt by hand, the cause of fuel leakage may be the wear of the working surface of the shaft or the bearing needs to be repaired.A large number of split planes and mating surfaces of parts required the use of a large number of seals and seals. As a rule, they are made of high-quality material and serve for a long time until they are damaged during repair or maintenance. In this case, do-it-yourself Bosch injection pump repairs use standard repair kits.It is enough to simply replace the seal on the shaft position sensor and on the injection advance control during repair. For a better fit on new rings and rubber bands, you can drop a couple of drops of spindle or engine oil. Image - Do-it-yourself plunger pump repair

For preventive repair of the Bosch injection pump with your own hands, you will need to disassemble the pump in approximately the following order:

remove the metering valve from the end part of the injection pump. To do this, unscrew the four screws of the pressure plate, carefully release the injection advance valve cable. After removing the three screws securing the metering valve, you can carefully remove it from the socket;

by unscrewing the mount on the top cover, you can remove the control board and gain access to the electronics;
set the position of the shaft, as shown in the photo, remove the camera and get access to the insides of the injection pump;

after dismantling the bearing with the help of a special puller, we get the opportunity to study the potential culprit for the poor performance of the injection pump - the piston of the injection advance unit. Often there is surface wear and tearing on the edges on the part. You can try to repair the surface by polishing, replacing the entire part is much more expensive.

After repair, the assembly is carried out in the reverse order with washing the parts with diesel fuel.

Often, in addition to scuffing, there is another reason on the surface of the pistons why the injection pump does not develop the necessary pressure. This cause may be debris, films or paraffin deposits deposited on the filter screen inside the pump. There is a mesh on the side of the inlet pipe. Flushing the channels is troublesome and inefficient, it is easier to remove the mesh and blow it with compressed air.

Broken pieces of debris can jam the plunger piston or even cause the pump drive shaft to break or break. Therefore, cleaning should be carried out very carefully to avoid contamination of the internal cavities of the pump.

Among the many reasons for the failure of the electronic "liver" of the high-pressure fuel pump, the breakage or burnout of the contacts of the control board and the failure of power transistors are more common than others. If the knowledge and skills of working with electronic devices allow you to “diagnose” the performance of transistors and repair, you should try to identify the cause and replace the culprit with a serviceable element.

To check the condition of the “culprit”, you need to carefully open the black cover, tightly seated on the rubber seal with screws. It should be removed carefully so as not to damage the seal itself.

The reason for the failure of not only the transistor, but the entire board could be air that got into the cavity due to poor performance of the drainage system or a check valve. Often they try to eliminate airing by spinning the starter, hoping to pump diesel fuel into the high-pressure fuel pump in this way. At this moment, the transistor is open and loaded to the maximum, which leads to intense heating. In an air environment with poor heat dissipation, it will inevitably burn out. In some German cars, there is protection that prevents an attempt to start the engine in the absence of fuel in the line. To do this, use the fuel sensor in the tank.

The failure of the transistor can be established by a "dialing" tester or by appearance. The best option for repairing such a malfunction would be to replace the entire control board. Perhaps this is more expensive than soldering, but it will give guaranteed quality and stable operation of the high-pressure fuel pump after repair. As a last resort, give the board and transistor for soldering to specialists - electronics engineers.

When installing and reassembling after repair, check the tightness of all fasteners.

If during the revision process you did not make rash and unreasonable replacements of parts, the assembled pump should work with approximately the same parameters as before. As a standard, for testing and adjusting the injection pump after a major overhaul, use the Bosch EPS-815 stand.

On the video you can learn how to increase the plunger pressure in the Bosch VE injection pump:

Any owner is pleased with a good technique, proven in practice and more than once justified itself. The latest technology always surprises and alarms with its characteristics, which are superior to those of very old technology, which is still in use by many.Some craftsmen always try to acquire equipment of well-known companies of a certain brand for their business and persuade their friends and acquaintances to do this, others are guided by the price and buy only expensive things for themselves, and the manufacturer does not interest them. Image - Do-it-yourself plunger pump repair

Where is the guarantee that any equipment we purchase fully complies with the quality certificate under which it is sold? Where is the durability promised by the manufacturer if we operate their equipment in our conditions, and moreover, “feed” it with our fuel and according to our recipes?

Nowadays, there is a lot of equipment that can be sold at different prices in different outlets. No one will say where and who assembled the very lawn mower or chainsaw that you purchased. A well-known brand, and assembly can be carried out in a nearby garage for components, perhaps even in a handicraft way.

The big problem that causes all sorts of breakdowns in most budget chainsaws is their poor-quality assembly, the mismatch of components, or even neglect of the entire assembly process by untrained assemblers.

Many chainsaw owners have noticed an oil stain where their chainsaw rested or was stored. Oil under the saw does not begin to leak immediately. And with poor assembly, more precisely, with poor assembly of the chainsaw, an oil stain may appear immediately after refueling.

Excluding mechanical damage to the oil reservoir and oil supply system, there are few reasons for oil leakage.

Not a tight connection of the oil supply line with the inlet channel of the chainsaw oil pump and poor tightness between the oil tank opening and the line.
Technical compliance with the dimensions of the plunger and the pressure chamber of the oil pump.
Loose connection of the supply line with the oil pump outlet to the saw chain lubrication point.
Violation of the tightness of the plunger chamber of the oil pump.

I will dwell on the latter option in more detail, since it is in the event of a loss of tightness of the plunger chamber that oil leaks, and in saw designs where the oil tank is located above the oil pump in level, oil flows out after a couple of days of idle chainsaws.

Eliminate oil leak from chainsaw oil pump you can and all this happens quickly if someone is good with a screwdriver and wrenches. If your chainsaw has passed a small working resource, then the problem is solved simply.

As I mentioned earlier, the guarantee of trouble-free operation of your chainsaw is ensured not only by observing optimal operating conditions for it and using the manufacturer's recommendations, it is also ensured by the appropriate quality of components, and most of all by the highest quality assembly.

Let the part be made on high-precision equipment, but when it is installed incorrectly or it is not fixed with the appropriate effort, the promised warranty from the manufacturer will disappoint you.

Like plunger type oil pump, installed on most models of budget-priced chainsaws, is simple in design. The principle of its operation does not differ from the operation of some plunger oil pumps of other categories of chainsaws.

I will briefly describe in my own words the principle of operation of a plunger-type oil pump of similar models, so that it would be a little clearer when familiarizing myself with my method of fixing oil leaks through a chainsaw oil pump.

The oil pump on chainsaws is valveless and is mounted on the chainsaw crankcase from the saw chain drive side. The role of the valve in these pumps is performed by a segment cutout at the end of the plunger. The plunger is driven from the clutch by a drive through a pair from the worm hub. It turns out that the pump plunger rotates in the same direction and at the same time it itself closes the inlet and outlet channels of the oil pipeline in a cycle, combining the function of the valves.

When the segment cutout at the end of the plunger opens the inlet of the oil supply line, the plunger extends slightly from the working chamber of the pump, thereby capturing oil from the line through the open hole.

As the plunger continues to rotate, the inlet channel of the oil chamber of the pump is blocked and the opening of the discharge channel opens. At the same time, the plunger moves inward and pushes the trapped oil into the oil supply channel to the lubrication point by the piston.

With one rotation around its axis, the plunger performs one reciprocating movement along its axis, the stroke of which is regulated by a screw with an eccentric installed transversely at the end of the plunger shaft. Some people like to call him a fist.

The eccentric rests against the central protrusion at the end of the plunger shaft, and the greater the angle of deviation of the adjusting screw, the further the eccentric located on it will push the plunger shaft away from itself. At the largest deviation of the eccentric, oil cannot be pumped by the pump. The saw chain is not lubricated.

In addition to the central protrusion at the end of the plunger shaft, there is an annular protrusion with a profiled surface that determines the amount of plunger travel along its axis. That is, the level of capture and injection of oil.

A metal spring is mounted on the plunger shaft, which, resting on one side against the oil pump housing, constantly presses the plunger shaft towards the adjusting screw.

The profile surface of the annular protrusion is in contact with the cylindrical body of the adjusting screw. In the place of their contact, a conjugation is formed, which, when the plunger shaft rotates, sets a value that limits the movement of the plunger along its axis and affects the process of capturing and pumping oil by the plunger.

The oil pump will operate at maximum efficiency, provided that the eccentric of the adjusting screw does not come into contact with the central protrusion on the end of the plunger shaft. As the adjusting screw rotates, the eccentric will approach the ledge and push the plunger shaft away from itself. In this case, the amount of oil supplied by the lubrication pump will depend on the position of the eccentric relative to the protrusion on the plunger shaft, and in this example, the amount of oil supplied by the pump is adjustable.

It often happens that oil is not supplied to the saw chain, even when the adjusting screw is set to maximum oil supply. There are not many reasons:

after dismantling the oil pump, the adjusting screw is set to a position of 180 about its original position.

It is enough to rearrange the adjusting screw or leave it as it is. Then the positions of the screw for maximum and minimum oil supply ( ) will change places.

The profile surface of the annular protrusion is worn out and no longer looks like a profile, but flat. The plunger does not move along its axis.

We change the oil pump or form a profile and grind the central protrusion at the end of the plunger shaft. In this case, the volume of the working chamber of the pump will slightly increase.

When adjusting the profile and the protrusion, it is necessary to maintain the same maximum height dimensions relative to each other, so that when the adjusting screw is in the minimum mode, the plunger pumps oil a little. The new pump has a central protrusion at the end of the plunger shaft above the level of the annular profile by about 0.3 ... 0.6 mm and in the position of the adjusting screw with a minimum oil supply, the oil pump does not work.

Wear on the inner surface of the pump plunger chamber and the outer surface of the plunger.

This usually manifests itself with a previous defect or with what I will describe next. We change the oil pump or sort out sets according to sizes from used ones.

Violation of the tightness of the working plunger chamber.

A little oil can be supplied to the lubrication point, but there is a lot of oil on the crankcase of the saw on the side of the chain drive.

The last example speaks of a plunger collar, which in many cases is installed in the opposite direction, with the collar facing out. Some masters claimed that this was a cuff that captures oil into the pump chamber. But how will this cuff behave when injected? Will oil pass through itself?

Some pick up rubber rings instead, but believe me, this is not easy and very caring for the inexperienced. This method is good, but the density of the sealing ring must be taken into account. If the ring sits tightly in place, then it will be necessary to replace the plunger spring, and there will be increased wear on the interface between the adjusting screw and the plunger shaft. The wear of the plastic hub of the worm pair of the pump drive will also be added.

The ease of movement of the plunger is maintained by the use of a cuff, which does not prevent the reverse movement at the moment the plunger captures oil and maintains sufficient tightness of the working chamber when oil is pumped.

At the first opportunity at the chainsaws that come to me, I always disassemble the oil pump in order to be completely sure of the condition of the plunger and its cuff. In the case when the cuff is installed with the collar out, then I reinstall it the other way around, with the collar towards the working plunger chamber of the oil pump.

Video (click to play).

This is my method, which always justifies itself, provided that no one interfered with the design of the oil pump and oil was supplied to the pump through the oil filter.

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