How to Adjust the Oil Flow on a Chainsaw
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Chainsaw chain not lubricated
During the long-term operation of the chainsaw, some of its elements and components may become unusable.
How to adjust the oil supply to the chain in a conventional chainsaw. Proper lubrication of the chainsaw chain
One of the most vulnerable components is the oil pump. In this regard, many owners of saws have a question about how to repair the oil supply on a chainsaw.
The task of the oil pump is to supply lubricant to the chain. This is necessary for its smooth movement along the guide rail. When the oil pump fails, the lubrication of the chain deteriorates, and therefore the efficiency of the chainsaw decreases. In some cases, this leads to an open circuit. To prevent negative moments, it is necessary to start repairing the oil supply in a timely manner. How to do it?
Principle of operation and pump arrangement
Oil pumps can be made of metal and plastic. They are also divided into two types, which differ in their design:
The pump is driven by the movement of the drive sprocket. During the movement of the chain, oil is supplied to a special channel located on the guide rail. At idle (when the drive sprocket does not rotate), the pump does not provide lubrication. This is done to save.
The speed and volume of lubricant supply to the chain directly depends on the number of revolutions of the sprocket. In some models of chainsaws, a manual adjustment system is provided with a special screw located on the device’s body. On expensive saw models, the oil supply is automatically adjusted during operation.
Main problems with oil supply
When working a chainsaw, there can be two types of problems with the supply of lubricant to the chain:
- Inadequate oil flow that can be caused for various reasons. If measures are not taken in time, the quality of work will noticeably deteriorate, and the chain itself may even become worthless.
- Excessive amount of oil. In this case, after prolonged use, pools of grease may accumulate under the saw. This not only affects the consumption of oil, which will have to be constantly added, but also negatively affects the environment.
Both of these problems must be fixed as soon as possible after they are discovered. This will extend the life of the saw and reduce the consumption of lubricating fluid.
If the oil is supplied to the chain in excessive quantities, not only during the operation of the saw, but also at idle, manual adjustment should be made (if the pump design provides such an opportunity). This is done with a screw, which is located on the housing near the guide rail, usually from the bottom or side. By tightening the screw, the oil supply is reduced, by loosening. Vice versa. If the adjustment does not help, it is necessary to check the serviceability of the pump, as well as inspect the tire. Perhaps at the place of its connection with the housing, a gap has formed through which oil flows past the chain.
A lack of oil can be caused by several reasons, each of which has its own solution:
- Faulty oil pump. As a rule, it consists in unsuitable laying. In order to replace it, it is necessary to carefully disassemble the pump so as not to damage its moving parts. Next, a new gasket is installed, after which the pump is assembled and installed in place.
- Damage to the oil pipe. In the event that the pump gasket is in good condition, or its replacement has not led to a result, the tightness of the hose should be checked. If it is faulty, you need to replace it. Otherwise, it will not be superfluous to clean it and fix it with sealant.
If the reason is not the failure of the pump, it is necessary to inspect all conductive holes and channels for clogging, and if necessary, clean them of foreign objects. This can be done with a jet of compressed air.
Do not want to bother with a chainsaw, but need to adjust the flow of oil? Contact our specialists for help diagnosing and repairing the chainsaw, and if necessary, carry out repairs and adjust the lubrication level. Your saw will be like new!
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Tires Chainsaws chains. Chain lubrication system, adjustment and sharpening.
Partner Chainsaw Chain Oil Adjustment
Most modern chainsaw oil pumps are designed the same way: in the body (photo 1 pos. 1) there is a cylinder (photo 1 pos. 2), into which a plunger (photo 1 pos. 3) is inserted, making rotational-translational movements in it.
Cylinder in the lower part it has two holes (only one of them is visible in photo 1 item 4): it is sucked in through one oil, and pushed out into the second.
Plunger (photo 2). This is a steel rod, on the one hand it has a milling groove. Flats, and on the second. A plastic or steel gear. When the plunger rotates, the flats alternately open and close the inlet and outlet openings of the cylinder. When translating upward, the flat first opens the inlet (while closing the outlet) and creates a slight decrease in pressure. Due to this, a portion of the oil is sucked into the cylinder. Then, turning, the plunger moves down, opening the outlet hole with the flat (while closing the inlet) and pushing the oil out of the cylinder. So it is fed to the bus in small portions. Due to the high frequency of cycles, a constant and continuous flow of lubricant is created.
Are used two types of oil pumps (photo 3): with an adjustable oil flow rate and an unregulated flow rate. In the first case, the gears of the plunger have an oblique tooth, and the translational upward movement is provided by an additionally installed spring. Oil flow control is carried out by changing the stroke length of the plunger in the cylinder. An example is an oil pump for Chinese saws with an engine displacement of 45-52 cc
In the case of an unregulated oil pump, the plunger has an oblique closed groove in which the fixed stop of the body abuts. The rotation causes the groove to slide along the stop, and since it is oblique, this movement causes the plunger to go forward backward. With such a scheme, it is impossible to limit the stroke of the plunger and oil is supplied in constant quantities. Example. Husqvarna 137, 142 chainsaw oil pump
The torque from the engine to the plunger is transmitted through a special drive unit, which also has a gear. The counterpart of the gear on the plunger. In fact, this is a worm pair. The oil pump drive is driven either by the drive chain sprocket (photo 4 pos. 1), or by the crankshaft itself (photo 4 pos. 2).
In the first case, the plunger is mechanically connected to the drive sprocket and rotates only with it. The photo 4 pos. 1 shows the Stihl MS-180 chainsaw drive. The steel antennae clings to a special recess on the cup of the drive sprocket. When the sprocket rotates, the drive rotates with it. In this case, there is no oil supply at idle.
In the second case, the drive is rigidly fixed on the shaft and constantly rotates with it. Photo 4 pos. 2 shows the drive of the Husqvarna chainsaw oil pump 137, 142. It is pressed onto the shank of the crankshaft and rotates with it constantly. Therefore, oil is constantly supplied, even if the saw is in idle mode.
Usually, one of the gears (either on the plunger or on the drive) is made plastic in order to secure the part with a more complex structure or complicated installation. The first part will break and wear out the plastic part.
On some saws, the oil pump with the drive may be additionally closed with a special cover (photo 5, the cover of the oil pump of the Chinese chainsaw 45-52 cc), which protects the worm joint and the pump itself from dirt and wood dust. On some saws, such as Husqvarna 137, 142, the oil pump housing itself closes the connection between the drive and the plunger, thereby acting as a protective cover.
For normal operation of the tire and chain, a certain amount of lubricant is required.
Adjustment of oil supply to the chainsaw chain
In order for the design of the lubrication system existing on a chainsaw to give out, the oil must have a suitable viscosity. Judging by the mechanics, the oil pump does not care what kind of oil you use: automobile, transmission or special. The main thing is that the viscosity lies in the established acceptable range. However, this does not mean that any oil can be poured. The task of chain oil is not to save you money on its purchase, but to lubricate the parts of the tire and chain. Different oils do this differently. But more about that in another article “Chain oil. What to pour? “.