This article describes in detail how to install a dispenser on MTZ tractors.
hydrostatic steering(GORU) Belarus MTZ-82.1, 80.1, 82.2 is designed to control the rotation of the guide wheels and reduce the force on the steering wheel when turning.
Fig.1. Hydrostatic steering and differential lock crane Belarus MTZ-820, 82.2
Fig.2. Hydrostatic steering and differential lock valve Belarus MTZ-82.1, 80.1
1 - oil line of the differential lock clutch; 2 - blocking valve; 3 – combined oil tank of HNS and HSC; 4 - dosing pump; 5 - drain filter; 6 - emergency oil pressure sensor; 7 – HPS power supply pump; 8 - suction hydraulic line; 9 - rotary lever; 10 - conical fingers; 11 – turning hydraulic cylinder; 12 - grease fittings; 13 - cylinder bracket; P - injection hydraulic line; T - drain hydraulic line; L - hydraulic line of the left turn; R - hydraulic line of the right turn.
The HSC of tractors Belarus MTZ-82-1, 80-1, 82-2 consists of a dosing pump 4, a steering hydraulic cylinder 11, a gear pump 7 powered by an engine, a combined oil tank 3 and hydraulic fittings (fittings, oil pipelines, sleeves high pressure, hoses and parts of their fastening).
The oil tank is the combined oil tank 3 of the hydraulic mounted system (HNS) and the HSC hydraulic system. The oil is filtered through a drain filter 5 installed in the hydraulic system of the hitch (nominal filtration fineness 25 microns).
In the drain hydraulic line "T" there is a blocking valve 2, designed to control the hydraulic clutch of the differential lock rear axle tractor.
The connection between the steering wheel and the steered wheels is carried out hydraulically by means of oil pipelines and high-pressure hoses connecting the dosing pump 4 mounted on the steering column and the differential hydraulic cylinder 11 mounted on the FDA housing or the front axle.
When the steering wheel is turned left or right in the metering pump 4, the centering leaf springs are compressed and the distribution grooves of the spool (the spool is connected to the steering wheel shaft through the splines) are displaced relative to the grooves of the sleeve, as a result of which the oil from the supply pump 7 flows under pressure through the metering gerotor the dosing pump assembly into the corresponding cavity "R" or "L" of the steering hydraulic cylinder 11 in a volume proportional to the amount of rotation of the steering wheel, and oil from another cavity of the hydraulic cylinder 11 enters through the channels in the spool and sleeve into the drain hydraulic line "T" and drains into the oil tank .
When the steering wheel stops turning, the sleeve, under the influence of the centering leaf springs of the metering pump, returns to a neutral position relative to the spool, the cylinder hydraulic lines “L” and “R” are locked, and oil from the pressure hydraulic line “P” flows through the channels in the spool and sleeve to the drain " T", which ensures pressure relief in the discharge hydraulic line "P" and unloading of the power pump 7.
The locked volume of oil in the cavities of the hydraulic cylinder 11 ensures the stability of the direction of movement of the tractor Belarus MTZ-82.1, 80.1 when the steered wheels hit the uneven road or soil. At normal conditions operation, when the power pump 7 provides the oil pressure necessary to turn the guide wheels, the maximum force applied by the operator to turn the steering wheel does not exceed 30 N.
If the oil flow from the power pump is too small or absent (for example, in case of malfunctions of the diesel engine, the power pump, if the pressure oil line is destroyed or there is no oil in the oil tank), then when the steering wheel is rotated, the metering pump 4 performs the function hand pump, pumping oil from one cavity of the hydraulic cylinder 11 to another, which ensures the rotation of the guide wheels.
The force on the steering wheel applied by the operator to create the necessary oil pressure in the hydraulic cylinder 11 during manual control increases significantly, in some cases up to 600 N.
Technical characteristics of the mount Belarus MTZ-82-1, 80-1
Effort on the steering wheel, N, not more than - 30
Steering wheel backlash, hail, not more than - 25
The speed of "sliding" of the steering wheel in the extreme positions when a force of 100 N is applied to the steering wheel is 3 rpm
Power Pump:
Type - gear
Direction of rotation - left
Working volume, cm3/rev - 10
Dosing pump:
Type - gerotor, with open center, without reaction working volume, cm3/rev - 100/160
Safety valve setting pressure, MPa - 14+1
Anti-shock valve setting pressure, MPa - 20+2
Swing mechanism: hydraulic cylinder and steering trapezoid
Piston diameter, mm - 50
- rod diameter, mm - 25
- stroke, mm - 200
The hydraulic circuit diagram of the HSC of tractors Belarus MTZ-82.1, 80.1 is shown in the figure.
Fig.3. Scheme of a hydraulic HSC with a differential lock valve
1 – combined oil tank of HNS and HSC; 2 – HPS supply pump; 3 - dosing pump; 4 – steering hydraulic cylinder; 5 - emergency oil pressure sensor in the HSC; 6 - differential lock clutch; 7 - crane for blocking the rear axle differential (with foot control); 8 – HPS hydraulic system; 9 – HPS pump; 10 - drain filter; P - injection hydraulic line; T - drain hydraulic line; L - hydraulic line of the left turn; R - hydraulic line of the right turn.
Steering metering pump
Dosing pump Belarus MTZ-82-1, 80-1 - gerotor type with an "open center" and no reaction on the steering wheel anti-vacuum valve 8 and check valve 9.
The gerotor pumping unit I consists of a stator 1 fixed on the housing 10 and a rotating rotor 2 connected to the spool 3 through cardan shaft 4. Distributor II consists of a sleeve 5, a set of leaf springs 11 and a spool 3 connected by splines to the shank of the steering drive shaft
columns.
Non-return valve - ensures the operation of the dosing pump in manual control mode as a hand pump when the power pump is not running.
Safety valve 6 protects the pump and HSC hydraulic system from overload, limiting the maximum pressure in the discharge line in the range from 14 to 15 MPa.
Anti-shock valves 7 (right and left) protect the sleeves of the cylinder hydraulic lines from peak pressures that arise in the cavities of the hydraulic cylinder at the moment the steered wheels hit obstacles. The setting pressure of anti-shock valves is from 20 to 21 MPa.
Anti-vacuum valves 8 (right and left) protect the HPS hydraulic system from vacuum and cavitation when anti-shock valves actuate.
Fig.4. Dosing pump Belarus MTZ-82.1, 80.1
1 - stator; 2 - rotor; 3 - spool; 4 - cardan shaft; 5 - sleeve; 6 - safety valve; 7 - shockproof valves; 8 - anti-vacuum valves; 9 - check valve; 10 - body; 11 - leaf springs; I - pumping unit; II - distributor.
Steering cylinder
The differential steering hydraulic cylinder Belarus MTZ-82.1, 80.1 is installed in front of the front axle or the FVM-822 body or behind the FVM-72 body and with the help of the steering trapezoid ensures the rotation of the tractor guide wheels.
The rod of the hydraulic cylinder through the conical pin 10 is connected to the rotary lever 9 of the left wheel gear, and the body of the hydraulic cylinder is connected to the bracket 13 mounted on the FDA body.
The hydraulic cylinder consists of a body, a rod 6, a piston 17, a front cover 11, a union nut 12. The piston is attached to the rod with a nut 2, which is locked by punching the belt into the grooves of the rod 6.
The cover 11 has a wiper 13, stem seals 14 and 15 and guide rings 16, which prevent friction between the stem and the cover. A combined seal 3 is installed on the piston, which eliminates friction between the piston and the housing sleeve.
Spherical spherical bearings 1 are installed in the lugs of the body and the rod, having channels on the inner ring for lubricating the friction surfaces. The hinges are closed from contamination by bushings 19 and protective rubber covers 18.
The hinges are lubricated through the grease fittings in the conical pins 10.
Fig.5. Steering hydraulic cylinder Belarus MTZ-82-1, 80-1
1 - articulated spherical bearing; 2 - piston nut; 3 - piston seal; 4, 7, 10 - sealing rings; 5 - body; 6 - stock; 8 - protective ring; 9 - locking screw; 11 - front cover; 12 - union nut; 13 – wiper; 14, 15 - stem seals; 16 - guide rings; 17 - piston; 18 - protective cover (for cylinder Ts63); 19 - bushing (for cylinder Ts63); 20 - retaining ring.
Signaling emergency state HSC hydraulic systems
In the drain hydraulic line "T" at the outlet of the metering pump 4, a sensor 6 of the emergency oil pressure in the hydraulic steering system Belarus MTZ-82.1, 80.1 is installed.
When the oil pressure in the drain hydraulic line drops below 0.08 MPa (due to lack of oil flow due to insufficient oil level in the oil tank, failure of the feed pump or breakage of hoses), the sensor is triggered and the warning lamp for emergency pressure reduction lights up on the control lamp unit oil in the HSC hydraulic system (red).
Hydrostatic steering with power steering housing
Hydrostatic steering (HSU) with a dosing pump on the body of the power steering Belarus MTZ-82-1, 80-1 is designed to control the rotation of the guide wheels and reduce the force on the steering wheel when turning.
Fig.6. Hydrostatic steering with a dosing pump on the power steering housing
1 - check valves; 2 - hydraulic booster housing; 3 - dosing pump; 4 - differential lock sensor; 5 – HPS supply pump; 6 - suction hydraulic line; 7 - bipod; 8 - rotary lever; 9 – turning hydraulic cylinder; 10 - cylinder bracket; P - injection hydraulic line; T - hydraulic line
drain; L - hydraulic line of the left turn; R - hydraulic line of the right turn.
HSC Belarus MTZ-82-1, 80-1 with a metering pump on the power steering housing consists of a metering pump 3, a steering hydraulic cylinder 9, a gear pump 5 powered by an engine, a hydraulic booster housing 2 and hydraulic fittings (fittings, valves, oil pipelines , high-pressure hoses, hoses and parts of their fastening).
The hydraulic booster housing 2 is the oil reservoir. The oil is filtered through a drain filter installed in the hydraulic booster housing (nominal filtration fineness 80 microns).
On the body of the hydraulic booster, a lock sensor 4 is installed, designed to control the hydraulic clutch for locking the differential of the rear axle of the tractor.
The connection between the steering wheel and the steered wheels is carried out hydraulically by means of oil pipelines and high-pressure hoses connecting the metering pump 3 mounted on the hydraulic booster housing and the differential hydraulic cylinder 9 mounted on the front axle housing.
When the steering wheel is turned left or right in the metering pump 3, the centering leaf springs are compressed and the distribution grooves of the spool (the spool is connected to the steering wheel shaft through the splines) rotate relative to the grooves of the sleeve, as a result of which the oil from the supply pump 5 flows under pressure through the metering gerotor the metering pump unit 3 into the corresponding cavity "R" or "L" of the steering hydraulic cylinder 9 in a volume proportional to the amount of rotation of the steering wheel, and the oil from the other cavity of the hydraulic cylinder 9 enters through the channels in the spool and sleeve into the drain hydraulic line "T" and drains into hydraulic booster housing.
When the steering wheel stops turning, the sleeve, under the influence of the centering leaf springs of the metering pump 3, returns to a neutral position relative to the spool, the cylinder hydraulic lines “L” and “R” are locked, and the oil from the pressure hydraulic line “P” flows through the channels in the spool and sleeve to the drain "T", which provides pressure relief in the discharge hydraulic line "P" and unloading of the power pump 5.
The locked volume of oil in the cavities of the hydraulic cylinder 9 ensures the stability of the direction of movement of the tractor Belarus MTZ-82.1, 80.1 when the steered wheels hit the uneven road or soil.
If the oil flow from the supply pump 5 is too small or absent (for example, when the engine is stopped, if the engine, the supply pump malfunctions, if the pressure oil line is destroyed or there is no oil in the hydraulic booster housing), then when the steering wheel is rotated, the metering pump 3 performs the function of a manual pump, pumping oil from one cavity of the hydraulic cylinder 9 to another, which ensures the rotation of the guide wheels.
Check valves 1 are installed in the drain hydraulic line to prevent air from entering the metering pump during manual control (when the engine is stopped, in case of malfunctions of the engine, power pump, in case of destruction of the pressure oil line or lack of oil in the hydraulic booster housing).
The force on the steering wheel applied by the operator to create the necessary oil pressure in the hydraulic cylinder 9 with manual control increases significantly.
The device and principle of operation of the metering pump and the steering hydraulic cylinder of tractors with a mounted HSC with a power steering housing are similar to tractors with a mounted HSC.
Adjustment of the axial stroke of the rotary shaft:
To adjust the axial stroke of the rotary shaft 4, loosen the lock nut 26, screw the adjusting bolt 24 until it stops against the end of the shaft, then unscrew it by 1/8 - 1/10 of a turn and lock it with the lock nut 26.
The steering kit is designed to install a dosing pump on MTZ-82 with a front drive axle.
The installation kit for the dispenser on the MTZ-82 with a leading front axle includes:
1. MTZ bracket for installation of hydraulic cylinder TsS-50 102-2301023-01
2. Bracket of the dispenser pump to the MOUNTAIN MTZ
3. Tie rod MTZ with HSC for hydraulic cylinder 1220-3003010
4. Lever steering MTZ left with MOUNTAIN 72-2308075-01
5. Steering lever MTZ right with MOUNTAIN 72-2308074
6. Steering hydraulic cylinder MTZ TsS 50-3405215 (equipped with pins and fittings for connecting high pressure hoses.)
7. Pump dispenser ND-160 (Danfoss Orsta Lifum) MTZ for connecting the steering shaft and fittings for connecting.
2. Tie rod MTZ reinforced with HSC (1220-3003010)
3. Steering lever MTZ left with HSC (70-3001040-01)
4. Steering lever MTZ right with HSC (70-300104)
5. Steering hydraulic cylinder MTZ Ts 50-3405215A (equipped with pins and fittings for connecting high pressure hoses.)
6. Dosing pump with a volume of 160 with a roller for connecting the steering shaft and fittings for connecting.
7. High pressure hoses S24 * 1.5m (HPR) with a fitting at L-90 degrees (4 pcs.)
The MTZ dosing pump is an integral part of the hydrostatic complex that controls the tractor. It contributes to the correct distribution of fluid and its supply to the hydraulic cylinders, which, in turn, greatly simplifies the control of the tractor.
This allows the operator to apply much less effort to turn the wheel, which is very important when the tractor is heavily loaded.
1 The device and principle of operation of the MTZ pump
The MTZ dispenser pump is produced at the tractor plant in Minsk. The manufacturer has simplified the device as much as possible to ensure good wear resistance of the mechanisms and ease of maintenance. The unit includes 3 main components:
There are several parts in the oscillating pump assembly: a fixed stator and a rotor, to which the spool of the device fits. The spool is attached with 2 springs and connected to the steering column shaft. Moving, the steering column drives the spool and, moving relative to the central axis, supplies oil to the inside of the pump.
The special valve block of the body contains anti-vacuum, safety, check and shock valves. check valves required in case of hydraulic motor failure. Then the valve closes the drain channel of the hydraulic amplification system, preventing the movement of fluid. Safety valves regulate the pressure in the oil pipeline system.
Anti-vacuum valves assist in the movement of oil into the hydraulic cylinders in the event of a system failure. Anti-shock valves regulate the pressure in the lines at a very high load when driving on uneven sections of the route.
It is necessary to install the dosing pump on equipment moving at a speed not exceeding 50 km/h, and located in the volumetric hydraulic drive of the machine.
Acting on the control system, the dosing pump supplies the working fluid to the hydraulic cylinder and enhances the operator's actions. In the absence of influence on the control system, the position of the pump becomes neutral, and it passes the liquid directly to the drain system.
2 How to properly install the dosing pump?
When installing a metering pump on MTZ 80 and MTZ 82, a partial replacement of the power steering system (hydraulic steering control) with a HSC (hydraulic volumetric steering) is performed.
The GRU set includes:
If necessary, they also buy a crane that blocks the differential of the HSC mechanism. It is used to replace the lock used on power steering. This crane provides the ability to lock the steering wheel on unstable road sections, which improves trafficability.
2.1 Installation algorithm
- First of all, remove the power steering box (distributor). To do this, remove the control levers, then remove the anther plates, seals and anthers. Then you need to remove the covers and pull out the spools.
- On the next step change bearings if the existing ones are worn out.
- Remove the worm of the unit.
- In place of the worm, a dispenser shaft is installed.
- The dosing device is screwed to the required bar. Hidden bolts are used for installation.
- Then the pump is checked and after that the dosing pump is installed on the MTZ in the hydraulic amplification system.
The rest of the HSC kit is changed before the unit is installed.
2.2 INSTALLATION OF THE DISPENSER PUMP ON MTZ OWN HANDS (VIDEO)
3 Pump malfunctions
Any malfunction of the dispenser on the MTZ 82 or the steering volumetric control system can cause complications in the functioning of the control system. To restore the system to working capacity, a clear understanding of what exactly has become unusable is necessary. This can be judged by such signs.
The power steering (GUR) MTZ-80, MTZ-82 is combined with the steering mechanism. Their purpose is to transmit and increase the force from the steering wheel, the drive to the bipod and the steering linkage swing arms, and thereby reduce the force on the steering wheel. The power steering enhances the control system, while the tractor driver needs to make much less effort in order to turn the wheels. Such a moment has special meaning if the tractor is heavily loaded and the power steering copes with this task, unless, of course, it is in working order. Over time, equipment components wear out, especially if the tractor has changed several owners. It happens that it is impossible to repair your own power steering, in these cases we install a dispenser. The dispenser is a hydro-volumetric steering system, it performs the same functions as the power steering. You can see the installation of the dispenser in my video. I showed an example of installation on a tractor with a front rolling beam, where the factory does not provide for the installation of a hydraulic cylinder, there is not even a casting (the casting is the surface where the hydraulic cylinder is twisted). In this case, we will notfactory cylinder bracket. We will need to make it ourselves, as well as drill and cut into M16 threads on the beam. More detailed information can be obtained from the link “Step-by-step instructions for manufacturing an MTZ cylinder mounting plate”. Here is a description with dimensions and photos that will help you quickly make a hydraulic cylinder mounting plate.
If the power steering is working, but the steering wheel is hard to rotate. I recommend reading my article
Homemade hydraulic cylinder mounting plate when installing the dispenser on the MTZ-80-82 tractor.
List of required parts.
1. We manufacture the MTZ bracket for the installation of a hydraulic cylinder
on one's own.
2. Bracket of the dispenser pump to the MOUNTAIN MTZ
3. Tie rod MTZ with HSC for hydraulic cylinder 1220-3003010
4. Lever steering MTZ left with MOUNTAIN 72-2308075-01
5. Steering lever MTZ right with MOUNTAIN 72-2308074
6. Steering hydraulic cylinder MTZ TsS 50-3405215 (equipped with pins and fittings for connecting high pressure hoses.)
7. Pump dispenser MTZ for connecting the steering shaft
8. High pressure hydraulic hoses with elbows under L-90 degrees . mustache. (4 pcs.) MTZ fittings - 4 pcs.
9. Hydraulic tank
Restoration of the trunnion, description of the front beam of the MTZ tractor, about this in my article
Dosing pump connection diagram.
Description of the installation of the dispenser (GRU) of the MTZ tractor.
A metering pump is located on the steering column bracket, which is connected to the oil pump using a hydraulic hose. The swivel cylinder is mounted on the front beam to homemade stove. It is connected by a dispenser with two hydraulic hoses, left and right turn. At the other end, the cylinder is fixed with a taper threaded pin with a lever, which subsequently gives turning movements through other levers to the tractor wheels. Output - unloading from the dispenser with a hydraulic hose connected to an oil tank.
Principle of operation.
When the engine is running, oil is transferred to the metering pump thanks to the oil pump NSh. In the process of rectilinear movement of the tractor, both cavities of the rotary hydraulic cylinders are blocked by spool bands, due to which the oil pumped by the feed pump NSh and directed to the dispenser is not distributed to them, but is redirected to the oil tank. By turning the steering wheel to one side, the displacement of the spool leads to the fact that the oil enters the metering pump, which, in an amount proportional to the angle of rotation of the steering wheel, transfers it to the corresponding rotary cylinder. This contributes to the involvement of the left or right rotary mechanism and turn the guide wheels in the desired direction.
The design of the dosing pump
The design of the dosing pump is quite simple, which provides it with high fault tolerance and long service life. operational period. Its structure includes:
housing with a block of valves (return, anti-shock, anti-vacuum, safety);
swing knot;
distributor.
The oscillating axial piston unit has in its design a stator attached to the housing, as well as a rotating rotor, which is connected to the spool. The spool itself is in contact with the steering shaft, due to the rotation of which it can be displaced in an axial position, allowing oil to enter the metering pump. The neutral position of the spool is provided by two fixing springs.
Thanks to the operation of the check valve, the drain hydraulic accumulator line is closed when the power unit. System safety valves provides a constraint maximum pressure in oil injection lines. It should not go beyond 14 MPa.
The presence of anti-shock valves will limit the pressure in the oil lines of the GRU cylinders when shock load. These valves are designed to control pressure at the level of 20 MPa. Anti-vacuum valves guarantee the possibility of supplying oil to the hydraulic cylinders of the system in case of an emergency, as well as when one of the anti-shock valves is triggered.
Characteristic signs of malfunctions of the dispenser (GRU) MTZ.
The occurrence of malfunctions in the hydraulic system of the steering wheel of the MTZ "Belarus" can be directly observed in the process of controlling the equipment. The main features include the following factors.
Difficult steering (more physical effort is required to turn the steering wheel)
This type of problem occurs when oil leaks from the system or is insufficient. Also, such a picture will be observed when the pump pumps air and the feed pump is poorly driven from the tractor motor.
Guide wheel instability
This malfunction is mainly due to excessive axial movement of the rotary shaft or the appearance of play in the steering rods.
Missing stop when turning the steering wheel
Such a picture can be observed both with an insufficient oil level, which does not allow the metering pump to perform its functions effectively, or with excessive wear of the seals of the rotary hydraulic cylinders.
Spontaneous rotation of the steering wheel
This failure is associated with the failure of the dosing pump spool to return to the neutral position and, as a result, permanent job one of the swivel cylinders.
Inconsistency of the right / left turn of the steering wheel with the corresponding turn of the wheels
This can be observed after replacing or repairing the metering pump, during which the pump outputs were incorrectly connected to the inputs of the rotary cylinders when the second one was not working.
The MTZ dosing pump is an integral part of the hydrostatic control system of the tractor. He is responsible for the correct distribution of fluid in the system and for its supply to the hydraulic cylinders. This strengthens the control system.
At the same time, the operator needs much less effort to turn the wheels. This moment is of particular importance if the tractor is heavily loaded.
1 The device and principle of operation of the dosing pump at MTZ
The MTZ dosing pump is manufactured at the Minsk Tractor Plant. The manufacturer has simplified the device as much as possible in order to ensure high wear resistance of the mechanisms and ease of maintenance. The device consists of three main components:
- housing equipped with a valve block;
- special swinging unit of the device;
- distribution mechanism.
The swing assembly of the device consists of several parts. It is represented by a fixed stator and a rotor, to which the spool of the device comes out. The spool, in turn, is fixed by two springs and is connected to the steering column shaft. When the steering column moves, the spool also sets in motion and, moving relative to the central axis, supplies oil to the inside of the device.
A special valve block inside the body includes anti-vacuum, safety, non-return and anti-shock valves. System check valves are required in case of hydraulic motor failure. In this case, the valve closes the drain channel of the hydraulic booster system, preventing fluid circulation. The pressure relief valves regulate the pressure within the oil piping system.
Anti-vacuum valves are responsible for transporting oil to the inside of the hydraulic cylinders in case of an emergency in the system. Anti-shock regulate the pressure inside the highways under excessive load in case of work in uneven sections of the road.
A dosing pump is installed on equipment whose speed does not exceed 50 km / h. It is located in the volumetric hydraulic drive of the machine.
During the impact on the control system, the metering pump supplies the working fluid to the hydraulic cylinders, thereby enhancing the actions of the operator. If there is no influence on the control system, the pump is in neutral mode and passes the liquid directly to the drain system.
2 How to properly install the dispenser on the MTZ 82?
Installing a metering pump on MTZ 80 and MTZ 82 involves a partial replacement of the power steering system (hydraulic steering) with the HSC mechanism (hydrostatic steering). The HORU kit includes:
- special hydraulic cylinder bracket;
- reinforced tie rod;
- two levers;
- hydraulic cylinders on the front axle with a set of fingers;
- dosing pump;
- high pressure channels;
- special adapter for the pump.
If necessary, a differential blocking valve for the HSC mechanism is also purchased. It is used to replace the lock that is used on the power steering. Such a crane allows you to block the gearbox on unstable sections of the road, which increases the maneuverability of the equipment.
The dosing device is installed on the machine according to the following algorithm:
- First of all, you need to remove the power steering system box (also called the distributor). To do this, the control levers are removed. After that, the anther plates, anthers and seals are removed. Then the covers are removed and the spools are pulled out.
- The next stage is the replacement of the bearings of the system with new ones in case of wear of the already installed ones.
- The worm of the device is removed.
- The metering shaft is installed in place of the worm.
- We fasten the dosing device to the corresponding plate. Installation is made by means of countersunk bolts.
- This is followed by checking the pump and after that its installation in the hydraulic booster system.
Replacement of the rest of the HSC kit is carried out before the installation of the pump.
2.1 Do-it-yourself installation of the dosing pump on the MTZ (video)
2.2 Malfunctions of the MTZ dispenser pump and their symptoms
Any malfunction of the metering device or the volumetric steering system leads to complications in the operation of the control system. To restore the functionality of the system, you should clearly know which node failed. There are a number of signs for this:
- The front axle has become more unstable. This symptom in most cases indicates a displacement of the axis of the rotary shaft. It is also possible to form gaps in the steering rod or in the pump assemblies.
- Turning the steering wheel has become more difficult and requires additional effort. The reason is not enough oil inside the dispenser. The second option is a large number of air inside the hydraulic system and as a result - partially idle operation of the device.
- Arbitrary change in the position of the steering wheel. Self-rotation of the steering wheel is a consequence of the incorrect position of the spool inside the pump. Two tensile springs are responsible for its neutral position. In the event of a failure of one of them, oil is constantly supplied to one of the cylinders, and the steering wheel turns accordingly.
- Weak emphasis in the process of turning or its complete absence. This phenomenon occurs if there is not enough oil in the dispenser. Accordingly, its functionality decreases. The second cause of the problem may be abrasion of the seals on the cylinders responsible for turning the machine.
- When the steering wheel is turned, the tractor wheels turn in the opposite direction. In this case, the problem is that the leads to the machine's hydraulic cylinders are not properly connected to the metering pump. As a result, the spool supplies oil to the wrong cylinder, and, accordingly, the wrong side is strengthened.
Also one of the problems in the work pumping equipment the hydraulic booster circuit is its pollution. When the device valves become clogged with dirt and other particles, they are unable to pass fluid through the system and regulate pressure. As a result, the functionality of the system is reduced and it may break down.
2.3 Device maintenance
Since the pump is not completely protected from dirt entering the system, it can become clogged. As a result, it must be washed periodically to prevent serious damage.
This event is held after complete disassembly devices. Wash the pump with kerosene or similar liquid. Before starting washing, it is necessary to remove the sealing rubber rings from all parts. This will prevent damage to them. Each piece is washed individually and very carefully. Special attention should be given to two bushings of the device. They are equipped with a series of small holes that quickly clog.
After all the parts are washed, the device is assembled in the reverse order. Here important point is an correct installation gerotor pair and distributor leaf spring. The first part should be installed by turning the pump with the holes away from you. The pair is installed in such a way that two teeth are located on a line along the front from the master.