ZL-30G Payloader

This machine is a single bucket wheel joint loader of the fronal type.It is applied in site areas, in ports, cargo terminals. warehouses and other places. It loads granular earth, sand, coal, garbage and other granular materials using basket.Besides, it can be used for towing, surfacing, raking, stall and other operations. The machine is a universal and high efficient construction equipment.
Special features of the loader :
1) Jointing frame. Small turning radius, flexibility and versatility, operation in hard conditions.
2) Hydromechanical transmission, full application of power and torque moment allows to develop high towing force.Besides, the loader automatically switches transmissionsin conformity with changing of road conditions.This prolongs the service life of engine and transmission.
3)Automatic hydromechanical gear box, hydraulic control of operating parts. Easy and convenient control, all operations are performed stable and reliable.
4) OTR of low pressure. Joint frame affords to accomodate to road conditions, thus improving the passability, so the loader can operate on uneven ground.
1. Specifications
(1) General size (mm)
 

(2) Characteristics

 (3) Engine

(4) Gear box
1.Hydro-transformer

Type	YJ315X
Form	Unicameral, with three details
Circulatory circus diameter	315 mm
Gear ratio change	К=3,2
Cooling method	Oil circulation under pressure
Oil feed pressure	560 кРа

2.Gear box)
 

(3) Frontal and rear driving axle
 

(4)Axles and wheels
 

(5) Braking system

(6) Steering gear
 

(7)Equipment control operation hydraulic system
 

Most important accessories, operation principles.

ichai YG6105G-640H, engine is applied, its detailed specifications can be found in accompanying documents .

1) Fluid converter
Fluid converter consists of 3 most important parts including pump. turbine, stator.
These parts are integrated into the whole system, where the liquid circulates.The oil is continuously fed from the gear box to the fluid converter by the pump. This allows to secure fluid converter's operation, and gear of the torque moment from the engine. Besides, during the operation the oil flow retracts the heat from the fluid converter..
The oil is fed to the turbine by oil pump and the oil flow changes its direction. Then the turbine passes the relevant torque moment to the fluid converter outlet shaft,from which the power is taken.The torque moment in the fluid converter is created by pump wheel, turbine wheel and the stator. The oil flow, rotating the turbine has sufficient residual energy. The stator directs the flow back to the impeller of the pump wheel thus making it to rotate faster and increasing the torque moment.As the stator is connected with the fluid converter by overruning clutch that can rotate in the single direction only, then owing to the special shape of the stator's and tubrine's blades the oil blow is directed to the back side of the stator's blades.Owing to this the stator is clogged and remains static, passing the maximal amount of the oil residual energy, retained after its rotation of the turbine to the inlet of the pump.When the stator is in static state, the torque moment, geared by fluid converter reaches maximum.The fluid converter can operate in this mode when taking off.As the speed increases the slipping motion of the turbine relatively to the pump decreases, and the moment comes when the oil flow takes the stator's wheel and begins to rotate it in the direction of free motion of the overrunning clutch. The fluid converter stops to increase the torque moment and comes to ordinary hydraulic coupling regime.
The turbine has lesser speed as compared to the pump.THis ratio of the turbine's rotatin speed and the pump speed drops as the speed increases.When turbine rotations are 80% of the pump rotation, the turbine and pump rotation ratio is closer to one. Fluid converter operates as fluid coupling.
2) Dynamic gear switchbox .
Dynamic gear switchbox with parallel shaft has fixed spindles.It is equipped with multidisk hydraulic friction clutches.The gear changes without break of power.Friction packages are compressed by piston and oil effect and open by effect of return spring when the pressure drops. When the friction clutches are compressed, the torque moment changes.The rotation passes by pinions, freely rotating on the shafts.Pinions of constant mesh box. All the pinions, bearings and frictions of the box are greased by preliminary cooled oil.
The box has theree packages of friction clutches. When the gears change, the relevant package of friction clutches is blocked by fluid converter. When the pressure in cylinders drops, the friction clutches' disks open.
3) Memo for operation of automatic gearbox .
When the loader is not in operating condition, the oil from fluid converter, radiator and pipes can flow to the case . Therefore, prior to work it is necessary to make the idle run of the motor and heat the oil in the box.Oil level is controlled by oil probe, it should be between its upper and lower scales.
Attention: If you stop te engine, the oil level in the box can raise.Oil level raising height can vary, it depends on the place of mounting of automatic gear box. When is oil removes from automatic gearbox, the oil from fluid converter and gear box can be removed only partially.When changing the oil the oil filter should be replaced or cleaned.
When cleaning the filter of the main oil pipe it is necessary to avoid ingress of dirt or dirty oil to oil pipelines. Besides it is necessary to cap the handle brake gear to avoid ingress of th oil inside. While replacing the filter it is necessary to be careful not to damage its body..
While specifying the oil level it is necessary to keep to the safety rules. Stop the loader, turn the parking brake on, put antirecoiling device under wheels, put the level of the gearbox in neutral position.
 

Fig 4. Gearbox
1. Body
2. Big end cover
3. Reverse shaft in assembly
4. Input shaft flange
5. Input shaft in assembly
6.Middle shaft in assembly
7.Output flange shaft.
8. Slip bushing for freeing rear axle
9. Low and high gear toothed bushing.
10.Oil case
11. Frontal outlet flange
12. band brake
It is necessary to put the gearbox lever in (N) position, only after that the engine may be started. To provide safety it is recommended to use the handle brake before the start of the machine. During coasting it is strictly forbidden to switch the automatic gearbox lever to neutral position.When stopping the loader turn the parking brake on. Before leaving the vehicle unattended, put antirecoiling device under the wheels to avoid unforesen situations.In case of long parkings switch automatic gearbox lever to neutral position.If the vehicle is stopped, but the engine still drives the gearbox, then the engine can switch off automatically. Besides, it is possible that the machine will move slowly on the level surface. This happens because the fluid converter still exerts sufficent torque moment of the wheels whereas gearbox lever is in neutral position.This is why it's necessary to use the brake.The gears should be switched in turns and not to miss them when the vehicle is moving.In the case of braking the engine rotations can make a sudden raise from low to the high, this possibility is especially high if miss the gears.Then the engine rotation speed drastically changes, it is very dangerous for the engine. It is permissible to switch from low gear only at the highest possible rotations of the engine. In the case of necessity, if it is required to stop the engine, it may be switched upward on low rotations.If the speed is comparativery high and it is necessary to switch on rear gear, slow down the loader first. Reverse movement speed cannot exceed 10 km/hr.If the situations allows it is necessary to use frist and second gears only.When towing the loader the towing speed should not exceed 10km/hr, the distance of tugging should not exceed 10 km, otherwise the gear box can fail.When it is required to transport the loader for longer distance, cargo platforms are used.Rated operation pressure of fluid converter is 80 -110C.Short-time temperature of 115 C is permissible.If the fluid converter's temperature exceeded 120 C, it is necessary to stop the machine.Let it operate idle with 1200-1500 rpm/min. Check and make sure there are no oil leakage.Under such conditions liquid converter's temprerature drops abruptly (it takes 2-3 min). If it doesn't happen, then some breakage took place, so it is necessary to troubleshoot and recommence operation. In the case of gear box failure it is necessary to stop the machine and call master. 4)Driving axles.The loader's frontal axle is fixed, the rear axle swings on the frame. To improve towing performance and operation four wheel drive is used. Driving axle consist of beam and main gear (reducer including), half axles, wheel reducer's gears and other details.Axle beams are fixed to the frame. They take load from the frame and transfer it to the wheels.Besides, the beams are bearing casings for the main gear (reducer including), half axles, wheel reducer's gears and other details. The main gear is a single reduction gear unit with slant toothed conical pinions.The main function of the main gear is to step up torque moment, reduce rotation speed, transferred by thee gear box and rotate wheels forward and backward. The differential consists of two conical pinions, fixed on half axles, crossbar and four accessory pinions, left and right casing of the differential. The differential transfers different rotations to left and right wheels and distributes the torque moment by half axles. Right and left half axles transfers torque moment from main gear via differential to wheel reducer.Wheel reducers are of planetary type .Pinions with inner teeth are fixed on the drive shaft.Inner toothed pinion are in coupling engagement with inner pinions, their brackets are fixed to the wheels.The torque moment is transferred to the wheels via half axles and wheel reducers. Wheel reducers serve to step up the torque moment and slow down rotation.This provides required operation speed. Wheels are the most important part of the travel carriage of the loader.The loader use wide cross section low pressure tires of 17.5-25. They have large cross section, flexibility and resilience, and low specific ground pressure, thus proving good cargo capacity and passability .
 

The brake system is used for fast stop of the loader. The brake system can work and stop the loader both on level surface and on the slopes. The loader is equipped with two brake systems:
1)Operating brake system, usable in routine situations to stop or slow down the motion. There are dry disk hydraulic air-boostered brakes for four wheelsThey provide streadiness of braking and actuation of brake gears. The brake are safe, reliable, simple in design, easy serviceable and repairable and have other advantages.Clearances between disks and pads are set, no adjusting is required. The brakes scatter excessive heat, they have long service life and operate noiselessly.
2) Emergency brake system: It is applied to hold the braked loader both on the level surface and on the slopes, besides, it is employed for emergency brake and stop the loader in the case of failure of operating brake system.In the case of insufficient pressure in pneumatic system (below 0.45 Mpa) this system actuates automatically.The loader can be stopped automatically, this makes it safer and more reliable.
3) Main parts
(1) Multifunction relief valve.Multifunction relief valve separates water from the oil and is a compound complex valve of air pressure controller. The valve performs as follows: it adjusts automatically operating air pressure in the system and retains its rated value. This valve makes the brake system operate safely, separate water, oil and admixture from the compressed air and makes automatic discharge by using unloading function.It is possible to inflate tires by revolving ear nut. Multifunction relief valve consists of body, upper and lower caps.Inside the valve there are separated cavity for separating water and oil, filterin element 15, check valve 13, safety valve 12 and also air pressure adjustment details, drain valve details etc. See the valve on the picture below :
 

Picture 5. Multifunctional unloading valve
1.Pipe connecting branch
2. Thredded hole for bush
3. Membrane
4. Upper cap
5.Upper control valve
6. Inner spring
7. Adjusting spring
8. Adjusting spring saddle
9. Adjusting screw
10. Control piston
11. Flow control valve
12. Safety valve in assembly
13.Check valve
14. Washer
15.Filtering element
16. Plug
17. Lower control valve
18. Filtering fed pad
19. Thread head of the filter
20.Oil settling vessel
21. Water discharge drain valve
22. Lower casing
23.Air discharge piston
24.Sealing gasket
25.Connecting pipe
26. Ear nut
Air pressure adjusting valve of multifunction unloading valve consists of control piston 10, upper control valve 5, lower control valve 17, adjusting spring 7, adjusting screw 9, and membrane 3. The cavity below the membrane is connected to the system's air actuatorП using flow control valve 11. The hole of the lower control valve 17 connects to the cavity «D» of air abd liquid discharge drain valve. The air and liquid drain valve mainly consists of air discharge piston 23, water discharge valve21, lower casing22, valve saddle, valve disk, valve spring. Connecting holes of upper part of multifunction unloading valve are inlet hole of air compressor, I, hole of compressed air cylinder "O", air and liquid drain hole А.
(2) Brake hole
The brake valve operates as follows: It is necessary to press the brake pedal 7, the pedal presses on the rod and the rod presses of levelling spring 10, the spring actuates piston 11, valve 13 opens, the air from press air cylinder will start to go in.The air will go through the valve and outlet hole on front and rear wheels actuator and on the booster pump.When the brake valve is released, the pressure on the piston will be minimal, the piston will raise by action of the spring and the air pressure, the valve will shut, air feeding from the cylinder will stop and the air from the booster pump will bleed outside, simultaneously, the braking will stop.
 

Picture 6. Brake valve
1.Spring saddle
2. Spring
3. Bracket
4. Nut
5. Screw
6. Bolt
7. Brake pedal
8. Rod
9. Duster
10. Adjusting spring
11. Piston
12.Valve's body
13. Valve in assembly
14. Air discharge valve in assembly
 

ZL30G hydraulic system consists of operating hydraulic system and steering hydraulic system.
1. Operating hydraulic system
(1) System's operation principle:
Operating hydraulic system is used to change the bucket's and lift arms positions. Main parts of the system:operating pump, multifunction switch valve, double action safety valve, hydrocylinder of the bucket's turn by its longitudinal axis, hydrocylinders of the bucket's lift arms, oil pipes ets. Hydraulic system's operation principle is shown on picture 7:
 

When switching valves of the bucket's lifting arms and bucket's turn of the distributing valves are in middle position, the oil, delivered by operating pump passes the distributing valves block and goes back directly to the oil tank. Upper and lower cavities of hydrauluic cyclinders of bucket's and bucket turn's lift arms are blocked, the bucket and lift arms are in initial position. The switching valve of the lift arms can raise and lower the bucket, and place it in free swaying position. The switching valve of the bucket turn can tilt the bucket forward and backward aroung its longitudinal axle. There are double action safety valves in frontal and rear chambers of hydraulic cylinder of the bucket turn. They rule out lack of coordinatuin in the cylinder rod operation.
(2) Main details and their description:
1) Gear pump
ZL30G employes CBG toothed gear pump. This is a pump with oil-pumping chambers located along the outer side of tooched wheels, beyond the band of contact.(See. pictures 4-5).
There are similar drive tooth wheel 11 and driven wheel 16 mounted in the pump. Besides. the pump consists of frontal cover 4, sealing ring 5, bearings 6, tongue and groove shaft 7, side plates 9, pump body 10, sealing washer 12, rear cover 14 etc.There's some axial clearance between pinions and side plates. The pump is fastened completely with bolts 15.
On the picture the pump shaft rotate leftwise, so further we'll describe the operation principle for left rotation.
Electric engine and other sources of rotation actuate the the driving pinion of the oil pump 11 via splined shaft/ The driving pinion rotates counterclockwise, the driven pinion rotate clockwise.It leads to depression in the pump's cavitiesm the oil is suctioned via inlet «Р», pushed forward by rotating pinions and pushed via "O" outlet. After that pressurized oil go to the oil pipe.
 

Picture 8
1. Spindle
2. Sealing washer
3. gland
4. Upper cover
5.Sealing ring
6.Bearing
7.Stud
8. Ring gasket
9. Side plate
10.Pump body
11.Drive pinion
12. Sealing washer
13. Sealing gasket
14.Rear cover
15. Bolt
16.Driven pinion
2)Multifunction control valve(Distributing valve)
Multifunction control valve consists of three main parts:control valve of the bucket turn , control valve of lift armsof the bucket, safety valve. The valve changes the direction of the oil flow for its feeding to hydraulic cylinder of the bucket's turn and the hydraulic cylinders of the bucket's lift arms. Therefore the bucket's position may change in accordance with specific situation.The picture of multifunction control valve is given below. (Picture. 9):
 

Picture 10 Multichannel control valve
1. Check valve
2. Spring
3.Sleeve valve of the bucket's turn
4. Connecting branch
5. Valve body
6.Stopper (pressure gauge connection)
7.Safety valve
8. End cover
9. Spring cap
10.Piston to return the bucket to initial position
11. Spring
12. End cap
13.Steel ball
14. Piston to return bucket lift arms to initial position
15. Sleeve valve of the bucket lift arms
16.Inner holding barrel
А)Operation principle of multichannel switching valve:
Among multichannel switching valves, the bucket's multichannel switching valve is a triple station six way valve. It serves to perform three operations, namely it tilts the bucket forward and backward and holds the bucket.Multifunction switching valve of the bucket's lift arms is a 4-station six way valve. / It performs 4 operations: lifting and dropping of the bucket, fixing of the basket, free swaying. The safety valve holds pressure in the system on the required level,when the pressure exceeds the rated value, the valve opens and discharge the oil to the oil tank. This safeguards the valve details of damaging by high pressure.The valve has inlet hole "P" and outlet hole "O". «А1» and «В1» hole are for of bucket hydraulic cylinder big and small chambers, respectively, «А2» and «В2» are for big and small chambers, respectively, of hydraulic cylinderes of bucket lift arms. Right and left side of the oil channel are symmetrical in respect to each other, medium position to corresponds the pressure unloading funcion.Thus the valve has 3-channel construction. The switching valve changes direction of the oil flow and hydraulic force, the force is released, the resistance of return oil line declines.Each valve of multichannel switching valve has a check valve, mounted near the valve rod. The check valve prevents the oil flow back to the oil tank. This rules out the "pecks"during the loader operation.Besides, supporting pressure of the return line, resulting from the above, also stabilizes the operation of the system.
(1) Medium vertical position: Bucket turn sleeve valve and bucket lift arms sleeve valve are in medium positionm the oil fed by the pump turns back to the oil tank from outlet P via the holes P1 and O.
(2) Raising of the bucket's lift arms: Sleeve valve of the bucket lift arms shifts right and overlaps "O" cavity. The oil from cavity«Р1» goes to the hole «а», opens the check valve and goes to the lower chamber via hole A2. The lifting arms go upward. The oil from the upper chamber goes back to the oil tank via holes "B2", "B" and "O" cavity.
(3) Lowering of the bucket lift arms: The Sleeve valve of the bucket lift arms shifts left (see the diagram) and overlaps«О» cavity. The oil from«Р1» cavity goes to «в» hole, and then goes to hydraulic cylinder upper chamber via the hole "B2".Lift arms go down.The oil goes from the hydraulic cylinder lower chamber via the hole «А2», opens the check valve and goes back to the oil tank.
(4) Free swaying of the bucket Bucket lift arms valve shifts left (see the diagram). During this time A2 and B2 holes are in contact with b, o and P1 cavities. Upper and lower cavities of hydraulic cylinder contact one another. Oil pressure stays low. The bucket goes to arbitrary position and adjusts itself to uneveness and other outer impacts, occuring during the operations..
(5) Forward turn of the bucket: Bucket turn sleeve valve shift right and overlap P1 and O cavities. The oil goes from cavity P to hole C, opens the check valve and goes to rear chamber of the hydraulic cylinder via A hole. The bucket turns forward axially.The oil from the front chamber of hydraulic cylinder passes B1 hole, goes to D holem opens the check valve and goes back to the oil tank.
(6) Back turn of the bucket:bcuket turn sleeve valve shifts left and overlaps P1 and O cavities. The olf from P cavity goes to d hole, opens the check valve and goes to the upper chamber of the hydraulic cylinder via B1 hole. The bucket turns back axially. The oil from rear chamber of hydraulic cylinder passes A1 hole, goes to hole C, opens the check valve and goes bacj to the oil tank.When the pressure to the bucket turn sleeve valve stops, the latter, actuated by the return spring, goes to the initial direction.This corresponds to the medium position(holding).
B) Design features of multichannel switching valve:
Two multichannel switching valves are in successive connection. The outlet hole of the sleeve valve of the bucket lift arms is connected with oil channels of the bucket turn sleeve valve. Back oil flow holes of the oil tank of two sleeve valves are directly connected to general oil return line.Owing to oil lines connection the shift of control arm by bucket turn switching valve results in locking the line of switching valve of the bucket lift arms. If both control arms of switching valves are shifted simultaneously, the hydraulic cylinder of the bucket will be always in operation. If operation of all hydraulic cylinders of the bucket lift arms is required, it is necessary to put the control arm of switching valve of the bucket turn in medium position.Therefore return line of the switching valve of the bucket turn is considered to have a priority. It provides the priority in oil feeding to bcuket turn switching valve. This way of the valve connection makes it possible for the loader operator to control using a single arm.In the same way one can easily adjust to various operation conditions.(When driving the loader, when control arm of the switching valve of the bucket lift arms is shifted to lifting position, it is possible to turn the bucket. If the conrtol arm of the switching valve of the bucket turn is in medium position, the lift arms of the bucket will raise.If the conrtol arm of the switching valve of the bucket turn is shifted to the opposite side, then instead of raising the bucket arms the bucket will turn to the opposite side. In this way the control can be performed in various operation conditions, and the operations can be more efficient.
3) Hydraulic cylinders
(1) Hydraulic cylinders of lift arms:Hydraulic cylinders used for this frontal loader are one stage double action cylinders.Each cylinder has one double action rod and one barrel,
Main details of hydraulic cylinders of lift arms are as follows: cylinder barrel, cylinder rod, piston, stopping ring, covers, guide bushes, glands etc. The cylinder's piston has rings, they reduce friction and prevent wear of inner surface of the cylinders.In the place of connection of piston and rod, a joint ring is used, the clearance between piston and cylinder's barrel is leaktight.The glands and collars preventing dust in the cylinder are mounted in the front part of the cylinder.They prevent ingress of any dirt inside.
When control arm is put to lifting position, the oil goes to the big cavity of the cylinder, the piston is actuated, the rod is pushed outside. The oil goes from the small cavity of cylinder back to the oil tank. Using control arms, the lift arms can be put to down mode and free sway mode.
(2)Hydraulic cylinder of the bucket
Hydraulic cylinder of the bucket is also of single phase and double action.Its design is similar to that of hydraulic cylinders of lift arms.When control arm is put to bucket back tilting position, the oil goes to big cavity of the cylinder, the piston actuates, the rod is pushed outside and turns the bucket using the bucket arm. The cavity, that performs the back tilting of the bucket is the biigest one, therefore its uses the max force, used in digging. Frontal tilting of the bucket is performed similarly.
(3)Checking and adjustment
In routine checking at the operation ground it is necessary to check hydraulic system by putting up and down he bucket lift arms, and check the bucket turn. It is also necessary to check operation of the distributing valve, double action safety valves by pressure release, to check the sagging of the loaded bucket, etc.
1) Time checking
Put the bucket with rate load to the lowest position, diesel engine and hydraulics operate with normal operation temperature, press the accelerator's pedal, drive the engine to the rated rotations mode, check the operation of the distributing valve using control arms.The time of elevation of the bucket from the lowest to the highest position should not exceed 7 seconds.
Diesel engine on idle run. Put the distributing valve arm to down position. It should have 4 seconds to put the empty bucket to the lowest position.
At the highest position of the bucket the time of its turn from one exteme postion to another should not exceed 2 seconds.
2)Checking of pressure
(1) Checking of max working pressure in the system
Unscrew the screw plug of the distributing valve over the inlet oil pipe.Connect the pressure gauge with 25 Mpa calibration, put the bucket lift arms in horizontal position.Diesel engine and hydraulics operate at the rate working temperature, the engine is on rated rotations.Actuate the sleeve valve of bucket turn of the distributing valve, move the bucket backward, check the pressure gauge indications. The pressure should equal 16 Мра.If the pressure is not 16 Mpa it is necessary to adjust the safty valve of the distributing valve.
(2)Checking and adjustment of pressure of double action safety valve a. Checking and adjustment of pressure of double action safety valve of big cavity of hydraulic cylinder of the bucket
Unscrew the screw plug of the distributing valve over the inlet oil pipe.Connect the pressure gauge with 25 Mpa calibration, put the bucket lift arms to the highest position horizontal position. Diesel engine and hydraulics operate at the rate working temperature, the engine is on idle running.Actuate the sleeve valve of bucket turn of the distributing valve, move the bucket forward,then return the bucket to meduim position. After that using sleeve valve of bucket left arm put the arms to the lowest position. The pressure gauge should be equal 17.5 Mps if it is not, it is necessary to adjust the valve..
b. Checking and adjustment of pressure of double action safety valve of bucking hydraulic cylinder small cavity
Unscrew the screw plug of the distributing valve over the inlet oil pipe.Connect the pressure gauge with 16 Mpa calibration, put the bucket lift arms in horizontal position.Diesel engine and hydraulics operate at the rate working temperature, the engine is on rated rotations.Actuate the sleeve valve of bucket turn of the distributing valve, move the bucket backward, check the pressure gauge indications. The pressure should equal 8 Мра. If it is not 8 mPA, it is necessary to adjust the valve.
2.Hydraulic system of steering control
Hydraulic system of steering control serves to control the loader.It secures in-line motion and change of direction .
(1) Operation principle:
ZL30G frontal loader uses hydraulic system of changing the direction of movement.Its main components are as follows: oil pump of steering control, single flow stabilization and flow distribution valve, , hydrocylinders of articulated joint of the frame, oil filter, oil tank etc.See the diagram on picture 8 .
The oil going from steering control oil pump passes single-flow stabilization and flow distribution valve and some of it enters the steerin gear.When the steering wheel doesn't rotate. the oil goes back to the oil tank via internal cavity of the throttle valve.
When the steering valve rotates, the oil from the oil pump passes the steering control servo valve and goes to the batcher of the steering gear (rotor and stator of the gear drive). The oil pushes the rotor in conformity with rotation angle it its measured quantity goes to left or right cavity of the hydraulic cylinder.The hydraulic cylinder actuates the articulated joint of the frame, the oil drops from the idle cavity of hydraulic cylinder to the oil tank.
There is one more steering control complex valve (block of valves) mounted on the body of steering control valve.It is connected to the oil pump and steering control pump. It secures routine operation at rate pressure in all steering control system and in steering gear. At the same time, it perform safety functions as to rotary hydraulic cylinders, connecting oil lines and steering control pump.
Picture 11
 

(2) The most important details:
1) BZZ1-400fully hydraulic cycloidal steering gear (see pic. 12):
Fully hydraulic cycloidal steering gear mainly consists of servovalve of steering device and details of cycloidal gearing: The servovalve consists of body, valve barrel, throttle valve and return spring.It controls oil flows in steering control system. pair of cycloidal gearing of the valve constist of rotor, stator, coupling shaft and the lock. In the process of dynamic control it plays the part of the batcher of the oil quality.It secures accurate batching of oil, entering the cylinders and accurate ratio of oil qauntity as to steering wheel rotation angle.When the pump doesn't feed oil, it plays the part of a hand operated pump .
During the rotation of the steering wheel, the throttle valve 12 actuates and starts rotation. The compression force causes effect to return spring 9.Rotor 13 and valve barrel 11 are out of action for a moment. When the rotation angle exceeds 15o, the dispenser, connected with steering hydrocylinders opens. The oil will start rotating the rotor and go to hydrocylinder that changes the direction of the movement. The oil from the opposite part of the cylinder will come back and return to the oil tank via the upper hole of the servovalve.Oil amount, coming to hydralic cylinder of the loader turn depends on rotation angle of the steering wheel. This determines the rotation angle and position two parts of the frame. Simultaneosly, during the rotation of the rotor, the coupling shaft 14 connected to rotor will start its motion. As coupling shaft 14 and barrel lock of valve 10 are coupled, the barrel with start synchronous rotation as well, so, when the rotor's rotation angle will be in compliance with steering wheel rotation angle, the valve barrel will come back to medium position. The channel that feeds oil to hydraulic cylinders is locked so the oil flow will stop.
When the steering wheel doesn't rotate, valve barrel 11, sliding piston 12 are held in medium position by the return spring. The oil goes from the sliding piston and small hole of the end part of the valve barrel to the inner cavity of the sliding pistion and then goes back to the oil tank via return line. When the engine stops, the oil pump stops, and the steering wheel imparts the rotor by steering shaft, valve barrel and gearing shaft. In this case rotor and stator operate as hand operated pump.The oil from one cavity of hydraulic cylinder goes to the oil tank, absorbed by the check valve and returns to the opposite cavity of the rotation hydraulic cylinder. The loader turns at oil hydrostatic pressure .
 

Picture 12. Design of fully hydraulic gear of steering device.
1.Coupling head
2. Retaining ring
3. Frontal cover
4.Valve body
5. Steel ball
6. Separating plate
7. Stator
8. Rear cover
9. Return spring
10. Lock
11. Barrel valve
12. Throttle valve
13. Rotor
14.Gearing shaft
15. Arrester
16. Bolt
2) Operation principle of the valve block
Main details of the valve block: Safety valve(overflow valve), double
action overload valve (damp valve), inflow valve. The check valve is located near the oil inlet of the valve block . The oil, going from the oil pump of the steering wheel, passes the check valve andd goes to inlet hole of the steering device.The oil can flow in via hole A or "B" of the steering gear to hydraulic cylinders of the frame articulated joint as required.The oil pushes the cylinder rod, the loader rotates.
Safety valve consists of the sliding piston, pressure control spring, adjusting screw, etc. It is mounted on the valve block and is connected with oil inlet hole and oil discharge hole. When the oil pressure in the steering gear exceeds the rated value, the safery valve opens, discharges the oil excess and reduces the pressure. It protects the whole system of overloading and saves hydraulic cylinders of steering wheel and oil lines from damage. WHen the oil pressure reduces to the rated value, the safety valve closes. This affords to keep the rated pressure and to save power of the oil pump .
WHen during the turn the rotation hydraulic cylinder suddenly runs across a considerable outside resistance, and as result there can be a sudden short-time pressure increment in one of the cavities of hydraulic cylinder, and this pressure can surpass the limit of opening of double action overload valve. The overload valve opensm there will be discharge of oil and decrease of pressure. In this way the oil lines are kept safe from damage caused by increased pressure. At the same time when depression occurs in the opposite chamber of hydraulic cylinder, the feed valve activates and feed the oil to the chamber where the depression occured.This afford to avoid any sharp changes of pressure, noise, erosion and other troubles.
If diesel engine suddenly stops, then oil pump of the steering control stops as well. Then the check valve will be locked, the oil in the system will operate by closed cycle, the pressure will retain. The rotation will be performed by hand with the engine stopped.
3)One way stabilization valve
One way stabilization valve provides the stablity of the required amount of oil in the steering gear in the case of change of amount of oil, fed by the oil pump and change of load on the hydraulic system. There will be stable amount of oil in the hydraulic system, required for control. There can be valves as follow; separated flow valve, constant flow valve, external control valve etc. This loader uses permanent control valve.You can see at pic.13
 

Oil pump feeds the oil to "P" cavity. Partially, oil leaves "A" cavity via d variable passability hole, 'a" hole and fed for using in hydraulic system of the steering device. ANother part of oil is fed via "b" variable passablity hole.If flow separation device is used, this part of oil is used in the hydraulic system of steering control organs. In permanent oil flow device the oil, fed via 'b" hole goes back to the oil tank via "B" cavity. IN the case of excessive pressure in hydraulic system of the steering device, the safety valve opens, and the oil returns from the calibrated oil line to the oil tank via "B" cavity .
If the oil amount. fed to the hole of "P" cavity is below the stable weight level, then all the oil will go via variable passabilty hole and "a"hole and enter the steering control system from A cavity. 'b" variable passability hole will close. When oil amount exceeds the stable weight level, "b" hole will open, the excessive oil enter to "B" cavity hole, the pressure difference will not change, therefore oil flow going via "a" variable passability hole to A cavity remains unchanged.
In the case of pressure increase in A cavity and its hole durin the operation of the steering control system, there will be depression in "B" cavity. The throttle valve shifts to diminish b" variable passability hole. 'b' hole will be diminished, the throttle valve will retain the pressure difference on the level it was at initial size of variable passability hole.Therefore the oil flow through A cavity hole will remain unchanged.
4) Oil pump of steering control and hydraulic cylinderes of steering control
STeering control oil pup feeds oil to steering control system. It is a gear type oil pump.Its design and operation principle is similar to the pump of operation hydraulic system(see above).
Hydraulic cylinders of the steering control are actuators of the steering control system. A single-stage double actiob hydraulic cylinders are applied.Their design and operation principles are similar to lift arm hydraulic cylinders (see above). 3) maintenece and service of the system
1.Make sure the oil used in the hydraulic system is pure. In filtration rate B= 75 and more, the purity of oil-absorbinh filter element is not less than 400 um, the purity of oil return filter element is no less than 50 um.
2. After some time of operation of the auto loader it is necessary to perform the checking of the hydraulic fluid. If the oil purity is less than 10 grades by NAS1638 standard (or 16/19 by IOS4406 standard) it is necessary to refine the oil by filtration or peform oil changeout. After operation during 1200 hours the oil must be changed out. The oil is to be changed out as follows:
a. Turn the bucket to the upper position, raise the bucket lift arms to the highest posion. Stop the engine. Turn the bucket down, and drop the bucket lift arms by their own weight, to let all oil bleed.
b. To remove slugs and precipitate is it necessary to bleed oil until it cools.
c.Open drain cup of the oil tank and drain hoses in the lower part of the bucket hydraulic cylinder and lift arms hydraulic cylinders. Wash the oil tank and filters with kerosene or diesel oil.
d. After adding fresh oil it is necessary to operate in turns by bucket and lift arm to circulate the system and remove air.
3. Dismountling of details of the hydraulic system should be done in clean environment to rule out ingression of litter, dirt and alien objects.
4. In disassembling and mounting of new details it is necessary to check the state of gaskets and sealings.It is necessary to replace old, damaged, deformed and untight gaskets.
5.Dismounted details of the hydraulic system should be kept sage from shocks and damages.
 

Electric equipment system of this loader serves to start the engine, to provide operation of lighting devices and light signals, operation of test devices, elecrtic control equipment and energy supply for other auxiliary devices.Electric equipment system provides safety of motion and operation of the loader. It consists of charging device, launching equipment, lighting and light indication equipment, control devices and other parts.Voltage -24 V DC. Single wire, negative contact.
(1) Charging equipment.This part of electric equipment consists of battery, generator, control relay and other parts. Please find below the info, required in the operation of the devices :
1) battery
There are two batteries with succesive connection. Negative contact of the first battery is connected to positive contact of the second battery.Negavite contact of the second battery feeds the body Positive contact of the first battery is connected to the main switch.Therefort after turning on of the central switch the feeding is supplied to all the electric equipment of the loader.In routine operation of the battery during operation of the loader the battery is charged and discharged simultaneously, so there's no necessity to dismount the batteries to charge them. Batteries are to be dismounted only in the case of long stopping. In such a case the batteries are to be dismounted and charged, at least once a month. The electrolyte level is to be checked once in 10-15 days or once in 5-6 days in winter and summer, respectively. Besides the batteries should be tested for damage. The batteries should be kept clean.To avoid short circuit do not put any metal things on the batteries.Do not close contact using wire or screwdriver, as the resultant strong short-time current can put the batteries out of order. After putting the batteries in the box it is necessary to fix them in order to avoid their falling out and damage during the loader operation.The terminals of the batteries should be in good contact, if necessary, the terminals should be tighted.
2) Generator
Generator with silicon rectifier is actuated with the loader's engine. At normal operational rotation of the loader all the elecric equipment devices are fed from the generator.Besides, the generator charges the battery when it uncharges.Thus excessive energy of the generator transforms to the battery's energy.This makes the start and operation of the loader easier.You can see detailed description of the engine in "Diesel Engine Operation and Maintenace Insturction".
3)Regulating relay
Loader regulating relay JFT245A-28V type. It has better strength, reliability, provides better stability of voltage and have longer service lifr as compared with traditional vibrational relay.Besides, no maintenance during the operation is required. The relay can resist dust, oil and has other advantages.
(2) Starting system
Main parts of the starting system:Engine key, main electrical breaker, electric starter and other accessories. During the start it is necessary to turn the ignition lock key to the position "ON" the main electrical breaker will turn on". Then it is necessary to turn the key to the position "start".The starter actuates, the engine flywheel starts rotating.During the start of the engine the starter should not be in "ON" position for more than 10 seconds. If you fail to continuously turn on the starter several times, it is necessary to make intervals (no less than 3 seconds) between turnings on. It is forbidden to turn the starter on until the engine stops rotations. To provide reliable start of the loader it is required to perform as follows;to check the contact connections, tighten them, if required.Check the charge of the battery, fuel fed to the engine etc.
(3) Lighting and indication equipment
The loader is equipped with frontal headlights, rear lights, operation searchlights, frontal turn signals, rear signal, dashboard lamps, frontal lights, rear turn signals, stop signals.