Komatsu wa180-1 service manual

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Let us know if you have any catalog for exchange. Switch to mobile version. Payment Conditions. IO Electrical transmission control. IO Combination switch. IO Transmission cut-off function. IO Parking brake function. IO Kick-down switch. The motive force from engine 3 passes through the engine flywheel and is transmitted to torque converter 2 , which is connetted to the input shaft of transmission 1.

The transmission speed ranges are selected manually. The motive force from the output shaft of the transmission passes through center drive shaft 61, front drive shaft 5 and rear drive shaft 71, and is then transmitted to front axle 4 and rear axle 8 to drive the wheels.

The motive force from engine I passes through the flywheel and is transmitted to torque converter 2. The torque converter uses oil as a medium.

It converts the transmitted torque in accordance with the change in the load, and transmits the motive force to the input shaft of the transmission. In addition, the motive force of the engine passes through the pump drive gear of the torque converter, and is transmitted to hydraulic, steering pump 41, 3 and torque converter charging pump 5 to drive each l. The transmission speed range is selected manually.

The output shaft of transmission 6 transmits the power to the front and rear axles. At the front, the power is transmitted to front axle 11 through center drive shaft 91, flange bearing 91, and front drive shaft IO. At the rear, the power is transmitted to rear axle 17 through rear drive shaft The motive force transmitted to front axle 11 and rear axle 17 has its speed reduced by the bevel gear and pinion gear of differentials 12 and , and is then transmitted to the sun gear shaft through the differential mechanism.

The motive force of the sun gear is rduced further by the planetary mechanism and is transmitted to the wheels through the axle shaft.

The oil from the torque converter charging pump passes through the oil filter and flows to the brake booster. From the brake booster, it flows to the main regulator valve and is divided into three lines: the torque converter circuit, clutch circuit, and solenoid pilot circuit. The oil flowing to the torque converter circuit enters the torque converter.

The oil pressure is adjusted by the torque converter outlet port valve, the oil is cooled by the oil cooler, lubricates the transmission and returns to the transmission case. Transmission case 2. Strainer 3. Torque converter charging pump Oil filter Priority valve Main regulator valve Torque converter Torque converter outlet valve 9. PTO lubrication Oil cooler 4.

Transmission lubrication Pilot reducing valve Pilot oil filter Quick return valve Modulation fill valve Accumulator Solenoid valve Speed spool Directional spool Emergency manual spool. Operation The oil from the torque converter charging pump enters filter inlet port A. It is filtered from the outside of element 2 to the inside, and flows to outlet port B.

If element 2 becomes clogged with dirt, or the oil temperature is low and the pressure rises at inlet port A, the oil from inlet port A opens relief valve I and flows directly to outlet port 6 in order to prevent damage to the pump or element 2. Transmission control valve 2. Oil filter 3. Accumulator valve 4. Transmission 5. Parking brake lever. The motive force from the torque converter passes through the transmission input shaft and enters the transmission.

The transmission uses the combination of the forward or reverse clutches and the four speed clutches to shift to Fl - 4 or RI - 4, and transmits the motive force from the input shaft to the output shaft. Spacer 7. Thrust washer 8. Spacer 2. Thrust washer 3. The oil sent from the transmission valve passes through the oil passage inside shaft I , and goes to the rear face of piston 6 to actuate the piston. When piston 6 is actuated, clutch plate 2 is pressed against clutch disc 3 and forms shaft I and clutch gear 4 into one unit to transmit the motive force.

Oil is drained from oil drain hole 5 at this time, but this does not affect clutch operation since less oil is drained than supplied. The piston is returned to its original position by wave spring 7 , so shaft I and clutch gear 4 are separated. When the clutch is disengaged, the oil at the rear face of the piston is drained by centrifugal force through oil drain hole 5 , preventing the clutch from remaining partially engaged. The power is then transmitthrough output gear 34 to output shaft.

The power is then transmitted to 4th gear , 4th shaft 39 , and 4th gear l. The power of 4th gear 40 is transmitted to 4th gear 41 , which forms one unit with 3rd gear 33 , so the power passes through 3rd gear 33 , is transmitted to output gear 34 and output shaft Pilot oil pressure measurement port To oil cooler From pump Pump oil pressure measurement port Clutch oil pressure measurement port.

Upper valve body Main regulator valve Pilot reducing valve Priority valve Modulation fill valve pressure adjusting screw 6. Modulation fill valve 7.

Accumulator 8. Quicck return valve. The oil from the pump passes through the torque converter oil filter, enters the transmission valve, and is divided into the pilot circuit and the clutch actuation circuit. The priority valve gives priority to the oil sent to the pilot circuit, so the pilot pressure is always kept the same. The pressure of the oil flowing to the clutch actuation circuit is adjusted by the modulation fill valve and actuates the clutch. The oil which is relieved is sent to the torque converter.

The quick return and modulation fill valve are interconnected during gear shifting. They act to raise the clutch oil pressure smoothly, thereby reducing the shock when shifting gear. During traveling, the clutch pressure is kept the same. The pressure of the oil which flows to the circuit is adjusted by the pilot reducing valve. The transmission solenoid valve is installed to the transmission together with the transmission valve.

When the directional lever or speed control lever are operated, the solenoid valve is actuated and moves the spool inside the transmission valve.

The torque converter outlet port valve is installed in the outlet line of the torque converter and adjusts the maximum pressure of the torque converter. When the pressure at port a rises, the pressure at port c also rises.

This overcomes the tension of spring 2 and moves spool I to the left in the direction of the arrow to allow oil to flow from port a to port b. If the pressure at port a becomes even higher, spool I is moved further to the left in the direction of the arrow, and the oil flows from port a to port b and drain port d. Cold relief. The pilot reducing valve controls the pressure used to actuate the directional selector spool, H-L selector spool, range selector spool.

The oil from the pump enters port a, passes through port b of pilot reducing spool I , enters spool 2 in the lower valve, and fills the pilot circuit. The oil at port b passes through the orifice 3 and flows to port c.

When the pressure in the pilot circuit rises, the pressure at port c also rises. This overcomes the tension of spring 4 and moves pilot reducing spool I to the right in the direction of the arrow. For this reason, port a at port b are shut off, so the pressure at port c is maintained. There are four solenoid valves installed to the transmission control valve. Operation 1.

Solenoid valve OFF The oil from pilot reducing valve 3 flows to ports a and b of gear shift spools I and 2. The oil at ports a and b is stopped by solenoids 4 and 51, and gear shift spools I and 2 move to the right in the direction of the arrow. As a result, the oil from the pump flows to the 2nd clutch. The oil at ports a and b of gear shift spools I and 2 flows from ports c and d to the drain circuit. Therefore, ports a and b become the low pressure circuit, and the gear shift spool is moved to the left in the direction of the arrow by the tension of spring 6.

As a result, the oil at port e flows to the 4th clutch and the clutch is switched. The priority valve gives priority to sending oil to the pilot circuit of the lower valve. When the pressure in the circuit goes above the set pressure, it acts as a main relief valve to protect the circuit. The oil from the pump is divided into two lines. One oil flow enters port a, passes around priority valve 21, goes through pilot reducing valve I , and flows to the pilot circuit of the lower valve.

The other oil flow goes to priority valve 2. The oil flowing to priority valve 2 passes through orifice 3 and flows to port b. As a result, it pushes priority valve 2 to the left in the direction of the arrow against the force of spring 4 , and flows to port c. When the pressure at port b goes above the set pressure, priority valve 2 is pushed further to the left in the. The main relief function. The main regulator valve controls the flow of oil to the clutch circuit, and sends any excess oil to the torque converter circuit.

The oil from the pump enters port a of priority valve I , and then passes from port c through modulation fill valve 3 and main orifice 21, and flows to the clutch circuit. The oil passing through orifice 4 and entering port b moves the spool to the left in the direction of the arrow against the force of spring 51, so the oil passes through port c and flows to the torque converter circuit.

The pressure of the transmission clutch is raised smoothly by the modulating action. This reduces any shock when shifting gear and prevents the generation of peak torque and the power train. Therefore, it reduces operator fatigue and ensures a comfortable ride for the operator.

At the same time, it also increases the durability of the power train. At the same time, the oil from the pump flows to REVERSE clutch 51, but while the oil is filling the clutch, the clutch pressure is low. As a result, the oil pressure at port a of quick return valve 6 also drops, so check. At the same time, quick return valve 6 is moved to the left in the direction of the arrow by the pressure of the accumulator, and the oil from accumulator 8 is suddenly drained from port c.

Accumulator 8 is returned fully to the left by the force of spring 9. To reduce the shock when shifting gear, the pressure in the clutch circuit must be completely lowered and accumulator 8 must move fully to the left.

As a result, the pressure at port a rises, so quick return valve 6 is moved to the right in the direction of the arrow, and closes drain port c. Because of the differential pressure created by modulation fill valve I I , a constant flow of oil passes through 1st orifice IO and enters accumulator 8.

As this oil flows in, the accumulator piston gradually moves to the right in the direction of the arrow, and spring 9 is compressed, so the accumulator pressure rises. As this accumulator pressure rises, it raises the clutch pressure. When accumulator piston 8 moves to the end of its stroke, the rise in the pressure at port d finishes, so the specified pressure is maintained and the REVERSE clutch is completely engaged. When the gear shift spool is operated, the action is the same as above.

The modulation fill valve adjusts the pressure and controls the amount of oil flowing to the accumulator while allowing the clutch pressure to rise. When this happens, the pressure in chamber c and chamber d drops, and spring 2 moves modulation fill valve 3 to the right to open port a.

Clutch pressure starting to rise point c point d When the oil from the pump fills the clutch piston, the pressure in the clutch circuit starts to rise. When this happens, the drain circuit of the quick return valve is closed. When the drain circuit of the quick return valve closes, the oil passing through port a enters chamber d and pressure P2 in chamber d starts to rise. PI rises and P2 also rises at the same time. The oil from the torque converter outlet port circuit forms the pilot pressure to the modulation fill valve and flows to port e.

The pressure at port e changes according to the engine speed. Therefore, pressure P2 rises at the same time by the same amount that pressure P4 changes, so it is possible to create oil pressure characteristics that matches the engine speed. When at neutral. Solenoid valves 4 and 5 are OFF and the drain port is closed. The oil from the pilot circuit passes through the oil hole in the emergency manual spool and fills ports a and b of the directional spool.

When this happens, the directional spool moves to the left, and the oil at port c flows to port e and is supplied to the FORWARD clutch. Emergency manual spool at neutral The oil from the upper valve pilot reducing valve passes around emergency manual spool I , and is blocked by solenoid valves 2 and 3. When the operating condition is normal, the emergency manual spool is at the neutral position. As a result, directional spool 4 moves to the left in the direction of the arrow, and the oil flows to the FORWARD clutch to engage the clutch.

The oil from pump I passes through priority valve 2 and is divided to the pilot circuit and clutch actuation circuit. The oil filling ports a and b is drained and directional spool 7 and gear shift spool 9 move to the left. Gear shift solenoid 5 is closed, and H-L spool 8 is pushed fully to the right, so the oil flows from clutch pressure port e to port f, passes through spool 9 and engages the 1st clutch.

When the oil completely fills the clutch cylinder, the action of accumulator IO and quick return valve II raises the oil pressure gradually, and when it reaches the set and 1st clutches pressure, the FORWARD are completely engaged.

When the transmission shifts gear, the accumulator valve slowly reduces the oil pressure to the clutch that was first engaged in order to prevent loss of torque and to reduce the transmission shock when shifting gear. It temporarily stores the clutch oil pressure in order to allow gear shifting to be carried out smoothly without any time lag.

To make it possible to reduce the oil pressure to the clutch slowly, there are throttles installed in the directional spool, H-L spool and range spool of the transmission control valve. When the kick-down is operated, the Fl clutch is engaged, but the oil pressure in the accumulator is maintained for the 2nd clutch until the torque is transmitted to the 1st clutch.

In this way, it is possible to shift gear smoothly without losing the torque. When shifting to R2 after completi,ng digging operations, the R2 clutch is engaged, but the oil pressure for the FORWARD clutch and 1st clutch is maintained in the accumulator. This makes it possible to reduce the loss of torque due to the reaction force to the product being handled, and to move back smoothly without shock.

This opens or closes the solenoid valves and moves the spool inside the transmission valve. The motive force from the engine passes through the torque converter and the transmission. Some of it is transmitted from rear drive shaft 4 to the rear axle, while the rest goes from center drive shaft 3 through flange bearing 2 and front drive shaft I to the front axle. The drive shaft has the following purpose in addition to simply transmitting the power. The drive shaft has a universal joint and sliding joint to enable it to respond to changes in the angle and length.

This enables the drive shaft to transmit the motive force when the machine is articulated and to protect the components from damage from shock when the machine is being operated or shock from the road surface when the machine is traveling. The motive force from the engine is transmitted to the front and rear axles via the torque converter, the transmission and the propeller shaft. The motive force of the sun gear is further reduced by planetary gear-type final drive, and transmitted to the axle shaft and wheel.

When moving straight forward. When moving straight forward, the speed of rotation of the left and right wheels is equal, so pinion gear 4 in the differential assembly does not rotate, and the motive force of carrier 6 is transmitted equally to the left and right sun gear shafts 2 via the pinion gear 4 and side gear 3. When slewing. When slewing, the speed of rotation of the left and right wheels is unequal, so pinion gear 4 and side gear 3 in the differential assembly rotate according to the difference in the left and right rotation speeds, and the motive force of carrier 6 is transmitted to the sun gear shafts 2.

Because of the nature of their work, 4-wheeldrive loaders have to work in places where the road surface is bad.

In such places, if the tires slip, the ability to work as a loader is reduced, and also the life of the tire is reduced. The torque proportioning differential is installed to overcome this problem. In structure it resembles the differential of an automobile, but differential pinion gear 4 has an odd number of teeth. Because of the difference in the resistance from the road surface, the position of meshing of pinion gear 4 and side gear 3 changes, and this changes the traction of the left and right tires.

Operation When traveling straight equal resistance from road surface to left and right tires. Therefore the left side traction TL and the right side traction TR are balanced. When traveling on soft ground resistance from road surface to left and right tires is different. On soft ground, if the tire on one side slips, the side gear of the tire on the side which has least resistance from the road surface tries to rotate forward.

Because of this rotation, the meshing of pinion gear 4 and side gear changes. The position is balanced as follows. Outline l As the final function the final drive operates to reduce the rotative speed of the motive force from the engine and increases the driving force. Ring gear 2 is press-fitted in the axle housing and fixed in place by a pin. The motive force transmitted from the differential to the sun gear shaft I is reduced using a planetary gear mechanism, increasing the driving force.

The increased driving force is transmitted to the tires via planetary carrier 4 and axle shaft 5. Front axle. The front axle I receives the force directly during operations, so it is fixed directly to the front frame 2 by tension bolts 5. Rear axle. The rear axle 4 has a structure which allows the center of the rear axle to float, so that all tires can be in contact with the ground when traveling over soft ground.

Outline l The front frame 1 and rear frame 2 are connected through a bearing by the center hinge pin 31, 4. The steering cylinders are connected to the left and right front and rear frames, so when the cylinders are operated, the frame bends at the middle to give the desired angle, that is the desired turning radius.

Main control valve Steering valve orbit-roll Hydraulic tank Priority valve Hydraulic pump Steering pump Cushion valve Steering cylinder. The priority valve is in the circuit between the steering pump and the steering valve and main control valve. It acts to divide the flow of oil from the steering pump and send it to the steering valve or main control valve circuit. It also sets the oil pressure in the circuit from the priority valve to the steering valve to Steering wheel at neutral When the engine is stopped, spool 3 are pushed fully to the left by the tension of spring 4.

In this condition, the circuits between ports M and N are fully open, while the circuits between ports M and Q are fully closed.

If the engine is started and the steering pump start to turn, the oil from the pump goes from port M to port N, and then enters port A of the steering valve. The oil entering port A is throttled by orifice a, so the pressure in the circuit rises. When this happens, the oil passing through orifices m in spool 3 enters port P.

It then compresses spring 41, and moves spool 3 to the right in the direction of the arrow. This stabilizes the condition so that the circuits between ports M and Q are almost fully open and the circuits between ports M and N are almost fully closed. Therefore, the oil from the steering pump almost all flows to the work equipment circuit.

From steering pump. Steering wheel turned to left When the steering wheel is turned to the left, an angle variation is generated between the spool and sleeve of the steering valve, and the oil flow is switched. The oil from the pump flows from port M to port N, and enters port A. The degree of opening of the sleeve pot-t A and spool port B of the steering pump creates a difference between the pressure up to port A and the pressure beyond port B.

Some of the oil from port B flows to the Girotor E, and then goes to the front right cylinder. The remaining oil passes through orifice b, flows to port J, and then enters port R. When this happens, spool 3 stabilizes at a position where the differential pressure between the circuit up to port A and circuit beyond port B pressure of port P - pressure of port RI and the load of spring 4 are balanced.

It adjusts the degree of opening from port M to ports N and Q, and distributes the flow to both circuits. The ratio of this distributed flow is determined by the degree of opening of port A and port B, in other words, the angle variation between the sleeve and spool of the steering valve.

This degree of opening is adjusted steplessly by the amount the steering wheel is turned. Steering cylinder at end of stroke If the operator tries to turn the steering wheel further when the steering cylinder has reached the end of its stroke, the circuit from pot-t M through port N to port S is kept open and the pressure rises. When this pressure rises above Because of this flow of oil, a differential pressure is created on both sides of orifice r.

Therefore, the balance is lost between the load of spring 4 , and the pressure up to port A and the pressure beyond port 6. As a result, the pressure up to port A becomes relatively higher. For this reason, the pressure at port P moves spool 3 even further to the right from the condition in Item 2.

It stabilizes the condition at a position where the circuits between ports M and N are almost fully closed, and the circuits between ports M and 0 almost fully open. When there is a reaction to the sudden rise in the pressure of the steering cylinder, the cushion valve acts to prevent shock by relieving the momentary high pressure oil to another line.

If high pressure oil suddenly enters from port R, the high pressure oil compresses spring 3 , and pushes open poppet 4. It then passes through the center groove of spool 81, goes through poppet II of port L, and flows to port L.

At the same time, the high pressure oil passes through orifice 5 and goes to the pressure chamber of plug 6. When it becomes greater than the pressure at port L and the force of spring 71, it pushes spool 8 fully to the left.

This shuts off the flow of high pressure oil from port R through poppet 4 to port L. This temporary flow of oil has a cushion effect. The valve is not actuated any further, so there is no effect. When the pressure rises slowly and there is no need for any cushion effect, spool 8 closes more quickly than poppet 4 opens, so there is no unnecessary cushion action.

The steering valve is connected directly to the shaft of the steering wheel. It switches the flow of oil from the steering pump to the left and right steering cylinders to determine the direction ,of travel of the machine. The steering valve, broadly speaking, consists of the following components: rotary type spool 3 and sleeve 51, which have the function of selecting the direction, and the Girotor set a combination of rotor 8 and stator , which acts as a hydraulic motor during normal steering operations, and as a hand pump in fact, the operating force of the steering wheel is too high, so it cannot be operated when the steering pump or engine have failed and the supply of oil has stopped.

Spool 3 is directly connected to the drive shaft of the steering wheel, and is connected to sleeve 5 by center pin 4 it does not contact the spool when the steering wheel is at neutral and centering spring The top of drive shaft 6 is meshed with center pin 41, and forms one unit with sleeve 5 , while the bottom of the drive shaft is meshed with the spline of rotor 8 of the Girotor.

There are four ports in valve body 2 , and they are connected to the pump circuit, tank circuit, and the circuits at the head end and bottom end of the steering cylinders. The pump port and tank port are connected by the check valve inside the body. If the pump or engine fail, the oil can be sucked in directly from the tank by this check valve. When the steering wheel is at neutral, centering spring 12 makes spool 3 and sleeve 5 stop at a position where center pin 4 is at the center of the oblong hole in spool 3.

At this point, pump port A of the sleeve and ports E, F, and G to the steering cylinder and Girotor, and vertical grooves B, C, and D of the spool are shut off. However, orifice a of pump port A is connected to orifice d connected to drain port H of the spool. Orifice b of port J from the priority valve is connected to vertical groove B of the spool.

In addition, port K of the sleeve is connected to drain port L of the spool and vertical groove B. By shutting off and connecting these ports and grooves, the oil from the pump passes from port A through orifices a and d, and is drained to the hydraulic tank. In addition, the oil which forms the pilot pressure of the priority valve passes from port J through orifice b, then through vertical groove B and port K, and is returned to the hydraulic tank from port L. When the steering wheel is turned to the left, spool 31, which is connected by the spline of the steering shaft, also turns to the left.

The spool and sleeve 5 are interconnetted by centering spring , so the spool compresses the centering spring. Therefore, a difference in the angle of rotation angle variation is generated between the spool and sleeve equal to the amount that the centering spring is compressed.

When this happens, first, port A and vertical groove B are connected. Finally, vertical groove C and port G to the head end of the right cylinder are connected. In addition, vertical groove B is kept connected to orifice b of port J to the priority valve, but port K of the sleeve gradually closes the connection of vertical groove B and port L. Port F from the head end of the left cylinder is connected to vertical groove D connected to drain port H at the same time as port A and vertical groove B are connected.

By shutting off and connecting the above ports and grooves, the oil from the pump enters vertical groove B from port A, then flows to port E to the Girotor, and turns the Girotor.. The oil entering vertical groove B passes through orifice b and flows to port J. From port J, it becomes the pilot pressure of the priority valve. The oil from the head end of the left cylinder enters vertical groove D from port F and is drained to the hydraulic tank.

Steering wheel stopped When the operation of the steering wheel is stopped, the difference in rotation between the spool and sleeve is returned to the neutral condition by the reaction of centering spring The diagrams above show the connections with the sleeve ports used to connect the suction and discharge ports of the Girotor. If the steering wheel has been turned to the right, ports a, c, e, g, i, and k are connected by the vertical grooves in the spool to the pump side.

At the same time, ports b, d, f, h, j, and I are connected to the head end of the left steering cylinder in the same way. In the condition in Fig. They are connected to ports I, b, and d, so the oil is sent to the cylinder.