A winch is installed on the car, designed to pull the car out when overcoming difficult sections of the road, as well as to assist other cars stuck on the way
The winch (fig. 1) is mounted in front of the vehicle, bolted to the front buffer and front cross member.
The front buffer is bolted to detachable spars extensions.
The winch is driven by a cardan shaft from a power take-off mounted on the gearbox.
The drum 5 of the winch rotates freely on the shaft and is rigidly connected to the shaft using a coupling 29.
When the handle of the fork 35 for turning on the drum is moved to the extreme left position, the clutch for turning on the drum moves on the shaft along two keys and the end cams engage with the end cams of the drum.
The drum activation fork is installed on the winch traverse.
The switching fork is equipped with a brake shoe hinged in the lugs of the crosshead on the axle.
When the clutch is turned off, the brake shoe, under the action of a pressure bolt with a spring, rests against the end of the drum flange, slows down its rotation and prevents the cable from self-unwinding when unwinding it manually.
The brake is adjusted by tightening or loosening the spring of the thrust bolt using a nut with a locknut, and, if necessary (when the spring force is not enough), by moving this bolt by screwing in or out of the threaded bushing.
The spring pressure is adjusted correctly if the cable is unwound under the action of the force of the hand without self-dissolving in the drum flange on the inside there is a cavity in which the end of the cable is laid, securing it with a bracket and nuts.
The winch cable is steel, non-spinning, with a metal core. A hook is attached to the free end of the rope.
The drum shaft rotates in three bronze bearings, two of which are installed in the gearbox housing and one in the traverse.
The traverse and the gearbox housing are bolted to the cross members.
The bearing of the drum shaft in the traverse is lubricated through an oiler 30.
The bearings of the drum shaft in the crankcase are lubricated by oil flowing from the worm gear of the gearbox and from the walls of the crankcase cover.
The surfaces of rotation of the drum on the shaft are lubricated through two oilers 18 located at the hubs of the drum.
The winch gearbox (Fig. 2) consists of a globoid single-thread steel worm 21, a worm wheel 3 with a bronze crown, a split crankcase, a drum shaft 7, an automatic brake, bearings and their covers.
The worm wheel of the gearbox is mounted on the winch drum shaft on two keys and secured against axial movement with a pin.
The movement of the drum shaft with a worm wheel in the axial direction is carried out by changing the thickness of the set of gaskets under the washer 4 installed between the right end of the gearbox housing and the end of the undercut in the cover 6. Washer 4 is attached to the end of the shaft with bolts.
In the gearbox housing cover there is an inspection hatch closed by cover 11.
The worm 21 is installed in the gearbox housing 13 on two tapered roller bearings.
The bearings are closed with covers 14 and 22. A cuff 18 is pressed into the cover 14. The bearing caps are bolted to the gearbox housing.
A drum 15 of the automatic brake of the winch gearbox and a flange 16 of the cardan shaft are installed at the rear end of the worm shaft.
The brake drum is mounted on a key, and the flange is splined; from axial movements, they are fixed with a nut. The brake drum is closed with a cover. The cover has a felt cuff 17, which prevents dirt from entering the brake.
There is a sealing ring made of copper or paronite between the end face of the inner bearing ring and the end face of the brake drum hub.
The drum is braked by a brake band 9 with a friction lining. One end of the brake band is rigidly fixed in the wall of the bearing cover, and the other end is movably through a spring.
The spring tightens the tape in the opposite direction to the rotation of the worm shaft when winding the winch cable. The tape under the action of friction force compresses the spring, which leads to a weakening of the pressure of the tape on the drum, that is, to a decrease in braking
Due to the rigid fastening of the opposite end of the tape during reverse rotation, under the action of friction, the tape self-tightens, causing the worm to slow down.
At a low speed of the worm shaft, the braking force generated by the automatic brake is insignificant and does not prevent the cable from unwinding.
In the event of a shear due to an overload of the safety pin, when the winch drum starts rotate in the opposite direction with increased speed, the brake action becomes significant and serves as a supplement to the self-braking action of the worm gear, which prevents the winch drum from rotating quickly and unwinding the cable.
The tension of the brake band is adjusted with nut 24.
Turning the nut clockwise increases the spring force. The brake must be adjusted so that when the cable is unwound, its drum does not heat up excessively
Winch cable guides are bolted to the lower shelf of the front buffer and the rear cross member of the winch.
At the front, between the guides, there is a guide roller for the winch cable and a rod that keeps the cable from falling out.
The roller rotates on an axis fixed with nuts in the guides. Lubricate the roller bearings through an oiler installed at the left end of the roller axis.
The cardan shaft of the winch (Fig. 3) is tubular, with two hinges. A fork with a safety pin is installed at the front end of the cardan shaft, and a sliding fork is installed at the rear end on the slots.
When the load increases above the limit, the pin is cut off, protecting the winch parts from breakage.
Maintenance of the winch consists of checking and tightening all fastening parts, lubricating the bearings, changing the oil in the gearbox, checking the quality of the seals, adjusting the bearings, checking and adjusting the axial clearance of the drum shaft and the gearing of the worm gear
The crankcase of the winch gearbox is filled with oil through the hatch in the upper part of the gearbox to the level of the control filler hole.
After 15-20 pull-ups of the car, check the oil level.
If necessary, add oil up to the level of the control hole. The oil in the gearbox should be changed within the time specified in the lubrication chart.
The hinges, splines of the drive shafts of the winch drive, the bearings of the drum shaft and the guide roller must be lubricated according to the lubrication map.
Removing the winch from the vehicle
Disconnect driveline. Release the brackets 9 (Fig. 4) from the attachment and remove them together with the guide roller 14 and the guide rod 13 of the cable.
Unscrew the bolts securing the safety bracket 4 of the winch to the front cross member 15 of the winch and remove the bracket.
Unfasten the removable brackets 2 of the front buffer. Unscrew the bolts securing the front buffer brackets to the frame and the bolts securing the winch front cross member to the front buffer.
Remove the bolts securing the front buffer to the front buffer mounting brackets 8. Using a hoist, remove the front buffer assembly with the winch and disconnect it from the buffer. Place the winch on the stand for disassembly.
Before disassembly, the winch should be cleaned of dirt and dust, washed in a degreasing solution and blown with compressed air. The disassembly of the winch is carried out in exceptional cases, since it works intermittently and its parts do not have intensive wear.
Disassembly of the winch
Removing drum.
Unwind the cable, unscrew the bolts securing the traverse 10 to the winch crossbars, remove the cotter pin and knock out the pin 12 of the winch drum engagement fork, then remove the traverse, brake shoe 11, winch clutch, remove the keys from the grooves of the shaft, remove the drum 16 of the winch cable (Fig. 5).
When disassembling, it is forbidden to remove the drum 15 (see Fig. 2) of the winch worm brake by screwing the bolts all the way into the cuff, which leads to its damage and loss of tightness.
In order for the bolts not to rest against the cuff, screw the bolts 7-8 mm, hook the bolts with a puller and remove the drum.
Disassembly of the winch gearbox
Unscrew the bolts and remove covers 6 and 26 (see Fig. 2).
Unpin and unscrew the mounting bolts of the drum shaft 7 and remove the mounting washer 4 and shims 8.
Unscrew the mounting bolts and remove the cover 12 of the crankcase 13 of the gearbox.
Remove shaft 7 of the drum assembly with worm wheel 3.
Unlock the nut securing the flange 16 of the worm shaft 21 of the gearbox, unscrew the nut, remove the washer and the flange manually.
If the flange cannot be removed manually, use a puller mod. 20P-7968.
Unscrew the bolts securing the cover of the automatic brake of the winch gearbox, remove the cover with the cuff 17 as an assembly and the thrust washer.
Unscrew cover bolts 10 of spring 23 and remove cover. Loosen the brake band nuts and remove the band 9.
Remove the brake drum 15 with the collar using a puller.
The way to remove the winch brake drum is shown in fig. 5.
Unscrew the fastening bolts and remove covers 14 and 22 with gaskets (see Fig. 2).
Install the crankcase 13 of the gearbox assembly with the worm on the press and press out the worm shaft assembly with the bearing rings (Fig. 7).
This presses out one outer race of the bearing. If necessary, another ring can be pressed out using a mandrel or a puller.
Press the inner bearing races off the worm shaft using a puller mod. 20P-7968 (Fig. 6).
Remove the bearings 2 (see Fig. 2) of the winch drum shaft, press out the pin connecting the shaft 7 and the worm wheel 3.
Install the worm wheel under the press on a hollow stand, directing the drum shaft through it, then press the shaft out of the worm wheel hub (Fig. 9) and remove the keys from the grooves of the shaft.
Disassembling the cardan drive of the winch
Disassembly of the driveline of the winch is carried out in the same way as the disassembly of the driveline of a car.
The driveline of the winch is shown in fig. 3
Details winches
If there are cracks and breaks on the gearbox housing, covers and other parts of the winch, they should be replaced.
It is allowed to weld several cracks on parts made of gray and malleable cast iron. Damage to the threads on the parts of the winch is allowed no more than two threads.
Worn holes in the gearbox housing for the outer rings of the bearings should be repaired by installing repair bushings.
The misalignment of the crankcase bore hole and the repair sleeve hole for the bearing is allowed no more than 0.05 mm.
The non-perpendicularity of the ends of the gearbox housing under the bearing caps relative to the surface of the holes for the bearings is allowed no more than 0.08 mm.
Worn journals of shafts and axles of excess dimensions can be repaired by chromium plating with subsequent processing to nominal dimensions. Shafts that are bent or twisted must be replaced.
The runout of the necks of the worm shaft under the bearing is allowed no more than 0.05 mm. The runout of the end surfaces of the worm shaft at the interface with the bearings is not more than 0.03 mm.
The runout of the end of the crown of the worm wheel (when installing the shaft on the supports) is not more than 0.12 mm. The runout of the end of the shaft, installed with journals on the supports, is not more than 0.06 mm.
Bearings with increased backlash, ring cracks, nicks and corrosion spots on the working surfaces should be replaced.
Flanges must not show any damage to mating surfaces. The nicks on the flange surface or on the brake drum must be removed by grinding.
If there is wear on the fork legs or wear on the groove in the sliding clutch of excessive dimensions in the drum engagement mechanism, they should be replaced.
A bent fork can be repaired by straightening. In case of breakage or wear of a worm tooth or a tooth of a worm wheel crown of excessive dimensions, they should be replaced.
Worn oversized bushings and friction linings of the brakes must be replaced.
Misalignment of the inner surfaces of the bushings of the cable guide roller pipe is allowed no more than 0.1 mm.
Assembling and adjusting the winch
Winch parts must be washed in a degreasing solution before assembly, blown with compressed air and checked for suitability for assembly. Cuffs, seals and gaskets in case of damage must be replaced with new ones.
The winch is assembled in the reverse order of disassembly.
Before pressing the cuff of the gearbox worm bearing cover, the outer surface of the cuff casing and the cuff seat should be lubricated with a thin layer of AK-20 glue.
The tapered roller bearings must be adjusted with preload when installing the bearing caps of the gearbox.
The torque required to rotate the worm shaft in the bearings should be 0.1-0.6 Nm.
After adjustment, the worm shaft should turn freely with the bearing cap bolts fully tightened, but have no axial clearance.
Adjustment of tapered bearings is carried out using shims placed under the flange of the covers.
If the worm shaft rotates too freely or has an axial clearance, it is necessary to remove part of the spacers of equal thickness from under the front and rearth bearing caps; if the worm shaft rotates with a torque greater than 0.6 Nm, spacers of equal thickness should be added under both bearing caps.
The number of spacers under the rear and front bearing caps should be approximately the same or have a difference in the thickness of the spacers no more than 0.1 mm.
Change the thickness of the gaskets under the covers is possible only when adjusting the meshing of the teeth of the worm gear.
Adjustment of the conical bearings of the gearbox is carried out before installing the worm wheel assembly with the shaft, flange and brake drum in the gearbox.
After adjusting the brake, bolts, gaskets and nuts for fastening the brake drum should be put on AK-20 glue.
After installing the worm wheel on the winch shaft, press and center the pin.
Before installing the drum shaft with worm wheel assembly, check the wear of the bushings and journals of the drum shaft.
The allowable gap between the diameter of the bushings and the necks should not exceed 0.6 mm.
If the gap is larger, the bushings must be replaced. The locating pin of the bushing must not protrude beyond the surface of the inner diameter of the bushing.
After installing the switching mechanism and the traverse on the drum shaft, fix the mounting washer and adjust the axial movement of the shaft.
The shaft should rotate freely, but should not have an axial clearance of more than 0.1 mm (when measured by an indicator on the left end of the drum shaft) when the wheel is moved in the axial direction.
After adjusting the worm shaft bearings and adjusting the axial clearance of the drum shaft, it is recommended to check the correct engagement of the teeth of the worm wheel and the worm on the “paint” along the contact patch.
With a correctly adjusted gear, the contact patch on the working side of the tooth of the worm wheel should correspond to the patch shown in fig. 10.
The correct location of the contact patch relative to the axis of symmetry of the tooth is achieved by corresponding movement of the drum shaft with a worm wheel in the opposite direction to the displacement of the contact patch.
To move the worm wheel with the drum shaft to the right or left, remove or add part of the spacers under the end of the support washer
Adjustment of the size of the contact patch along the height of the tooth is achieved by moving the worm relative to the worm wheel; for this, it is necessary to shift the gaskets from under the bearing cover from one side to the other, without changing the preload in the bearings.
A worm gear can only work reliably if it is properly engaged.
Incorrect adjustment causes the gearbox to become very hot.
When installing an automatic brake, it must be adjusted.
The result of the adjustment should be checked while the cable is unwinding, while the brake drum should not get very hot due to friction of the brake band.
Weak smoking of the brake band during running-in cannot be a rejection sign.
The tension of the brake band is adjusted with a nut (Fig. 11), which, when rotated to the right, increases the tension of the band and braking.
To check the tightening of the worm brake, it is allowed to remove the gearbox brake cover and the spring cover before winding the cable onto the drum.
The gap between the coils of the brake band spring should be within 1-1.5 mm.
After assembling the winch, you need to check the operation of the mechanism for turning on the winch drum.
When the clutch is turned off, the brake shoe 2 (Fig. 12) during the rotation of the drum should slow down the drum 1, which will prevent the possibility of self-unwinding of the cable when unwinding manually.
The brake is adjusted by tightening or loosening the pressure bolt spring 3 using a nut with a locknut, and if necessary (when the spring force is not enough) - by moving this bolt by screwing in or out the guide pressure bolt.
The brake spring pressure is set correctly when the cable unwinds by hand without self-release.
When installing the winch cable guide roller, tighten the roller fastening nut by applying a torque of 120 Nm and bend the edges into the groove.
Installing the winch on the car
Fix the front and rear crossbars to the winch. Connect the front buffer to the winch front cross member.
Install the winch assembly with the front buffer on the vehicle frame I, with the help of a lifting device, and fix the rear cross member of the winch to the first cross member of the frame, and the buffer assembly with removable brackets to the frame side members.
Attach the safety bracket to the front winch cross member and the first frame cross member at the same time as the winch rear cross member.
Fasten the cable guide bracket from below to the front buffer and rear cross member of the winch.
Connect the driveline to the gearbox flanges and the power take-off mounted on the gearbox hatch.
Check the correct position of the power take-off lever; adjust if necessary.
Start the engine, including the power take-off gears, check the operation of the winch.