Middle axle reducer KamAZ 6520 35 teeth

alternative reality

Maxim Shelepenkov, photo by the author

Taking a quick glance at the photographs, many will shrug their shoulders - an ordinary KAMAZ-6520 dump truck. But the specialist will immediately note the wheels measuring 12.00R24 and the Betsema-Istra dump truck, which is unusual for a truck from Naberezhnye Chelny, which was previously installed exclusively on imported trucks.

It is no secret that the KAMAZ-6520 dump trucks are inferior to modern imported dump trucks in terms of their technical characteristics, mainly in terms of the weight of the cargo transported. Its maximum load capacity of 20 tons compared to 25–28 tons of foreign analogues is, to put it mildly, not impressive. Of course, KAMAZ is beyond competition in terms of cost, but practice shows that more expensive, but heavy-duty trucks are more profitable to operate - they bring more profit.

An ordinary, unusual dump truck

However, recent jumps in exchange rates, economic sanctions that have squeezed the banking sector, as well as the government’s announced import substitution policy force us to take a fresh look at the current state of affairs.

A fresh look at KAMAZ-5320 was offered by Naberezhnye Chelny, which has long and quite successfully specialized in the production of non-standard equipment based on production KAMAZ vehicles. The company’s specialists decided to correct the main drawback of this dump truck and offer consumers a product at the level of imported analogues. At least in terms of characteristics.

The standard KAMAZ-6520-K4 (Euro 4) dump truck chassis was chosen as the basis, which underwent major modernization. The vehicle has a reinforced front steer axle with a permissible load of 9 instead of 7.5 tons, like the standard KAMAZ-6520, and rear drive axles with a permissible load of 32 tons instead of 25.6 tons. In addition, larger wheels are installed 12.00R24 instead of 12.00 R20. The chassis frame of the car in the most loaded rear part is equipped with additional reinforcements, and to ensure optimal weight distribution along the axles, the wheelbase of the car has been increased from 3600 to 3800 mm, i.e. by 200 mm.

As a result, the total weight of the KAMAZ-R6520 road-quarry dump truck allowed by its design (the letter “P” before the digital index means RIAT) increased to 41 tons. For the standard KAMAZ-6520 this value is 33.1 tons. As a result, the load capacity of the modified dump truck increased from 20 to 28 tons, which allowed the KAMAZ-R6520 dump truck to transport almost one and a half times more cargo than a standard vehicle in one trip.

Of course, such weight characteristics of the vehicle are somewhat beyond the permissible axle loads on public roads, but the vehicle can be fully used in quarries and on industrial roads, while it remains an ordinary road dump truck, which, at partial load, is not prohibited from traveling on ordinary roads. roads.

The car is equipped with a powerful Cummins ISLe-400 turbodiesel with a Common Rail power system and a time-tested 16-speed ZF 16S 1825 gearbox with a mechanical control drive. These units allow the dump truck to have a sufficient supply of power and torque in any road conditions.

Technical specifications

Rice. 450 Rear axle KamAZ 6520 : 1 - wheel reducer; 2 — wheel hub; 3 — brake drum; 4 — brake mechanisms; 5 — axle housing; 6 — left axle shaft; 7 — main gear of the rear axle; 8 — axle shaft right

Rice. 451 Middle axle KamAZ 6520 : 1 - wheel reducer; 2 — wheel hub; 3 — brake drum; 4 — brake mechanisms; 5 — axle housing; 6 — left axle shaft; 7 — main gear of the rear axle; 8 — rear axle drive gear; 9 - right axle shaft; 10 — rear axle drive shaft; 11 — ball bearing; 12 — bearing cover; 13 — output flange

The wheel drive (Fig. 454) is planetary, with cylindrical straight gears.

The wheel drive contains a sun gear 19, which is connected to the main gear by means of an axle shaft 12, five satellites 2 mounted on axles 1 with needle bearings located in the carrier 17, and a ring gear 15, fixedly connected to axle 13 of the axle housing. The axles of 1 satellites are pressed into coaxial holes in the carrier of the 17th wheel drive. The carrier 17 has a welded casing 16 connected to the wheel hub 7, a thrust washer 20 and a nut 22 for adjusting the temperature gap between the rubbing surfaces. In the cover 23 of the wheel drive there are drain plugs 18 and filler plugs 21.

The bridge housing is welded from stamped steel beams. Welded to the crankcase beams are a crankcase cover, a flange for attaching the main gear, end flanges for attaching brake calipers, levers for attaching reaction rods and springs. The crankcase journal is welded to the beams using friction welding.

The drive axle axle shafts are completely unloaded.

Wheel hubs (Fig. 454). Wheel hubs 7 are mounted on tapered roller bearings 11 and 14 and rest on the axle housing axle. The adjustment of the hub bearings is carried out using an adjusting nut 5, which is locked from turning using a screw 4 with a lock washer.

Brake drums 9 and wheel rims are attached to the hubs 7 of the wheels with special wheel bolts 6 and nuts. In addition, the brake drums 9 are additionally fixed to the wheel hubs 7 with two screws 10. The bearings 11 and 14 of the hub are protected from dirt and dust by two cuffs 8, pressed into a cup that is installed in the wheel hub.

Wheel hubs provide for the installation of steel and aluminum wheel rims.

The main and wheel gear housings of the bridge have filler and drain holes closed with plugs.

To equalize the pressure inside the axle crankcase, a safety valve is installed in the upper part of the crankcase.

Rice. 454 Wheel drive and wheel hub: 1 - satellite axis; 2 — satellite; 3 — roller bearing; 4 — locking bolt; 5 — hub bearing nut; 6 — wheel mounting bolt; 7 — wheel hub; 8 — hub lip seal block; 9 — brake drum; 10 — locking screw; 11 and 14 — tapered, roller bearings; 12 — axle shaft; 13 — axle housing axle; 15 — crown gear; 16 — carrier casing; 17 - carrier; 18 - drain (control) plug; 19 — sun gear; 20 — thrust washer; 21 - filler plug; 22 — adjusting nut; 23 — lock washer; 24 — wheel drive cover

All the best in one platform

The vehicle is equipped with a dump platform of the Istra series (BTsM 271.1) with a volume of 16 m3 produced by BETSEMA JSC with front and rear inclined sides, which allows for a more uniform distribution of cargo in the body and optimal distribution of the load along the axles. The body of the dump truck is made of high-strength and wear-resistant Hardox 450 steel. The thickness of the bottom is 8 mm, and the thickness of the sides is 5 mm.

The design of the dump truck uses a set of hydraulic equipment from Binotto (Italy), which ensures lifting of the body at an angle of up to 50°.

The Istra dump truck platform has a more efficient exhaust gas heating system compared to its analogues due to the use of a double bottom. With this design, hot exhaust gases are supplied directly into the double floor space, bypassing the power elements of the underbody. This means that exhaust gases are better and more evenly distributed over the entire floor area of ​​the platform and retain heat better. But the main thing is that condensation from exhaust gases no longer accumulates in the power elements of the underbody and they are less susceptible to corrosion and internal destruction.

In the standard version, the Istra body is equipped with a sliding awning and a spare wheel holder with a cable lifting and lowering mechanism. It is worth noting that, unlike the standard version, the KAMAZ-R6520 dump truck is equipped with steel rear fenders and powerful protection for the rear lights. In addition, there is a lifting underrun guard installed at the rear, which can be raised when leaving paved roads to avoid damage.

Among the chassis modifications carried out by RIAT, it is worth noting the rear-mounted backlash-free towing device and prepared pneumatic and electrical outlets. This allows, if necessary, to use the KAMAZ-R6520 as a ballast tractor, for example, for heavy-duty trailers.

So far, the first prototype has been produced, which must undergo comprehensive testing and receive the go-ahead for serial production. In particular, it is necessary to modify the vehicle’s braking system under the increased load so that its effectiveness does not deteriorate.

The main competitive advantage of this machine over imported analogues is the low cost of ownership and availability of spare parts.
We also do not forget that the listed chassis modifications have been agreed upon with KAMAZ PJSC and therefore the maintenance of the KAMAZ-R6520RG dump truck is fully supported by its proprietary service network. Technical characteristics of the KAMAZ-R6520 dump truck