ZIS-15

The ZIS-5 truck, which was massively built in the USSR, was in its design a development of the American Autocar Dispatch SA truck of AutoCar Truck, the USSR acquired the license for the construction in 1928. And, although Soviet engineers made significant improvements to the base American model, by the end of the 1930s the ZIS-5 was thoroughly outdated. The creation of a new truck design made it possible to reduce the backlog from the world level. In addition, it became possible to fully take into account the rich experience accumulated by that time in operating the ZIS-5 family of vehicles.

Back in 1937, a prototype car with a new metal all-metal cab, streamlined with an inclined windshield, was built at ZIS. This work was developed when creating a new truck, which received the designation ZIS-15.

The prototype ZIS-15, the construction of which was timed to the XVIII Congress of the All-Union Communist Party (Bolsheviks) , received a more powerful engine than the ZIS-5 , a gearbox with helical gears, and new tires measuring 36 "× 8". Due to the increased wheelbase up to 4100 mm, the cardan transmission was double, with an intermediate support. The brake drive remained mechanical, but received a vacuum booster. In addition, a transmission disc brake was introduced. The gas tank capacity has been increased to 100 liters. The main external difference was the modern all-metal, 3-seater streamlined cabin with an inclined V-shaped windshield (from two halves).

By mid-1939, the first prototype ZIS-15 passed more than 5,000 km in road tests with a load reaching 5 tons. Test results were found to be positive. Only engine power of 82 liters. with. considered insufficient for the machine increased capacity.

In 1939, prototypes were built with two wheelbases - 4100 mm and 4400 mm. The third prototype, which began to be assembled in mid-1939, made a number of important improvements. A forced engine was installed (with aluminum pistons and a compression ratio increased to 5.7), the power of which was increased to 90 hp. at 2700 rpm The 5th accelerating gear appeared in the gear change box, which allows saving fuel when driving empty. The car received new wheels with 8 studs. The appearance of the wings, radiator and hood trim has changed.

On the basis of the ZIS-15 it was planned to build a series of cars:

• ZIS-15 is a base truck.
• ZIS-16 - bus hood layout.
• ZIS-17 - bus carriage layout.
• ZIS-23 is a three-axle all-wheel drive (6 × 6) truck.
• ZIS-24 - a two-axle all-wheel drive (4 × 4) truck.
• ZIS-25 - gas generating vehicle.
• ZIS-26 - a truck tractor.
• ZIS-D7 - a variant of a truck with a diesel engine ZIS-D7 with a capacity of 96 hp
• ZIS-28 is a gas-generating vehicle with an engine based on ZIS-D7.

In 1940, a long-base model ZIS-15 was demonstrated at the All-Union Industrial Exhibition (now - VVC). The plant was preparing for production. The new family was planned to be put on the conveyor until the end of the third five-year plan (1938-1942), but the outbreak of war did not allow these plans to be realized. As a result, of all the cars of the ZIS-15 family, only the ZIS-16 bonnet bus went into the series.

However, the efforts of designers, technologists and testers were not in vain. In 1943, when there was a turning point in the war, work on a new truck was resumed at ZIS. The prototype built in 1944, which received the designation ZIS-15K, completed the development of the ZIS-15 family - after modifications were made, it became the prototype of a 4-ton truck of the new ZIS-150 model, which was mass-produced from 1947 to 1957.

ZIS-15 was a two-axle truck with a wooden side platform with a lifting capacity of up to 5 tons on the highway and up to 3.5 tons on dirt roads.

The ZIS-15 engine is a further modernization of the 6-cylinder ZIS-5 engine, the power of which was brought to 82 liters. with. at 2650 rpm with the same working volume. The increase in power was achieved by increasing the compression ratio (from 4.7 to 5.3), improved filling of the cylinders with a working mixture (increased valve lift and variable valve timing) and a change in the shape of the combustion chamber. In the third prototype, a forced engine with aluminum pistons was installed, which had a compression ratio of 5.7, the power of which was increased to 90 hp. at 2700 rpm An increased capacity pump was introduced into the engine cooling system.

The clutch is a two-disk one, similar in design to that used on the ZIS-5 . Gearbox - 5-speed, mechanical, with direct 4th gear and accelerating 5th. The gearbox was significantly different from that used at the ZIS-5 - the gears of constant gearing and the gears of the 3rd and 5th gears were helical, and the bearings were reinforced. The first samples were equipped with a 4-speed gearbox without accelerating gear and with slightly different gear ratios.

Cardan shaft - double, with an intermediate support. The main gear is a two-stage one, with a pair of spur gears and a pair of bevel gears with a spiral tooth. The total gear ratio is 7.63 (6.9 in the first samples). Compared to the ZIS-5 , the bevel gears and the drive gear bearing were significantly strengthened. The drive roller of the drive bevel gear, as well as the drive roller of the driven bevel and small cylindrical gears, was mounted on tapered roller bearings. The differential box, as on the ZIS-5 , rotated on a pair of ball bearings.

The rear axle beam - with cast from the ductile iron cast crankcase of the main gear, into which sleeves (stockings) of alloy steel are pressed.

Axles of the rear axle - unloaded type. The front axle is similar in design to the ZIS-5 , but is reinforced in all elements, since the load on it has grown to 2.5 tons.

Steering gear - worm and crank with removable finger. The worm rotated on two thrust ball bearings. The gear ratio is 22.3 (in the first samples - 15.9). The brake system is mechanical. It consisted of working (foot) brakes and a parking (manual) transmission brake.

The service brakes acted on the 4-wheel pedal and had a mechanical drive, but, unlike the ZIS-5 , they had a vacuum booster with a direct-acting valve. Another difference from the ZIS-5 was the replacement of the front wheel brake cable drive with rigid traction. Brakes on all wheels - drum type, two-track, direct action. Pads were made of malleable cast iron (width of pads: rear - 100 mm, front - 70 mm; areas, respectively, 429 and 300 cm²). Brake drums - cast iron with a reinforced rim. The diameter of the drums of the front and rear wheels is 410 mm.

The parking (manual) disc brake was located on the intermediate driveshaft at the second universal joint and acted on the rear wheels (as used on the ZIS-6 ). Wheels - disk, steel, with a rim for tires dimension 36 "× 8". On 1939 models , the wheel design inherited from the American AutoCar-SA truck with 6 studs for a more solid, with 8 studs (from then until now, medium-tonnage trucks manufactured by ZIL have 8-stud wheels). In dual rear wheels, each drive was mounted independently.

Suspension of front and rear wheels - on longitudinal semi-elliptic springs . To increase ride smoothness, the front springs were lengthened by 50 mm compared to the ZIS-5 . An additional spring was lengthened in the rear suspension - to increase ride smoothness under load.

Frame - stamped from steel sheet with a thickness of 6 mm (steel 1025). The frame side members are a channel - shaped section with a variable height (increased compared to the ZIS-5 ). Cabin - all-metal, triple, streamlined shape with an inclined windshield. For a more comfortable driver’s landing, the cab was slightly elongated compared to the ZIS-5 .

Prototypes were distinguished by a long base, engine power and gearbox design. The following are the technical specifications of the 1938 prototype:

Weight characteristics:

• lifting capacity on a dirt road: 3.5 tons
• highway loading capacity: up to 5 tons
• weight at full load (3.5 tons): 6800 kg
  - of which to the rear axle: 4900 kg
  - front axle: 1900 kg

Geometrical characteristics:

• machine length: 6560 mm (without bumper)
• machine width: 2235 mm
• machine height (cab): 2565 mm
• wheelbase: 4400 mm (a variant with a base of 4100 mm was also provided)
• front wheel track: 1630 mm
• track of back wheels: 1780 mm
• wheel dimension: 36 "× 8"

Sizes of a cargo platform:

• platform length: 3600 mm (3800 mm on early specimens)
• platform width: 2300 mm (2400 mm on early specimens)
• side height: 620 mm
• loading height without load: 1165 mm
• loading height with load: 1090 mm

Engine:

• type: carburetor, 4-stroke
• configuration: in-line, 6-cylinder
• cylinder diameter: 101.6 mm (4 ")
• piston stroke: 114.3 mm (4½ ")
• working volume: 5560 cm³
• compression ratio: 5.3 (5.7 with aluminum pistons)
• power: 82 hp at 2650 rpm (90 hp at 2700 rpm with aluminum pistons)
• cylinder working order: 1-5-3-6-2-4
• gas distribution system: lower valve, with 2 valves per cylinder (located in a row on the right side of the cylinder block)
• cooling system: water, with forced circulation (centrifugal pump increased productivity)
• lubrication system: under pressure, from gear pump
• ignition system: battery
• power system: carburetor MKZ-6
• fuel supply: diaphragm pump

Clutch: Double Disc

Gearbox:

• type: mechanical, 3-shaft, 3-way
• gears: 1st, 2nd and reverse gears are spur gears, 3rd, 5th and permanent gears are helical gears.
• number of steps: 5 forward, 1 - reverse (4-speed on early specimens)
• gear ratio of 1 transmission - 6.25 (6.00 on early samples)
• gear ratio 2 transfers - 3.33 (3.34 on early samples)
• gear ratio 3 gears - 1.9 (1.76 on early samples)
• gear ratio 4 gears - 1.00
• gear ratio 5 gears - 0.81 (not available on early samples)
• 6.97 rear gear ratio (6.94 on earlier samples)
• gear shifting: swinging floor lever

Cardan drive: double, with an intermediate support.

Drive axle:

• main gear: two-stage, with a pair of bevel gears and a pair of cylindrical gears (bevel gears with a spiral tooth)
• total final drive ratio: 7.63 (6.9 on earlier samples)
• differential: conical, with 4 satellites
• half shafts: fully unloaded
• drive axle beam: composite, with cast from main duct cast iron of main gear housing, into which sleeves (stockings) of alloy steel are pressed.

Steering axle and steering:

• steering axle beam: stamped steel, I-section
• steering gear: worm and crank with removable finger. The gear ratio is 22.3 (in the first samples - 15.9).
• steering draft: longitudinal

Suspension:

• front wheels: dependent on longitudinal semi-elliptic springs
• rear wheels: dependent on longitudinal semi-elliptic springs, with additional sheets

Ground clearance (clearance):

• under the steering axle: 330 mm
• under the drive axle: 300 mm
• under flywheel housing: 428 mm

Maximum speed: 65 km / h.

• Drozhinsky. New truck ZIS-15 (Russian) // Behind the Wheel: a magazine. - 1938. - No. 21 . - S. 24-25 .
• Briefly: Truck ZIS-15 (Russian) // Behind the Wheel: a magazine. - 1939. - No. 8 . - S. 15.17 .
• New ZIS cars (Russian) // Behind the Wheel: a magazine. - 1939. - No. 9 . - S. 12 .
• Trucks ZIS-15 (Russian) // Behind the Wheel: a magazine. - 1939. - No. 12 . - S. 12 .
• Car ZIS-15 (Russian) // Behind the Wheel: a magazine. - 1940. - No. 9 . - S. 14-15 .
• Yuliev N. In the pavilion of mechanization (Russian) // Behind the Wheel: a magazine. - 1940. - No. 11 . - S. 3 .
• Sokolov M. Long work on mistakes (Russian) // Automobile historical portal: electronic edition. Archived on April 17, 2012.