Starter device for VAZ-2106 and VAZ-2103 cars

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To start the engine, a starter ST-221 with a power of 1.3 kW is used, with electromagnetic engagement of the drive gear, with a freewheel and remote control. Since 1986, an interchangeable starter 35.3708 with a two-winding traction relay and an end collector has been installed on cars.

The ST-221 starter is a four-brush, four-pole DC motor with mixed excitation and consists of a housing 41 with excitation windings, an armature with a drive, two covers 11 and 28 and a traction electromagnetic relay. The covers and the body are pulled together into a single whole by two pins screwed into the cover 11.

Four poles 40 are fixed with screws inside the steel case. Winding coils are put on the poles. The housing, together with the poles and coils, forms the starter stator. Two stator winding coils are serial, i.e. are connected to the armature winding in series, and the other two are shunt connected in parallel to the armature winding. Therefore, the excitation of the starter is called mixed. It provides a relatively low idle speed of the armature without load, which reduces wear on the armature shaft bearing bushings, facilitates the operation of the overrunning clutch and prevents armature runaway.

The starter armature consists of a shaft 37, a core with a winding 42 of copper tape and a collector 33 made in the form of a plastic sleeve with copper plates embedded in it. The armature shaft rotates in two ceramic-metal bushings 38, pressed into the starter covers and soaked in oil. The axial free play of the armature shaft is regulated by the selection of washers 54 and should be within 0.07-0.7 mm (starter 35.3708 - no more than 0.5 mm).


At the front end of the armature shaft, a starter drive is installed, consisting of a roller overrunning clutch and gear 1. The purpose of the overrunning clutch is to transmit torque from the starter armature shaft to the flywheel crown when starting the engine, and after starting, while operating in overtaking mode, to prevent torque transmission from flywheel to anchor. Otherwise, the armature winding may be ejected from the core slots due to "spacing" - excessively high frequency of rotation of the armature by the flywheel of a running engine.

The overrunning clutch consists of an outer ring 5 with rollers 3 and an inner ring combined with drive gear 1. The outer ring has three slots with holes, in which there are steel rollers with springs, plungers and guide rods. Grooves for rollers - with variable width. In the wide part of the groove, the rollers can rotate freely, and in the narrow part they are wedged between the outer and inner rings.

The starter electromagnetic traction relay is used to engage the drive gear with the flywheel ring and to close the power circuit of the armature and stator windings. The magnetic system of the relay is formed by flanges 15 and 20, the yoke (winding) and core 19, pressed into flange 20. A relay coil is wound on a frame made of brass tube and plastic cheeks. Starters manufactured in 1981 have two windings: holding and retracting. Both windings are wound in the same direction. The beginning of the windings are soldered to the plug "50". The end of the holding winding is welded to the flange 20 of the relay (those. connected to "weight"), and the end of the retracting winding is connected to the lower contact bolt 27 of the relay.


The starter 35.3708 differs from the ST-221 starter in the use of an end collector and stator windings. The end manifold is made in the form of a plastic disk with copper plates embedded in it. Such a collector contributes to a more stable and long-term operation of the brush contact, copper consumption is reduced, and the mass of the starter is reduced. The stator winding consists of three serial coils and one shunt coil, which made it possible to increase the armature torque. Otherwise, the design of the starter 35.3708 is the same as that of the ST-221 starter.

Starter operation

When the key is turned to position II ("Starter") contacts close "30" And "50" ignition switch, and current begins to flow through the windings of the traction relay.

Under the influence of this current, a magnetic force of about 10-12 kgf arises, which retracts the armature of the relay until it comes into contact with the core 19. In this case, the contact plate closes contacts 25 and 27.

For a starter with a two-winding traction relay, when the contact bolts are closed, the retracting winding is de-energized, since both of its ends are connected to "a plus" battery. Since the armature is already drawn into the relay, a relatively small magnetic flux is required to hold the armature in this position, which is provided by one holding winding.

Moving, the anchor of the relay through the lever 9 will mix the overrunning clutch with the gear. The overrunning clutch hub, turning on the screw splines of the starter armature shaft, also turns gear 1, which facilitates its engagement with the flywheel crown. In addition, the chamfers on the lateral edges of the teeth of the gear and the flywheel ring, as well as the buffer spring that transmits the force from the lever 9 to the hub 47 of the clutch, facilitate the engagement of the gear and soften the impact of the gear on the flywheel ring.

Through the closed contacts of the relay, the power supply current of the stator and armature flows. The starter armature begins to rotate together with the hub 47 and the freewheel outer ring. Since the clutch rollers are displaced by springs into the narrow part of the groove of the outer ring, and the gear is braked by the flywheel ring, the rollers are wedged between the overrunning clutch rings, and the torque from the armature shaft is transmitted through the clutch and gear to the flywheel ring.

After starting the engine, the speed of the gear begins to exceed the speed of the starter armature. Sprag Inner Ring (combined with gear) drags the rollers into the wide part of the groove of the outer ring 5, compressing the springs of the plungers. In this part of the groove, the rollers rotate freely without jamming, and the torque from the engine flywheel is not transmitted to the starter armature shaft.

After the key is returned to position I ("Ignition") the power supply circuit of the windings of the traction relay opens. The armature of the relay under the action of spring 12 returns to its original position, opening contacts 25 and 27 and returning the overrunning clutch with the gear to its original position. Spring 12 through the lever, disk 44 and limiter 43 presses on the anchor towards the cover 28. The steel brake disk 31 of the armature shaft rests against the brake disk 30 of the cover, and the anchor quickly stops rotating. At the starter 35.3708, the armature is braked due to the friction of the brushes on the collector.