RU2150602C1 - Automobile starter-generator - Google Patents

Abstract

FIELD: transport- engineering; electrical equipment. SUBSTANCE: proposed starter- generator is designed for use in automobiles for starting internal combustion engines and generating power for automobile consumers. Starter-generator is made on base of starter with planetary reduction gear of latest models of VAZ and GAZ cars in which DC machine with unreliable commutator-brush unit operating at 25,000 rpm is replaced by noncontact induction brushless machine and separate parts of planetary reduction gear are changed to provide automatic decrease of transmission ratio at changing from starter to generator duty. Automobile starter- generator is installed in standard place designed for starter, and no expensive changes of layout of car separate units are required. EFFECT: increased reliability and reduced overall dimensions of starter-generator. 2 dwg

Description

 The invention relates to electrical equipment of transport and can be used on cars as for starting an internal combustion engine (ICE), and generating electricity for the needs of an onboard network. There are many different starter-generators designed for transport, using a contactless asynchronous machine (AM), powered by a transistor or thyristor voltage inverter / 1, 2 /. However, they have not yet found application in automobiles, partly because installing them requires an expensive change in the layout of various components (engine, gearbox, etc.).

 Known ASTG / 2 / s AM, connected to a transistor voltage inverter, and a planetary gearbox, the output shaft of which is connected to the ICE shaft using a belt drive.

 The specified device, thanks to the installation of a planetary gearbox, can significantly increase the frequency of rotation AM and, accordingly, reduce the moment on the shaft, the mass of the machine, and therefore the cost of active materials. The reduction in torque allows to reduce inrush currents from the battery and increase its service life. The disadvantage of this device is the low reliability of the belt drive, since in the starting mode the starting torque of the internal combustion engine can be 200 Nm. In addition, the belt drive coefficient is limited by the size of the pulleys and it is necessary to increase the dimensions of the planetary gearbox, performing it in two stages.

 The essence of the invention lies in the fact that in order to increase the reliability of this device, simplify the planetary gearbox and reduce the dimensions of the ASTG, connect the output shaft of its planetary gearbox with the drive gear to the flywheel of the ICE. In addition to the indicated positive effect, it should be noted that the ASTG can be performed on the basis of a starter with a planetary gearbox / 3 / of the latest cars VAZ 2110 and GAZ 3302. Therefore, the ASTG is installed at the regular position of the specified starter, which does not require an expensive change in the layout of individual vehicle components . To do this, it is necessary to change the following nodes and their connections to each other, not requiring changes in its installation dimensions.

 Replace a DC collector machine operating at a speed of 25,000 rpm with a structurally more reliable contactless AM with a squirrel-cage rotor, powered by a three-phase transistor voltage inverter connected from the DC side to the battery (Fig. 1). The inverter is implemented as a separate unit together with a control circuit and is placed in any free space under the hood or in another place of the car. In the starter mode, the inverter works as a converter of DC voltage to an alternating three-phase voltage of adjustable frequency and allows you to accelerate the internal combustion engine with frequency control. In the generator mode, the inverter operates as a source of reactive power, exciting AM and allowing you to maintain constant voltage on the DC bus due to frequency control as a function of the deviation of the output voltage / 4 /. In this mode, the inverter’s reverse bridge diodes also perform the functions of a three-phase rectification bridge circuit.

 Make the drive gear non-detachable with the flywheel crown and directly fix it on the shaft together with the carrier, bypassing the overrunning clutch and the trip mechanism controlled by the traction relay and the drive lever, the need for which is no longer necessary. the device must operate in starter and generator modes.

 Automatically switch the planetary gear operation so that in the starter mode the rotation of the AM shaft with the drive gear is transmitted to the drive gear shaft through the planetary gear, and in the generator mode after the internal combustion engine starts, the specified gear is transmitted directly to the AM shaft, bypassing the planetary gear, so that the speed her and shaft AM were the same. To do this, the AM rotor shaft is hollow and a smaller diameter carrier shaft, made of alloy steel and mounted on bearings mounted inside the AM shaft, is passed inside. Chromium steel overrunning clutch rollers are installed next to the bearing between the carrier shaft and the AM internal shaft. Overrunning clutch cam profiles are cut on a flexible roller and, like the internal surface of a hollow shaft, have increased hardness. A flexible twisting shaft protects the AM rotor from torsional vibrations in the generator mode when transmitting torque to it and is specially worked out so that its surface layer is hardened with a soft core. After starting the internal combustion engine, the frequency of rotation of the flexible shaft increases, the overrunning clutch rollers jam under the action of centrifugal force and it engages with the rotor shaft AM. As a result, the rotational speed of the carrier and the rotor shaft AM with the driving gear will be the same, and the gears of the satellite will be stationary. It is clear that in this case, the gear wheel with internal gearing should rotate freely with the carrier’s rotation speed and a ratchet mechanism is required to disengage this wheel from the housing in the generator mode and clutch in the starter when the gears - satellites are run around this already stationary gear wheel and rotate from the shaft AM is transmitted to the carrier shaft with a decrease.

 The ratchet mechanism is made as follows. The gear wheel with internal gearing is detached, mounted in a housing on a bearing. The ratchet wheel is attached with pins to the housing. On the ledge of the wheel with internal gearing dogs are attached. They are using springs as a clock, one end of which is fixed on the axis of the dog, and the other presses it against the ratchet wheel. Therefore, the specified wheel can rotate freely only in one direction. In this case, the dog, overcoming the force of the spring under the action of centrifugal force, disengages from the ratchet wheel.

 ASTG (Fig. 2) consists of a housing cover 1, a drive gear 2, mounted on a shaft 3, a planetary gear carrier 7 mounted on the same shaft, a flexible roller 10 working on twisting and also connected to the shaft 3 by means of a spline connection, a fixed ratchet wheel 4 connected to the housing by means of pins, a gear wheel with internal gearing 6 mounted in the housing on a bearing, dogs 5 located on the protrusion of the specified wheel 6 and pressed against the ratchet wheel 4 by means of clockwise springs, satellite gears 8, an AM stator with a three-phase winding 11, a squirrel-cage rotor 12 with a hollow shaft 13, inside which a flexible roller 10 is mounted on bearings with an overrunning clutch 14, which engages said roller with the AM shaft after starting the engine, and the shaft bearing cover AM.

 The operation of the starter generator is as follows. After turning on the control device and supplying control signals to the power transistors (Fig. 2), the latter will begin to switch, a three-phase current will flow along the stator winding AM and its rotor will begin to rotate counterclockwise when viewed from the AM side. The drive gear, rigidly connected with the rotor shaft 13, transmits rotation to the satellite gears 8, which, rolling around the gear wheel with internal gearing 6, create a force on it, tending to rotate it clockwise. But this rotation is prevented by a ratchet mechanism. As a result, the specified gear wheel will remain stationary, and the carrier 7 together with the satellite wheels 8 will rotate counterclockwise, rotating the drive gear 2 rigidly connected to it by the common shaft. The latter, being constantly engaged with the crown of the ICE flywheel, will spin it, and this the overrunning clutch installed between the carrier shaft and the AM rotor shaft will be wedged.

 When the speed of the internal combustion engine exceeds the frequency of rotation AM, the freewheel wedges, the rotation from the internal combustion engine through the gear of the drive 2 will be transmitted to the carrier 7 and through its flexible shaft directly to the hollow shaft of the rotor AM. Since the rotational speeds of the carrier and the rotor shaft coincide with the driving gear 13, the satellite gears are braked and carry along with the carrier an internal gear 6, which will rotate in a counterclockwise direction. With this rotation, under the action of centrifugal forces, the dogs on the gear wheel are squeezed from the fixed ratchet wheel and out of engagement with it. The entire gearbox together with the gear wheel 6 will rotate idle. Thus, in the generator mode, the AM rotor will rotate directly from gear 2, coupled to the crown of the ICE flywheel, bypassing the overdrive of the planetary gearbox.

LITERATURE
1. Kostyrev M.L., Skorospeshkin A.I. Autonomous asynchronous generators with valve excitation. - M .: Energoatomizdat, 1993, 160 p.

 2. United States Patent Number 4883973. Automotive electrical system ha-ving a starter / generator induction machine. / General Motors Corporation, Detroit, Mich. / Filed: Aug. 1, 1988 / Date of Patent: Nov. 28, 1989.

 3. Jutt V.E. Electric equipment of cars - M .: Transport, 1995, 303 p.

 4. A.S. 588610 USSR, MKI N 02 P 9/44. A control method for an autonomous asynchronous squirrel-cage generator / M.L. Kostyrev. A.I. Skorospeshkin et al. // B.I. 1978, N 2.

Claims (1)

 An automobile starter-generator, comprising an squirrel-cage asynchronous machine, the shaft of which is connected to the drive gear of the planetary gearbox, and the output shaft of the latter is connected to the shaft of the internal combustion engine, characterized in that the planetary gearbox is single-stage with automatic change of the gear ratio, and the output shaft using the drive gear, it is connected to the flywheel of the internal combustion engine.

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