RU2056314C1 - Crawler vehicle steering gear - Google Patents

Abstract

FIELD: crawler vehicles. SUBSTANCE: transmission is divided at each side into control circuit and power flow. Power flow is divided into two parts, one of which is first transmitting flow which includes spur gear differential with one output shaft; second flow has gear train, second spur gear differential with feedback to housing of first differential, and worm gear drive. The latter serves simultaneously as element of control circuit and power flow. Control circuit has driving and driven units with gears arranged in diameter decreasing and increasing order and connected by toothed screw paths with different number of starts and intermediate gear connecting driving and driven units and located on oblique guide for travel along guide with simultaneously rolling over similar toothed screw paths of driving and driven units. Clutch is installed on control circuit to provide sharp turns. EFFECT: enhanced reliability of operation, enlarged operating capabilities. 3 cl, 2 dwg

Description

 The invention relates to tracked vehicles.

 Known friction mechanism of rotation of tracked vehicles, in which the transmission of torque to the tracked engines is carried out through separate friction clutches on each side. In this case, the tractor is controlled by friction clutches and brakes made separately on each side.

 The disadvantage of this design of the mechanism of rotation of the tracked vehicle is the presence of friction pairs, which are short-lived and unreliable.

 Also known rotation mechanism, combined with the gearbox. The presence of two secondary shafts allows you to get two separate power flows on each side and the tractor is controlled by switching different gears on each side, interrupting the transmission of torque to one of the sides and braking the engines of the disconnected side, turning on the front and rear gears on different sides.

 The possibility of obtaining various control schemes, the high maneuverability of the tractor and the combination of the turning mechanism with the gearbox make it possible to obtain a sufficiently reliable and compact turning mechanism. However, the presence of two power flows from the gearbox complicates the design of the tractor transmission. In addition, the presence of hydraulic clutch between the gears of adjacent gears reduces the durability of the gearbox. With the combined design of the rotation mechanism with the gearbox, the frequency of use of hydraulic clutch increases, which reduces the durability and reliability of the entire transmission. At the time of gear shifting on one of the secondary shafts of the gearbox, two gears will be engaged simultaneously, which creates a circulation of power within the gearbox. This leads to a loss of engine power and to increased wear of friction pairs.

 The closest design to the achieved result is a planetary rotation mechanism, where the number of friction pairs used is reduced, which allows a compact design with sufficient reliability.

 The disadvantage of this design of the rotation mechanism is the large transmitted moment through the rear axle shaft and, as a consequence, the need for powerful brakes in the control mechanism. Therefore, to maintain the steering mechanism in normal operating condition, a clean adjustment of the brakes and frequent replacement of wearing brake adjustments are required.

 The aim of the present invention is to increase durability and reliability, as well as increasing the functionality of the rotation mechanism of the tracked vehicle.

 This goal is achieved by eliminating friction pairs from the power flow circuit, for which the transmission is divided into a control circuit and a power flow. Moreover, the power flow, consisting of two parallel flows having feedback between themselves, transmits torque to the propulsors. The transmitted moment and the angular velocity of the output link associated with the propulsors are controlled through a control circuit. The coordination of the operation of the control circuit and the power flow is carried out through a worm gear. The worm gear can transmit torque only from the worm to the wheel, which allows the worm to adjust the angular speed of the output shaft of the rear axle. The elements of the control circuit have a small angular velocity and a small transmitted moment, therefore they are mainly used to transmit rotational motion to the worm.

 To make a turn in the control circuit of each side, there are provided: a gearbox having a driving and driven units with different diameters of the gears, arranged respectively in decreasing and increasing diameters, each of which has a toothed helical track of different orientation, and an intermediate gear located on an oblique guide with the possibility of move on it. The intermediate gear allows you to smoothly change the gear ratio of the gearbox from one value to another when moving it along an oblique guide with the simultaneous connection of the leading and driven units through the gear helical tracks of the same designation. Moreover, left-handed spiral tracks serve to obtain a fixed turning radius, and right-handed ones to return to rectilinear motion. In the control circuit for the implementation of a sharp turn on each side, a clutch is provided, which opens the control circuit and stops the rotation of the worm. The cessation of the rotation of the worm causes the propellers to stop on the same side.

 An increase in the functionality of the rotation mechanism is achieved by the identical movement of the intermediate gears in the gearboxes on each side, as a result of which the tracked vehicle receives additional translational speeds. This will simplify the design of the gearbox.

 The invention is illustrated by drawings, where figure 1 shows a General kinematic diagram of the rotation mechanism; figure 2 diagram of the gearbox for changing the gear ratio without breaking the power flow.

 The proposed rotation mechanism consists of a power circuit (a) and a control circuit (b). In turn, the power circuit consists of a common main gear 1 on both sides, a gear 2 separately on each side, a main 3 and a closing 4 differentials, the housings of which are connected by a gear 5, providing feedback, and a worm pair 6. The control circuit forms a drive gear 7, bevel pair 8, gear 9 for changing the gear ratio without breaking the power flow and the worm pair common with the power flow.

 The gearbox for changing the gear ratio without breaking the power flow consists of driving gears 10, 11 and 12 arranged in decreasing diameters and connected by gear helical paths 13 and 14 of different orientation, from driven gears 15, 16 and 17 arranged in increasing diameters connected by gear helical tracks 18 and 19 of different designations, an oblique guide 20 of square cross section with a sleeve 21 and an intermediate gear 22. mounted on it on the bearing. A clutch 23 is provided in the control circuit.

 The proposed rotation mechanism works as follows.

 When the tracked vehicle moves straight, the intermediate gear wheel for changing the gear ratio without breaking the power flow on both sides is in extreme positions, therefore the angular speeds of the worms on both sides are the same. As a result of this, the bodies of both closing differentials have the same angular velocity, which leads to the rotation of the output shafts of the main differentials with the same angular velocity. In this case, the torque is transmitted through the power flow to the propulsors, and through the control circuit, the rotational movement. The worm pair allows you to separate the control circuit from the power flow, since it can transmit torque only from the worm to the wheel.

 To obtain the left fixed turning radius of the tracked vehicle, the intermediate gear of the left gearbox to change the gear ratio must be moved along with the oblique guide to the middle gear to its width, and then along the oblique guide and left-handed helical tracks until it engages with the middle gears. In this case, the intermediate gear will be rolled along the helical tracks of the same direction and the gear ratio of the control circuit will decrease. This will lead to a decrease in the angular velocity of the worm on the port side and the speed of the left propellers. The tracked vehicle makes a left turn with a fixed radius. To obtain a smaller fixed turning radius, the intermediate gear is moved to the extreme right position. In this case, the angular speeds of the worms will differ more from each other and the tracked vehicle makes a left turn with a smaller radius.

 Right-toothed toothed helical tracks located between the drive and driven gears serve to return the intermediate gear to its original position, that is, to move the tracked vehicle into straight motion from the “fixed radius” position.

 Obtaining fixed turning radii occurs without the use of friction pairs of friction.

 To make a sharp left turn, you must disconnect the clutch on the left side control circuit. This leads to the cessation of rotation of the left worm. The rotation is not transmitted to the left thrusters, since in the main and closing differentials of the left side the satellites are driven in relative to the closing bevel gears.

 The locking bevel gear of the locking differential is rigidly connected to the worm and the cessation of rotation of the worm also leads to the stopping of the locking bevel gear of the main differential, which has a rigid connection with the propellers. Thus, the rotation will be stopped and left friction brakes will be inhibited without friction pairs of friction. The tracked vehicle then makes a rotation about the center of the left track. As soon as the control circuit clutch is engaged, the rotation of both worms is aligned and the tracked vehicle will move straight.

Claims (3)

 1. MECHANISM OF TURNING A TRACKED MACHINE, containing the main gear, final planetary gears in the form of differentials, one of the central gears of each of which is connected to the link of the propulsion unit, and the other to the differential control mechanism, characterized in that it is equipped with additional differentials, one for each a bead, a worm pair and a gearbox with a variable gear ratio to each bead, while the other central gears of the final drives are connected to the main gear and kinematically from one of the center gears of additional differentials and a gearbox with a variable gear ratio, the output shaft of which through a worm pair is connected to another central gear of additional differentials, while the differential housings on each side are engaged with each other.  2. The rotation mechanism according to claim 1, characterized in that the gearbox is made in the form of a driving and driven gear blocks, arranged respectively in decreasing and increasing diameters and an intermediate gear located between them with the possibility of moving along an oblique square guide with simultaneous connection of the master and slave blocks through the gear tracks of the same designation.  3. The rotation mechanism according to claims 1 and 2, characterized in that it has a clutch mounted in the control circuit to stop the rotational movement of the worm and to obtain the rotation of the tracked vehicle relative to the center of the track.

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