RU2149768C1 - Transfer case - Google Patents

Abstract

FIELD: transport engineering. SUBSTANCE: transfer case has housing, input, intermediate and output shafts, differential, planetary reduction gear and control clutch sleeves. Planetary reduction gear has sun gear secured on input shaft, carrier connected with differential carrier by intermediate shaft and epicyclical gear connected by tubular shaft with rim arranged between support of housing and rim of intermediate shaft. Distance between rims exceeds width of rim. Control clutch sleeves are intercoupled by slider. One clutch sleeve is mounted on rim of tubular shaft of epicyclical gear. Other clutch sleeve arranged on rim of differential output gear. Half of torque conveyed to epicyclical gear is transmitted to output shaft of rear axle drive. Second half of torque is transmitted through sun gear to output shaft of forward axle drive. EFFECT: increased load capacity of transfer case at decreased materials usage. 2 dwg

Description

 The invention relates to transport engineering, to the transmission of transport vehicles.

 Known transmission units with a step change in gear ratios and power distribution between the output shafts, comprising a housing, bearings, shafts, gears, differential, control clutches (1. Cars: Design, construction and calculation. Transmission. Edited by A.I. Grishkevich .-Mn .: Higher school, 1985, -240 p.).

 These units are structurally complex, material-intensive.

 Closest to the proposed transfer case (RC) is a two-stage, three-axis RC of a heavy-duty four-axle MAZ vehicle (2. Army vehicles: Design and calculation. Part 1. Edited by A. S. Antonov. - M.: Military Publishing, 1970, 543 S., see Fig. VI.14. S. 335).

 The RK consists of a housing with supports located in it on three axes by shafts, five gears, a differential and two control couplings. The differential drive shafts of the front and rear axle carts are aligned.

 Such a PK is also complex, has excessive material consumption and low load capacity, which limits the scope of such PKs. Load capacity - the ability to transfer and transform high torques is limited by a single-pair interaction of external gears, which also leads to excessive loading of the supports and reduce their service life.

 The objective of the invention is to increase the load capacity of the transfer case while reducing material consumption.

 The technical result is achieved by the fact that instead of external gears a simple three-link planetary mechanism is used. The sun gear of the planetary gearbox is fixed on the input shaft, the carrier of this gearbox is rigidly connected by the intermediate shaft to the differential carrier, a crown is fixed in the middle part of this shaft, the epicyclic planetary gear wheel is rigidly connected to the crown located between the housing support and the intermediate shaft crown, the distance between the crowns are larger than the width of the crown, the control couplings are coaxial and interconnected with one slider, one coupling is located on the crown of the tubular shaft of the epicyclic ring and the other - on the crown gear differential output.

 In FIG. 1 shows a circuit of the RC with an asymmetric differential when the creeping speed is on and the differential is locked.

 In FIG. 2 shows a PK circuit with a symmetric differential when creeping speed is switched on and the differential drive of the output shafts (upper position) and direct gear (lower position of the couplings) are engaged.

 In the support of the housing 1 (see Fig. 1), an input (primary) shaft 2 is mounted on which the sun gear 3 of the planetary gear is fixed. Satellites 4 are mounted on the carrier 5 of this gearbox and engaged with the sun gear 3 and the epicyclic wheel 6. The carrier 5 of the gearbox is interconnected by the shaft 7 with the carrier 8 of the differential, on which the satellites 9 are mounted, engaged with the epicyclic wheel 10 and the sun gear 11 of the differential. The epicyclic wheel 10 is mounted on the output shaft 12 of the rear axle drive (rear axle bridges), and the sun gear 11 is connected by a tubular shaft 13 to the gear 14. engaged with the gear 15 mounted on the output shaft 16 of the front axle drive. The crown 17 is fixed in the middle part of the intermediate shaft 7, and the crown 18 with a tubular shaft 19 is rigidly connected to the gear wheel 6 and is located between the housing and the crown 17. The distance between the crowns 17 and 18 is greater than the width of the crown. The control clutch 20 is installed on the crown 18, and the clutch 21 is on the ring gear 14, both couplings are interconnected with the slider 22.

 Depending on the loading conditions of the bridges, the differential can be either asymmetric (see figure 1) or symmetric (see figure 2).

 Separate drive of control couplings is allowed.

 Transfer box works as follows.

 1 position - "creeping" speed with a locked differential.

 Clutches 20 and 21 are shifted to the left position (see figure 1). The clutch 21 blocks the differential connecting the carrier 8, the shaft 7, the crown 17 with the ring gear 14, the tubular shaft 13 and the sun gear 11 differential. The coupling 20 connects the housing 1 to the crown 18 and the tubular shaft 19, stopping the epicyclic wheel relative to the housing 1.

 Torque from the input shaft 2 enters the sun gear 3, which rotates the satellites 4. Satellites 4, rolling on a stopped epicyclic wheel 6. move the carrier 5 in the direction of rotation 2. The increased torque from the carrier 5 is transmitted by the intermediate shaft 7 to the carrier 8 of the differential and the satellites 9 are distributed to the epicyclic wheel 10 and the sun gear 11. From the epicyclic differential wheel 10, the force is transmitted to the output shaft 12 of the rear axle drive (rear axle carriage). From the sun gear 11, the tubular shaft 13, gears 14 and 15 force is transmitted to the output shaft 16 of the front axle drive.

 II position - "creeping" speed in differential mode.

 The couplings 20 and 21 are shifted to the middle position (see Fig. 2 the upper position of the couplings). The coupling 20, as in position I, stops the epicyclic wheel 6 relative to the housing 1, the increased torque along the shaft 7 is supplied to the differential carrier 8. The clutch 21 disconnects the crown 17 of the shaft 7 from the crown of the gear 14. The differential distributes the torque from the carrier 8 in proportion to the radii of the gears 10 and 11. From the gear 10, the moment is transmitted to the shaft 12, and from the gear 11 through the tubular shaft 13 to the gears 14 and 15, further on the shaft 16.

 III position - direct transmission in differential mode.

 The couplings 20 and 21 are shifted to the right position (see Fig. 2 lower position of the couplings). The clutch 21 unlocks the differential, and the clutch 20 blocks the planetary gear, connecting the carrier 5 with the shaft 7, the crown 17 and the epicyclic wheel 6 with the tubular shaft 19 and the crown 18.

 Torque from the input shaft 2 via the locked planetary gearbox and shaft 7 is supplied to the differential carrier 8, where the satellites 9 are distributed to gears 10 and 11. From gear 10, half of the torque transmitted to the differential is transmitted to the output shaft 12 of the rear axle drive. The second half of the torque from the gear 11 by the tubular shaft 13, gears 14 and 15 is transmitted to the output shaft 16 of the front axle drive.

 The economic effect is expressed in increasing the load capacity of the unit - the ability to transmit and transform high torques due to the multi-pair planetary gearing of the planetary mechanism, which also relieves bearings from radial and axial forces, and this reduces the material consumption of the Republic of Kazakhstan. The proposed RK fully implements the capabilities of the planetary mechanism - when the epicyclic wheel is stopped and the force is transferred from the sun gear to the carrier, we get the maximum gear ratio equal to the ratio of the number of gear teeth and gear increased by one, the transmission works with high efficiency.

 The interconnection of couplings with one slider facilitates the control of the RC.

 Separate connection of couplings with sliders complicates the control of the RC, but allows independent differential lock.

Claims (1)

 Transfer case containing a housing with shafts, gears, differential, control clutches located in it, characterized in that the planetary gear reducer’s sun gear is fixed to the input shaft, the gear carrier of this gearbox is rigidly connected by the intermediate shaft to the differential carrier, a crown is fixed in the middle part of this shaft, the epicyclic planetary gear wheel with a tubular shaft is rigidly connected to the crown located between the housing support and the intermediate shaft crown, the distance between the crowns is greater than the crown width, mu you control are aligned and interconnected with one slide, one clutch is located on the crown of the tubular shaft epicyclic wheel, the other - on the crown gear differential output.

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