HYDRODYNAMIC AUTOMATIC TRANSMISSION

Abstract

The invention relates to a hydrodynamic transmission gear-box that contains two pump wheels, which are round flat disks, on the front peripheral part of which installed firmly are radially directed blades. The first wheel is rigidly connected to the input shaft. The second and subsequent pump wheels, each with a diameter greater than the previous one, are mounted with their own hubs onto the hubs of the preceding pump wheels with the possibility of free rotation on them. On the back side of each disk, a device is installed to block it with the next pump wheel, and the last pump wheel—with the turbine wheel. The turbine wheel is mounted on the input shaft and in the crankcase of the drive device on bearings and is connected to vehicle's reverse mechanism and running gear. Reduction in weight and size, increase of service life and performance improvement are achieved.

Claims

1. A hydrodynamic transmission gear-box for a vehicle, comprising: at least two pump wheels, which are round flat discs, on a front peripheral part of which firmly mounted are radially directed blades, wherein a first wheel is rigidly connected with an input shaft; wherein a second wheel and subsequent pump wheels, a diameter of each of the subsequent pump wheels is larger than a diameter of a preceding one of the subsequent pump wheels, have hubs that are mounted onto the hubs of preceding pump wheels and are permitted to freely rotate thereon, but are restricted from mutual axial movement, wherein a device is installed on a back of each of the round flat discs to block each of the round flat discs with a corresponding one of the subsequent pump wheels, and a last of the pump wheels with a turbine wheel; wherein a front side of the second wheel and the subsequent pump wheels and a front side of the turbine wheel include cylindrical rings with internal teeth for coupling with the locking device; wherein blades of the turbine wheel from a side that faces blades of the pump wheels are covered with a cone-shaped ring disc, wherein a larger diameter of the cone-shaped ring disc is equal to a diameter of the round flat disc of the last pump wheel, and a smaller diameter of the cone-shaped ring disc equals a smaller diameter of blades of a first one of the pump wheels; and wherein the turbine wheel is mounted on the input shaft within a crankcase of a drive device on bearings and is connected to a reverse mechanism and drive gear of the vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Embodiments of the proposed invention is explained by drawings:

[0009] FIG. 1 is a general front and partially cross-sectional view of an embodiment of a hydrodynamic automatic transmission gear-box,

[0010] FIG. 2 is a front and partially cross-sectional view of an embodiment of a device for blocking and unblocking pump wheels in an unblocked position,

[0011] FIG. 3 is a front and partially cross-sectional view of an embodiment of the device for blocking and unblocking pump wheels in a blocked position.

[0012] In the Figures: [0013] a-a—axis passing through the points of hinge attachment of the ends of servomechanism springs on the stock arms; and [0014] b-b—axis passing through the points of hinge attachment of servomechanism springs on the internal pump wheel.

DETAILED DESCRIPTION

[0015] How an embodiment of the hydrodynamic automatic transmission works is described below with reference to FIGS. 1-3.

[0016] With reference to FIG. 1, when the input shaft 9 rotates, the first pump wheel 17, rigidly connected to the input shaft 9, creates a flow of working fluid, which fills the internal cavity of the gear-box. The velocity of the working fluid flow has radial and tangential components. On the hub 10 of the first pump wheel (internal) 21, a second (external) pump wheel 22 is mounted with the possibility of free rotation on it. The flow of the working fluid falling on the blades 3 of the external pump wheel 22 sets it in motion. Similarly driven are subsequent pump wheels (there can be any number of them), who also rotate freely on the hubs 10 of the preceding pump wheels. In this case, a cone-shaped ring disk 14 directs the working fluid flow accelerated by the pump wheels 22 to the peripheral part of a turbine wheel 1. The flow of the working fluid, reaching the blades 3 of the turbine wheel 1, which is rigidly connected to the housing and the output shaft 9 through holes 15, transmits to them the torque from the input shaft 9. To hermetically seal the gear-box and to prevent leakage of the working fluid, oil and tightening seals may be used.

[0017] At the start of low-speed rotation of the input shaft 9 (vehicle's neutral gear), no torque is transmitted to the turbine wheel 1 because the value of the flow rate and internal sliding of the working fluid is insignificant. When the number of revolutions of the input shaft 9 increases and the flow rate of the working fluid increases in the radial and tangential directions, the turbine wheel 1 receives torque first only from the first pump wheel 17 (vehicle's first gear). In this case, the second and subsequent pump wheels, rotating freely on the hubs of preceding pump wheels, do not create resistance to the transference of the working fluid flow in the radial and tangential directions.

[0018] With further increase in the number of revolutions of input shaft 9 and first pump wheel 17 rigidly connected to it, when a certain number of revolutions is reached, with the help of pump wheel blocking device 11, the first pump wheel 17 is blocked with the second pump wheel (second gear of movement), then jointly rotating first and second pump wheels with the subsequent one (third gear) and so on. And upon reaching a certain number of revolutions of the jointly rotating pump wheels 17, the last pump wheel is blocked with turbine wheel (housing) 1.

[0019] When the vehicle's speed decreases due to changes in external conditions, and the number of revolutions of the turbine wheel 1 decreases to a certain value, the housing of the turbine wheel 1 is unblocked from the last pump wheel. With a further decrease in the speed of rotation of the turbine wheel 1 caused by a further decrease in the vehicle's speed, the speed of rotation of the last of the pump wheels decreases, and when their rotation speed decreases to a certain value, a sequential unblocking of the next pump wheel 17 from the other blocked wheels occurs. Thus, when a certain number of revolutions is reached, a reverse gear shift occurs.

[0020] The number of revolutions at which the pump wheels 21, 22 lock and unlock is set for the locking mechanism of each pump wheel 17. In FIG. 1, reference numeral 34 refers to a key, reference numeral 5 refers to a washer, reference numeral 6 refers to a bearing, reference numeral 7 refers to an oil seal, reference numeral 8 refers to a locking ring, reference numeral 12 refers to cylindrical rings with internal teeth, reference numeral 13 refers to internal slots of the drive shaft, reference numeral 16 refers to lugs for connecting halves of the housing of the turbine wheel 1; and reference numeral 17 refers to the first pump wheel.

[0021] The blocking and unblocking of the pump wheels 21, 22 is described below with reference to FIGS. 2 and 2.

[0022] When the internal pump wheel 21 rotates, under the action of centrifugal force, the teethed segment 23 and stock 24 start moving radially from the center to the periphery, overcoming the counteraction of springs 25, 26 and 29, and blocking the blocking of the pump wheels 21 and 22. Moreover, with an increase in the number of revolutions and increase in the centrifugal force, the counteracting force from servomechanism 28 with springs 26 will decrease due to a change in the angle of application of forces, and when axes a-a and b-b coincide, the counteracting force will become zero. The moment axis a-a passes axis b-b, a sharp movement of the stock arms 27 to the periphery will occur, since the force of the springs 26 of the servomechanism 28 will also be added to the centrifugal force, which will also be directed to the periphery. The stock arms 27 will abut the cup 30 of the sleeve with arms 31, overcoming the resistance of weak spring 25, and the whole system will connect the teeth 35 of the teethed segment 23 of the inner wheel 21 with the teethed ring edge 36 of the outer pump wheel 22. The sleeve with arms 31 will close the rear side of the toothed segment 23 with the cams of the eccentrics 32, which will ensure a reliable engagement of the two disks. With that, the pin 33 will end up at the lower (nearer to the center of the disk) edge of the groove or slot 34.

[0023] When the speed of joint rotation of the blocked pump wheels 21 and 22 is reduced to a certain limit, the stock 24 and the toothed gear segment 23, under the action of spring 25, overcoming the counteraction of the servomechanism 28, begin to move radially from the periphery to the center of the pump wheels 21, 22 (unblocking them). After axis a-a crosses the line of axis b-b, the resistance of the servo-mechanism 28 stops, and under the action of the springs 26 and 29, there will be a sharp movement of the stock 24 to the center of the pump wheels 21, 22, and the sleeve with arms 31 will unlock via eccentric 32 the toothed segment 23, which will be released from engagement and the pump wheels 21 and 22 will rotate separately. In FIGS. 2 and 3, reference numeral 37 refers to a guide sleeve, reference numeral 38 refers to a thrust washer, and reference numeral 39 refers to a stock limiter.

[0024] Thus, the proposed design provides simultaneous performance of functions of the torque converter and automatic transmission gear-box, which allows to exclude complex gear transmission mechanisms from the design, the simple design of the locking device also includes a small number of interconnected parts, which leads to simplification of design, increased reliability, maintainability and reduction in weight and size of gear-box as a whole.