Continuously Variable Hydrodynamic Automatic Transmission

Abstract

The invention relates to a hydrodynamic transmission. The continuously variable hydrodynamic automatic transmission comprises an input shaft on which a central disk with radially oriented grooves is rigidly fixed. On both sides of the central disk, two mirror-identical frying pan-shaped pump wheels are mounted on the input shaft. In the space between the part adjacent to the hub and the peripheral blades of each pump wheel, holes are concentrically drilled at a certain distance from the center of the pump wheel, into which the shafts of the movable blades curved along a certain arc are rotatably inserted. The plate can rotate in the holes in a limited manner. Both ends of the blade shaft have slits, into which the roots of the blades are rigidly fixed. The other end of the root has a protrusion parallel to the blade shaft. The blades of the two turbine wheels are covered with a conical or donut-shaped annular disk, while the radially oriented blades are rigidly fixed. The transmission body is mounted on bearings in the crankcase of the drive shaft and the flywheel of the drive and is connected to the reversing mechanism and the running gear of the vehicle. This will achieve improved mass and dimensional characteristics, increased force transmission, longer service life, simplified structure, and improved repairability and operability in vehicle automatic transmissions.

Description

Detailed Description of the Invention

[0001] [Technical field to which the invention pertains] F16H 47 / 00, B60K 31 / 00The present invention relates to the transport machinery and equipment manufacturing industry and to the elemental structure of a continuously variable transmission used in an automatic transmission of a vehicle. Automatic gearboxes and hydromechanical gearboxes in which the gear shifting is performed by gears are known (RU 2341384, RU 2585093, RU 2659163, RU 2481511). Disadvantages of the known gearboxes are their large weight and size, their complex structure with a large number of gears and transmission mechanisms, and their complex maintenance and repair. Moreover, the inclusion of a torque converter in the structure of the known automatic gearboxes further increases the mass and size characteristics of the vehicle transmission.

[0002] The known hydrodynamic automatic transmission closest to the claimed one (RU 2700106) also comprises at least two pump wheels, which are flat circular disks with radially oriented blades rigidly attached to their front periphery, the first pump wheel being rigidly connected to the input shaft, the second and subsequent pump wheels being each larger in diameter than the previous one, and being mounted such that the hub of the pump wheel can freely rotate on the hub of the previous pump wheel but cannot move axially relative to each other, with the rear surface of each pump wheel being fitted with a blocking device with the next pump wheel and the rear surface of the last pump wheel being fitted with a blocking device with the turbine wheel, respectively. The front surface of the second and subsequent pump wheels and the turbine wheel are fitted with a cylindrical ring with internal teeth for coupling with a locking device. The blades of the turbine wheel on the side facing the blades of the pump wheels are covered by a conical annular disk, the major diameter of which is equal to the diameter of the disk of the last pump wheel and the minor diameter of which is equal to the minor diameter of the blades of the first pump wheel. In addition, the turbine wheel is attached to the input shaft and the crankcase of the drive unit through bearings, and is connected to the vehicle's reversing mechanism, mode changer, and running gear. The disadvantages of the above transmissions are the presence of multiple pump wheels, which complicates the transmission structure, the need for speed change, and the complexity of setting the automatic transmission mechanism.

[0003] The problem to be solved by the claimed invention and the technical result of the claimed invention are: simplification of the automatic transmission by reducing the number of complex mechanisms for the pump wheels and their blocks and improving the mass and dimensional characteristics of the vehicle, as well as improving the driving comfort characteristics of the transmission by making low-speed / high-speed shifts smoother.

[0004] To achieve this technical result, a continuously variable hydrodynamic automatic transmission (CVHDAT) is claimed. Said CVHDAT consists of an input shaft on which a central disk of constant diameter with radial grooves arranged concentrically at a constant distance from the center is rigidly fixed, and two mirror-identical frying pan-shaped pump wheels, with flat-bottomed hubs mounted in them facing the central disk, arranged on the input shaft so that they can rotate only limitedly on both sides of the central disk but cannot move axially. The diameter of the pump wheels is larger than that of the central disk, the pump wheels are rigidly interlocked by an axle that runs circumferentially through the space behind the central disk, and a constant mass L-shaped control weight is mounted on said axle, the larger part of which is oriented counterclockwise as viewed from the input shaft side and can be moved from the central disk to the transmission body by limited rotation thereon. On the side of the control weight facing the transmission body, a friction pad is mounted. The second part of the control weight, directed from the axis of rotation towards the central disk, fits with its end into the outer groove of the central disk. A return spring, mounted between the central disk and the pump wheel, keeps the central disk free within its limits in an extreme counterclockwise position relative to the pump wheel. Radially oriented blades are rigidly fixed to the concave peripheral part of the pump wheel and to the part adjacent to the hub. In the space between the blades adjacent to the hub and the peripheral blades of each pump wheel, holes are opened concentrically at a certain distance from the center of the pump wheel, into which the shafts of the movable blades curved along a certain arc are rotatably inserted. Both ends of the blade shafts protrude on the back side of the pump wheel and have slits, into which the roots of the blades are rigidly fixed perpendicular to the blade shafts, and the other end of the root, at a certain distance from one end of the root, has a protrusion parallel to the blade shaft, which is inserted into the corresponding groove of the central disk.On both sides of the pump wheel, two turbine wheels are arranged, on which the blades are rigidly fixed, radially oriented to the blades of the pump wheel, and the above turbine wheels are simultaneously two halves of a dismantlable transmission body. Viewed from the side facing the pump wheel, the blades of the turbine wheel are covered with a donut-shaped annular disk, the small diameter of which is equal to the diameter of a circle passing along the blade ends, rigidly fixed at the hub of the pump wheel, away from the center, and the large diameter is smaller by a certain value than the diameter of a circle passing along the blade ends, rigidly fixed away from the center. The transmission body is mounted on bearings in the crankcase of the drive shaft and the flywheel of the drive, filled with hydraulic fluid (oil), and connected to the reversing mechanism and running gear of the vehicle.

[0005] The subject matter of the claimed invention is illustrated by the following drawings. Figure 1 - Overview of a continuously variable hydrodynamic automatic transmission, where: 1 - Main unit 2 - Pump wheel 3 - central disc 4 - Input shaft 5 - peripheral blades of the pump wheel 6 - moving blades of the pump wheel 7 - Blades of the pump wheel adjacent to the hub 8 - Turbine wheel blades 9 - Base of moving blade 10 - central disc groove 11 - Bearings 12 - movable blade axis 13 - Donut-shaped annular disk 14 - Seal 15 - Blade base protrusion 16 - Output shaft 17 - Control weight 18 - Control weight shaft 19 - L-shaped protrusion of weight 20 - outer groove of the central disc 21 - Servo mechanism spring 22 - Friction plate Figure 2 Control weight Figure 3 Pump wheel Figure 4 Movable blade and control weight Figure 5. Assembled pump wheel The continuously variable hydrodynamic automatic transmission works as follows: At the first moment, without torque on the input shaft 16, the central disc 3 is in its extreme (left) counterclockwise position relative to the pump wheel 2, as seen from the input shaft, due to the action of a return spring (not shown). In such a position of the central disc relative to the pump wheel, the root 9 of the movable blade 6, with its projection 15 of the root 9 located in the groove 10 of the central disc 3, places the movable blade 6 in a radially directed state, as shown by the main lines in FIG. 1. Meanwhile, the control weight is in its uppermost position (near the transmission body). When the input shaft 4 starts to rotate, a force is generated between the central disc 3, which is rigidly connected to the input shaft 4, and the pump wheel 2, due to the resistance of the hydraulic fluid to the rotation of the pump wheel and its inactivity. The central disc overcomes the resistance of the return spring and moves to its extreme (right) clockwise position relative to the pump wheel. Therefore, the root projection of the movable blade 15 located in the groove of the central disk 3 and the L-shaped projection 19 of the control weight 17 enter the rightmost position which moves the blade and the control weight to a lying position, as shown by the dotted line in Figure 1. In this position of the movable blade, only the blades rigidly fixed near the hub and to the periphery of the pump wheel participate in the process of pumping the working fluid from the center to the periphery and further to the turbine wheel, and the flow of the fluid caused by them becomes small.

[0006] When the speed of the input shaft 4 with the rigidly fixed central disc 3 and the limitedly rotating pump wheel 2 increases, the control weight 17, under the action of the centrifugal force, overcomes the force transmitted from the input shaft side through the outer groove 20 of the central disc and starts to move to the periphery, while the L-shaped projection 19 of the control weight 17 located in the outer groove 20 of the central disc starts to return the central disc to its initial position relative to the pump wheel 2. Meanwhile, the central disc 3, located in the groove 10 containing the projection of the root of the movable blade 15, starts to rotate the root 9 counterclockwise on its axis, which causes the movable blade to rise from its lying position. The raised movable blade (whose angle of attack has changed) increases the flow of the pumped liquid and the force transmitted to the turbine wheel, i.e. the output shaft, increases, but at the same time the counter force acting on the movable blade from the side of the pumped liquid, which tries to make the movable blade lie down, also increases.

[0007] When the load from the transmission side increases while the torque of the input shaft remains the same, the rotational resistance of the pump wheel increases, and the clockwise pressing force applied from the center disc to the protruding part at the base of the movable blade increases. As a result, the blade lays flat to a certain extent, and the load on the input shaft is reduced, allowing the rotation speeds of the input shaft and pump wheel to be initially matched.

[0008] When the force from the input shaft side is removed and the vehicle continues to move, the return spring and the centrifugal force of the rotating control weight and blades move the central disc to its initial position (counterclockwise) relative to the pump wheel, the blades move to their extreme radially oriented positions, the control weight blocks the pump wheel and turbine wheel, and the drive begins to brake the vehicle, similar to engine braking when a manual transmission is used.

[0009] Thus, two forces are always in opposition: the first is the total force from the input shaft and the hydraulic forces tending to lay down the moving blade and the control weight, and the second is the centrifugal force acting on the control weight and the blade, equal to the product of their total mass, the radius of their centres of mass and the square of the angular velocity of the pump wheel (F=mrω∧2), which tends to lift the moving blade.

[0010] Meanwhile, the balance between the force applied from the drive shaft, the rotation angle of the movable blades, the rotation speed of the pump wheel, and therefore the rotation speed of the output shaft, which corresponds to these parameters, is automatically adjusted and maintained.

[0011] To block the pump wheel with the turbine wheel when a certain speed is reached, a servo mechanism is used, consisting of a spring, one end of which is hinged to the pump wheel, and the other end of which is hinged to a special protrusion of the L-shaped weight, as shown in Figure 2. The mass, size and quantity of the control weight and the stiffness of the spring of the servo mechanism are selected based on the size and type of vehicle and the type of engine used. For example, for a gasoline engine, the above items are selected so that when 2200-2400 revolutions per minute are reached, the surface of the control weight, coated with friction material, reaches the inner surface of the ring attached to the half of the body, while the servo mechanism blocks the transmission body and the pump wheel with an additional force to the centrifugal force that increases proportionally to the increase in the radius of the center of mass of the control weight and proportionally to the square of its angular velocity, and a synchronizer and a toothed locking device are applied to the control weight to eliminate the possibility of slipping. After blocking the transmission body and the pump wheel, the entire transmission rotates on the bearings as a solid body, the slip between the pump wheel and the turbine wheel is eliminated, and the movement of the hydraulic fluid in the transmission is stopped.

[0012] In order to increase the power transmitted from the drive to the transmission, taking into account the small axial dimensions of the transmission without increasing the diameter size of the installation location, several such transmissions can be mounted on one drive shaft in sequence and their bodies connected to each other, or the diameter of the transmission can be increased.

[0013] Such automatic transmissions can be installed in various types of vehicles, such as passenger cars, freight cars, agricultural machinery, ships, rail vehicles, as well as in powerful electric drive inactivation units to reduce starting currents and self-propelled vehicles such as motorcycles. [Brief description of the drawings]

[0014] [Figure 1] - Overall view of the continuously variable hydrodynamic automatic transmission. [Diagram 2] Control weight [Diagram 3] Pump wheel [Figure 4] Movable blade and control weight [Diagram 5] Pre-assembled pump wheel

Claims

【Request 1】 A continuously variable hydrodynamic automatic transmission (CVHDAT) comprising an input shaft on which a central disk of constant diameter is rigidly fixed, with radial grooves arranged concentrically at a fixed distance from the center, and two mirror-identical frying pan-shaped pump wheels, each of which has a flat-bottomed hub mounted in a direction facing the central disk, arranged on the input shaft so as to be able to rotate only to a limited extent on either side of the central disk but not to move in an axial direction, the diameter of the pump wheels being greater than that of the central disk. The concave peripheral portion of the pump wheels and the portion adjacent to the hub have radially oriented blades rigidly fixed thereto, and the space between the blades adjacent to the hub and the peripheral blades of each pump wheel has holes arranged concentrically at a fixed distance from the center of the pump wheels. A shaft is rigidly attached to one end of the blades so as to be able to rotate only to said holes and perpendicular to the plane of the pump wheels, both ends of the blade shaft protruding to the back side of the pump wheels and having slits. The above-mentioned slits are rigidly fixed with the root of the blade perpendicular to the blade axis, and the other end of the root at a certain distance from one end of the root has a protrusion parallel to the blade axis, which is inserted into the corresponding groove of the central disk. Between the pump wheels, a shaft is rigidly fixed, on which an L-shaped control weight of a certain mass is mounted so as to be able to rotate in a limited manner. One end of the above-mentioned L-shaped control weight is inserted into the outer groove of the central disk, while the other end with a certain mass is directed counterclockwise and can be moved from the central disk to the transmission body. On both sides of the pump wheel, two turbine wheels are arranged on which the blades are rigidly fixed, which are radially oriented to the blades of the pump wheels, and the above-mentioned turbine wheels are simultaneously two halves of the transmission body that can be dismantled.The turbine blades from the side facing the pump wheel are covered with an annular disk, the small diameter of which is equal to the diameter of a circle passing along the blade ends rigidly fixed at the hub of the pump wheel away from the center, and the large diameter of which is a constant value smaller than the diameter of a circle passing along the blade ends rigidly fixed away from the center. The body is filled with hydraulic fluid, mounted on bearings in the crankcase of the drive shaft and the flywheel of the drive unit, and connected to the reversing mechanism and running gear of the vehicle.

Images