CS237014B1 - Ring variable speed gearbox - Google Patents

Abstract

An annular, variable speed gearbox is intended to change gear ratio continuously. Annular, variable speed gearbox has at least two axially separated drive pairs and driven bevel gears where adjacent driving and driven bevel gear pairs outer rings and center wheels are incorporated, expanded by a disc spring.

Description

BACKGROUND OF THE INVENTION The present invention relates to an annular, variable speed gearbox in which a continuous gear ratio change is provided.

The hitherto known design, in particular of automotive gearboxes, solves the problem of continuously changing the transmission ratio by means of a belt transmission between a driving and driven pair of mutually adjustable bevel wheels. In this case it is possible to transmit power up to 50 kW, with a V-belt life of around 40,000 km, resulting in limited use of these gearboxes.

The essence of the annular gearbox according to the invention is based on at least two axially spaced, adjacent pairs of drive and driven bevel gears, wherein outer rings and center wheels, expanded by a disc spring, are interposed between adjacent drive and driven bevel pairs.

The main advantages of the arrangement of the annular gearbox according to the invention are that it allows a continuous change of the transmission ratio to transmit power up to 250 kW, with a durability of friction surfaces of up to 500,000 kilometers. By increasing the number of friction surfaces, the adverse effect of the coefficient of friction in the oil bath is reduced. The contact force of the frictional surfaces causes the tensile stress of the shafts, thus eliminating the unfavorable bending stress of the shafts and also the unfavorable stress on the bearings. The pairs of adjacent tapered disks rotate relative to each other in a relative direction, which has a positive impact on their durability. The transmission makes it possible to optimally utilize the power that is transmitted and reduce fuel consumption.

In the drawing, FIG. 1 is a front elevational view of a kinematic diagram of an embodiment of an annular gearbox according to the invention.

The transmission works in an oil bath. The torque is transmitted from the drive shaft 1 of the gear wheels 2, 3 to the drive shaft 4 and from there to a pair of drive bevel gears 5. At the same time it is transmitted to the gear wheels 6, 7, 8, 9 by the drive shaft 4 The contact force is exerted by the threaded connection of the gear 3 and the drive shaft 4. This threaded connection is secured against loosening. The torque is transmitted from the bevel gear pairs 5, 10 by the center discs with the disc springs 11, 12 and the rings 13, 14 to the bevel gear pairs 15, 16. The bevel gear drive pairs 15 onto the driven shaft 17 and the bevel gear drive pairs 16 gears 18, 19, 20 and gear 21 to the driven shaft 17. The transmission ratio is controlled by shifting the center discs with the disc springs 11, 12 in the same direction, while disagreeing radially in the direction of the center and from the center of the bevel gears 5. 10. The axial displacement of the driven shaft 17 occurs during regulation.

As the gearing loads, the slip increases and the sliding force increases. In the case of a gearbox, it is possible to prevent the rolling contact from being subjected to a static load, or to a combination with a freewheel clutch.

Claims (1)

SUBJECT An annular variator gearbox characterized in that it comprises at least two pairs of axially spaced drive bevel wheels (5, 10) and driven bevel wheels (15, 16). According to the invention, the central wheels with a disc spring (11, 12) and outer rings (13, 14) are incorporated between them.