RU2398146C2 - Procedure for stepless change of speed of mecanical gear and geared variator - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: geared variator contains at least two gearings. Sliding gears (1, 2) of the first gearing are mounted on their proper shafts (3, 4) and are made in form of rotation conic solids with curvilinear teeth of random cross section. When gears slide along shafts, teeth coils incline angles change in the point of gears conjugating. The gears proper are in gearing at any moment of torque transfer. Rotation of an input shaft is resoluted to rotation around two or more axles at transfer of torque from driving shaft (3) to driven shaft (11); resultant from the said resolution of input shaft rotation is transferred to the input shaft.

EFFECT: invention expands functionality of technical devices.

6 cl, 2 dwg

Description

Field of Invention

The present invention relates to mechanical engineering and can be used as a mechanism for smoothly changing the speed of a mechanical transmission, as well as as a differential.

State of the art

Various variator circuits are currently known.

So, in the patent of the Russian Federation No. 2140028 a multi-disk planetary variator is described, which uses beaded discs and pressure devices with elastic elements of axial action.

In US patent No. 58984820 (publ. 16.11.1999), a variator is described in which the gear ratio is changed by moving the contact ring along the surfaces of the cones installed inside this ring so that their generators farthest from the axis of the ring are parallel to this axis.

The disadvantage of both of these mechanisms is that the gear ratio is changed in them using friction, therefore, such variators cannot be used to transfer large powers.

In USSR author's certificate No. 887836 (publ. 07.12.1981), a variator is described in which a bevel or spherical drive gear is used, with respect to the generatrix of which the helical driven wheel moves.

US patent No. 5597056 (publ. 28.01.1997) discloses a variator, in which to change the gear ratio used several located funnel-shaped elements with conical parts, on the surfaces of which slide guides associated with the shafts.

These two documents describe gear variators, which have the disadvantage that tilting forces are applied to the elements transmitting rotation from the drive wheel to the follower.

Thus, the objective of the present invention is to develop such a method for smoothly changing the speed of a mechanical transmission and such a gear variator that implements this method, which would be free from these disadvantages, and in addition, would provide a technical result in the form of an expansion of the arsenal of technical means.

SUMMARY OF THE INVENTION

In the first object of the present invention, the problem is solved with the achievement of the specified technical result by providing a method for smoothly changing the speed of a mechanical transmission, which consists in the following: transmit rotation from the drive shaft to the driven shaft by means of at least two gears; gears of each of said gears are arranged in such a way that the wheels are in gear gear at any moment of transmission of rotation; the rotation of the input shaft is rotated around two or more axes by changing the angle of inclination of the teeth at the mating point of the bevel gears of one of the mentioned gears; transmit to the output shaft the resultant from said decomposed rotation of the input shaft.

In the second object of the present invention, the problem is solved with the achievement of the specified technical result by providing a gear variator, comprising: at least two gears; gears of the first mentioned gearing mounted on own shafts with the possibility of sliding without relative rotation, made in the form of conical bodies of revolution, on the surfaces of which curved teeth are cut with an arbitrary transverse profile, so that when the wheels move along the shafts, the angle of inclination of the tooth turns in the place of mating wheels, and the wheels themselves at any moment of transmission of rotation are in gear mates; gears of said gears, mounted so that at least two wheels of different gears are mounted coaxially and combined into a single unit having two rotation axes, one of which coincides with the single rotation axes of the second wheels of the respective gears, while the wheels of each of said gears in any moment of transmission of rotation are in gearing.

Brief Description of the Drawings

The present invention is illustrated by drawings, illustrating its possible options for implementation. In all the drawings, the numbers of the reference numerals relating to the same or similar elements are the same.

Figure 1 shows an embodiment of a gear variator of the present invention in which a converted input shaft rotation speed is transmitted to the output shaft.

Figure 2 presents an embodiment of a gear variator of the present invention, in which the converted input shaft rotation speed is transmitted and redistributed between the two output shafts.

List of Terms Used

In this description and in the claims, the following terms and expressions are used.

"Gearing" - two gears meshed with one another.

"Teeth ... made with variable angles of inclination, from one base to another of the bodies of rotation of the wheels" - teeth, angles of elevation of the turns of which, from one base to another of the bodies of rotation of the wheels, are changed.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows a drawing of a variator containing two gears. The wheels 1, 2 constituting the first gearing are conical-shaped screws (worms) with curved teeth 5 made on the lateral (conical) surfaces. The teeth 5, as well as the gaps between the teeth, along the entire length of gears 1 and 2, have the same value, as a result of which the angle of inclination of the teeth, from a smaller base to a larger one, of the corresponding wheel cones smoothly change. Wheels 1 and 2 are mounted on shafts 3, 4, with shaft 3 through bearings mounted in housing 8, and shaft 4 through bearings mounted on frame 7. Shafts 3 and 4, as well as axial bores of wheel hubs 1 and 2, in their cross sections have a square or any other shape that allows the wheels to slide freely along the shafts without relative rotation. The frame 7 is movably fixed on the shaft 3, so that its axis of rotation coincides with the axis of rotation of the wheel 1. The gear 1 through the thrust bearing is spring loaded 6, from the side of the base of its own cone. In addition to the wheel 2, the gear wheel 9 is rigidly mounted on the shaft 4, which is in gear meshing with the wheel 10 mounted on the shaft 11. The shaft 11 is output, and its axis of rotation coincides with the axis of rotation of the wheel 1.

The variator of figure 1 works as follows.

The torque from the input shaft 3 through the gear wheel 1 is transmitted to the gear wheel 2. From the wheel 2, through the shaft 4 and the wheel 9, the torque is transmitted to the wheel 10 and the output shaft 11.

With a slight load on the output shaft 11 of FIG. 1, the axial forces in the gearing of the wheels 1, 2 are small, and the wheels are on the shafts in the extreme upper and left positions, respectively. The movement of the frame 7, wheels 2 and 9 relative to the wheel 1 is absent. The speed of rotation of the shaft 3 is equal to the speed of rotation of the shaft 11.

When the load on the output shaft 11 of FIG. 1 increases, the forces in the meshing of the wheels 1 and 2 push the wheels apart along their geometric axes. The spring 6 counteracts these movements, so that after some movement of the wheels along its own shafts, a new position is established in which, due to changes in the angle of inclination of the teeth and the diameters of the wheels at the mating point of the wheels, it becomes more difficult for the wheel 2 and the shaft 4 to rotate in the frame 7. Frame 7 comes into rotation, thereby compensating for the lack or complete absence of rotation of the wheel 2 around its own geometric axis. By means of the frame 7, the wheel 2 simultaneously rotates around two axes - its own geometric axis and the axis of the wheel 1. The resulting biaxial rotation of the wheel 2 by means of the wheel 9 rolling in the wheel 10 is transmitted to the output shaft 11. Changing the ratio of the rotational speeds of the shaft 4 and frame 7, and also changing the diameters of the wheels 1 and 2 allows you to change the speed of rotation and the magnitude of the torque transmitted to the output shaft of the transmission.

The mechanism of figure 1, in addition to a smooth change in speed, can be used as a differential, redistributing the load on the output shaft.

Figure 2 shows the construction of a gear variator in which the converted input shaft rotation speed is transmitted and redistributed between the two output shafts.

Structurally, the mechanism of FIG. 2 repeats the variator of FIG. 1, with the difference that the rotation is transmitted from the hub of the frame 7, and the shafts 3 and 11 are driven. For clarity, the gears 12 and 13 are added to the structure, through which the rotation is transmitted on the frame 7. The wheel 13 is rigidly mounted on the shaft 14, and the wheel 12 is mounted on the hub of the frame 7.

The principle of operation of the variator in figure 2 is similar to the operation of the mechanism in figure 1. The torque from the shaft 14, through the wheels 13 and 12, is supplied to the frame 7. From the frame 7, the moment is transmitted through the shaft 4, the wheels 2, 9, 10 and 1 to the shafts 11 and 3.

With an increase in the load on one of the output shafts, for example, on the shaft 3, the axial forces in the gearing of the wheels 1 and 2 push the wheels along their geometric axes, in the direction of smaller and larger bases, respectively. The spring 6 counteracts these movements, so that after some movement of the wheels along its own shafts, a new position is established in which it becomes difficult for the wheel 2 and the shaft 4 to rotate around its own geometric axis. Frame 7 comes into rotation. The resulting biaxial rotation of the wheel 2, by means of the wheel 9, running in the wheel 10, and the wheel 1, is transmitted to the output shafts 11 and 3, respectively. Since when moving wheels 1 and 2, their diameters at the point of mutual coupling change, the magnitudes of the torques transmitted to the output shafts also change.

Thus, the mechanism of FIG. 2 can be used to redistribute the rotational speeds of two output shafts, as well as as a differential that distributes the load between two output shafts.

The presented examples of embodiments of the present invention illustrate the operation of the proposed method for smoothly changing the speed of a mechanical transmission and a gear variator.

All of these examples in the detailed description are intended for illustrative purposes only, and not to limit the scope of this invention. In the examples given, various modifications may be made without departing from the spirit of the present invention. Therefore, the scope of this invention is determined by the attached claims taking into account possible equivalent features.

Claims (6)

1. The method of smoothly changing the speed of a mechanical transmission, which consists in transmitting rotation from a drive shaft to a driven shaft by means of at least two gears; gears of each of said gears are arranged so that the wheels are in gear mate at any moment of transmission of rotation; the rotation of the input shaft is rotated around two or more axes by changing the angle of inclination of the teeth at the mating point of the bevel gears of one of the mentioned gears; transmit to the output shaft the resultant from said decomposed rotation of the input shaft. 2. The method according to claim 1, in which, depending on the load, the decomposed rotation of the input shaft is transmitted to two or more output shafts. 3. A gear variator comprising at least two gears; gears of the first mentioned gearing mounted on own shafts with the possibility of sliding without relative rotation, made in the form of conical bodies of revolution, on the surfaces of which curved teeth are cut with an arbitrary transverse profile so that when the wheels move along the shafts, the angle of inclination of the tooth turns in place pairings of wheels, and the wheels themselves at any moment of transmission of rotation are in gear pairing; gears of said gears, mounted so that at least two wheels of different gears are mounted coaxially and combined into a single unit having two axis of rotation, one of which coincides with the only axis of rotation of the second wheels of the respective gears, while the wheels of each of said gears at any moment of transmission of rotation are in gearing. 4. The variator according to claim 3, in which one of the wheels of the first said engagement, mounted to move along its own shafts, is spring loaded in the direction opposite to the said movement, with an increase in the load on the output shaft. 5. The variator according to claim 3, in which the input link of the power supply is the central axis of rotation of the wheels of the various mentioned gears combined into a single unit, and the output axis is one or more axles of the second wheels of the respective gears. 6. The variator according to claim 3, in which the input link of the power supply is the axis of any of the wheels of said gears, capable of rotating only around its own geometric axes.

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