GEARBOX WITH GEARS WITH CONICAL COAXIAL FRONT TOOTHED WHEELS

Abstract

A gearbox (10) is provided and includes a driving wheel (4) and a driven wheel (3) rotating on a common axis (13) and a cursor (9) arranged transversally to the axis (13) and sliding with respect to it. The wheels (4, 3) have crown gears (5A, 5B) arranged on different diameters of the drive (4) and driven wheels (3). The crown gears (5A, 5B) have teeth protruding from facing surfaces (21, 22) of the wheels (4, 3). The cursor (9) has two gears (7A, 7B) arranged at its ends, rotating around the axis (19) of the cursor (9) and configured to transmit motion from the driving wheel (4) to the driven wheel (3), engaging each gear (7A, 7B) in respective crown gears (5A, 5B) of the driving wheels (4) and driven wheels (3). The cursor (9) slides inside a seat (15) made in the axis (13).

Claims

1. A gearbox with gears, comprising: a driving wheel and a driven wheel, the driving wheel and the driven wheel rotating on a common axis, and with a cursor arranged transversely to the common axis of the driving wheel and the driven wheel and sliding with respect to the driving wheel and the driven wheel, wherein the gearbox comprises respective crown gears arranged on different diameters of the driving wheels wheel and, respectively, of the driven wheel, wherein the crown gears have surfaces facing the driving wheel and, respectively, the driven wheel and are made with teeth protruding from surfaces facing the driving wheel and, respectively, the driven wheel, wherein the cursor has opposite ends and further comprises two gears arranged at its opposite ends, wherein the cursor has an axis and the gears at the opposite ends of the cursor rotate around the axis of the cursor and are configured for transmitting motion from the driving wheel to the driven wheel, wherein each gear at a respective opposite end of the cursor engages in respective crown gears arranged on different diameters of the driving wheel and, respectively, of the driven wheel, and wherein the cursor slides inside a seat formed in the common axis of the driving wheel and the driven wheel.

2. The gearbox according to claim 1, wherein the common axis of the driving wheel and the driven wheel is fixed and the gears at the opposite ends of the cursor are integral with each other and fixed to the axis of the cursor.

3. The gearbox according to claim 1, wherein the driving wheel and the driven wheel have surfaces that are conical in shape, inclined with respect to the common axis of the driving wheel and the driven wheel by an angle and the crown gears are arranged on the surfaces of the driving wheel and, respectively, of the driven wheel.

4. The gearbox according to claim 3, wherein the axis of the cursor has an inclination and wherein the angle of the surfaces of the driving wheel and of the driven wheel is equal to the angle of inclination of the axis of the cursor.

5. The gearbox according to claim 1, wherein the driving wheel and the driven wheel mirror each other.

6. The gearbox according to claim 1, wherein the common axis of the driving wheel and of the driven wheel is fixed and has the task of supporting the rotation of the driving wheel and of the driven wheel and of guiding the sliding of the cursor.

7. The gearbox according to claim 1, wherein the driving wheel is movable, the driven wheel is fixed, the common axis of the driving wheel and of the driven wheel rotate together with the cursor and the two gears at the opposite ends of the cursor act as satellites.

8. The gearbox according to claim 1, wherein the gearbox further comprises means for controlling the axis of the cursor configured to move the cursor upwards or downwards along the axis of the cursor, moving it by a distance equal to the distance between the crown gears to obtain a change in the rotation speed of the driven wheel with respect to the driving wheel.

9. The gearbox according to claim 1, wherein the cursor is designed to be moved by a cursor moving mechanism, which is housed in the common axis of the driving wheel and the driven wheel, a movement of the cursor being performed manually by means of levers or rack rods or gears.

10. The gearbox according to claim 1, wherein the cursor is designed to be moved by a cursor moving mechanism, which is housed in the common axis of the driving wheel and the driven wheel, a movement of the cursor being performed, automatically by using an electric motor or sliding magnets.

11. (canceled)

Description

[0009] The present invention will be better described by some preferred embodiments thereof, provided by way of non-limiting example, with reference to the attached drawings, in which:

[0010] FIG. 1 is a perspective view of an embodiment of a gearbox with coaxial face gears according to the present invention;

[0011] FIG. 2 is a top view of an embodiment of a gearbox with coaxial front gear wheels according to the present invention; and

[0012] FIG. 3 is a sectional view of an embodiment of a gearbox with coaxial face gears according to the present invention.

[0013] With reference to the Figures, a preferred embodiment of the gearbox 10 with coaxial gear wheels of the present invention is illustrated and described; such gearbox 10 comprises a driving wheel 4 and a driven wheel 3 rotating on an axis 13, for example a fixed axis, and a cursor arranged transversely to the axis 13 and sliding with respect to it, preferably inside a seat 15 formed in the axis 13.

[0014] The gear wheels 4, 3 preferably comprise respective crown gears 5A, 5B arranged on different diameters of the driving wheels 4 and driven wheels 3, said crown gears 5A, 5B being made with teeth protruding from facing surfaces 21, 22 of the wheels 4, 3.

[0015] The cursor 9 also comprises two gears 7A, 7B arranged at its ends, said gears 7A, 7B being preferably integral with each other and fixed to the axis 19 of the cursor 9, rotating around it and configured to transmit the motion from the driving wheel 4 to the driven wheel 3, engaging each gear 7A, 7B in respective crown gears 5A, 5B arranged on different diameters of the driving wheel 4 and driven wheel 3.

[0016] Preferably, the surfaces 21, 22 of the drive 4 and driven 3 wheels are conical in shape, inclined with respect to their axis 13 by an angle which is preferably equal to the angle of inclination of the axis 19 of the cursor 9, and the crown gears 5A, 5B are arranged on said surfaces 21, 22; in a preferred way, the driving wheels 4 and driven wheels 3 are specular.

[0017] In a first configuration of the gearbox 10 with gears with coaxial front gear wheels of the invention, the axis 13 is fixed and has the task of supporting the rotation of the driving wheels 4 and driven wheels 3 and of guiding the sliding of the cursor 9.

[0018] Other configurations of the invention are possible, in which the functions of the components can be exchanged or used in any other way, such as for example the movable driving wheel 4, the fixed wheel 3, the axis 13 can rotate together with the cursor 9 and the two gears 7A, 7B behave like satellites.

[0019] The operation of the gearbox with coaxial front gear wheels will be described below in the first configuration of the invention shown in the figures and described above.

[0020] In this configuration, the driving wheels 4 and the driven wheels 3 are specular, each comprising four crown gears 5A, 5B arranged on different diameters and made on the surfaces 21, 22 inclined by the angle equal to the inclination angle of the axis 19 of the cursor 9, so as to allow the cursor 9 to slide and move radially with respect to the wheels 4, 3, and to bring the gears 7A, 7B integral with each other, to mesh with the crown gears 5A, 5B arranged on different diameters of the two wheels 4, 3, the first gear 7A meshed with the driving wheel 4 and the second gear 7B meshed with the driven wheel 3.

[0021] The inclination angle of the axis 19 of the cursor 9 allows the gearbox to operate: in fact the cursor 9 can slide along its axis 19 to effect the change of ratio between the driving wheel 4 and the driven wheel 3, allowing the former gear 7A to mesh only with the crowns 5A of the driving wheel 4, without interfering with the driven wheel 3, and allowing the second gear 7B to mesh only with the crowns 5B of the driven wheel 3, without interfering with the driving wheel 4, which would prevent the gearbox from functioning, as is evident from the figures.

[0022] As a result, the driving wheel 4 transmits the motion to the first gear 7A, through one of the crowns 5A, which in turn transmits it to the second gear 7B which finally transmits it to the driven wheel 3, through one of the crowns 5B.

[0023] The gearbox with gears with coaxial front gear wheels of the invention further comprises means for controlling the axis 19 of the cursor 9, not shown in the figures, configured to move the cursor 9, when the ratio is required, upwards or downwards along its axis 19, moving it by a distance equal to the distance between the crowns 5A, 5B, obtaining a change in the rotation speed of the driven wheel 3 with respect to the driving wheel 4, increasing or reducing the speed of the driven wheel 3 depending on the cursor movement direction 9.

[0024] In the configuration just described, there are four crown gears 5A, 5B and they allow obtaining four ratios, but the number of crown gears varies according to the need for ratios and to the manufacturing skills.

[0025] The cursor 9 is designed to be moved by a cursor moving mechanism, which, according to a preferred embodiment, is housed in the central axis 13, which is usually fastened to the chassis, and therefore unmoving. This movement, necessary for changing the gear ratio, can be performed manually by means of levers, rack rods, gears, etc. (not shown), as well as by using a small electric motor, or sliding magnets, in order to make the gear ratio selection automatic.

[0026] Another important feature, made possible by the above described embodiment, is that the mechanism can be completely closed and also made waterproof, by installing a tube (not shown) on the external circumference between the conical wheels 3, 4, equipped with suitable gaskets, which anyway allows a free rotation of the mechanism, which closes the room interposed between the wheels 3, 4. Of the conical wheels 3, 4, one (4) is the driving wheel and receives a motion to be transmitted, the other (3) is the driven wheel and, due to the control system through the central axis 13, becomes the carrier hub of a traction wheel of the means on which the gearbox of the invention is used.