GB2298259A

GB2298259A - A mechanical transmission having an angled intermediate shaft

Info

Publication number: GB2298259A
Application number: GB9600978A
Authority: GB
Inventors: Renato Biancanelli
Original assignee: Imer International SpA
Current assignee: Imer International SpA
Priority date: 1995-02-21
Filing date: 1996-01-18
Publication date: 1996-08-28
Anticipated expiration: 2016-01-18
Also published as: FR2730779B3; GB9600978D0; ES1033231U; ES1033231Y; FR2730779A3; DE29601093U1; IT1277822B1; GB2298259B; ITFI950030A0; ITFI950030A1

Abstract

A mechanical transmission, eg a mixer for the building industry, comprises an input shaft 1 connected to an output shaft 5 by an angled intermediate shaft 3. The shafts 1 and 3 each have, on one end, integrally formed helical teeth 10, 30. Helical teeth 10 engage with a helical gear wheel 20 integral with the intermediate shaft 3 while helical teeth 30 engage with a helical gear wheel 40 keyed to the output shaft 5. The helical teeth have an angle of inclination defined in relation to angle ' between the axis of the input shaft 1 and that of the intermediate shaft 3, and to angle '' between the axis of the latter and that of the output shaft 5. In fig 1 there is a right angle between the shafts 1 and 5, however this may be varied. Also the diameters of the gear wheels 20, 40 and/or shafts 1, 3 may be adjusted to provide a reduction or a multiplication of the speed. The shafts 1, 3 and 5 are fitted into a housing 6 which contains transmission oil.

Description

The present invention relates to a mechanical transmission with shafts and toothed wheels.

Transmissions are known having two shafts, one of which for the input, that is, a driving element, and one for the output, that is, a driven element, in which the axes of said shafts are orthogonal to each other and coplanar, or orthogonal and skew: the coupling between the driving shaft and the driven shaft being conventionally accomplished either by a bevel gear pair or a gear pair formed by an endless screw and a helical toothed wheel.

However, the said known devices exhibit some drawbacks. In fact, the bevel gear pair transmissions are of complex and costly fabrication, especially owing to the high degree of accuracy required for the machining of the mechanical elements of the pairs. And the endless screw transmissions, in addition to being expensive, are characterized by a poor mechnaical efficiency, which may be less than 50%, and do not allow high values of revolutions per minute on output.

The main object of the present invention is to overcome the above mentioned drawbacks.

This result has been achieved, according to the invention, by conceiving a mechanical transmission having the characteristics set forth in the characterizing part of claim 1. Further characteristics are indicated in the dependent claims.

The advantages deriving from the present invention lie essentially on the fact that such a transmission is of high mechanical efficiency and allows a motion transmission with reduced loss of power between the input and the output shaft regardless of the angle formed by the respective axes and of the transmitted power; that it is of simple, cost-effective and reliable construction even after a prolonged service life.

These and other advantages and characteristics of the invention will be best understood by anyone skilled in the art from a reading of the following description in conjunction with the attached drawings given as a practical exemplification of the invention, but not to be considered in a limitative sense, wherein: - Fig. 1 shows schematically the side view of a mechanical transmission according to the invention, in which the axis of the driving shaft and that of the driven shaft lie on orthogonal planes (B=90 ); - Fig. 2 shows schematically the front view of the transmission of Fig. 1.

Reduced to its basic structure, and reference being made to the attached drawings, a mechanical transmission according to the invention comprises a driving or input shaft (1) which is connected to a corresponding mover (M), a driven or output shaft (5) of the transmission and coupling means for transmitting the motion from the input (1) to the output (5) shaft.

Advantageously, according to the invention, the said means for coupling the input shaft (1) with the output shaft (5) comprise a shaft (3) at one end of which a wheel (2) is provided solid thereto having a toothing (20) meshing with a corresponding toothing (10) of the input shaft (1): the other end of said shaft (3) being provided with a toothing (30) to be engaged with a corresponding toothing (40) provided at one end of the output shaft (5).

Advantageously, according to the invention, the said toothing is formed on a wheel (4) keyed on the output shaft (5).

Advantageously, said toothings (10) and (30) are directly formed on the shafts (1) and (3), respectively.

Advantageously, according to the invention, said meshing toothings (10, 20, 30, 40) consist of helical teeth whose inclination is suitably defined in relation to the angle (ss') between the axis of the input shaft (1) and that of the intermediate shaft (3), and to the angle (ss'') between the axis of the latter and that of the output shaft (5), so that the angle (ss) formed by the planes passing through the axes of the input (1) and output (5) shafts of the transmission will result of predetermined amplitude.

Advantageously, according to the invention, the number of teeth of the gears defined by said toothings (10, 20) and (30, 40) may vary according to the wanted transmission, so as to achieve either a reduction or a multiplication of the revolutions per minute of the input shaft (1).

Advantageously, according to the invention and with reference to Fig. 1 of the attached drawings, said angle (B) is of 90".

However, it will be appreciated that said angle (ss) may be other than 90'.

By way of non limitative example, the present invention is applicable as a reducer to machines for the building industry, such as mixers and the like, thanks to its simple and functional construction in conjunction with a high efficiency obtainable even under elevated output powers.

It is understood that said shafts (1, 3, 5) may be suitably fitted on corresponding bearing supports which, in turn, may be received in a box (6) for housing the transmission and serving also to delimit a chamber for the lubrication oil.

The operation of the above transmission is as follows.

The gear (2) driven by the shaft (1) puts into motion the intermediate shaft (1) whose toothing (30), by meshing with toothing (40), causes the rotation of the output shaft (5) thereby transmitting the motion from shaft (1) to shaft (5), the revolutions per minute of the latter being therefore related to those of the shaft (1), according to the preset transmission ratio.

Practically, all the construction details may vary in any equivalent way as far as the shape, dimensions, elements disposition, nature of the used materials are concerned, without nevertheless departing from the scope of the adopted solution idea and, thereby, remaining within the limits of the protection granted to the present patent for industrial invention.

Claims

1) Mechanical transmission comprising a driving or input shaft (1) which is connected to a corresponding mover (M), a driven or output shaft (5) of the transmission and coupling means for transmitting the motion from the input (1) to the output (5) shaft, characterized by the fact that said means for coupling the input shaft (1) with the output shaft (5) comprise an intermediate shaft (3) at one end of which a wheel (2) is provided solid thereto having a toothing (2G) meshing with a corresponding toothing (10) of the input shaft (1): the other end of said shaft (3) being provided with a toothing (30) to be engaged with a corresponding toothing (40) provided at one end of the output shaft (5).

2) Transmission according to claim 1, characterized by the fact that said toothing (40) is formed on a wheel (4) keyed on the output shaft (5).

3) Transmission according to claim 1, characterized by the fact that said toothings (10) and (30) are directly formed on the shafts (1) and (3), respectively.

4) Transmission according to claim 1, characterized by the fact that said meshing toothings (10, 20, 30, 40) consist of helical teeth whose inclination is suitably defined in relation to the angle (ss') between the axis of the input shaft (1) and that of the intermediate shaft (3), and to the angle (D") between the axis of the latter and that of the output shaft (5), so that the angle (ss) formed by the planes passing through the axes of input (1) and output (5) shafts of the transmission will result of predetermined amplitude.

5) Transmission according to claim 1, characterized by the fact that the number of teeth of the gears defined by said toothings (10, 20) and (30, 40) may vary according to the wanted transmission ratio, so as to achieve either a reduction or a multiplication of the revolutions per minute of the input shaft (1).

6) Transmission according to claims 1 and- 4, characterized by the fact that said angle (ss) is of 90".

7) Transmission according to claims 1 and 4, characterized by the fact that said angle (ss) is other than 90 .

8) Transmission according to one or more preceding claims, characterized by the fact that it is mounted on a machine for the building industry.

9) Transmission according to one or more preceding claims, characterized by the fact that it is mounted on a mixer for the building industry.

10) Transmission according to one or more preceding claims, characterized by the fact that said shafts (1, 3, 5) may be suitably fitted on corresponding bearing supports which, in turn, may be received in a box (6) for housing the transmission and serving also to delimit a chamber for the lubrication oil.