US2419392A

US2419392A - Drive unit

Info

Publication number: US2419392A
Application number: US513221A
Authority: US
Inventors: Doniak Michael
Original assignee: Individual
Current assignee: Individual
Priority date: 1943-12-07
Filing date: 1943-12-07
Publication date: 1947-04-22
Anticipated expiration: 1964-04-22

Description

April 22,-' 1947. j M. DONIAK 2,419,392

DRIVE NIT` Y Filed Dec. fr, 1945 l mllll vrolls to remove the corrugations.

Patented Apr. 22, 1947 UNITED STATES PATENT OFFICE DRIVE UNIT Michael Doniak, Lynwood, Calif.

Application December 7, 1943, Serial No. 513,221

2 Claims. 1

My invention relates to a drive unit and has particular reference to an improved type of drive unit which finds particular utility when employed as the final drive unit in such mechanisms as paper making machines and the like.

In the conventional paper mill drive the relative arrangement of parts is such that the interconnection between an adjustable speed jack shaft and the drive for the main rolls must be effected by a iinal drive unit which provides a gear reduction in the order of six to one and which provides also a 90 change in the direction of the drive. In the conventional arrangements this is accomplished by providing on the variable speed jack shaft a bevel pinion which meshes with a bevel ring gear mounted on the drive shaft for the main rolls. The drive ratio employed is usually about six to one which is eifected by using a fourteen tooth bevel pinion meshing with an eighty-four tooth bevel ring gear.

Because of the high rotational speed of the bevel pinion as compared with the bevel ring gear and because of the six to one ratio in diameters between these two gears, the arrangement just described is susceptible to very rapid wear of the :bevel pinion. This wear shortly introduces considerable vibration during the operation of the machine. This vibration is highly objectionable because it imposes undue stresses upon other parts of the machine and thus hastens the wearing out of such parts. What is more important, the vibration is transmitted to the rubber covered main drive rolls with the result that there is produced in this rubber covering a series of corrugations, making it necessary to frequently reg-rind these Since only a limited number of regrinding operations may be performed, it is often necessary to replace the roll after a relatively short useful life. In addition, the rapid Wearing out of the bevel pinion results in the ultimate failure of the pinion requiring its replacement.

Each of the disadvantages mentioned above result in considerable loss of time, both because of the time required to make the repairs or replacements and because of the time lost in getting the machine back into smooth and satisfactory operation, a process which often requires the eX- ypenditure of considerable time in the making of adjustments in the speed of the machine and in 2 the rate at which the pulp or other material is supplied to the machine.

It is, therefore, an object of my invention to provide an improved drive unit which may be used in place of the final drive referred to in the' preceding paragraphs and which overcomes the disadvantages above noted by employing a double reduction unit of novel arrangement. l

It is also an object of my inventionto provide a drive unit of the character referred to in the preceding paragraph in which the functions of gear reduction and direction change are performed by separate parts of the unit, and in which the desired gear ratio is obtained by a double reduction unit.

It is an additional object of my invention to provide a drive unit of the character previously referred to in which the direction changing unit is provided with a drive ratio of unity and positioned between the two parts of the double reduction unit.

It is a still further object of my invention to provide a drive unit of the character referred to in the preceding paragraphs in which the two parts of the double reduction unit provide approximately equal drive ratios, each substantially equal to the square root of the desired overall drive ratio.

It is additionally an object o-f my invention to provide a drive unit of the character referred to hereinbefore in which the parts are compaotly arranged to occupy but little more space than the conventional drive unit which it replaces.

Other objects and advantages of my invention will be :apparent from a study of the following specifications, read in connection with the accompanying drawings, wherein:

Fig. 1 is a schematic representation of one form of drive system, there having been selected for illustration in Fig. 1 the driving system employed for paper making machines; and

Fig. 2 is a sectional view illustrating the preferred embodiment of the improved drive unit of my invention adapted for use with a driving system such as that represented in Fig. 1.

Referring to the drawings, I have chosen for illustration in Fig. 1 the drivingl arrangement of a paper making machine as a typical form of driving system with which the drive unit of my invention is particularly adapted to use. This respective shafts.

driving system derives its power from a suitable power source shown in Fig. 1 as comprising an electric motor I. The electric motor I is drivably connected, as by means of a belt and pulley ari rangement 2, to a line shaft 3. The line shaft 3 is connected to a variable speed jack shaft 4 by a variable radio transmission illustrated in Fig. l as comprising cone pulleys 5 and 6 mounted on the shafts 3 and ll, respectively, and interconnected as by means of a belt 'I.

The jack shaft li is connected through the medium of a nal drive unit indicated generally by the reference character 8 to a shaft 9 which comprises the drive shaft for the main rolls of the paper making machine. In the conventional arrangements the shaft i and the shaft 9 are disposed at ri-ght angles to each other and the requirements of the machine are such as to employ within the drive unit 9 a gear reduction of approximately six to one between the shafts 4 and 9. As has been hereinbefore indicated, in

the conventional constructions this is accom plished by means of a bevel pinion mounted on the shaft 4 meshing with a large bevel ring gear mounted on the shaft 9.

I have illustrated in Fig. 2 an improved drive unit which, by preference, is used as the drive unit 8 above referred to. As is shown in Fig. 2, the drive unit 8 may include a suitable housing I9 within which one end of the shaft l may be journaled as by means of a journal l I and within which may also be journaled one end of the shaft 9 as by means of a journal I2.

Within the housing IE! there are mounted two countershafts I3 and I4, the former being disposed parallel to the shaft Il and the latter being disposed parallel to the shaft 9, both the shafts I3 and I4 being suitably journaled for rotation as by means of bearings or journals I5, IES, II and I8,

The shaft I3 is drivably connected to the shaft 4 by means of a lrstspeed reduction unit I9 illustrated in Fig. 2 as comprising a chain and sprocket drive employing a small diameter sprocket 29 secured to the shaft d and a large diameter sprocket 2i secured to the shaft I3, the sprockets 20 and 2! being drivably interconnected by means of a chain or link belt 22.

The shaft I3 is arranged to drive the shaft I4 at an equal speed by means of intermeshing bevel or

miter gears

23 and 24 mounted upon the are of the same size so as to provide a drive ratio of unity between the shafts I3 and I4.

The shaft I4 is likewise drivably engaged with the shaft 9 by means of a second speed reduction unit 25 illustrated in Fig. 2 as comprising a chain and sprocket unit including a small diameter sprocket 26 mounted upon the shaft I4 and a large diameter sprocket 27 mounted upon the shaft 9, the sprockets 29 and 27 being drivably interconnected by means of a chain or link belt 28. For example, roller chain may be used, in which event no pre-tensioning of the chain is required.

It will be noted that with the arrangement above described the required change cf direction is effected by the miter gears 23 and 2d, whereas the speed reduction between the shafts 4 and 9 is effected by the double reduction drive unit comprising the speed reduction portions I9 and 25. While I have shown these speed reduction units as comprising, by preference, chain and sprocket drives, it will be appreciated that under circumstances indicating the desirability of such an alternative arrangement, a direct geared connec- By reference these bevel gears tion between the respective shafts or pulleys and belts may be used, if desired.

As has been hereinbefore stated, the conventional drive unit provides a gear reduction of six to one between the shafts 4 and 9. This same reduction may be obtained with the improved unit just described by making the drive ratio of the parts I9 and 25 approximately equal to the square root of six. For example, one convenient arrangement consists in providing one of the drive units with a drive ratio of 2.67 to one and the other unit with a ratio 2.25 to one. Such drive ratios may be realized by providing twelve teeth on each of the sprockets 29 and 2S and by providing twenty-seven and thirty-two teeth, respectively, on the two larger sprockets.

Attention is directed to the fact that in the arrangement described, the total required speed reduction between the shafts 4 and 9 is accomplished by using a double reduction unit, and particular attention is directed to the fact that the required direction change is accomplished by using miter gears having a drive ratio of unity and that these miter gears are interposed between the two parts of the double reduction unit.

I have found that with this arrangement a very substantial increase in thev operating life of the drive unit as a whole may be readily realized. The provision of two speed reducers instead of the usual single speed reducer diminishes to onehalf the forces imposed on each of the speed reducer components, such as sprocket teeth, chain rollers, etc., reducing the wear of these parts. Furthermore, because the forces imposed on each of the component parts of the speed reducers are much more nearly equal than in the conventional drive system, the parts tend to wear more equally, with the result that the rate at which the parts wear is greatly reduced and the development of undesired vibrations of the shaft 9 is practically prevented.

Also, by effecting the change in drive direction by miter gears having a one to one ratio, the loads imposed on each of the elements of this part of the system are made equal so that any wear involved is equally divided, thus reducing to a minimum any difference in the rate at which each part wears.

I have found through actual use that a system of the type described permits a material increase in the length of time a paper making machine may be operated without requiring adjustments or repairs.

While I have shown and described the preferred embodiment of my invention, I do not desire to be limited to any of the details of construction shown or described herein, except as dened in the appended claims.

I claim:

l. In a drive mechanism for driving rolls of paper mills for obtaining a speed reduction between a drive shaft and a driven shaft extending at right angles to said drive shaft, the combination of a drive shaft; a jack shaft disposed parallel to said drive shaft; a chain and sprocket speed reducing drive connecting said jack shaft to said drive shaft; a driven shaft; another jack shaft disposed parallel to-said driven shaft; .another chain and sprocket speed reducing drive connecting said other jack shaft to said driven shaft; and coupling means drivably interconnecting said jack shafts and comprising intermeshing miter gears of equal diameters.

2. In a drive mechanism for driving rolls of paper mills for obtaining a desired speed reduction of about siX to one between a drive shaft and a driven shaft extending at right angles to said drive shaft, the combination of: a drive shaft; a jack shaft disposed parallel to said drive shaft; a chain and sprocket speed reducing drive connecting said jack shaft to said drive shaft; a driven shaft; another jack shaft disposed parallel to said driven shaft; another chain and sprocket speed reducing drive connecting said other jack shaft tov said driven shaft; and couplin-grmeans drivably interconnecting said jack shafts and comprising intermeshing miter gears of equal diameters, said chain and sprocket drives each having drive ratios approximately equal to the square root of said desired speed reduction.

MICHAEL DONIAK.

` 6 REFERENCES CITED The following references are of record in the 111e of this patent:

UNITED STATES PATENTS Number Name Date 849,100 Balandras Aug. 7, 1939 2,248,792 Taylor July 8, 1941 964,802 Moo-n et al July 19, 1910 10 2,028,282 Hoe Jan. 21, 1936 2,337,586 Bowen Dec, 28, 1943 1,082,349 Likness Dec. 23, 1913 FOREIGN PATENTS Number Country Date 23,974 British Oct. 21, 1912