Title:
GEAR DRIVE WITH MEANS FOR THE REMOVAL OF THE PLAY OF THE TOOTHED PROFILE
United States Patent 3636789
Abstract:
A gear drive with means for removal of the play of the toothed profile, in particular laying mechanism for armored turrets, rotary ring gun carriages or the like of weapons, which comprises a double pinion shaft axially displaceable by means of a pressure medium and equipped with oblique toothing of opposite spiral directions including pinions of equal size. Counter gears are coaxially disposed and mounted independently from each other. The pinions are in mesh at least directly with the counter gears. Each of the counter gears are connected each with a further gear by means of a shaft. The further gears are of equal size and disposed directly adjacent each other. A still further counter gear is disposed outside of the drive housing, and the further gears mesh as driven gears jointly the still further gears.
US Patent References:
Speed reducer unit or drive
York - August 1964 - 3143899
Rotary shear drive
Hallden - October 1968 - 3405580
Speed reducer unit or drive
York - August 1964 - 3143899
Rotary shear drive
Hallden - October 1968 - 3405580
Application Number:
05/075352
Publication Date:
01/25/1972
Filing Date:
09/25/1970
View Patent Images:
Export Citation:
Assignee:
Rheinmetall GmbH (Dusseldorf, DT)
Primary Class:
Other Classes:
89/41.010
International Classes:
F16H57/12; F41A27/20; F16H57/00; F41A27/00; F16H55/18
Field of Search:
74/409,410,412
Primary Examiner:
Gerin, Leonard H.
Claims:
I claim
1. A gear drive with means for removal of the play of the toothed profile, in particular laying mechanism for armored turrets, rotary ring gun carriages or the like of weapons, comprising
2. The gear drive, as set forth in claim 1, wherein
3. The gear drive, as set forth in claim 1, which includes
4. The gear drive, as set forth in claim 1, which includes
5. The gear drive, as set forth in claim 4, wherein
6. The gear drive, as set forth in claim 1, which includes
7. The gear drive, as set forth in claim 1, which includes
1. A gear drive with means for removal of the play of the toothed profile, in particular laying mechanism for armored turrets, rotary ring gun carriages or the like of weapons, comprising
2. The gear drive, as set forth in claim 1, wherein
3. The gear drive, as set forth in claim 1, which includes
4. The gear drive, as set forth in claim 1, which includes
5. The gear drive, as set forth in claim 4, wherein
6. The gear drive, as set forth in claim 1, which includes
7. The gear drive, as set forth in claim 1, which includes
Description:
The present invention relates to a gear drive with means for the removal of the play of the toothed profile, in particular, laying mechanism for armored turrets, rotary ring gun carriages or the like of weapons.
The perfect working of laying mechanism (height and/or side), in particular, with stabilizing devices depends extensively from the play-free transmission of the rotary movement of the driving motor over the laying mechanism to the turret or the gun carriage.
Drives are known, in which a gear rack is pushed by means of a spring onto a pinion, whereby though play freedom is obtained, however, a rotary movement and a longitudinal movement, respectively, takes place only for a limited rotary range and a limited longitudinal stroke, respectively, with smallest numbers of revolutions.
Drives are also known, in which a radially divided worm is in mesh with a counter gear, whereby the one-half of the worm is rigidly connected with a shaft, while the other half of the worm is axially displaceable on this shaft and is disposed capable of being arrested by nuts. Drives are known likewise with output division, in which a pinion of the driving shaft meshes with a gear of the driven shaft and simultaneously a second pinion, axially displaceable on the driving shaft, obliquely toothed and capable of being arrested by nuts, with a correspondingly obliquely toothed spur gear and rigidly secured with the driven shaft. By axial displacement of the loose pinion, a rotation of the shafts relative to each other is obtained, until the play freedom of the gears disposed thereon is obtained. In these drives, however, the play freedom stands after the setting in dependency upon the degree of wear of the toothed profiles, in addition, it is obtained only in a drive step within the drive.
In a laying mechanism the perfect operation depends extensively from the play-free transmission of the rotary movement from the driving motor over the laying mechanism to the turret and the gun carriage. In the drives used before particular requirements are made to the surface quality of the toothed profiles, as well as the maintenance of smallest tolerances in the gear production, in order to reduce to a minimum the play of the tooth profiles of the individual drive steps. The largest play of the tooth profiles occurs, however, of necessity by the summary of the individual plays within the drive between the driving gear and the counter gear, which is mostly designed as a tooth segment and a tooth ring, respectively, thus outside of the actual laying mechanism. Jointly with rotary errors of the toothing in tooth segments and tooth rings, respectively, and by mounting errors, the play of the toothed profile can amount up to several tenths of a millimeter.
It is, therefore, one object of the present invention to provide a gear drive, with means for the removal of the play of the toothed profile, wherein the drawbacks concerning the play of the toothed profile are avoided.
It is another object of the present invention to provide a gear drive with means for removal of the play of the toothed profile, wherein the drive is secured for a pendulum movement and its driven gear is pressed onto the gear ring by means of pressure springs. In this case, however, the teeth of the one gear are pressed into the tooth gaps of the counter gear such, that a high friction force, a strong wear at the teeth between the driven part and the drive of the turret and of the gun carriage drive, respectively, and also a heavy run of the drive is created, which makes itself recognizable in particular in case of a low number of revolutions, for example, during fine laying, disadvantageously in case of sudden movements.
It is still another object of the present invention to provide a gear drive with means for removal of the play of the toothed profile, wherein the drive is secured for a pendulum movement and its driven gear is pressed onto the gear ring by means of pressure springs. In this case, however, the teeth of the one gear are pressed into the tooth gaps of the counter gear such, that a high friction force, a strong wear at the teeth between the driven part and the drive of the turret and of the gun carriage drive, respectively, and also a heavy run of the drive is created, which makes itself recognizable in particular in case of a low number of revolutions, for example, during fine laying, disadvantageously in case of sudden movements.
It is still another object of the present invention to provide a gear drive with means for removal of the play of the toothed profile, wherein in drives in particular in a laying mechanism of the above stated type measures are taken for the removal of the play of the tooth profile, which measures assure, on the one hand, also in case of an enlargement of the tolerances on the driven pinion of the drive, a steady play-free drive in both directions of rotation and play freedom at the returning point in case of a change of the direction of rotations, on the other hand, however, also assure a quiet run, connected with an easy movement of the drive even with smallest numbers of revolutions and a reduction of the wear of the tooth profile, as well as a solution which is more favorable as to the manufacture as well as to costs.
It is yet another object of the present invention to provide a gear drive with means for removal of the play of the toothed profile, wherein by a double-pinion shaft axially displaceable under the effect of a pressure medium and equipped with oblique teeth of opposite spiral directions, the pinions of which are meshed directly and with intermediate arrangement of further transmission steps mounted independently from each other with the same transmission-ratio and with correspondingly toothed coaxial counter gears mounted likewise independently from each other, whereby each of the counter gears is connected each with a further gear each by means of a shaft, and whereby the last-mentioned gears are of equal size and disposed directly adjacent each other and as driven gears mesh jointly into a counter gear disposed outside of the drive.
A drive designed in this manner stands by use of a suitable pressure medium for the axial displacement of the double-pinion shaft with continuous play freedom with the gear and tooth ring, respectively, to be driven and warrants a quiet run which is low on noise and low on friction even under extreme operational conditions.
In order to maintain as small as possible a laying mechanism of the type in accordance with the present invention, in view of the narrow space conditions in weapons in their outer dimensions, in accordance with a further feature of the present invention, of the two coaxial counter gears, one is secured to a solid shaft and the other to a hollow shaft surrounding this solid shaft, whereby the driven gears are disposed at the ends projecting from the driving housing.
In accordance with the present invention the pressure medium for the axial displacement of the double pinion shaft is a spring, which supports itself, on the one hand, on the double-pinion shaft and, on the other hand, on a bushing threaded with the driving housing and surrounding the spring.
This spring can be designed, by example, as a helical pressure spring or as a cup spring package.
In order to be able to transmit in such drive the calculated torque, in a further development of the concept of the present invention, the spring force, by example, the helical pressure spring is settable for the axial displacement of the double-pinion shaft by means of threaded bushing. A securing against nonintended loosening or setting of the threaded bushing can be provided thereby in addition.
Since, by example, armored turrets or rotary ring gun carriages of weapons are mostly driven by means of hydraulic or pneumatic means, in accordance with a further development of the present invention, the drive can be driven by a hydraulic or pneumatic driving motor, which is connected by means of a conduit with a cylinder secured to the drive housing, in which a piston is subjected to a pressure medium on the cylinder side and engages on the drive side the double-pinion shaft. By this arrangement, during an increase of the rotary- and braking-moment, respectively, of the gear driving motor in the cylinder, a pressure buildup takes place, which effects by means of the piston over the pinions of the double-pinion shaft directly onto the toothed profiles of the driven gears, as well as of the counter gear such, that only the just necessary toothed profile pressure is obtained and thus the toothing is protected.
In accordance with the present invention the double-pinion shaft can be driven in addition also by means of one or a plurality of spur gear steps, which in turn are likewise designed play-free in known manner.
The drive can thereby take place by a loose gear joining the movement on a shaft, which gear is put to a rotational movement on the driving side by means of a spur gear and transmits this rotary movement to another spur gear, which is rigidly connected with the double-pinion shaft and whereby the connecting line between the three axle center points result in a triangle. The play freedom of this driving step prearranged to the double-pinion shaft takes place such, that the shaft of the loosely rotating gear is mounted floatingly and is designed to be movable by one or a plurality of screws to the driving axle and to the axle of the double-pinion shaft and in play-free engagement of the two profiles are designed securably in this position.
With these and other objects in view which will become apparent in the following detailed description, the present invention will be clearly understood in connection with the accompanying drawings, in which:
FIG. 1 is a longitudinal or axial section of a two-stepped drive designed in accordance with the present invention;
FIG. 2 is a fragmentary axial section of the drive disclosed in FIG. 1, in which the double-pinion shaft is axially displaced by means of a spring;
FIG. 3 is a schematic showing at an enlarged scale of the play-free engagement of the driven gears meshing with a counter gear;
FIG. 4 is a fragmentary elevation, partly in section, indicating the displacing of the double-pinion shaft in accordance with FIG. 1, however, by means of a hydraulic or pneumatic medium;
FIG. 5 is an axial section of a preferred embodiment indicating a four-step drive in an arrangement similar to that shown in FIG. 1; and
FIG. 6 is a side elevation of the embodiment in accordance with FIG. 5 seen in the direction of the arrow, the housing end wall being partly broken away, for the purpose of a better demonstration.
Referring now to the drawings and in particular to FIG. 1, the gear drive designed in accordance with the present invention comprises a drive housing 1 in which a double-pinion shaft 2 is mounted. The latter is driven over a knurled toothing 2a by means of a handwheel or a motor (not shown) and on which two pinions 2b and 2c of equal size and with equal oblique toothing disposed in opposite spiral directions are rigidly arranged. The double-pinion shaft 2 is designed displaceably in axial direction by means of a helical pressure spring 3. The spring 3, which does not participate in a rotary movement of the shaft 2, supports itself thereby, on the one hand, by means of a spring plate 4 and a ball bearing 5 at a collar of the double-pinion shaft and, on the other hand, on a threaded bushing 6, which is screwable onto a flange formed on the drive housing. The pinion 2b meshes with a spur gear 8 secured to the solid shaft 7. The shaft 7 is mounted by means of a ball bearing 9 inside of the drive housing and by means of a second ball bearing 10 outside of the drive housing to an arm 11 rigidly connected with the drive housing. A gear 12 characterized as a driven pinion is mounted at the end of the shaft 7 projecting from the drive housing, which gear 12 is screwed to a flange 13 formed on the shaft 7. The pinion 2c stands in mesh with a spur gear 14 which is secured to a hollow shaft 15 surrounding the solid shaft 7, which hollow shaft 15 in turn is mounted by means of ball bearings 16 and 17 within the drive housing. At the end of the hollow shaft 15 on the output side is secured the gear 18 corresponding with the gear 12. Both driven gears 12 and 18 engage a counter gear 19 which is directly connected with a laying device.
The operation of the drive described above is in principle as follows:
In case of an axial displacement of the double-pinion shaft 2 by means of the spring 3 (FIG. 2) opposite rotary movements of the solid shaft 7 and of the hollow shaft 15 are produced by means of pinions 2b and 2c due to the oppositely arranged oblique toothing of the pinions 2b and 2c as well as of the corresponding spur gears 8 and 14, which rotary movements are transmitted to the driven spur gears 12 and 18 so far, until the toothed profiles of the latter come to an engagement play-free at the profiles of the counter gear 19 (FIG. 3). This freedom of play remains also during operation of the drive, since slight rotations of the driven spur gears 12 and 18, by example, due to rotating errors of the toothing of the counter gear 19 or mounting errors, makes themselves recognizable always in an axial displacement of the double-pinion shaft 2 in or against the direction of force of the spring 3.
FIG. 4 shows in contradiction to FIG. 2, the possibility of axial displacement in accordance with FIG. 1, however, by means of a hydraulic or pneumatic medium.
From a hydraulic- and pneumatic-pump, respectively, (not shown) a drive motor 21 is driven by means of a conduit 20. The return flow of the driving means takes place through a conduit 22. By means of a special valve 23, which is settable in known manner, the direction of rotation of the motor 21 can be reversed. From the conduit 20 branches a conduit 24 which terminates by means of a control valve 25 in a cylinder 26 closed on one side and flanged to the drive housing 101 and in which cylinder 26 is disposed a piston 27, which presses by means of the pressure means 28 over a ball bearing 105 to the double-pinion shaft 102 guided in the drive housing 101. The double-pinion shaft 102 engages with its oppositely obliquely toothed pinions 102b and 102c in correspondingly toothed counter gears 108 and 114, which correspond with the gears 8 and 14 in FIG. 1 and leads to the driven part of the drive, whereby the double-pinion shaft 102 is connected by means of the knurl toothing 102a forcibly with the motor 21. A limit of the axial stroke of the piston 27 is obtained by a collar 101a, which projects into the cylinder 26 from the driving side.
The effect of the hydraulic and pneumatic device, respectively, for the axial displaceability of the shaft is as follows:
In case of an increase of the rotary- and brake-moment on the drive motor 21 a pressure is built up for a short time period on the driving side of the motor, which is transmitted by means of the conduits 20 and 24 and the control valve 25 likewise onto the piston 27. The latter exerts thereby a stronger pressure upon the double-pinion shaft 102, so that the already above-described freedom of play of the drive is maintained up to the driven part even during the strongest load variations, as they occur, by example, in case of reversal of the direction of rotation. Upon reaching the load number of revolutions, such pressure will be set, that the double-pinion shaft 102 is subjected with the axial pressure still necessary for the freedom of play.
FIGS. 5 and 6 show in contradiction to FIG. 1 a fourstep drive, however, with the same effect as in connection with the device disclosed in FIG. 1.
A pinion shaft 30 mounted in the drive housing 29 drives with its straight toothed pinion 30a by means of a spur gear 31 a spur gear 33 secured to a double-pinion shaft 32. The double-pinion shaft 32 is, in the same manner as shown in the embodiment of FIG. 1, under the influence of a spring 34, the pressure force of which is settable by means of a threaded bushing 35 threaded with the drive housing 29, and displaceable in axial direction. Concerning the operation of the spring, reference is made to the description of FIG. 1.
In accordance with FIG. 6, the spur gear 31 is movable with its shaft in a guide (not shown) radially in the direction towards the pinion 30a and the spur gear 33 is movable by means of a setscrew 36 and after play-free engagement of the toothed profiles of the mentioned gears securable by means of a counter nut 37 in this position.
The drive takes place from the double-pinion shaft 32 over the oppositely obliquely toothed pinions 32a and 32b to correspondingly toothed spur gears 38 and 39, which are connected each with a pinion 40 and 41. The drive steps 38, 40 and 39, 41 formed of the pinions and spur gears are mounted independently from each other in the drive housing 29. The pinion 32a meshes with a spur gear 43 secured to the solid shaft 42 by means of the drive step 38 and 40. The shaft 42 is mounted by means of a ball bearing 44 inside of the drive housing and by means of a second ball bearing 45 outside of the drive housing in an arm 46 rigidly connected with the drive housing. At the end of the shaft 42 projecting from the drive housing, a gear 47 is mounted which is characterized as a driven pinion, which gear 47 is screwed to a flange 48 formed on the shaft 42. The pinion 32b is in mesh with a spur gear 49 by means of the drive step 39 and 41. This wheel 49 is secured on a hollow shaft 50 surrounding the solid shaft 42, which hollow shaft 50 in turn is mounted within the drive housing by means of ball bearings 51 and 52. On the end of the hollow shaft 50 at the output side of the drive a gear 53 is secured a gear 53 corresponding with the gear 47. Both driven gears 47 and 53 engage jointly in a gear rim 54 which runs on a wire ball bearing 55.
While I have disclosed several embodiments of the present invention, it is to be understood that these embodiments are given by example only and not in a limiting sense.
The perfect working of laying mechanism (height and/or side), in particular, with stabilizing devices depends extensively from the play-free transmission of the rotary movement of the driving motor over the laying mechanism to the turret or the gun carriage.
Drives are known, in which a gear rack is pushed by means of a spring onto a pinion, whereby though play freedom is obtained, however, a rotary movement and a longitudinal movement, respectively, takes place only for a limited rotary range and a limited longitudinal stroke, respectively, with smallest numbers of revolutions.
Drives are also known, in which a radially divided worm is in mesh with a counter gear, whereby the one-half of the worm is rigidly connected with a shaft, while the other half of the worm is axially displaceable on this shaft and is disposed capable of being arrested by nuts. Drives are known likewise with output division, in which a pinion of the driving shaft meshes with a gear of the driven shaft and simultaneously a second pinion, axially displaceable on the driving shaft, obliquely toothed and capable of being arrested by nuts, with a correspondingly obliquely toothed spur gear and rigidly secured with the driven shaft. By axial displacement of the loose pinion, a rotation of the shafts relative to each other is obtained, until the play freedom of the gears disposed thereon is obtained. In these drives, however, the play freedom stands after the setting in dependency upon the degree of wear of the toothed profiles, in addition, it is obtained only in a drive step within the drive.
In a laying mechanism the perfect operation depends extensively from the play-free transmission of the rotary movement from the driving motor over the laying mechanism to the turret and the gun carriage. In the drives used before particular requirements are made to the surface quality of the toothed profiles, as well as the maintenance of smallest tolerances in the gear production, in order to reduce to a minimum the play of the tooth profiles of the individual drive steps. The largest play of the tooth profiles occurs, however, of necessity by the summary of the individual plays within the drive between the driving gear and the counter gear, which is mostly designed as a tooth segment and a tooth ring, respectively, thus outside of the actual laying mechanism. Jointly with rotary errors of the toothing in tooth segments and tooth rings, respectively, and by mounting errors, the play of the toothed profile can amount up to several tenths of a millimeter.
It is, therefore, one object of the present invention to provide a gear drive, with means for the removal of the play of the toothed profile, wherein the drawbacks concerning the play of the toothed profile are avoided.
It is another object of the present invention to provide a gear drive with means for removal of the play of the toothed profile, wherein the drive is secured for a pendulum movement and its driven gear is pressed onto the gear ring by means of pressure springs. In this case, however, the teeth of the one gear are pressed into the tooth gaps of the counter gear such, that a high friction force, a strong wear at the teeth between the driven part and the drive of the turret and of the gun carriage drive, respectively, and also a heavy run of the drive is created, which makes itself recognizable in particular in case of a low number of revolutions, for example, during fine laying, disadvantageously in case of sudden movements.
It is still another object of the present invention to provide a gear drive with means for removal of the play of the toothed profile, wherein the drive is secured for a pendulum movement and its driven gear is pressed onto the gear ring by means of pressure springs. In this case, however, the teeth of the one gear are pressed into the tooth gaps of the counter gear such, that a high friction force, a strong wear at the teeth between the driven part and the drive of the turret and of the gun carriage drive, respectively, and also a heavy run of the drive is created, which makes itself recognizable in particular in case of a low number of revolutions, for example, during fine laying, disadvantageously in case of sudden movements.
It is still another object of the present invention to provide a gear drive with means for removal of the play of the toothed profile, wherein in drives in particular in a laying mechanism of the above stated type measures are taken for the removal of the play of the tooth profile, which measures assure, on the one hand, also in case of an enlargement of the tolerances on the driven pinion of the drive, a steady play-free drive in both directions of rotation and play freedom at the returning point in case of a change of the direction of rotations, on the other hand, however, also assure a quiet run, connected with an easy movement of the drive even with smallest numbers of revolutions and a reduction of the wear of the tooth profile, as well as a solution which is more favorable as to the manufacture as well as to costs.
It is yet another object of the present invention to provide a gear drive with means for removal of the play of the toothed profile, wherein by a double-pinion shaft axially displaceable under the effect of a pressure medium and equipped with oblique teeth of opposite spiral directions, the pinions of which are meshed directly and with intermediate arrangement of further transmission steps mounted independently from each other with the same transmission-ratio and with correspondingly toothed coaxial counter gears mounted likewise independently from each other, whereby each of the counter gears is connected each with a further gear each by means of a shaft, and whereby the last-mentioned gears are of equal size and disposed directly adjacent each other and as driven gears mesh jointly into a counter gear disposed outside of the drive.
A drive designed in this manner stands by use of a suitable pressure medium for the axial displacement of the double-pinion shaft with continuous play freedom with the gear and tooth ring, respectively, to be driven and warrants a quiet run which is low on noise and low on friction even under extreme operational conditions.
In order to maintain as small as possible a laying mechanism of the type in accordance with the present invention, in view of the narrow space conditions in weapons in their outer dimensions, in accordance with a further feature of the present invention, of the two coaxial counter gears, one is secured to a solid shaft and the other to a hollow shaft surrounding this solid shaft, whereby the driven gears are disposed at the ends projecting from the driving housing.
In accordance with the present invention the pressure medium for the axial displacement of the double pinion shaft is a spring, which supports itself, on the one hand, on the double-pinion shaft and, on the other hand, on a bushing threaded with the driving housing and surrounding the spring.
This spring can be designed, by example, as a helical pressure spring or as a cup spring package.
In order to be able to transmit in such drive the calculated torque, in a further development of the concept of the present invention, the spring force, by example, the helical pressure spring is settable for the axial displacement of the double-pinion shaft by means of threaded bushing. A securing against nonintended loosening or setting of the threaded bushing can be provided thereby in addition.
Since, by example, armored turrets or rotary ring gun carriages of weapons are mostly driven by means of hydraulic or pneumatic means, in accordance with a further development of the present invention, the drive can be driven by a hydraulic or pneumatic driving motor, which is connected by means of a conduit with a cylinder secured to the drive housing, in which a piston is subjected to a pressure medium on the cylinder side and engages on the drive side the double-pinion shaft. By this arrangement, during an increase of the rotary- and braking-moment, respectively, of the gear driving motor in the cylinder, a pressure buildup takes place, which effects by means of the piston over the pinions of the double-pinion shaft directly onto the toothed profiles of the driven gears, as well as of the counter gear such, that only the just necessary toothed profile pressure is obtained and thus the toothing is protected.
In accordance with the present invention the double-pinion shaft can be driven in addition also by means of one or a plurality of spur gear steps, which in turn are likewise designed play-free in known manner.
The drive can thereby take place by a loose gear joining the movement on a shaft, which gear is put to a rotational movement on the driving side by means of a spur gear and transmits this rotary movement to another spur gear, which is rigidly connected with the double-pinion shaft and whereby the connecting line between the three axle center points result in a triangle. The play freedom of this driving step prearranged to the double-pinion shaft takes place such, that the shaft of the loosely rotating gear is mounted floatingly and is designed to be movable by one or a plurality of screws to the driving axle and to the axle of the double-pinion shaft and in play-free engagement of the two profiles are designed securably in this position.
With these and other objects in view which will become apparent in the following detailed description, the present invention will be clearly understood in connection with the accompanying drawings, in which:
FIG. 1 is a longitudinal or axial section of a two-stepped drive designed in accordance with the present invention;
FIG. 2 is a fragmentary axial section of the drive disclosed in FIG. 1, in which the double-pinion shaft is axially displaced by means of a spring;
FIG. 3 is a schematic showing at an enlarged scale of the play-free engagement of the driven gears meshing with a counter gear;
FIG. 4 is a fragmentary elevation, partly in section, indicating the displacing of the double-pinion shaft in accordance with FIG. 1, however, by means of a hydraulic or pneumatic medium;
FIG. 5 is an axial section of a preferred embodiment indicating a four-step drive in an arrangement similar to that shown in FIG. 1; and
FIG. 6 is a side elevation of the embodiment in accordance with FIG. 5 seen in the direction of the arrow, the housing end wall being partly broken away, for the purpose of a better demonstration.
Referring now to the drawings and in particular to FIG. 1, the gear drive designed in accordance with the present invention comprises a drive housing 1 in which a double-pinion shaft 2 is mounted. The latter is driven over a knurled toothing 2a by means of a handwheel or a motor (not shown) and on which two pinions 2b and 2c of equal size and with equal oblique toothing disposed in opposite spiral directions are rigidly arranged. The double-pinion shaft 2 is designed displaceably in axial direction by means of a helical pressure spring 3. The spring 3, which does not participate in a rotary movement of the shaft 2, supports itself thereby, on the one hand, by means of a spring plate 4 and a ball bearing 5 at a collar of the double-pinion shaft and, on the other hand, on a threaded bushing 6, which is screwable onto a flange formed on the drive housing. The pinion 2b meshes with a spur gear 8 secured to the solid shaft 7. The shaft 7 is mounted by means of a ball bearing 9 inside of the drive housing and by means of a second ball bearing 10 outside of the drive housing to an arm 11 rigidly connected with the drive housing. A gear 12 characterized as a driven pinion is mounted at the end of the shaft 7 projecting from the drive housing, which gear 12 is screwed to a flange 13 formed on the shaft 7. The pinion 2c stands in mesh with a spur gear 14 which is secured to a hollow shaft 15 surrounding the solid shaft 7, which hollow shaft 15 in turn is mounted by means of ball bearings 16 and 17 within the drive housing. At the end of the hollow shaft 15 on the output side is secured the gear 18 corresponding with the gear 12. Both driven gears 12 and 18 engage a counter gear 19 which is directly connected with a laying device.
The operation of the drive described above is in principle as follows:
In case of an axial displacement of the double-pinion shaft 2 by means of the spring 3 (FIG. 2) opposite rotary movements of the solid shaft 7 and of the hollow shaft 15 are produced by means of pinions 2b and 2c due to the oppositely arranged oblique toothing of the pinions 2b and 2c as well as of the corresponding spur gears 8 and 14, which rotary movements are transmitted to the driven spur gears 12 and 18 so far, until the toothed profiles of the latter come to an engagement play-free at the profiles of the counter gear 19 (FIG. 3). This freedom of play remains also during operation of the drive, since slight rotations of the driven spur gears 12 and 18, by example, due to rotating errors of the toothing of the counter gear 19 or mounting errors, makes themselves recognizable always in an axial displacement of the double-pinion shaft 2 in or against the direction of force of the spring 3.
FIG. 4 shows in contradiction to FIG. 2, the possibility of axial displacement in accordance with FIG. 1, however, by means of a hydraulic or pneumatic medium.
From a hydraulic- and pneumatic-pump, respectively, (not shown) a drive motor 21 is driven by means of a conduit 20. The return flow of the driving means takes place through a conduit 22. By means of a special valve 23, which is settable in known manner, the direction of rotation of the motor 21 can be reversed. From the conduit 20 branches a conduit 24 which terminates by means of a control valve 25 in a cylinder 26 closed on one side and flanged to the drive housing 101 and in which cylinder 26 is disposed a piston 27, which presses by means of the pressure means 28 over a ball bearing 105 to the double-pinion shaft 102 guided in the drive housing 101. The double-pinion shaft 102 engages with its oppositely obliquely toothed pinions 102b and 102c in correspondingly toothed counter gears 108 and 114, which correspond with the gears 8 and 14 in FIG. 1 and leads to the driven part of the drive, whereby the double-pinion shaft 102 is connected by means of the knurl toothing 102a forcibly with the motor 21. A limit of the axial stroke of the piston 27 is obtained by a collar 101a, which projects into the cylinder 26 from the driving side.
The effect of the hydraulic and pneumatic device, respectively, for the axial displaceability of the shaft is as follows:
In case of an increase of the rotary- and brake-moment on the drive motor 21 a pressure is built up for a short time period on the driving side of the motor, which is transmitted by means of the conduits 20 and 24 and the control valve 25 likewise onto the piston 27. The latter exerts thereby a stronger pressure upon the double-pinion shaft 102, so that the already above-described freedom of play of the drive is maintained up to the driven part even during the strongest load variations, as they occur, by example, in case of reversal of the direction of rotation. Upon reaching the load number of revolutions, such pressure will be set, that the double-pinion shaft 102 is subjected with the axial pressure still necessary for the freedom of play.
FIGS. 5 and 6 show in contradiction to FIG. 1 a fourstep drive, however, with the same effect as in connection with the device disclosed in FIG. 1.
A pinion shaft 30 mounted in the drive housing 29 drives with its straight toothed pinion 30a by means of a spur gear 31 a spur gear 33 secured to a double-pinion shaft 32. The double-pinion shaft 32 is, in the same manner as shown in the embodiment of FIG. 1, under the influence of a spring 34, the pressure force of which is settable by means of a threaded bushing 35 threaded with the drive housing 29, and displaceable in axial direction. Concerning the operation of the spring, reference is made to the description of FIG. 1.
In accordance with FIG. 6, the spur gear 31 is movable with its shaft in a guide (not shown) radially in the direction towards the pinion 30a and the spur gear 33 is movable by means of a setscrew 36 and after play-free engagement of the toothed profiles of the mentioned gears securable by means of a counter nut 37 in this position.
The drive takes place from the double-pinion shaft 32 over the oppositely obliquely toothed pinions 32a and 32b to correspondingly toothed spur gears 38 and 39, which are connected each with a pinion 40 and 41. The drive steps 38, 40 and 39, 41 formed of the pinions and spur gears are mounted independently from each other in the drive housing 29. The pinion 32a meshes with a spur gear 43 secured to the solid shaft 42 by means of the drive step 38 and 40. The shaft 42 is mounted by means of a ball bearing 44 inside of the drive housing and by means of a second ball bearing 45 outside of the drive housing in an arm 46 rigidly connected with the drive housing. At the end of the shaft 42 projecting from the drive housing, a gear 47 is mounted which is characterized as a driven pinion, which gear 47 is screwed to a flange 48 formed on the shaft 42. The pinion 32b is in mesh with a spur gear 49 by means of the drive step 39 and 41. This wheel 49 is secured on a hollow shaft 50 surrounding the solid shaft 42, which hollow shaft 50 in turn is mounted within the drive housing by means of ball bearings 51 and 52. On the end of the hollow shaft 50 at the output side of the drive a gear 53 is secured a gear 53 corresponding with the gear 47. Both driven gears 47 and 53 engage jointly in a gear rim 54 which runs on a wire ball bearing 55.
While I have disclosed several embodiments of the present invention, it is to be understood that these embodiments are given by example only and not in a limiting sense.