Apparatus for transmitting rotation utilizing an oscillating input

A new type of apparatus for transmitting rotation utilizing an oscillating input utilizes a self-locking worm (1) and worm gear (3) combination with different types of means for rotating said worm about its axis of rotation relative to said worm gear described. An input to the worm gear (3) is transmitted without relative movement to the thread of the worm (1) to cause the thread and hence the rotor to rotate about an axis of the worm gear. The means preferably rotates the worm thread relative to the worm gear teeth under certain conditions when it is not desired to transmit rotation. A system for transmitting an oscillating input (4) to a single directional output (5) incorporates some of the worm and worm gear combinations with spider or bevel differentials.

BACKGROUND OF THE INVENTION 
This invention relates to a combined transmission system that transmits an 
oscillating input into a single direction output. 
The prior art transmissions have not successfully transmitted high torque 
levels. One common type of transmission device is a one-way clutch. In 
these known systems: such as in U.S. Pat. No. 5,333,517 by Rodney Bryson, 
Aug. 02, 1994, rollers or other drive members are engaged within notches 
or openings in a driven member. The rollers engage and move the driven 
member when rotation is transmitted in a first direction, but will slip 
when rotation is transmitted in a second direction. The invention 
disclosed in U.S. Pat. No. 5,333,517 has a ratio between the worm and worm 
gear of 5, however, the number of threads on the worm is more than one, 
and the worm does not have a self locking feature. These types of clutches 
have enjoyed wide usage, but have been unable to transmit high torque 
loads. One proposal suggests using a pair of such clutches with an 
oscillating input to perform as a part of a vehicle transmission. Due to 
the low torque load, this system would be impractical. A main disadvantage 
of these types of clutches is a discrete characteristic of changing of 
contact. It leads to mechanical shocks during every new contact between 
driving and driven elements. Drive systems for providing speed in a single 
rotational direction from a reversible input are also well known (U.S. 
Pat. No. 5,333,517 by Rodney Bryson, Aug. 02, 1994). But this system has a 
gear train with some backlashes and it is not able to provide a small 
amplitude of vibration. Besides, the input and output shafts are 
perpendicular to each other, and therefore, this drive system cannot be 
used in many applications. 
In one system disclosed in a Soviet inventor certificate number 1,495,110 
(1989) granted to the inventor of this invention, a self-locking 
transmission is utilized to transmit rotation. In the disclosed system, a 
worm and a worm gear combination are utilized to transmit rotation. The 
rotation is transmitted utilizing the engaged teeth and thread of the 
gears such that there is not relative movement between the two gear 
members during this rotation. With such a system, many valuable benefits 
result. In particular, one is able to accurately and efficiently transmit 
rotation through the self-locking transmission. A main advantage of these 
types of clutches is continuous contact between the driving and driven 
elements. 
In addition, the standard power supply utilized with such systems has 
difficulty allowing any of the structure to freely turn about 360 degrees. 
Instead, electrical supply lines have typically limited the operative 
members to a restricted range of rotation. This is, of course, 
undesirable. 
The term "self-locking" as is utilized in this application to describe the 
inventive worm and worm gear combination, requires that the teeth of the 
worm gear when in contact with the thread of the worm, are incapable of 
rotating the worm about its axis. The teeth do not slip on the thread 
causing the thread to rotate about its own axis. By carefully selecting 
the material of the respective teeth and threads, and the respective 
angles, a worker of ordinary skill in the art would be able to achieve 
this goal. 
There are some deficiencies in the system disclosed in the prior inventor's 
certificate, however, and this invention and a parent patent application 
of the same inventor, Ser. No. 08/732,150, filed Oct. 16, 1996 entitled 
"Worm/Wormgear Transmission And Apparatus For Transmitting Rotating 
Utilizing An Oscillating Input" disclose improvements to the prior art 
system, and PCT International Application No. PCT/US96/02918. 
SUMMARY OF THE INVENTION 
The present invention describes the effect of "self-lock" between a worm 
and worm gear which is used for designing a one way clutch. Typically, in 
previous art, free motion of a worm has been provided by an electric 
motor. This is important for the purpose of reversing the direction of 
transferring torque, but the worm has to rotate effectively at a rate 
which is equal to the ratio of the gear teeth and thread of the worm gear 
and worm. New in this invention are a gear train or pulley drive (flexible 
shaft is optional) comprising an on/off clutch and input of the train 
(drive) being driven by said worm gear and the worm being driven from the 
output of the train (drive). 
The worm and worm gear combination is incorporated into a system wherein 
the worm is mounted for rotation in a rotor. The rotor surrounds a driving 
worm gear. A rotational input is applied to the worm gear. The worm gear 
teeth engage the thread on the worm, the worm and the rotor rotate about 
the axis of the worm gear. This rotation is without relative movement 
between the engaged teeth of the worm and worm gear. 
An auxiliary motor (or an on/off clutch) is preferably mounted on the 
rotor, and rotates the worm relative to the worm gear to either return the 
worm gear to its original position, or allow the worm gear to move 
relative to the worm when an oscillating input is utilized. When subjected 
to an oscillating input, the worm and rotor act as a mechanical diode, 
resulting in a single direction output. When we use the motor instead of 
the gear train comprising an on/off clutch, we need to synchronize on/off 
action of the clutch according to oscillation of the worm gear. 
In describing different versions of transmissions, the base of the design 
is a grounded rotor which is holding the worm. Due to this, there is no 
problem connecting the electrical connections to the operative members 
even when the operative members freely rotate more than 360 degrees. 
Balancing of the rotor also becomes easy. Versions of designs with a worm 
gear attached to the different members of the spider differential and 
bevel differential are the foundations of the invention. Transmissions 
with different ratios are provided as combinations of these designs. 
Examples, shown in this patent application are not described in the parent 
patent application. The usage of this invention not only transmits the 
rotation utilizing an oscillating input but also transmits the torque for 
the conventional power transmission. For example, this system can be 
utilized as part of a vehicle transmission or a gear box with changeable 
ratio. 
These and other features of the present invention may be best understood 
from the following specification and drawings, of which the following is a 
brief description.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
An apparatus for transmitting rotation utilizing an oscillating input is 
shown in FIG. 1. The apparatus includes a worm 1 which is enclosed in a 
rotor 2. The rotor 2 forms a rigid support to mount bearings. For best 
results, the worm 1 is enveloping and wraps around a worm gear 3. The worm 
gear 3 is also enveloping and wraps around the worm 1. During the rotation 
of the worm 1, the worm gear 3 rotates with low speed. The minimum ratio 
between the number of worm gear teeth and one worm thread provided on the 
worm 1 is two (2). On the other hand, by rotation of the worm gear 3 worm 
1 rotates with higher speed. This invention comprises means for rotating 
the worm 1 about its axis of rotation relative to the worm gear 3. Said 
means can be the auxiliary motor (described in parent patent application 
Ser. No. 08/732,150) or in a gear train comprising a hypoid-gear set, 
spiroid-gear set, bevel-gear set or helicon-gear set, may consist of gears 
6, 7 with the on/off clutch 8. Input of the train is driven by the worm 
gear 3 from the input shaft 4 and the worm 1 is driven by the output 
(on/off clutch) of the train. The rotor 2 is connected to the output shaft 
5. On/off clutch 8 can be a friction electromechanical clutch with natural 
conditions like "on" or "off". The ratio of the train is more or equal to 
the ratio between the number of teeth on the worm gear 3 relative to the 
threads on worm 1. The worm 1 and worm gear 3 have the property of 
self-lock. 
Examples of drive means for rotating the worm 1 about its axis of rotation 
relative to the worm gear 3 is shown in FIG. 2.sub.-- 1 and FIG. 2.sub.-- 
2. The means as disclosed in FIG. 2.sub.-- 1 is a gear train comprising 
spur gears 9, 10, flexible shaft 11 and the on/off clutch 8. The drive 
means as disclosed in FIG. 2.sub.-- 2 is a pulley drive comprising pulleys 
50, 51 with belt 52, the flexible shaft 11 and the on/off clutch 8. The 
drive means with flexible shaft 11 is easy to assemble in a single 
reduction unit. To provide a preload in a direction around an axis of the 
worm 1 and to eliminate a backlash between the teeth of the worm gear 3 
and the thread of the worm 1, it is better to use an auxiliary motor. 
When the rotor 2 is grounded, the worm gear 3 is connected to one of the 
members of the differential gear set. As illustrated in FIG. 3, the 
differential gear set is a spider differential comprising sun gears 12, 13 
with a spider gear 14, a housing 15 and a carrier 16 wherein the sun gear 
12 is connected to the worm gear 3. For simplicity of illustration, the 
drive means is the auxiliary motor 17. 
As illustrated in FIG. 4, the differential gear set is a spider 
differential comprising a sun gear 13, a ring gear 18 with a spider gear 
20, a housing 15, and a carrier 16 wherein the sun gear 13 is connected to 
the worm gear 3. 
As illustrated in FIG. 5, the differential gear set is a spider 
differential comprising a sun gear 13, a ring gear 18 with a spider gear 
20, a housing 15, and a carrier 16 wherein the ring gear 18 is connected 
to the worm gear 3. 
As illustrated in FIG. 6, the differential gear set is a spider 
differential comprising sun gears 12, 13 with a double spider gear 14, a 
housing 15, and a carrier 16 wherein the carrier 16 is connected to the 
worm gear 3. 
In an example illustrated in FIG. 7, the differential gear set is a spider 
differential comprising a sun gear 13, a ring gear 18 with a spider gear 
20, a housing 15, and a carrier 16 wherein the carrier 16 is connected to 
the worm gear 3. 
As illustrated in FIG. 8, the differential gear set is a bevel differential 
comprising bevel gears 19, 24 with an idler bevel gear 21, a housing 22 
and a carrier 23 wherein the bevel gear 24 is connected to the worm gear 
3. 
As illustrated in FIG. 9, the differential gear set is a bevel differential 
comprising bevel gears 19, 24 with an idler bevel gear 21, a housing 22 
and a carrier 23 wherein the carrier 23 is connected to the worm gear 3. 
To change the ratio of the transmission or to reverse the direction of 
rotation, a pair of worms 1 and 25 with the rotors 2 and 2', with each of 
the worm gears 3, 26 can be driven by independent shafts 4 and 5 and have 
a differential for connecting the worm gears with members of the 
differential. 
As illustrated in FIG. 10, the differential gear set is a bevel 
differential comprising bevel gears 19, 24 with a spider bevel gear 21, a 
housing 22 and a carrier 23 wherein the carrier 23 is connected to the 
worm gear 26. Bevel gear 24 is connected to the worm gear 3. An extra 
shaft 28 can provide an opposite direction of rotation. For simplicity, 
the drive means are auxiliary motors 17 and 27. 
As illustrated in FIG. 11, the differential gear set is a spider 
differential comprising sun gears 12, 13, 18 with a spider gear 29, a 
housing 15 and a carrier 16 wherein the sun gear 18 is connected to the 
second worm gear 26, and the carrier 16 is connected to the first worm 
gear 3. For simplicity, the drive means are auxiliary motors 17 and 27. 
As illustrated in FIG. 12, the differential gear set is a spider 
differential comprising sun gears 12, 13 and a ring gear 18, a housing 15, 
a spider gear 14 and a carrier 16 wherein the sun gear 13 is connected to 
the first worm gear 3 and the ring gear 18 is connected to the second worm 
gear 26. For simplicity the drive means are auxiliary motors 17 and 27. 
As illustrated in FIG. 13, the differential gear set is a spider 
differential comprising sun gears 12, 13 and a ring gear 18, a housing 15, 
a spider gear 14 and a carrier 16 wherein the carrier 16 is connected to 
the first worm gear 3 and the ring gear 18 is connected to the second worm 
gear 26. For simplicity the drive means are auxiliary motors 17 and 27. 
As illustrated in FIG. 14, the differential gear set is a spider 
differential comprising sun gears 12, 13, 18 with a spider gear 29, a 
housing 15 and a carrier 16 wherein the sun gear 18 is connected to the 
second worm gear 26 and the carrier 16 is connected to the first worm gear 
3. The first drive means are gears 6 and 7 with on/off clutch 8 and the 
second drive means is auxiliary motor 17. 
As illustrated in FIG. 15 the differential gear set is a spider 
differential comprising sun gears 12, 13 and a ring gear 18, a housing 15, 
a spider gear 14 and a carrier 16 wherein the carrier 16 is connected to 
the first worm gear 3 and the ring gear 18 is connected to the second worm 
gear 26. The first drive means are gears 6 and 7 with on/off clutch 8 and 
the second drive means is auxiliary motor 17. 
As illustrated in FIG. 16, the differential gear set is a spider 
differential comprising sun gears 12, 13 and a ring gear 18, a housing 15, 
a spider gear 14 and a carrier 16 wherein the sun gear 13 is connected to 
the first worm gear 3 and the ring gear 18 is connected to the second worm 
gear 26. The first drive means are gears 6 and 7 with an on/off clutch 8 
and the second drive means are gears 30, 31 with an on/off clutch 32. 
FIG. 17 is a combination of FIG. 1 and FIG. 9. As illustrated in FIG. 17, 
the differential gear set is a bevel differential comprising bevel gears 
19 and 24 with an idler bevel gear 21, a housing 22 and a carrier 23 
wherein the carrier 23 is connected to the worm gear 3 and to the worm 
gear 26. The rotor 2 is grounded. 
As illustrated in FIG. 18, the differential gear set is a spider 
differential comprising sun gears 12, 13, a housing 15 with a carrier 16 
and a bevel differential comprising bevel gears 19, 24 and an idler bevel 
gear 21, wherein the carrier 16 is connected to the first worm gear 3 and 
the sun gear 12 is connected to the second worm gear 26 and the carrier 
23. The first drive means are gears 6 and 7 with an on/off clutch 8 and 
the second drive means are gears 30, 31 with an on/off clutch 32. 
FIG. 19 discloses a half worm 33 enclosed in the rotor 34 and an auxiliary 
motor 35. For balancing, the body of the rotor 34 holds removable 
balancing elements 36. Half of a worm 33 is easy to assemble with the worm 
gear 37. 
FIG. 19 is a cross-sectional view of congruent surfaces of the lands on the 
half of the worm 33 and the teeth of the worm gear 37. Design of these 
surfaces are described in U.S. Pat. No. 3,895,700 issued to John Hugh Kerr 
in 1975. 
FIG. 21 is a cross-sectional view of the half worm 33 and worm gear 37 with 
a train of a torsion spring 38 and with a friction clutch 39. 
FIG. 22 is a cross-sectional view of two halves of worms 33 and 40 and the 
worm gear 37 with two trains including the torsion spring 38 with the 
friction clutch 39 and the torsion spring 41 with friction clutch 42. 
As shown in FIG. 1, the input shaft 4 drives worm gear 3. Output shaft 5 
rotates with the rotor 2. Electrical power is supplied to the on/off 
clutch 8 or alternatively to an auxiliary motor. A brush commutation 
connection could be utilized for the inventive purposes described in this 
application. A control system (not shown) interrupts power between the 
source of electricity and the auxiliary motor or the on/off clutch. For 
the on/off clutch application with normal condition "on", the appearance 
of power changes the condition to "off". 
For positive rotation fo the input shaft 4, the clutch 8 has an "off" 
condition. Rotation of the shaft 4 in a positive direction with worm gear 
3 rotating about its axis causes the worm 1 to rotate about the axis of 
worm gear 3 with rotor 2. This rotation is without relative movement 
between the worm 1 and worm gear 3. That is, the teeth of the worm gear 3 
directly engage the thread on the worm 1, and there is no relative 
movement during this transmission. This rotation is provided by a normal 
force from the worm gear teeth against the thread on the worm. There is no 
relative movement, and thus the efficiency is maximum. This way, rotation 
of the output shaft 5 is achieved. This rotation is achieved if the teeth 
and threads are designed to be "self-locking" as described above. A worker 
of ordinary skill in the art would recognize how to design a self-locking 
gear set. For negative rotation of input shaft 4, clutch 8 has an "on" 
condition. Rotation of the shaft 4 also rotates gears 6, 7 and the worm 1. 
This rotation is provided such that the thread on the worm 1 a voids any 
forces from the teeth on worm gear 3, thus avoiding any transmission of 
rotation to the worm 1, and rotor 2. Even when the ratio of the gear train 
is more than the ratio of worm gear/worm, the clutch 8 permits sliding to 
prevent the gear train from crushing. Rotation from the input shaft 4 is 
not transferred to the output shaft 5. 
As explained in more detail in the parent U.S. applications, it is also 
desirable to have some gap between the teeth on the worm gear 3 and the 
worm 1. The gap is taken up prior to any transmission of rotation, and it 
is desirable that the contact be initially taken up as a low torque load. 
These features are explained in more detail in the above parent 
application. 
As an example, worm 1 as shown in FIG. 2, rotates by transmission of 
rotation through flexible shaft 11. This design takes less space. The 
ratio between the worm 1 and worm gear 3 would require an auxiliary motor 
or gear train, turning the worm 1 to avoid interaction with the teeth on 
worm gear 3 that would be impractical when the input speed is very high. 
Most preferably, the ratio between worm and worm gear is less than 12. It 
is possible that only 2 teeth need to be utilized on the worm gear 3. As 
explained above, the transmission of power from the worm gear 3 to the 
worm 1 occurs without relative movement and is typically the case with the 
worm and worm gear combination. Rather, the teeth of the worm gear 3 are 
brought into contact with the thread on the worm 1, and the worm gear 3 is 
prevented from rotation about its own axis. A force is applied to the worm 
gear 3 which drives the worm 1 about the axis of the worm gear 3 , thus 
imparting rotation to the rotor 2. 
Since the worm and worm gears are not utilized as in standard gears to have 
interengaging teeth and threads, the material selected for the members is 
different than that which has been utilized in the past. In the past, the 
worm and worm gears have been formed of materials having low coefficients 
of friction and a lubricant is typically utilized. In this invention, 
lubricant would not be needed. Moreover, the worm and worm wheel are made 
from a strong material such as steel. The shape of the teeth and threads 
and the worm and worm gears are designed to achieve a self-lock feature. 
Even though a worker of ordinary skill in the art would recognize these 
designs, he would come within the scope of this invention. 
In addition, a material that actually increases the friction may be placed 
on the teeth and threads. Again, it is a goal to achieve the self-locking 
property, rather than any smooth movement between the worm and the worm 
gear. The reduction of the number of teeth on the worm gear also reduces 
the inertia of the worm gear, thus increasing the speed at which the worm 
gear can shift between its oscillating inputs. Finally, rather than simply 
reducing the number of worm gear teeth, the thickness of the worm thread 
could be reduced to result in an acceptable gap. 
The gear train or pulley drive with on/off clutch or auxiliary motor will 
be of a relatively low torque. Its function is to turn the worm without 
any interaction relative to the teeth of the worm gear and to stop under 
overload even when the worm is fixed by the worm gear. Thus, a high torque 
motor or on/off clutch needs not be utilized. For that reason, only a low 
amount of electrical energy is required to operate the on/off clutch or 
auxiliary motor. 
The supply of electric energy to rotate the on/off clutch or the auxiliary 
motor leads to additional inconvenience. Besides, for many applications 
there is a need to change transferring torque or speed of rotation and 
change direction of the output shaft. For this purpose we use a 
differential which has 2 degrees of freedom. By taking off (freezing) one 
degree of freedom, it transforms the differential into a planetary 
transmission. Different examples of such designs are shown in FIG. 3-FIG. 
9. 
FIG. 3 and FIG. 6 describe transmissions for transferring positive/negative 
rotation of the input shaft 4 with different torque or disconnecting the 
output shaft 5 from the input shaft 4. The ratio depends on the number of 
teeth in gears 12 and 13. 
FIGS. 4, 5 and 7 describe transmissions for changing the direction of 
rotation from the input shaft 4 with a different torque or disconnecting 
the output shaft 5 from the input shaft 4. The ratio depends on the number 
of teeth in gears 18 and 13. 
FIGS. 8 and 9 describe transmissions for changing the direction of rotation 
with the same torque or disconnecting the output shaft 5 from the input 
shaft 4. 
When adding the pair of worms 1 and 25, rotors 2 and 23 with the means 
(auxiliary motor 17 and auxiliary motor 27 or gear train with gear 6, gear 
7, on/off clutch 8 and gear train with gear 30, gear 31, on/off clutch 32) 
and the worm gear 3 and the worm gear 26 with each of the worm gears being 
driven by an independent input shaft to a differential for connecting the 
worm gears with the members of the differential, we are able to change the 
ratio from the first number to the second number or to change the 
direction of rotation. 
FIG. 10 discloses a transmission for changing the direction of rotation 
from the shaft 4 to shafts 5 or 29 or disconnecting the output shaft 5 
from the input shaft 4. When the worm gear 3 is held by the worm 1, then 
the shaft 28 has the direction of rotation of the input shaft 4. When worm 
gear 26 is held by worm 25, the shaft 5 has an opposite direction of 
rotation from the input shaft 4. 
FIGS. 11-16 disclose the designs of a transmission with a ratio of 1 (one) 
for connecting the input shaft 4 with the output shaft 5, when the worm 
gear 26 is held by the worm 25. Also, these designs are used for changing 
the ratio between the input 4 and the output 5 when the worm gear 3 is 
held by the worm 1 or disconnecting the input shaft 4 from the output 
shaft 5 when the worm gear 3 and the worm gear 26 are free. FIGS. 11-13 
are different from FIGS. 14-16 in the drive means used for rotating the 
worms 1 and 25. 
By combination of the transmission devices described in FIGS. 1-16 we can 
make many different designs of transmissions. Examples of such kinds of 
designs are FIG. 17 and FIG. 18. FIG. 17 is a combination of the device of 
FIG. 1 with the device of FIG. 9. Only rotor 3 is grounded. In FIG. 18 the 
rotors 3 and 23 are grounded. But this combination has other properties. 
When the worm 25 holds the worm gear 26, the ratio between the input 4 and 
the output shaft 5 is 1 (one). When the worm 1 holds the worm gear 3, the 
ratio between the input 4 and the output shaft 5 is -1 (minus one). 
When the enveloping worm has an angle of envelop of more than 45.degree., 
assembling the worm with a gear becomes complicated. Using only half of a 
split enveloping worm along the axis of its rotation makes assembling more 
simple (FIG. 19). When congruent surfaces of the lands on the half worm 
and the teeth of the worm gear are sloped (FIG. 20) so that there is 
normal free-wheeling of the worm upon rotation of the worm gear in one 
direction but there is locking action upon rotation of the worm gear in 
the other direction, it is not necessary to use complicated means with the 
gear train or auxiliary motor. In this case (FIG. 21) half of a split worm 
33 can be provided with means which include a train of a torsion spring 38 
with a friction clutch 39 where the worm 33 is attached to the torsion 
spring 38 and the friction clutch 39 is attached to a rotor 34. Torsion 
spring 38 helps to remove clearance between the thread of the worm 33 and 
the tooth of a worm gear 37 after each change in direction of rotation of 
the input shaft 4. FIG. 22 shows that each of the worms 33 and 40 and the 
worm gear 37 combinations described above can transmit very high torque 
loads. 
All of the above described designs show that a transmission may be utilized 
to transmit the oscillating input on the shaft 4 into a single directional 
rotation on the output shaft 5 but also have more functions to compare 
with the prior art. 
The new invention described above has some advantages: it provides the fast 
reverse of a movement of the output shaft by changing the direction of 
rotation by an auxiliary motor; it requires little or no lubrication 
between the working parts because a worm and a worm gear have relative 
motion only when the worm is unloaded and eliminated of backlash between 
the worm gear and the worm. 
Several embodiments of the present invention have been disclosed. A worker 
of ordinary skill in the art would recognize that certain modifications 
would come within the scope of this invention. For that reason, the 
following claims should be studied to determine the true scope and content 
of this invention.