Transmission device

Transmission device utilizes a self-locking enveloping worm (1) and enveloping type worm gear (2) in combination with differentials. The worm gear has less than 24 teeth and enveloping angle one revolution of worm thread more than 15 degrees. Mechanical motion from the input of one member (4) of the differential is transmitted to the output (5) of another member of the differential. Control member of the differential connected to the worm gear. Unlocking motion of worm gear (2) controlling by rotation of enveloping worm, connected to auxiliary motor (17). The transmission device 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. 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 gearbox with changeable ratio.

BACKGROUND OF THE INVENTION 
This invention relates to a combined transmission systems that transmit 
input mechanical power into direction output. 
For this purpose the are two main system available in previous art: 
Mechanical oscillating energy transmits to the input, and than transmission 
device provides a unidirectional energy to the output. 
Continues unidirectional mechanical energy transmits to the input and 
transmission device changes speed to output. We can make analogy with 
electrical energy, where two sources of energy: direct and alternative 
current available, but electric motor using this energy, has 
unidirectional motion. 
In transmitting oscillation energy 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. 2, 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. 2, 1994). But this system has a gear 
train with some backlashes and it is not able to provide 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 1,486,686 
(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. 
In transmitting continues unidirectional energy and change the ratio by 
using self-locking properties of worm/worm gear transmission in the prior 
art t are different modifications. 
In general, prior art using combinations of strait worm and gear with 
combinations of differential means. 
Examples of these transmissions are in U.S. Pat. No. 2,583,140, to Else; 
U.S. Pat. Nos. 2,225,957 to Korff, 3,208,305 to Butterbaugh, U.S. Pat. No. 
4,346,728 to Harry; U.S. Pat. No. 4,917,200, to Lucius; U.S. Pat. No. 
4,346,728, to Sulzer, U.S. Pat. No. 4,987,788 to Bausch; U.S. Pat. No. 
4,973,295, to Lee; U.S. Pat. No. Re. 33,278, to Johnshoy; U.S. Pat. No. 
3,220,284, to Horvath; U.S. Pat. No. 5,033,996, to Frey; U.S. Pat. No. 
5,015,898, to Frey. 
To have a self-lock is better to use worm with only one thread, it makes 
lead angel smaller. In previous art with a strait worm it was possible by 
making only more than one revolution of the thread. It is why only two 
worm gear teeth and threads were in a mesh. When total worm gear teeth 
more than 24 it makes each tooth small and limits load capacity. Minimum 
ratio in previous art for ratio with one thread is 24, but to able to 
control motion of the worm its speed became in 24 times greater than speed 
of the worm gear. It is why previous art was noir realized in any 
reasonable real transmissions. Increasing size of the worm pitch diameter 
to make comparable with worm gear pitch diameter was also unpractical, 
because it makes very small threads relatively to the big body of the 
worm. Using of standard double enveloping worm/worm gear having more than 
24 worm gear teeth and enveloping angle for one revolution of a worm 
thread less than 15 degree has the same problem: small and weak teeth, 
high ratio, more 24. Enveloping worm has a middle part and periphery part. 
The middle part in mesh with worm gear on the top of the worm gear. The 
periphery part in mesh with the periphery worm gear on the side of the 
worm gear. To provide self-lock better to increase periphery mesh between 
worm and worm gear. But standard enveloping worm has only mesh on the top 
the worm gear. Increasing periphery mesh leads to more than 3 teeth in 
contact for single thread. But it makes difficult to assemble a worm with 
a worm gear and still has the same problem. 
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. 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 applications 
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" and Ser. No. 08/796,466, Filed Feb. 10, 
1997 entitled "Apparatus For Transmitting Rotation Utilizing an 
Oscillating Input" disclose improvements to the prior art systems. 
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 variable speed and 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. 
An auxiliary motor is preferably mounted on the rotor, and rotates the worm 
relative to the worm gear to either hold 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 to unlock the worm gear by the worm, the 
system acts as a mechanical amplifier. 
In describing different versions of transmission devices, the base of the 
design is a grounded 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 differentials and bevel differentials are 
the foundations of the invention. Transmissions device with differentials, 
having different ratios are variations of these designs. 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 gearbox 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 
A typical example of the enveloping worm with worm gear is illustrated in 
FIG. 1. A Transmission device comprising an enveloping worm 1 having at 
least one screw thread 6 engaged by a worm gear 2 and enveloping type of 
worm gear 2 with number of gear teeth less than 24. Said enveloping angle 
of said worm 1 is greater than 15 degrees for one revolution of said 
thread of said enveloping worm so that said thread 6 extends from top of 
the said worm gear to periphery of said worm gear. Enveloping angle is 
angle between ends of the worm thread defined with reference to the center 
of the worm gear. Said worm 1 and worm gear 2 are self-locking against 
driving from said worm gear 2. 
That thread 6 of said worm 1 is engaged by at least one tooth of an 
enveloping type worm gear 2 with six teeth. As shown in FIG. 1, the 
enveloping worm 1 has a single thread 6 in a preferred embodiment. The 
worm gear 1 has three teeth spaced about the circumference of the worm 
gear 2. Because of less than 24 worm gear teeth, possible to increase size 
of the worm pitch diameter to make it comparable with worm gear pitch 
diameter. 
The worm gear 2 and worm 1 are enclosed in the housing (not showed). 
Usually housing is made from metal and has forms a reservoir for a 
lubricant to both lubricates the gears, bearings, and seals to serve as a 
coolant for the unit. The housing forms a rigid support to mount the 
gears, bearings, seals and their associated parts (not showed in FIG. 1). 
The worm 1 wraps around the worm gear 2, and enveloping worm gear 2 also 
wraps around the worm 1. The minimum ratio between the number of worm gear 
2 teeth and one worm 1 thread 6 is 2 (two). Apposite, by rotation of the 
worm gear 2 worm 1 rotates with higher speed. 
Reason to use enveloping type of worm gear is that this type of worm gear 
has natural profile of tooth surface, which distinct from another types of 
thread followers. When worm gear teeth generated by thread of worm having 
different length for the same enveloping angle (shortened), profile of 
worm teeth is different. The main advantage enveloping type of worm gear 
is more capacity. For better torque capacity and better self-lock 
enveloping type of worm gear could has different enveloping angle. Adding 
envelope to the worm gear is necessary only for the bigger capacity but in 
most applications is enough to have only enveloping worm. 
This invention because of bigger enveloping angle of one revolution of worm 
thread makes more percentage of geometric lack than friction lock. For 
bigger enveloping angle easy to access mesh on the periphery of the worm 
gear. For purpose of self-lock better to eliminate middle part of the worm 
in mesh with the worm gear on the top of the worm gear by using part of 
split worm 1. It allow reduce the surface friction of worm and worm gears 
and provide unlocking worm gear motion by rotating the worm with less 
power. This increases efficiency of performance. FIG. 2 is a part of split 
worm 1, where 7 are the worm and 8 is the gear with 6 teeth. 
To have a self-lock is better to use worm with only one thread, it makes 
lead angel smaller. This invention comprises means for rotating said worm 
1 about its axis of rotation relative to said worm gear 2 to provide 
unlocking motion. 
Said means can be the auxiliary motor 4 or servo drives (not shown on 
picture 2). 
Said worm gear 1 being connected to one member of a differential gear set 
wherein two other. 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. 
FIG. 14 discloses a half worm 33 enclosed in the rotor 34 and an auxiliary 
motor 35. 
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. 
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. 
The simple profile of the worm is strait sided, like in standard double 
enveloping gearings, but also could be different. For example it could be 
involute profile. Profile of the worm gear is result of generation blank 
worm gear by the profile of the worm. 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. 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 needs not be utilized. For that reason, only a low 
amount of electrical energy is required to. Examples of deferent 
differentials connected to the worm gear are shown in FIG. 3-FIG. 9. When 
invention using to change a ratio in transmission, the self-lock with high 
percentage of geometric lock also not required high power of a motor. 
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 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 1 holds the worm gear 3, then the 
shaft 28 has the direction of rotation of the input shaft 4. When worm 25 
holds worm gear 26, the shaft 5 has an opposite direction of rotation from 
the input shaft 4. 
FIGS. 11-13 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 25 
holds the worm gear 26. Also, these designs are used for changing the 
ratio between the input 4 and the output 5 when the worm 1 holds the worm 
gear 3 or disconnecting the input shaft 4 from the output shaft 5 when the 
worm gear 3 and the worm gear 26 are free. By combination of the 
transmission devices described in FIGS. 3-13 we can make many different 
transmissions. When the enveloping worm has an angle of envelop of more 
than 45.degree., assembling the worm with a gear becomes complicated. 
Using only part of a split enveloping worm along the axis of its rotation 
makes assembling simple (FIG. 14). Figures from FIG. 3 to FIG. 13 could be 
also with a part of a split worm. 
All of the above-described designs show that a transmission device 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. For using invention to regulate speed in 
transmission it based on the principal of differential systems. These 
systems have three members: input and output and a control member. 
Combination of connecting these members with the worm gear has different 
performance and characteristics. Input power goes from input to output of 
the differential. Control member under internal reaction. When an input of 
a differential connected to constant speed of source unidirectional 
mechanical energy, the output speed depends from a speed of the control 
member of the differential. To provide motion of the control member 
auxiliary motor unlocks the worm gear by rotating the worm in direction 
with internal reactions on the worm (not against directions of internal 
reactions). Unlocking motion of the worm gear under load neither does nor 
required much power, compare to power transmitted from the input to the 
output of the differential. Low ratio enveloping worm and worm gear don 
not require much power for auxiliary motor. 
The new invention described above has some advantages: 
for transmitting oscillation motion 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; 
for speed regulation in variable speed transmission it allow lubrication 
between the working parts without losing self-locking that increases 
efficiency by reducing power to provide unlocking motion of 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.