CN113062962A

CN113062962A - Anti-rolling thrust hobbing gear and transmission device using same

Info

Publication number: CN113062962A
Application number: CN202110391671.5A
Authority: CN
Inventors: 王踊
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-04-12
Filing date: 2021-04-12
Publication date: 2021-07-02

Abstract

The invention relates to a movable gear and a transmission device using the same, relating to the field of mechanical transmission, and mainly aiming at providing a design scheme for preventing hobbing from rolling for a special movable gear, namely a thrust hobbing gear.

Description

Anti-rolling thrust hobbing gear and transmission device using same

Technical Field

The invention relates to a structure of a thrust hobbing gear and a transmission device using the hobbing gear as a transmission part, belonging to the technical field of machinery.

Background

Thrust-hobbing gears known to the public at present, such as those disclosed in chinese patent application 202011184382.X and 201810611813.2, or chinese patent [ CN209725128U ], are such that between at least two or more oppositely placed circulating raceways, there are arranged at least two rolling bodies contacting different raceways, whether the rolling bodies are of the same kind, distinguished by whether they are in full contact with the same raceway, whether the contacting raceways are of the same kind, and whether the contacting raceways are of the same kind. The diameters of the different types of rolling elements need not be equal, but it should be ensured that each type of rolling element is evenly spaced by another type of rolling element, i.e.: beside each rolling element is another rolling element. The rolling bodies are sequentially and uniformly arranged to form a complete cycle, the rolling bodies can roll relative to the roller paths, wherein at least one rolling body is partially exposed from the roller paths, and the exposed part is used as the tooth of the hobbing gear. The rolling bodies of different types can transmit thrust, and the roller paths and the rolling bodies can be combined into cylindrical hobbing, conical hobbing, planar hobbing or hobbing with other shapes. When used in a transmission system, the common features are: the thrust hobbing gear meshes with at least two gears simultaneously.

When using thrust hobbing gears in a transmission system, there is one application scenario, namely: the two ends of the same rolling body are respectively meshed with different gears, the number of the teeth of the two gears is different, so that the same rolling body can bear thrust in different directions, the rolling body can generate a rolling trend along the circumferential direction of the roller path under the action of the thrust in different directions at the two ends, and the rolling trend is more obvious when the diameter difference between the rolling body and the roller path is larger. That is, the rolling elements or the gear hobbing not only rotate around the geometric axis of the rolling elements or the gear hobbing and roll smoothly along the roller path, but also roll forward at one end and backward at the other end. This is disadvantageous for the transmission of the thrust hobbing gear.

Disclosure of Invention

A first object of the present invention is to improve the structure of a thrust hobbing gear, and to manufacture a thrust hobbing gear in which hobbing does not roll, so that it is more efficient and easier to manufacture. A second object of the invention is to make efficient use of such gears in transmission systems and to list several application scenarios.

The first object of the present invention: the structure of the thrust hobbing gear is improved, and the thrust hobbing gear with rolling-free hobbing is manufactured. The technical scheme is as follows: anti-rolling thrust hobbing gear, characterized by: the rolling element as the hobbing is arranged in the raceway, the hobbing can roll in the raceway and can be meshed with other gears, the hobbing is uniformly separated by another rolling element, the rolling element and the hobbing for separating the hobbing are respectively contacted with different raceway surfaces, a retainer capable of preventing the rolling element from rolling or preventing the hobbing from rolling is arranged in the thrust hobbing gear, wherein preferably, retainers are arranged at two ends of the thrust hobbing gear, the retainer is contacted with at least one rolling element or hobbing, and the retainers at the two ends are fixedly connected into a whole. Such thrust hobbing may be combined into cylindrical, conical, flat or other shaped hobbing with a retainer engaged therewith. When the hobbing gear is used in a transmission device, the hobbing gear needs to be meshed with at least two gears with different tooth numbers at the same time, and transmission is completed by thrust between the rolling body and hobbing.

The thrust hobbing gear can be applied to plane small tooth difference transmission, nutation transmission or other transmission devices.

The obvious advantages of the invention are: the integrated retainer can obviously inhibit the rolling of the rolling body, so that the rolling body always keeps the designed rolling posture, and the rolling thrust is stably utilized for transmission.

According to the thrust hobbing gear structure provided by the application, a retainer of the thrust hobbing gear can be designed, and the retainer is characterized in that: the cages contacting the different rolling elements are integrally connected, wherein preferably the cages are integrally connected at the ends of the rolling elements. The design can avoid relative sliding between the rolling body and the hobbing, and inhibit the rolling trend of the hobbing or the rolling body.

According to the thrust hobbing gear structure that this application provided, can design out a thrust hobbing gear, characterized by: the same side of the rolling body which is not used as the tooth is provided with a raceway which is contacted with the rolling body, and the raceways at the same side of the same rolling body are fixedly connected into a whole. The design can reduce asynchronous power at two ends of the hobbing, so that the hobbing or rolling of the rolling body is restrained. The volume and weight increase after the raceways are secured together, so that, as an option, the raceways or the connecting portions of the raceways may comprise foamed material or a hollowed-out design, with the aim of reducing the inertia of the movement.

According to the thrust hobbing gear structure that this application provided, can design out a single face internal cone tooth hobbing gear, characterized by: two rolling bodies are arranged between the circular raceways of the conical surfaces which are arranged oppositely, the contact raceway surfaces of the two rolling bodies are different, the cone vertex angles of the raceway surfaces are equal, the raceways are fixedly connected into a whole, only one part of the rolling bodies is exposed on one conical ring surface, and the exposed rolling bodies are used as the teeth of the inner bevel gear.

According to the thrust hobbing gear structure that this application provided, can design out a thrust hobbing gear, characterized by: the length of the contact line between the different rolling bodies is at least over one fifth of the axial length of the rolling bodies, wherein the rolling bodies are preferably one of cylindrical bodies and truncated cone bodies. The purpose of this design is to increase the axial friction between the rolling elements and thereby increase the resistance to hobbing. The design can also increase the stress limit of the hobbing at the same time, so that the hobbing is not easy to bend and roll.

According to the thrust hobbing gear provided by the application, the length of a contact line between a rolling body and a raceway which is not taken as a tooth exceeds one fifth of the axial length of the rolling body. The purpose of the design is to increase the rolling resistance of the rolling body or the hobbing, and simultaneously increase the stress limit of the hobbing, so that the hobbing is not easy to bend and roll.

According to the thrust hobbing gear structure provided by the application, a retainer of the thrust hobbing gear can be designed, and the retainer is characterized in that: the cage comprises an annular connecting portion circumferentially securing the cage parts, the annular connecting portion being mounted in the end of the raceway or in a groove in the raceway. The effect of cyclic annular connecting portion is similar with the strengthening rib, and the purpose makes the ware non-deformable to make the gear hobbing be difficult for rolling, the recess has the effect that increases lubrication simultaneously, also has the effect of accelerating the radiating of the help of lubricating oil flow.

According to the thrust hobbing gear that this application provided, can design a thrust hobbing gear, characterized by: such thrust-hobbing gears are cylindrical gears or conical gears, with cylindrical internal-tooth gears or conical internal-tooth gears being preferred. The purpose is to facilitate meshing with other fixed gears and use in transmissions.

Accordingly, the first object of the present invention is achieved.

The second purpose of the invention is to apply the gear in a transmission system with high efficiency, and the technical scheme is as follows: according to the thrust hobbing gear that this application provided, can be applied to plane few tooth difference transmission, nutation transmission or other transmission, thrust hobbing gear is at least simultaneously with the gear engagement that two tooth counts are different. The gear differential transmission comprising the thrust hobbing comprises an input shaft and an output shaft, and is characterized in that: the input shaft is connected with a planetary transmission, and the connection mode includes, but is not limited to, switching between two of a large ring gear, a planet carrier and a sun gear, or switching between the three, and the connection mode switching method includes, but is not limited to, using a mechanical gear shifter or a gear shifter capable of automatically shifting gears according to set conditions. It is preferred that the connection between the input shaft and the planetary transmission can be switched at least between the sun gear and the planet carrier, with the aim of obtaining two transmission ratios in the same direction by means of a simpler construction, making it smoother and faster at gear shifting.

According to the thrust hobbing gear that this application provided, can use thrust circular cone hobbing gear in nutation drive mechanism, perhaps use thrust cylinder hobbing gear in the poor drive mechanism of plane few tooth, its common characteristic is: the thrust hobbing gear is simultaneously meshed with two gears with different tooth numbers, and small tooth difference transmission is completed through plane pendulum shaft movement or nutation pendulum shaft movement.

The single-sided inner conical tooth hobbing gear is used in a nutation small-tooth-difference transmission mechanism and is characterized in that: the gear transmission mechanism is characterized by comprising two fixed-tooth gears arranged inside and outside, a first gear is arranged on an outer large ring, a second gear is arranged on an inner small ring, the first gear and the second gear are outer bevel gears with different tooth numbers, the axes of the first gear and the second gear are two crossed lines, the first gear and the second gear are simultaneously meshed with a third gear at different positions, the third gear is a single-face inner bevel gear with hobbing teeth, the axis of the third gear is a main axis, the main axis, an input shaft and an output shaft are the same line, the axes of the first gear and the second gear are secondary axes, the secondary axes are respectively arranged on two sides of the main axis, the vertexes of three gear conical surfaces are the same point, a bidirectional eccentric shaft head is connected with the input shaft, and the two secondary axes are driven to synchronously do nutation motion around the main axis when the bidirectional eccentric shaft head rotates.

The ball cage is installed to first gear, and the one end and the shell of ball cage are fixed, installs the universal joint at the summit position, and the centre of sphere and the conical surface summit position of universal joint are the same point, and the one end and the second gear of universal joint link firmly, and the other end and the torsion dish of universal joint link firmly, and the torsion dish links firmly with the output shaft. The universal joint and the ball cage can be replaced by, but not limited to, a bellows, or a crowned tooth connector, or a knuckle bearing, or other type of coupling capable of deflecting angles, one or two of the above.

The anti-rolling thrust hobbing gear or the transmission device using the gear provided by the invention is applied to a mechanical device and can form a speed changer. The range of applications for such transmissions includes, but is not limited to, use with turbomachines; or in conjunction with an electric motor. The obvious advantage is that a larger transmission ratio and a larger torque can be obtained with less space and less weight.

The anti-rolling thrust hobbing gear or the transmission device using the gear is combined with an engine to form a power output module. The range of applications for such power take-off modules may include, but is not limited to, applications at mechanical joints; or a robot joint; or a robotic arm joint; or in a vehicle steering system; or in the aircraft rudder drive system; or in a ship rudder drive system; or other steering alignment system.

To this end, the second object of the present invention is achieved.

The advantages of the present invention will be further apparent from the following description of embodiments with reference to the accompanying drawings. The drawings and the description of the drawings are for the purpose of illustrating the advantages of the invention in detail and are not intended to limit the scope of the invention.

Drawings

Fig. 1 is a schematic axial cross-sectional view of an integrated retainer in a cylindrical internal tooth thrust hobbing gear.

Figure 2 is a schematic axial cross-section of a cylindrical internal tooth thrust hobbing gear comprising the retainer of figure 1.

Fig. 3 is a schematic radial cross-section of the thrust hobbing gear of fig. 2.

FIG. 4 is a schematic illustration of a differential transmission incorporating thrust hobbing gear teeth, one method of connection when connecting a planetary transmission, wherein FIG. 4-1 is a schematic illustration of the input shaft of the differential transmission being connected to the planet carrier of the planetary transmission; FIG. 4-2 is a schematic illustration of the input shaft of the differential gear set connected to the sun gear of the planetary transmission.

Fig. 5 is an axially exploded view of a single-sided internally tapered toothed gear.

Figure 6 is a schematic cross-sectional view of the internally face tapered-toothed hobbing gear of figure 5 after installation.

Figure 7 is a cross-sectional view of one design case of a single-sided internally tapered toothed gear for use in nutating transmissions.

The symbols in the drawings illustrate that: a 1-first race; a11 — a retainer in the first race; a12 — an annular connection connecting the cage in the first race; a 2-second raceway; a21 — a retainer in the second race; a22 — an annular connection connecting the cage in the second raceway; a 3-third raceway; a31 — a cage in the third race; a32 — an annular connecting portion connecting the cage in the third raceway; a 4-annular connecting part that connects the retainers that contact different rolling elements into one; a 5-annular connecting part that connects the retainers that contact different rolling elements into one; b-grooves in the raceway; c-bolt hole; d-bearing; e 1-rolling elements; e 2-hobbing; e 3-meshing teeth; e 4-disengaged teeth; f-crankshaft; g1 — first fixed-tooth gear; g2 — second fixed-tooth gear; g 3-thrust hobbing gear; g4 — planetary gear; g5 — big ring gear of planetary gear transmission; g6 — planet carrier; g 7-Sun gear; g8 — differential tooth transmission input shaft gear; h-ball cage; h 1-outer wall of ball cage; h 2-inner wall of ball cage; h 3-Universal Joint; k-the housing; o-main shaft; o1 — shaft of first fixed-tooth gear; o2 — shaft of second fixed-tooth gear; o3 — input shaft of differential tooth transmission; o4 — input shaft; o5 — output shaft; t 1-half cone apex angle; t 2-half cone apex angle.

Detailed Description

Preferred embodiments of the present invention are described with reference to the accompanying drawings.

Fig. 1 is a schematic axial cross-sectional view of an integrated retainer in a cylindrical internal tooth thrust hobbing gear. The retainer a11 in the first raceway, the retainer a21 in the second raceway and the retainer a31 in the third raceway are independent columnar structures, wherein rolling elements contacted by the a11 are rolling elements which are not teeth, so that the rolling elements can penetrate up and down; the rolling bodies contacted by a21 and a31 are rolling bodies as hobbing, and a21 and a31 are respectively arranged at two ends of the hobbing. a11 are fixedly connected into a whole through an annular connecting part a 12; a21 are fixedly connected into a whole through an annular connecting part a 22; a31 are fixedly connected into a whole by an annular connecting part a 32. The annular connecting portion a4 and the annular connecting portion a5 fixedly connect the inner and outer retainers as a whole. Alternatively, the structure of the holders may be hollow.

Figure 2 is a schematic axial cross-section of a cylindrical internal tooth thrust hobbing gear comprising the retainer of figure 1. In this application, the rolling element contacted by the first raceway a1 is a rolling element e1 not serving as a tooth, e1 is a cylinder, a1 is divided into an upper part and a lower part for convenient installation and can be fixedly connected into a whole through a bolt hole c, a groove b is reserved inside the fixedly connected position, and an annular connecting part a12 connected with the retainer a11 in the first raceway is arranged in the groove b. The second rolling path a2 and the third rolling path a3 are in contact with a hobbing e2, an e2 is a cylinder, and a space between a2 and a3 exposes e2 to facilitate meshing with other gears. For ease of installation, annular connector a22 is provided at the end of a2 and annular connector a32 is provided at the end of a 3. The annular connecting part a4 and the annular connecting part a5 are arranged at the ends of the e1 and the e2, so that the whole retainer can be integrally connected, and the e1 and the e2 can be prevented from falling off from the raceways.

A bearing d is arranged between the first rolling path a1 and the second rolling path a 2; a bearing d is also provided between a1 and the third raceway a 3. In this case, the bearing d is a single-row angular contact ball bearing, and a double-row angular contact ball bearing or other bearings may be used instead.

Fig. 3 is a schematic radial cross-section of the thrust hobbing gear of fig. 2. A gap is left between the retainer a11 and the first raceway a1, and no contact is made; the rolling bodies e1 and a1 are in direct contact; a gap is left between the retainer a22 and the second raceway a2, and no contact is made; hobbing e2 and a2 are in direct contact; the rolling element e1 and the gear hobbing e2 are in direct contact and can transmit thrust between e1 and e 2.

FIG. 4 is a schematic illustration of a differential transmission incorporating thrust hobbing gear teeth, one method of connection when connecting a planetary transmission, where 4-1 is a schematic illustration of the input shaft of the thrust hobbing transmission being connected to the planet carrier of the planetary transmission; 4-2 is a schematic illustration of the input shaft of the thrust hobbing transmission being connected with the sun gear of the planetary transmission.

In fig. 4, 4-1 and 4-2 are different shift states in which the same differential gear and planetary transmission are connected, and in this case, the left half portions of 4-1 and 4-2 are differential gears, an input gear g8 of the differential gear is provided at an input shaft o3 of the differential gear, a thrust hobbing gear g3 is provided at an outer race, and inner races are a first fixed-tooth gear g1 and a second fixed-tooth gear g2, and g1 and g2 are gears having different numbers of teeth. g8 is rotated by the crankshaft to simultaneously engage g1 and g2 with g3 in a symmetrical orientation. g1 is fixed with the shell k through a crankshaft, so that g1 can not rotate; g2 is fixed with output shaft o5 through a crankshaft, so that g2 can drive o5 to rotate to form power output.

The right half of 4-1 and 4-2 in fig. 4 is a planetary transmission, wherein the input shaft o4 of the planetary transmission is provided with a sun gear g7, g7 is meshed with a planetary gear g4, g4 is simultaneously meshed with a large ring gear g5 of the planetary transmission, and g5 is fixed on a shell k. When g7 rotates g4, g4 rotates planet carrier g 6.

In fig. 4, the input shaft o3 of the differential gear is provided with large input gears g8, g8 of the differential gear and a sun gear g7 of the planetary gear. In 4-1, the input gear g8 and carrier g6 of the differential gear are meshed; in 4-2 g8 switches to mesh with sun gear g7, because g7 and g8 are equally large and the rotation directions before and after switching are the same, the switching is relatively fast and smooth. The structure similar to the embodiment is more suitable for application occasions requiring both speed and precision, such as a steering system with quick alignment or a mechanical joint for loading heavy objects.

Figure 6 is a schematic cross-sectional view of the internally face tapered-toothed hobbing gear of figure 5 after installation. As can be seen from the case of fig. 1, fig. 2 and fig. 3, the relationships between the components in the case of fig. 6 are similar, except that: figures 1 and 2 and 3 are examples of cylindrical internal tooth thrust hobbing gears; fig. 5 and 6 are internally tapered thrust hobbing gears. In the case of fig. 5 and 6, the first raceway a1, the second raceway a2, and the third raceway a3 are conical surface raceways having the same apex, the rolling element e1 and the hob e2 are also truncated cone bodies having the same apex, and the apexes of the rolling element, the hob, and the raceway surfaces are the same point. Therefore, the retainers a11, a21, a31 and the annular connecting portions a12, a22, a32, a4 and a5 all have shapes matched with the retainers, and preferably, the two opposite surfaces of the annular connecting portions a22 and a32 are spherical circular rings.

In the case of fig. 5 and 6, the following features are also present: the raceway conical surface of the first raceway a1 and the main shaft o form a half cone vertex angle t 2; the conical surfaces of the second raceway a2 and the third raceway a3 are the same conical surface, and the conical surface and the main shaft form a half cone apex angle t 1. Since t1 and t2 are at equal angles, a1, a2, a3 can rotate in the same direction and in synchronization during operation. Furthermore, it is possible to fixedly connect the rolling paths a1 and a2 and a3 into a whole, so that the positions of the rolling paths are relatively fixed, and only a part of the rolling teeth e2 is exposed between a2 and a 3. This design can suppress rolling of the rolling elements e1 and the hobbing e2, and can improve the meshing accuracy with other gears and reduce the manufacturing cost.

Figure 7 is a cross-sectional view of one design case of a single-sided internally tapered toothed gear for use in nutating transmissions. The single-sided inner-tapered-tooth gear is fixed on a shell k through a bearing d, a first fixed-tooth gear g1 is an outer-tapered-tooth gear, g1 is provided with a rotating shaft o1, a second fixed-tooth gear g2 is an outer-tapered-tooth gear, g2 is provided with a rotating shaft o2, o1 and o2 are auxiliary shafts, the two auxiliary shafts are respectively arranged on two sides of a main shaft o and intersect with the main shaft at the same point, the intersection point is the common vertex of the single-sided inner-tapered-tooth gear and g1 and g2, and the main shaft o is also the shaft of the single-sided inner-tapered-tooth gear.

A ball cage h is arranged between g1 and the shell k, the inner wall h2 of the ball cage is fixedly connected with g1, the outer wall h1 of the ball cage is fixedly connected with k, and the function of h is to enable g1 to do nutation pendulum shaft motion but not to rotate. A universal joint h3 is installed at the center of the single-side inner-tapered-tooth hobbing gear, the sphere center position of h3 and the vertex position of the gear are the same point, one end of h3 is fixedly connected with g2, the other end of h3 is fixedly connected with an output shaft o5, and o5 is fixed on a shell k through a bearing d. h3 is used to make g2 nutate pendulum shaft movement and complete transmission by rotating the rotation gear o 5.

g1 and g2 are fixed-tooth gears with different tooth numbers, g1 and g2 are simultaneously meshed with a hobbing e2 in a symmetrical direction, and the meshing position is e 3. When the two secondary shafts o1 and o2 synchronously nutate about the primary shaft o, g1 and g2 sequentially engage and disengage e2 in symmetrical directions, and the disengaged position is e 4.

Because g1 and g2 are gears with different tooth numbers, g2 can rotate when g1 is fixed on the shell k through the ball cage h, and g2 can drive the output shaft o5 to rotate through the universal joint h3, so that nutation small-tooth-difference transmission is completed.

In addition, the anti-rolling thrust hobbing gear provided by the invention can be used in combination with other types of transmission mechanisms.

Claims

1. Anti-rolling thrust hobbing gear, characterized by:

the rolling element as the hobbing is placed in the raceway, the hobbing can roll in the raceway and can be meshed with other gears, the hobbing is uniformly separated by another rolling element, the rolling element and the hobbing for separating the hobbing are respectively contacted with different raceway surfaces, a retainer capable of preventing the rolling element from rolling or preventing the hobbing from rolling is installed in the thrust hobbing gear, wherein preferably, retainers are arranged at two ends of the thrust hobbing gear, the retainer is contacted with at least one rolling element or hobbing, and the retainers at two ends are fixedly connected into a whole, including but not limited to that the retainers contacted with the same rolling element or two ends of the same hobbing are fixedly connected into a whole.

2. A thrust hobbing gear as claimed in claim 1, characterized in that:

the cages contacting the different rolling elements are integrally connected, wherein preferably the cages are integrally connected at the ends of the rolling elements.

3. A thrust hobbing gear as claimed in claim 1, characterized in that:

the same side of the rolling body which is not used as the tooth is provided with a roller path which is contacted with the rolling body, and the roller paths on the same side of the same rolling body are fixedly connected into a whole; as an option, the raceway or the connection of the raceways may comprise a foamed material, or a hollowed-out design.

4. A thrust hobbing gear as claimed in claim 1, characterized in that:

the length of the contact line between the rolling body and the hobbing is at least more than one fifth of the axial length of the rolling body, wherein the rolling body and the hobbing are preferably one of a cylinder and a circular truncated cone, and the thrust hobbing gear can be, but is not limited to, a cylindrical internal tooth gear or a conical internal bevel gear.

5. A thrust hobbing gear as claimed in claim 1, characterized in that:

the length of the contact line between the rolling body which is not a tooth and the raceway exceeds one fifth of the axial length of the rolling body itself, wherein the rolling body is preferably one of a cylinder and a truncated cone, and the thrust hobbing gear can be, but is not limited to, a cylindrical internal tooth gear or a conical internal bevel gear.

6. A thrust hobbing gear as claimed in claim 1, characterized in that:

the cage comprises an annular connecting portion circumferentially securing the cage parts, the annular connecting portion being mounted in the end of the raceway or in a groove in the raceway.

7. The thrust hobbing of claim 1, wherein a single face internally tapered gear is designed, and wherein:

two rolling bodies are arranged between the circular raceway surfaces of the conical surfaces which are arranged oppositely, the raceway surfaces contacted with the two rolling bodies are different, the angles of the vertex angles of the cones of the raceway surfaces are equal, the raceways are fixedly connected into a whole, only one part of the rolling bodies are exposed on one conical ring surface, and the exposed rolling bodies are used as the teeth of the inner bevel gear.

8. A thrust hobbing gear as claimed in claim 1 or 2 or 3 or 4 or 5 or 6 or 7, used in a flat differential or nutating transmission comprising an input shaft and an output shaft, characterized in that:

the input shaft or the output shaft is connected with a planetary transmission, and the connection mode comprises, but is not limited to, the connection mode can be switched between two of a large ring gear, a planet carrier and a sun gear, or can be switched between the three, wherein the connection mode between the input shaft or the output shaft and the planetary transmission is preferably switched at least between the sun gear and the planet carrier; the method of linkage switching includes, but is not limited to, using a mechanical shifter or a shifter that can be automatically shifted according to preset conditions.

9. A thrust hobbing gear as claimed in claim 1 or 2 or 3 or 4 or 5 or 6 or 7 for use in a nutating drive system, wherein:

the gear transmission mechanism comprises two gears which are arranged inside and outside, wherein a first gear is arranged on a large circle on the outer layer, a second gear is arranged on a small circle on the inner layer, the first gear and the second gear are outer bevel gears with different tooth numbers, the axes of the first gear and the second gear are two crossed lines, the first gear and the second gear are simultaneously meshed with a third gear, the third gear is a single-face inner bevel gear with a hobbing tooth, the axis of the third gear is a main axis, the main axis, an input shaft and an output shaft are the same line, the axes of the first gear and the second gear are secondary axes, the secondary axes are respectively arranged on two sides of the main axis, the vertexes of the conical surfaces of the three gears are the same point, in addition, a bidirectional eccentric shaft head is connected with the input shaft, and the two secondary axes are driven to synchronously do nutation motion around; the first gear is provided with a ball cage, one end of the ball cage is fixed with the shell, the other end of the ball cage is fixedly connected with the first gear, a universal joint is arranged at the common vertex position of the three gears, the sphere center of the universal joint and the vertex position of the conical surface are the same point, one end of the universal joint is fixedly connected with the second gear, and the other end of the universal joint is fixedly connected with the output shaft; the universal joint and the ball cage can be replaced by, but not limited to, a bellows, or a crowned tooth connector, or a knuckle bearing, or other type of coupling that can be angularly deflected, either or both.

10. A thrust hobbing gear as claimed in claim 1 or 2 or 3 or 4 or 5 or 6 or 7 for use in a gear change system, characterized by:

a transmission including a thrust hobbing gear, the power source of which includes but is not limited to a turbine, or an electric motor; the application scenarios include, but are not limited to, application at a mechanical joint, or a mechanical arm joint, or in a vehicle steering system, or in an aircraft steering rudder transmission system, or in a ship steering rudder transmission system, or in other steering alignment systems.