CN110701251A - Multistage coaxial surface contact oscillating tooth precision speed reducer - Google Patents

Abstract

The invention discloses a multi-stage coaxial surface contact movable tooth precision reducer, which mainly comprises a central gear, three planetary gears evenly distributed in the circumferential direction, a crankshaft, an eccentric disc, a shock wave, a casing, a movable tooth and a face gear ring , the output disk. The casing is fixed, and the high-speed rotation is input by a central gear coaxial with the casing. The central gear meshes with three planetary gears, each planetary gear is fixedly connected with a crankshaft, and three crankshafts offset in the same direction are composed of an eccentric disc. Rotating pair, the eccentric disc is placed on the shock wave, pushes the shock wave to rotate, drives the movable tooth to move axially, and the movable tooth meshes with the face gear, so that the face gear rotates at a low speed, and the face gear and the output disc are firmly connected , the output disc rotates at low speed. The reducer of the invention has the advantages of large speed ratio, uniform speed output, etc., and compared with the general reducer, it has large bearing capacity and compact structure, and can meet the needs of the reducer in the occasion of large speed ratio, high load and low backlash.

Description

A multi-stage coaxial surface contact movable tooth precision reducer

technical field

The invention relates to the field of transmission mechanism, in particular to the field of movable tooth transmission and the field of precision transmission, in particular to a multi-stage coaxial surface contact movable tooth precision reducer.

Background technique

With the continuous advancement of science and technology to the field of extreme working conditions, especially in the fields of robotics and aviation, precision reducers have put forward the requirements of zero-backlash precision, large speed ratio, high load and long life. The precision reducers on the existing market are mainly RV reducers and harmonic reducers.

Among them, the RV reducer is a two-stage reducer based on the principle of less tooth difference developed by Teijin in the 1980s. It has the advantages of large speed ratio, high precision, and stable transmission. It is sensitive and difficult to process. At the same time, the most important thing is that the improvement plan based on the RV reducer can no longer meet the expected requirements in the face of increasing the bearing capacity.

The harmonic reducer is also a precision reducer based on the principle of less tooth difference, which can achieve a large transmission ratio output. Not only is the efficiency, accuracy and lifespan affected during operation, but it is also prone to failure under complex dynamic conditions.

SUMMARY OF THE INVENTION

The purpose of the present invention is to realize a precision reducer that satisfies the requirements stated in the background section. The speed reducer eliminates the above-mentioned shortcomings of the existing precision speed reducer. In the process of force transmission, the speed reducer is higher than the existing precision speed reducer by means of surface contact and meshing in the process of force transmission. torque transfer capability. In addition, in the case of higher torque transmission capability, the accelerator of the present invention can select a larger range of transmission ratios, which can be arbitrarily selected from i=10 to i=150. With higher torque transmission capacity and higher gear ratios, the reducer of the present invention can carry input rotational speeds of at least 10,000 rpm.

In order to realize the reducer that meets the above requirements, the present invention provides a multi-stage coaxial surface contact movable tooth precision reducer, the reducer is composed of a high-speed input member, a low-speed output member and a housing, the high-speed input member. It includes an input shaft, a central gear fixedly connected with the input shaft, three planetary gears evenly distributed in the circumferential direction, and a crankshaft fixedly connected with the three planetary gears respectively, and an eccentric disc and a shock wave are sleeved on the three crankshafts; The output member is composed of movable teeth, a face gear ring and an output disc; the input shaft, the sun gear, the shock wave, the casing, the face gear ring and the output disc are coaxially arranged; the high-speed input member is a planetary gear train , the low-speed output member is a movable tooth reduction device; the high-speed input member and the low-speed output member together form a K-H-V type epicyclic gear train; the input bearing is connected to the high-speed input motion, and the three circumferentially evenly distributed planetary gears and The central gears mesh at the same time, the crank directions of the three crankshafts are the same, and are located in the three circumferentially evenly distributed stepped holes on the eccentric disk, and the eccentric disk is placed on the shock wave; There are N guide grooves, the lower end of the shock wave has a circumferentially arranged surface cam, and N movable teeth are evenly distributed on the surface cam, each movable tooth is respectively installed in a guide groove of the shell, and each Each movable tooth can move up and down along the guide groove where it is located. The lower end of the movable tooth meshes with the face gear ring. The toothed plate of the face gear ring includes 2N+2 identical teeth. The ring is fixedly connected to the output disc.

Further, in the multi-stage coaxial surface contact movable tooth precision reducer according to the present invention, the teeth on the surface gear ring gear plate are circumferentially evenly distributed on the end face of the surface gear ring, and the working curve shape of the teeth includes a symmetrical shape. In order to avoid top cutting, the two cylindrical helical lines are connected by an excessive curve, that is, a part is cut off at the top of the tooth; the tooth shape of the movable tooth and the face gear ring tooth The tooth profile of the teeth on the disc is the same; the theoretical profile of the surface cam of the shock wave device is formed by connecting two rising working curves, two descending working curves and four transition curves in turn, wherein the rising working curve and the descending working curve are A cylindrical helix with a smaller lead equal to the tooth profile lift of the ring gear, each transition curve is tangent to the two front and rear working curves, and is smooth, the curve function of the transition curve is arbitrary, but the transition curve is arbitrary There is a derivative at one point, and the circumferential arrangement of each curve is a sequential cycle from ascending curve to transition curve to descending curve to transition curve. The function of the transition curve is to make the moving teeth move up and down smoothly and to prevent shock.

The movable teeth are in contact with the surface cam, and the phases are different. At the same time, the height of each movable tooth is different. There is a clearance fit between the movable teeth and the guide groove, and the movable teeth can be guided along the guide groove. The groove moves up and down for axial guidance.

One or two contact planes are provided on the side contact surface of the movable tooth and the guide groove for realizing circumferential positioning.

Oil seals are provided between the ring gear and the casing, and between the output disc and the casing.

A shaft sleeve is arranged on the crankshaft between the eccentric disc bearing and the crankshaft bearing.

The rotation of the shock wave is driven by the revolution of the eccentric disc, and the revolution of the eccentric disc is driven by the crankshaft. The function of the eccentric disc is to connect the high-speed planetary gear train and the low-speed movable tooth reducer.

The teeth on the face gear ring gear plate, the movable teeth and the contour of the face cam of the shock wave device all adopt the following cylindrical helix,

The parametric equation of the cylindrical helix is as follows:

In the formula, r is the distance between a certain point on the movable tooth or the face gear ring relative to the central axis of the face gear ring, h is the height that the cylindrical helix rises after one rotation, which is called the pitch, and θ is the angle turned relative to the initial point at this point, x, y, z are the coordinates of the point.

Compared with the prior art, the beneficial effects of the present invention are:

In the reducer of the present invention, the casing is fixed, and the high-speed rotation is input by a central gear coaxial with the casing. The central gear is meshed with three planetary gears, each planetary gear is fixedly connected to a crankshaft, and the three coaxially offset The crankshaft and the eccentric disc form a rotating pair. The eccentric disc is placed on the shock wave, which drives the shock wave to rotate, and drives the movable tooth to move axially. The ring and the output disc are fixedly connected, and the output disc rotates at a low speed. The reducer of the invention adopts the axial shock wave and multi-tooth meshing mode, and compared with the general reducer, the speed ratio is large, the structure is compact, and the manufacture is convenient. It has the advantages of high bearing capacity, uniform output, high rigidity, stable transmission, and high reliability, and can meet the needs of the reducer in the occasions of large speed ratio, high load and low backlash.

Description of drawings

1 is a schematic cross-sectional view of a multi-stage coaxial surface-contacting movable tooth precision reducer of the present invention;

FIG. 2 is an isometric view including only the movable teeth 17 and the ring gear 20;

FIG. 3 is a schematic perspective view of the formation of tooth surfaces of the ring gear 20 shown in FIG. 1;

Fig. 4 is a schematic side view of the movable tooth 17 shown in Fig. 1;

FIG. 5 is a plan view containing only the movable teeth 17 and the ring gear 20;

Fig. 6 is the isometric drawing of the multi-stage coaxial surface contact movable tooth precision reducer of the present invention;

In the figure: 1- housing, 2- main bearing, 3- shock wave, 4- crankshaft bearing, 5- crankshaft, 6-eccentric disc bearing, 7-planet gear, 8-input shaft, 9-sun gear , 10-input shaft small bearing, 11-fixing bolt, 12-eccentric disc, 13-eccentric disc roller, 14-output disc, 15-oil seal, 16-shock roller, 17-movable tooth, 18-input Large shaft bearing, 19-crank shaft sleeve, 20-face gear ring, 21-moving tooth guide groove.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the related invention, but not to limit the invention. In addition, it should be noted that, for the convenience of description, only the parts related to the invention are shown in the drawings.

As shown in FIG. 1 and FIG. 6 , a multi-stage coaxial surface contact movable tooth precision reducer proposed by the present invention is composed of a high-speed input member, a low-speed output member and a housing 1, and the high-speed input member includes The input shaft 8, the central gear 9 fixedly connected to the input shaft 8, the three planetary gears 7 evenly distributed in the circumferential direction, and the crankshaft 5 fixedly connected to the three planetary gears 7 respectively, that is, a crankshaft 5 is fixedly connected to each planetary gear 7 , an eccentric disc 12 and a shock wave 3 driven by the eccentric disc 12 are sleeved on the three crankshafts 5; the low-speed output member is composed of a movable tooth 17, a face gear ring 20 and an output disc 14; , the central gear 9, the shock wave 3, the casing 1, the face gear 20 and the output disc 14 are arranged coaxially.

The high-speed input member is a planetary gear train, and the low-speed output member is a movable tooth reduction device; the high-speed input member and the low-speed output member together form a K-H-V type epicyclic gear train. The input shaft 8 bears the high-speed input motion, and the central gear 9 is fixedly connected with the input shaft 8 through splines. As shown in FIG. 6 , the three circumferentially evenly distributed planetary gears 7 mesh with the central gear 9 at the same time, and the three crankshafts 5 The directions of the cranks are the same and are located in the three circumferentially evenly distributed stepped holes on the eccentric disk 12. The eccentric disk 12 is placed on the shock wave 3 through the eccentric disk roller 13, and the shock wave 3 passes through the shock wave roller. 16 is placed on the housing 1, the eccentric disk 12 and the shock wave 3 are inclined planes at the position where the eccentric disk roller 13 is placed. The shock 3 and the housing 1 are also inclined at the position where the shock roller 16 is placed.

The housing 1 is provided with N guide grooves 21 for the axial guidance of the movable teeth, the lower end of the shock wave 3 is provided with a circumferentially arranged surface cam, and N movable teeth 17 are evenly distributed on the surface cam. , each movable tooth 17 is respectively installed in a guide groove 21 of the housing 1 , each movable tooth 17 can move up and down along the guide groove 21 where it is located, and the lower end of the movable tooth 17 meshes with the face gear ring 20 , the toothed disc of the face gear ring 20 includes 2N+2 identical teeth 201 , and the face gear ring 20 and the output disc 14 are fixedly connected by bolts 11 . The inner gear 20 and the output disc 14 are respectively placed on the housing 1 through a main bearing 2, and are fixed and preloaded by three bolts evenly distributed in the circumferential direction. The main bearings 2 are in face-to-face contact.

In the present invention, the input shaft 8 is designed as a stepped hollow shaft, and is placed on the output disc 14 and the face gear ring 20 through the small input shaft bearing 10 and the large input shaft bearing 18. The small input shaft bearing 10 and the large input shaft bearing 18 It is a tapered roller bearing in the opposite direction, which is mounted face-to-face. Each crankshaft 5 is placed on the output disc 14 and the face gear 20 by means of two crankshaft bearings 4, and on the eccentric disc 12 by means of an eccentric disc bearing 6, wherein the two crankshaft bearings 4 are conical in opposite directions The roller bearing adopts face-to-face installation, and the eccentric disc bearing 6 is an angular contact ball bearing with an upward direction. The crankshaft 5 is provided with a bushing 19 located between the eccentric disc bearing 6 and the crankshaft bearing 4. The function of the bushing 19 is to provide the axial positioning of the crankshaft bearing 4 at the lower end, thereby axially fixing the crankshaft. The role of axis 5. Oil seals 15 are provided between the ring gear 20 and the housing 1, and between the output disc 14 and the housing 1, and the oil seals 15 play a sealing role.

As shown in FIG. 3 , the teeth 201 on the toothed plate of the face gear 20 are evenly distributed on the end surface of the face gear 20 in the circumferential direction, and the working curve shape of the teeth 201 includes symmetrical cylindrical spirals 204 with opposite directions of rotation, which are To avoid top cutting, the two sections of cylindrical helix 204 are connected by a transition curve, and the adjacent section of ascending cylindrical helix and a section of descending cylindrical helix are connected by a transition curve, that is, a part 206 is cut off at the top of the tooth 201 , at the connection of the two teeth 201, the bottom end is filled with a filler 205; the tooth shape of the movable tooth 17 is the same as the tooth shape of the tooth 201 on the toothed plate of the face gear ring 20. The theoretical profile of the surface cam of the shock wave 3 is formed by connecting two sections of rising working curves, two sections of descending working curves and four sections of transition curves in turn, wherein the rising working curve and the descending working curve are the teeth of the face gear ring 20. A cylindrical helix with an equal profile lift and a smoother, i.e., a smaller lead, each transition curve is tangent to the two working curves before and after, and is smooth. , the arrangement of each curve in the circumferential direction is a sequential cycle from ascending curve to transition curve to descending curve to transition curve, in this way, the surface contact between the movable tooth 2 and the face gear ring 4 can be realized. The function of the transition curve is to make the moving tooth move up and down smoothly and to prevent impact.

As shown in FIG. 4 , the main body of the movable tooth 17 is a cylindrical body, the upper end is provided with a spherical surface 171, and the lower end is a tooth 172 with the same tooth shape as the tooth 201 on the toothed plate of the face gear 20, in order to prevent top cutting , a section of rising working curve and a section of descending working curve of the movable tooth are connected by a section of transition curve, that is, a part 173 is cut off at the lower end of the movable tooth 17 . The movable teeth 17 are in contact with the surface cam, and the phases are different. At the same time, the height and low positions of each movable tooth 17 are different. It can move up and down along the guide groove 21 to achieve axial guidance. One or two contact planes are provided on the side contact surfaces of the movable teeth 17 and the guide grooves 21 for realizing circumferential positioning.

In the present invention, the corresponding end face of the movable tooth 17 is in contact with the surface cam on the shock wave 3, and the face cam is a circular curved surface guided by a closed annular curve, which can push the movable tooth 17 to move up and down when the shock wave 3 rotates .

In the present invention, the rotation of the shock wave 3 is driven by the revolution of the eccentric disc 12, and the revolution of the eccentric disc 12 is driven by the crankshaft 5. The function of the eccentric disc 12 is to connect the high-speed planetary gear train with the low-speed Class movable tooth reducer.

The way that the reducer of the present invention realizes the deceleration effect is as follows: the high-speed input motion is input to the central gear 9 of the planetary gear train, and the central gear 9 transmits the motion to the planetary gear 7 and the crankshaft 5 to realize the first deceleration; the crankshaft 5 Drive the eccentric disk 12 to revolve around the central axis of the shock wave 3, drive the shock wave 3 to rotate, the shock wave 3 drives the movable tooth 17 to move up and down through the surface cam on the end face, and the movable tooth 17 is pushed by the complex curved surface of the lower end face. The ring gear 20 rotates to realize the second deceleration.

The purpose of improving the weak link in the force transmission process of the existing reducer is achieved by the following way. The movable teeth 17 and the face gear ring 20 of the reducer have complex tooth profiles, and the teeth 201 on the gear plate of the face gear ring 20 have complex tooth profiles. , The contour lines of the movable tooth 17 and the surface cam of the shock wave device 3 are all cylindrical helical lines, so that the surface contact between the movable tooth 17 and the surface gear ring 20 can be realized.

The parametric equation of the cylindrical helix is as follows:

In the formula, r is the distance between a certain point on the movable tooth 17 or the face gear ring 20 relative to the central axis of the face gear ring 20, h is the height that the cylindrical helix rotates once and rises, which is called the pitch, and θ is the rotation relative to the initial point. The angle of , x, y, z are the coordinate positions of the point, and the cylindrical helix 204 is the profile of the ring gear 20 .

By processing the end face of the movable tooth 17 and the working position of the tooth 201 on the tooth plate of the face gear 20 and the end face of the movable tooth 17 into a cylindrical helix, the movable tooth 17 and the face gear 20 can be in surface contact during the working process. , reduce the pressure on the contact position, and at the same time ensure that multiple groups of movable teeth 17 are evenly distributed in the circumferential direction. Under the drive of the shock wave 3, there are multiple movable teeth 17 meshing with the surface gear ring 20 at any time, especially It is pointed out that these movable teeth 17 are in different phases within the same up and down movement cycle. Through the above methods, the increased torque can be transmitted on the premise of ensuring uniform wear.

其中i是激波器和面齿圈之间的传动比，通常在10～40之间选取。回程段的主要作用是引导活齿向上脱离啮合，它的理论廓线也是圆柱螺旋线，与升程段不同的是z坐标的参数方程形式为

负号代表着高度方向与升程段相反。过度段是连接升程段和回程段的曲线，它主要作用是过度升程段和回程段之间活齿的轴向速度，防止速度突变引起的冲击，它的理论廓线可以任意选取，但要满足条件：与升程段和回程段相切，曲线连续光滑，例如可以选取和升程段和回程段同时相切的圆弧。面凸轮的实际廓线可以是任何光滑曲线沿理论廓线扫过的曲面，例如可以是一个圆扫过理论廓线形成的曲面，与此同时，活齿端面也应该是与该圆半径相等的半球面。The surface cam of shock wave 3 is a closed curved surface composed of multiple sections in turn. These sections can be classified into lift section, return section and transition section. The sections that appear in sequence on the surface cam are lift section, transition section and return section. , transition section, lift section, etc. The main function of the lift section is to push the movable tooth to move downward. Its theoretical profile is a cylindrical helix. Different from the cylindrical helix on the face gear, the parameter equation of the z coordinate is:

where i is the transmission ratio between the shock wave and the ring gear, which is usually selected between 10 and 40. The main function of the return section is to guide the movable teeth to disengage from meshing upward. Its theoretical profile is also a cylindrical helix. Different from the lift section, the parameter equation of the z coordinate is in the form of

A negative sign indicates that the height direction is opposite to the lift segment. The transition section is a curve connecting the lift section and the return section. Its main function is the axial speed of the movable tooth between the over-lift section and the return section to prevent the impact caused by the sudden change of speed. Its theoretical profile can be selected arbitrarily, but To meet the conditions: tangent to the lift segment and return segment, the curve is continuous and smooth, for example, an arc that is tangent to the lift segment and return segment at the same time can be selected. The actual profile of the face cam can be any smooth curve swept along the theoretical profile. For example, it can be a curved surface formed by a circle swept across the theoretical profile. At the same time, the end face of the movable tooth should also be equal to the radius of the circle. hemisphere.

As shown in Figure 1, when the reducer is working, the high-speed rotation input by the motor is directly transmitted to the input shaft 8, the input shaft 8 rotates at a high speed together with the sun gear 9, and the sun gear 9 drives the planetary gear 7 and the crankshaft 5 to rotate, and the three The crankshaft 5 acts together on the eccentric disc 12, so that the eccentric disc 12 revolves around the central axis of the shock wave 3, and the shock wave 3 drives the movable tooth 17 to move up and down through the surface cam located below, and the movable tooth 17 and the surface gear ring 20 move up and down. Meshing, drives the face gear 20 to rotate at a low speed, and the face gear 20 is fixedly connected with the output disc 14 to output the low-speed rotation. Since the planetary gears 7 are located on the output disc 14, the planetary gears 7 revolve with the output disc 14, thereby forming a closed structure. During the entire movement, the housing 1 is stationary.

As shown in Fig. 2, Fig. 3, Fig. 4 and Fig. 5, the toothed disc of the face gear ring 20 is composed of several identical non-repetitive wheels evenly distributed on a circular ring, and the movable teeth 17 are also uniformly distributed on this circular ring. On the ring, the number of movable teeth 17 is usually one less than half the number of non-repeating teeth. The shape of the tooth 201 of the toothed plate is the same as the shape of the movable tooth. On the ring with the same radius of the central axis of the face gear ring 20, the curve of a single non-repeated tooth 201 and the movable tooth 17 are in the same direction of rotation by two leads. Consists of opposite cylindrical spirals. Under different radii, the lead of the cylindrical helix on the face gear 20 and the movable tooth 17 is still the same.

In the present invention, assembly errors can be reduced, and preferably, the guide groove 21 of the movable tooth 17 is integrated with the housing 1 .

The above description is only a preferred embodiment of the present invention and an illustration of the applied technical principles. Those skilled in the art should understand that the scope of the invention involved in the present invention is not limited to the technical solution formed by the specific combination of the above-mentioned technical features, and should also cover the above-mentioned technical features without departing from the inventive concept. Other technical solutions formed by any combination of its equivalent features. For example, a technical solution is formed by replacing the above features with the technical features disclosed in the present invention (but not limited to) having similar functions.

Claims (8)

1. A multi-stage coaxial surface contact movable tooth precision reducer, consisting of a high-speed input member, a low-speed output member and a casing (1), the high-speed input member comprising an input shaft (8), and an input shaft (8) A fixed central gear (9), three planetary gears (7) uniformly distributed in the circumferential direction, and a crankshaft (5) fixedly connected to the three planetary gears (7) respectively, and an eccentric disc is sleeved on the three crankshafts (5). (12) and a shock wave device (3); the low-speed output member is composed of a movable tooth (17), a ring gear (20) and an output disc (14); the input shaft (8), the central gear (9) , the shock wave device (3), the casing (1), the face gear ring (20) and the output disc (14) are arranged coaxially; It is characterized by: The high-speed input member is a planetary gear train, and the low-speed output member is a movable tooth reduction device; the high-speed input member and the low-speed output member together form a K-H-V type epicyclic gear train; The input shaft (8) receives high-speed input motion, three planetary gears (7) evenly distributed in the circumferential direction mesh with the central gear (9) at the same time, and the crankshafts (5) of the three crankshafts (5) have the same crank direction and are located on the eccentric disc. In the three stepped holes uniformly distributed in the circumferential direction on the (12), the eccentric disk (12) is placed on the shock wave device (3); The housing (1) is provided with N guide grooves (21), the lower end of the shock wave device (3) is provided with a circumferentially arranged surface cam, and N movable teeth (17) are evenly distributed on the surface cam , each movable tooth (17) is respectively installed in a guide groove (21) of the housing (1), each movable tooth (17) can move up and down along the guide groove (21) where it is located, and the movable tooth ( The lower end of 17) meshes with the face gear ring (20), the toothed disc of the face gear ring (20) includes 2N+2 identical teeth (201), and the face gear ring (20) is connected to all the teeth (201). The output disc (14) is fixedly connected. 2. The multi-stage coaxial surface contact movable tooth precision reducer according to claim 1, characterized in that: the teeth (201) on the toothed plate of the surface gear (20) are evenly distributed on the end face of the surface gear (20) in the circumferential direction Above, the shape of the working curve of the teeth (201) includes symmetrical cylindrical helical lines (204) with opposite directions of rotation, and in order to avoid top cutting, the two cylindrical helical lines (204) are connected by excessive curves; The tooth shape of the movable tooth (17) is the same as the tooth shape of the tooth (201) on the toothed plate of the surface gear ring (20); the surface cam theoretical profile of the shock wave device (3) is operated by two upward steps The curve, the two descending working curves and the four transition curves are connected in sequence, wherein the ascending working curve and the descending working curve are cylindrical spirals with smaller lead equal to the tooth profile lift of the ring gear (20). The segment transition curve is tangent to the front and rear working curves, and any point of the transition curve has a derivative. The function of the transition curve is to make the moving tooth (17) move up and down smoothly and to prevent impact. 3. The multi-stage coaxial movable tooth surface contact precision reducer according to claim 1, wherein the movable tooth (17) is in contact with the surface cam, and the phases are different. At the same time, each movable tooth (17) There is a difference in the high and low positions of the movable tooth (17) and the guide groove (21), and the movable tooth (17) can move up and down along the guide groove (21) to realize the shaft guide. 4. The multi-stage coaxial movable tooth surface contact precision reducer according to claim 1, wherein one or two are provided on the side contact surface of the movable tooth (17) and the guide groove (21). Contact plane for circumferential positioning. 5. The multi-stage coaxial surface contact movable tooth precision reducer according to claim 1, characterized in that: between the surface gear ring (20) and the housing (1), the output disc (14) and the The casings (1) are all provided with oil seals (15). 6. The multi-stage coaxial surface contact movable tooth precision reducer according to claim 1, characterized in that: the crankshaft (5) is provided between the eccentric disc bearing (6) and the crankshaft bearing (4) Bushing (19). 7. The multi-stage coaxial surface contact movable tooth precision reducer according to claim 1, characterized in that: the rotation of the shock wave device (3) is driven by the revolution of the eccentric disk (12), and the eccentric The revolution of the disc (12) is driven by the crankshaft (5), and the function of the eccentric disc (12) is to connect the high-speed planetary gear train and the low-speed movable tooth reducer. 8. The multi-stage coaxial movable tooth surface contact precision reducer according to claim 1, wherein the teeth (201), the movable teeth (17) and the The profile of the surface cam of the shock wave device (3) adopts the following cylindrical helix, The parametric equation of the cylindrical helix is as follows:

In the formula, r is the distance between a certain point on the movable tooth (17) or the face gear ring (20) relative to the central axis of the face gear ring (20), h is the height that the cylindrical helix rises after one rotation, which is called the pitch, and θ is the relative The initial point is the angle that the point has turned, and x, y, and z are the coordinate positions of the point.

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