Transmission device and four-channel electric steering engine mechanism thereof

Abstract

The invention discloses a transmission device and a four-channel electric steering engine mechanism thereof, the transmission device comprises a motor lead screw assembly, the motor lead screw assembly comprises a ball screw assembly, a deflector rod and a guide rod, the ball screw assembly comprises a lead screw shaft and a lead screw nut, the lead screw shaft is rotatably connected with a first bearing seat and a second bearing seat, and the first bearing seat and the second bearing seat are rotatably connected with the deflector rod; one end of the lead screw shaft is connected with the motor; the deflector rod is connected with the lead screw nut, the lead screw shaft penetrates through the deflector rod and the lead screw nut, an insertion column is arranged on the deflector rod in the direction perpendicular to the axis of the lead screw shaft, and a first through hole allowing the guide rod to penetrate is formed in the deflector rod; the shifting fork output shaft assembly comprises a shifting fork, an output shaft and a potentiometer, the shifting fork is provided with a shifting fork groove with a specific shape line, the insertion column of the shifting rod is inserted into the shifting fork groove to be matched with the shifting fork groove, the shifting fork is connected with the output shaft, the output shaft is rotatably connected with the third bearing seat, and the potentiometer is used for measuring the rotating angle of the output shaft. The transmission device has the advantages of being capable of achieving a good transmission effect and adjustable in transmission ratio.

Description

Technical Field

[0001] The present invention relates to the field of electric steering gears, and in particular to a transmission device and a four-channel electric steering gear mechanism thereof. Background Art

[0002] The servo is the actuator of the guidance control system of missiles and other aircraft. Common transmission mechanisms include rack and pinion, worm gear, harmonic reducer, ball screw, etc. Among them, ball screw is widely used in the servo transmission mechanism due to its high efficiency, high rigidity, compact structure, high transmission accuracy, etc. The most common fork transmission mechanism of ball screw servo is the motor-reduction gear-ball screw-fork pair. Due to the characteristics of the mechanical structure, the transmission ratio of the screw fork pair is non-constant. The transmission ratio curve of the fork mechanism is the smallest at 0°, and the transmission ratio on both sides gradually increases in a parabolic shape.

[0003] Common technical indicators of servos include bandwidth, adjustment time, deflection speed, output torque and other parameters. Since the transmission ratio of the fork mechanism fluctuates within a certain range, the motor selection and design often requires the highest parameter selection, that is, the maximum transmission ratio still meets the speed requirements, and the minimum transmission ratio still meets the torque requirements, so that the motor performance has a large redundancy. In addition, the fluctuation of the transmission ratio also increases the complexity of the control system.

[0004] It should be understood that the above statements merely provide background technology related to the present invention and do not necessarily constitute prior art. Summary of the invention

[0005] Based on the aforementioned technical problems, the object of the present invention is to provide a transmission device and a four-channel electric servo mechanism thereof, wherein the transmission device combines a lead screw shaft and parallel guide rods to form a frame structure which is installed on the inner wall of a cabin, and has the effects of high rigidity and lightweight. The transmission device based on the present invention can achieve a better transmission effect, and at the same time, based on the structure, the fork mechanism can have a specific transmission ratio curve or a constant transmission ratio to meet the power output characteristic requirements of the servo, thereby solving the problem that the transmission ratio of the traditional servo lead screw fork transmission mechanism only depends on the size of the component, and the transmission ratio fluctuates within a certain range and cannot be corrected and adjusted.

[0006] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0007] A transmission device for a four-channel electric steering gear mechanism, comprising:

[0008] A motor screw assembly, comprising a ball screw assembly, a lever and a guide rod, the ball screw assembly comprising a screw shaft and a screw nut, the screw shaft being rotatably connected to a first bearing seat and a second bearing seat respectively, the first bearing seat and the second bearing seat being fixedly arranged, one end of the screw shaft being connected to a motor; the lever is connected to the screw nut and the screw shaft is arranged through the two, the lever and the screw nut are located between the first bearing seat and the second bearing seat, the lever is provided with an insertion column in a direction perpendicular to the axis of the screw shaft, the guide rod is arranged parallel to the screw shaft, the lever is provided with a first through hole for the guide rod to pass through, so that the lever can slide along the guide rod;

[0009] A shift fork output shaft assembly comprises a shift fork, an output shaft and a potentiometer, wherein the shift fork is provided with a shift fork groove of a specific shape, the insertion column of the shift rod is inserted into the shift fork groove and cooperates with it, the shift fork is connected to the output shaft, the output shaft is rotatably connected to a third bearing seat, the potentiometer is used to measure the rotation angle of the output shaft, and the potentiometer is fixedly arranged on the third bearing seat.

[0010] Optionally, the rotation center of the shift fork is set as the coordinate origin, and the deviation distance between the ball screw assembly and the rotation center of the shift fork is determined to be y0 according to the spatial layout. When the screw nut is at zero position, the position coordinate of the insertion column center of the shift rod is (x0, y0), and the range of the shift fork rotation angle θ is: θ1≤θ≤θ2. The transmission ratio curve function i=f(θ) is set, and the shift fork groove shape function is y=g(x), and the lead of the screw shaft is p. According to the kinematic relationship of the shift fork pair, the shape function of the shift fork groove satisfies:

[0011]

[0012] Solving formula (1), we can get the parametric equation of the shape function of the fork groove:

[0013]

[0014] Optionally, the shape function of the fork slot may be adjusted based on different transmission ratio requirements.

[0015] Optionally, the insertion column of the lever is a cylindrical structure.

[0016] Optionally, the shift rod is connected to the lead screw nut via a mounting flange.

[0017] Optionally, the potentiometer is coaxially installed with the output shaft, the potentiometer includes a potentiometer shaft, an insertion pin perpendicular to the axial direction of the potentiometer shaft is installed on the potentiometer shaft, a hole structure corresponding to the potentiometer shaft is provided at the butt end between the output shaft and the potentiometer, and a groove structure corresponding to the insertion pin is provided at the butt end, and a threaded hole and a second through hole are provided on both side walls of the groove structure respectively; in an assembled state, the potentiometer is coaxially installed with the output shaft, the potentiometer shaft cooperates with the hole structure of the output shaft, the insertion pin of the potentiometer cooperates with the groove structure of the output shaft, a bolt structure is inserted into the second through hole, the groove structure and the threaded hole and locked and fixed, so that the groove structure is deformed to clamp the insertion pin;

[0018] The potentiometer is fixed on the third bearing seat via a potentiometer bracket.

[0019] Optionally, the first bearing seat and the second bearing seat are fixedly disposed on the inner wall of a cabin of the servo mechanism, the first bearing seat comprises a first fan-shaped flange conforming to the inner wall of the cabin, the second bearing seat comprises a second fan-shaped flange conforming to the inner wall of the cabin, and radial threaded holes are provided at the contact positions of the first fan-shaped flange and the second fan-shaped flange with the inner wall of the cabin.

[0020] Optionally, the first bearing seat and the second bearing seat are respectively provided with a first seat hole and a second seat hole at a preset distance parallel to the axis of the screw shaft, the first seat hole and the second seat hole are coaxially arranged, the first seat hole is provided with a first waist-shaped groove with a width smaller than the width of the first seat hole in the extending direction of the axes of the two, a first screw through hole is provided in a direction perpendicular to the plane of the first waist-shaped groove, and the second seat hole is correspondingly provided with a second waist-shaped groove and a second screw through hole;

[0021] The guide rod comprises a first connection structure and a second connection structure respectively fitted with the first waist-shaped groove and the second waist-shaped groove, the first connection structure is provided with a first threaded hole corresponding to the first screw through hole, and the second connection structure is provided with a second threaded hole corresponding to the second screw through hole;

[0022] In the assembled state, the first connection structure and the second connection structure of the guide rod are respectively placed in the first waist-shaped groove and the second waist-shaped groove, the first connection structure and the first bearing seat are connected by screwing the screw structure into the first screw through hole and the first threaded hole and tightening them, and the second connection structure and the second bearing seat are connected by screwing the screw structure into the second screw through hole and the second threaded hole and tightening them;

[0023] In the assembled state, the shifting rod is located between the first connecting structure and the second connecting structure.

[0024] Optionally, the screw shaft is connected to the first bearing seat via a double-row angular contact ball bearing;

[0025] The screw shaft is connected to the second bearing seat through a deep groove ball bearing.

[0026] Optionally, a four-channel electric servo mechanism comprises:

[0027] A cabin body, wherein the four sets of the aforementioned transmission devices are arranged in the cabin body, and the first bearing seat and the second bearing seat of the transmission device are fixedly arranged on the inner wall of the cabin body.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] In a transmission device and a four-channel electric steering gear mechanism of the present invention, a frame structure is formed by combining a screw shaft and parallel guide rods and is installed on the inner wall of the cabin, which has the effect of high rigidity and lightweight. Based on the transmission device of the present invention, a better transmission effect can be achieved. At the same time, based on this structure, the fork mechanism can have a specific transmission ratio curve or a constant transmission ratio to meet the power output characteristic requirements of the steering gear, thereby solving the problem that the transmission ratio of the traditional steering gear screw fork transmission mechanism only depends on the size of the component, and the transmission ratio fluctuates within a certain range and cannot be corrected and adjusted.

[0030] Furthermore, in the transmission device of the present invention, the potentiometer and the output shaft are coaxially installed, an insertion pin is vertically arranged on the potentiometer shaft of the potentiometer, and corresponding hole structures and groove structures are provided at the butt ends of the output shaft and the potentiometer. Based on the above structure in combination with the bolt structure and the corresponding openings, a compact and reliable connection between the potentiometer and the output shaft can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of a fork mechanism of an existing fork servo mechanism;

[0032] Figure 2 for Figure 1 Schematic diagram of the motion model of the fork mechanism in FIG.

[0033] Figure 3 for Figure 1 Schematic diagram of transmission ratio curve of the fork mechanism in FIG.

[0034] Figure 4 It is a schematic diagram of the overall structure of a four-channel electric steering gear mechanism of the present invention;

[0035] Figure 5 It is a rear view of a four-channel electric steering gear mechanism of the present invention;

[0036] Figure 6It is a schematic diagram of a transmission device of one channel of a four-channel electric steering gear mechanism of the present invention;

[0037] Figure 7 for Figure 6 A schematic diagram of a transmission device from another perspective;

[0038] Figure 8 It is a sectional view of the overall structure of a motor screw assembly of the present invention;

[0039] Fig. 9 It is a partial structural schematic diagram of a motor screw assembly of the present invention;

[0040] Fig.10 It is a structural schematic diagram of a guide rod of the present invention;

[0041] Fig.11 It is a schematic diagram of the installation structure of a guide rod and a shift rod of the present invention;

[0042] Fig.12 It is a schematic diagram of a shift fork output shaft assembly of the present invention;

[0043] Fig.13 It is a schematic diagram of the installation of an output shaft and a potentiometer of the present invention;

[0044] Fig.14 The figure is a schematic diagram of the relative position relationship between a shift fork and a screw shaft of the present invention.

[0045] Description of reference numerals:

[0046] 10First sector flange

[0047] 11 Radial threaded holes

[0048] 12 First seat hole

[0049] 13 Second waist groove

[0050] 14 Second screw hole

[0051] 20 Plane structure

[0052] 21 connection threaded hole

[0053] 30 Insert column

[0054] 31 First through hole

[0055] 40 fork slot

[0056] 41 hole structure

[0057] 42 slot structure

[0058] 43 threaded holes

[0059] 44 Second through hole

[0060] 100 Cabin

[0061] 200 transmission

[0062] 210 Motor Screw Assembly

[0063] 211 Motor

[0064] 212 Ball Screw Assembly

[0065] 2121 Screw shaft

[0066] 2122 Screw Nut

[0067] 213 first bearing seat

[0068] 214 second bearing seat

[0069] 215 lever

[0070] 216 guide rod

[0071] 217 double row angular contact ball bearings

[0072] 218 deep groove ball bearing

[0073] 219 bearing end cover

[0074] 220 bearing nut

[0075] 221 sleeve

[0076] 230 shift fork output shaft assembly

[0077] 231 Fork

[0078] 232 Output shaft

[0079] 233 third bearing seat

[0080] 234 Install bearing

[0081] 235 Potentiometer

[0082] 2351 Potentiometer Shaft

[0083] 2352 Insert pin

[0084] 236 Potentiometer Bracket DETAILED DESCRIPTION

[0085] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0086] It should be noted that the drawings are in a very simplified form and use non-precise proportions. They are only used to conveniently and clearly assist in explaining the embodiments of the present invention, and are not used to limit the conditions for the implementation of the present invention. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention.

[0087] It should be noted that, in the present invention, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only the elements explicitly listed, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0088] like Figures 1 to 3 As shown in the figure, in the fork mechanism of the traditional typical fork servo mechanism, the fork groove line of the fork structure is a straight line structure, its transmission ratio is different at different angular positions, and its transmission ratio curve fluctuates greatly (see the paper "Analysis and Research on the Form of Ball Screw Servo Transmission Mechanism"). Based on this type of fork mechanism, when selecting the motor, in order to adapt to its larger transmission ratio range, the motor performance often has a large redundancy; at the same time, due to the fluctuation of the transmission ratio, the complexity of the servo control system is also greatly increased, which brings challenges to practical applications. On the other hand, due to the structural composition characteristics of the existing fork structure, its transmission ratio only depends on the size of the component. The transmission ratio of the traditional servo screw fork transmission mechanism only depends on the size of the component, and the transmission ratio can only fluctuate within a certain range and cannot be corrected and adjusted; on the other hand, if the fork groove line of the structure is changed, the structure cannot meet the better transmission effect, so the transmission ratio curve of this type of fork structure is difficult to adjust and cannot meet the needs of practical applications.

[0089] Based on the above, the present invention provides a transmission device 200 that can be used for a four-channel electric servo mechanism and a four-channel electric servo mechanism thereof. The transmission device 200 combines a motor screw assembly 210 and a fork output shaft assembly 230 to achieve a transmission ratio curve with a smaller fluctuation rate, that is, to obtain a transmission ratio curve that is a parabola with a more gentle fluctuation. On the other hand, based on the structure of the transmission device 200 of the present invention, a corresponding fork groove 40-shaped line can be generated according to the required transmission ratio curve. Even if the fork groove 40-shaped line is changed, the structure can still achieve better transmission, thereby meeting the actual application requirements.

[0090] Specifically, Figures 4 to 7 , which is a schematic diagram of a four-channel electric steering gear mechanism of the present invention, the four-channel electric steering gear mechanism comprises a cabin 100, and four sets of transmission devices 200 are evenly arranged and installed in the cabin 100. In this embodiment, the structures of the four sets of transmission devices 200 are completely the same, of course, in other embodiments, their structures may not be completely the same.

[0091] Furthermore, the transmission device 200 includes a motor screw assembly 210 and a shift fork output shaft assembly 230. Figures 6 to 11 As shown, the motor screw assembly 210 includes a ball screw assembly 212, a lever 215 and a guide rod 216, the ball screw assembly 212 includes a screw shaft 2121 and a screw nut 2122, the screw shaft 2121 is rotatably connected to the first bearing seat 213 and the second bearing seat 214 respectively, the first bearing seat 213 and the second bearing seat 214 are fixedly arranged on the inner wall of the cabin 100, one end of the screw shaft 2121 is connected to the motor 211; the lever 215 is connected to the screw The nut 2122 is connected and the screw shaft 2121 is arranged to pass through the two, the lever 215 and the screw nut 2122 are located between the first bearing seat 213 and the second bearing seat 214, the lever 215 is provided with an insertion column 30 in a direction perpendicular to the axis of the screw shaft 2121, the guide rod 216 is arranged parallel to the screw shaft 2121, and the lever 215 is provided with a first through hole 31 for the guide rod 216 to pass through, so that the lever 215 can slide along the guide rod 216. Figure 12 to Figure 14 As shown, the shift fork output shaft assembly 230 includes a shift fork 231, an output shaft 232 and a potentiometer 235. The shift fork 231 is provided with a shift fork groove 40 of a specific shape. The insertion column 30 of the shift rod 215 is inserted into the shift fork groove 40 to cooperate with it. The shift fork 231 is fixedly connected to the output shaft 232. The output shaft 232 is rotatably connected to the third bearing seat 233. The potentiometer 235 is used to measure the rotation angle of the output shaft 232. The potentiometer 235 is fixedly set on the third bearing seat 233.

[0092] As can be seen from the above, in the present invention, the motor screw assembly 210 adopts a split bearing seat, and is installed on the inner wall of the cabin 100 by combining the screw shaft 2121 and the parallel guide rod 216 to form a frame structure, which has the effect of high rigidity and light weight. Based on the above structure, in actual application, the motor 211 as a driving device can drive the screw shaft 2121 to rotate, and then make the screw nut 2122 reciprocate along the screw shaft 2121. Since the screw nut 2122 is connected to the lever 215, the lever 215 will reciprocate with the screw nut 2122. At the same time, since the insertion column 30 of the lever 215 is inserted into the fork groove 40 opened by the fork 231 of the fork output shaft assembly 230, the movement of the lever 215 will drive the fork 231 in contact with its insertion column 30 to move, and then drive the output shaft 232 connected to the fork 231 to deflect, so as to achieve a better transmission effect. As can be seen from the above, the transmission device 200 of the present invention combines the motor screw assembly 210 and the fork output shaft assembly 230 to achieve a better transmission effect; at the same time, based on this structure, the fork 231 mechanism can have a specific transmission ratio curve or a constant transmission ratio to meet the power output characteristic requirements of the servo, which solves the problem that the transmission ratio of the traditional servo screw fork 231 transmission mechanism only depends on the component size, and the transmission ratio fluctuates within a certain range and cannot be corrected and adjusted.

[0093] In this embodiment, the motor 211 is connected to the tail end of the screw shaft 2121 by direct drive. Specifically, the motor 211 shaft of the motor 211 has a hole, and the screw shaft 2121 is adapted to the hole. The connection is achieved by inserting the screw shaft 2121 into the hole of the motor 211 shaft. Of course, in practical applications, other methods can be used for connection, such as key connection or coupling connection, and the present invention does not limit this. Further, if Figure 8 As shown, the screw shaft 2121 is fixed to the first bearing seat 213 in a conventional manner at the middle shoulder position through a double-row angular contact ball bearing 217, a bearing end cover 219, a bearing nut 220, and a sleeve 221. The head end of the screw shaft 2121 is connected to the second bearing seat 214 through a deep groove ball bearing 218. Specifically, the deep groove ball bearing 218 is installed in the seat hole of the second bearing seat 214 and is floatingly installed at the head end of the screw shaft 2121. It can be understood that the connection method of the screw shaft 2121 with the first bearing seat 213 and the second bearing seat 214 is not limited to the above. In other embodiments, it can also be rotatably connected through another connection method, and the present invention is not limited to this.

[0094] like Fig. 9As shown, in this embodiment, the first bearing seat 213 and the second bearing seat 214 are fixedly arranged on the inner wall of the cabin 100 of the servo mechanism, the first bearing seat 213 includes a first fan-shaped flange 10 that is conformal to the inner wall of the cabin 100, and the second bearing seat 214 includes a second fan-shaped flange that is conformal to the inner wall of the cabin 100, and radial threaded holes 11 are provided at the contact positions of the first fan-shaped flange 10 and the second fan-shaped flange with the inner wall of the cabin 100. The radial threaded holes 11 are combined with the bolt assembly to install and fix the first bearing seat 213 and the second bearing seat 214 on the inner wall of the cabin 100.

[0095] Further, such as Fig. 9 As shown, the first bearing seat 213 and the second bearing seat 214 are respectively provided with a first seat hole 12 and a second seat hole at a certain center distance parallel to the axis of the screw shaft 2121, the first seat hole 12 and the second seat hole are coaxially arranged, the first seat hole 12 is provided with a first waist-shaped groove with a width smaller than the width of the first seat hole 12 in the axial extension direction of the two seat holes, a first screw through hole is provided in the vertical direction of the plane of the first waist-shaped groove, that is, the first screw through hole passes through a side wall of the first waist-shaped groove, and the second seat hole is correspondingly provided with a second waist-shaped groove 13 and a second screw through hole 14. On the other hand, the guide rod 216 includes a first connection structure and a second connection structure respectively fitted with the first waist-shaped groove and the second waist-shaped groove 13, the first connection structure is provided with a first threaded hole corresponding to the first screw through hole, and the second connection structure is provided with a second threaded hole corresponding to the second screw through hole 14. In the assembled state, the first connection structure and the second connection structure of the guide rod 216 are respectively placed in the first waist groove 13, the first connection structure and the first bearing seat 213 are connected by screwing the screw structure into the first screw through hole and the first threaded hole, and the second connection structure and the second bearing seat 214 are connected by screwing the screw structure into the second screw through hole 14 and the second threaded hole. Based on the above method, the guide rod 216 can be fixedly connected to the first bearing seat 213 and the second bearing seat 214.

[0096] like Fig.10As shown, in this embodiment, the guide rod 216 is a cylindrical long rod, and two plane structures 20 are symmetrically milled at both ends of the long rod to form a first connection structure and a second connection structure respectively, and a connecting threaded hole 21 is opened on the plane structure. During assembly, the cylindrical part of the guide rod 216 passes through the first seat hole 12 and the second seat hole coaxial with the first bearing seat 213 and the second bearing seat 214, and the planes at both ends of the guide rod 216 are respectively aligned with the first waist groove and the second waist groove 13 of the first bearing seat 213 and the second bearing seat 214. The connecting threaded holes opened on the planes at both ends of the guide rod 216 are respectively aligned with the first screw through hole and the second screw through hole 14, and the guide rod 216 is fixedly connected to the first bearing seat 213 and the second bearing seat 214 by screwing in the screws. On the other hand, the shift rod 215 is provided with a first through hole 31 at a position parallel to the axial direction of the screw shaft 2121 and a certain center distance therefrom. The first through hole 31 cooperates with the cylindrical surface of the guide rod 216. In the assembled state, the guide rod 216 passes through the first through hole 31 of the shift rod 215, and the shift rod 215 is located between the first connecting structure and the second connecting structure of the guide rod 216, so that the shift rod 215 slides on the guide rod 216 and inhibits the rotation of the screw nut 2122.

[0097] On the other hand, in this embodiment, the lever 215 is provided with a mounting flange fixed to the lead screw nut 2122 to achieve connection with the lead screw nut 2122. Fig.11 As shown, the insertion column 30 of the shift rod 215 is a cylindrical structure, and the insertion column 30 can move in the shift fork groove 40 opened by the shift fork 231 along the shape line of the shift fork groove 40. In practical applications, based on the above structure, the present invention can also adjust the transmission ratio of the transmission device 200 by adjusting the shape line of the shift fork groove 40 of the transmission device 200, so as to improve the transmission ratio curve of the steering gear transmission device 200 without changing the structure size, so that the transmission device 200 has a specific transmission ratio curve or a constant transmission ratio, thereby meeting the power output characteristic requirements of the steering gear.

[0098] Specifically, the transmission ratio curve of the transmission device 200 may be modified / improved based on the following contents:

[0099] (1) Set the rotation center of the shift fork 231 as the coordinate origin O (see Fig.14), according to the spatial layout, the deviation distance between the ball screw assembly 212 and the rotation center of the fork 231 is determined to be y0, when the screw nut 2122 is at the zero position of the servo, the position coordinate of the center of the insertion column 30 of the lever 215 is (x0, y0), and the range of the rotation angle θ of the fork 231 is: θ1≤θ≤θ2; wherein, the zero position means that the servo output shaft 232 is at the zero position. Generally, the output shaft 232 is connected to the rudder wing, and the rudder wing is defined as the zero position when it is parallel to the servo axis. In the present application, when the servo output shaft 232 is at the zero position, the position of the corresponding screw nut 2122 can be adjusted, and its zero position can be set according to the specific structure. Different zero positions correspond to slightly different shapes. On the other hand, the servo task book generally has index requirements for the angle range of the output shaft 232, and θ1 and θ2 are generally used as known input parameters.

[0100] (2) Designing a specific transmission ratio curve according to load characteristics, that is, determining the required transmission ratio curve and setting the transmission ratio curve function i = f(θ);

[0101] (3) Assuming that the shape function of the fork groove 40 is y=g(x), and the lead of the screw shaft 2121 is p (the distance the screw nut 2122 moves when the screw shaft 2121 rotates one circle), according to the kinematic relationship of the fork 231 pair, the shape function of the fork groove 40 satisfies:

[0102]

[0103] (4) By solving formula (1), the parametric equation of the shape function of the fork groove 40 can be obtained as follows:

[0104]

[0105] In practical applications, for different transmission ratio requirements, the shape function of the fork groove 40 can be adjusted based on the above formula (2), that is, different fork groove 40 structures can be processed to meet the corresponding transmission ratio requirements. For example, in one embodiment, the deviation distance y0 between the ball screw assembly 212 and the rotation center of the fork 231 is 37mm; the position coordinates of the center of the insertion column 30 are (17, 37), and the range of the rotation angle θ of the fork 231 is -20°≤θ≤-20°. The transmission ratio required in this embodiment is a constant transmission ratio, i=94.2, and the lead screw p is 2mm. Substituting the above data into formula (2) can obtain the shape function of the fork groove 40 that meets the requirements of this embodiment. It can be understood that in the present invention, the transmission ratio is not limited to a constant value, it can also be in other forms, for example, the transmission ratio curve is a parabola with a smaller fluctuation rate, that is, a parabola with a smoother fluctuation; or it can be adjusted based on the transmission ratio curve of the conventional fork 231 mechanism to obtain a ratio such as i=aθ 2+b transmission ratio curve; or the transmission ratio curve can also be a curve formed by splicing multiple sections of different functions. The fork groove 40-shaped line of the transmission device 200 in this application can be calculated by a pre-designed transmission ratio curve to meet the specific transmission ratio requirements of the mechanism.

[0106] As can be seen from the above, the transmission device 200 of the present invention can design the fork groove 40-shaped line through geometric calculation according to the target transmission ratio curve, the zero position of the screw shaft 2121, and the center distance between the screw shaft 2121 and the rotation center of the fork 231, so that the fork 231 mechanism has a specific transmission ratio curve or a constant transmission ratio to meet the power output characteristic requirements of the servo, and solve the problem that the transmission ratio of the traditional servo screw fork 231 transmission mechanism only depends on the size of the component, and the transmission ratio fluctuates within a certain range and cannot be corrected and adjusted. The correction design method that can be implemented by the transmission device 200 of the present invention can solve the problem that the transmission ratio of the traditional servo screw fork 231 transmission mechanism only depends on the size of the component, and the transmission ratio fluctuates within a certain range and cannot be corrected and adjusted. Therefore, the present application can correct the transmission ratio curve of the transmission device 200 according to the performance and load characteristic curve of the motor 211, so that the performance of the motor 211 can be maximized.

[0107] On the other hand, Fig.12 As shown, the output shaft 232 is fixed on the third bearing seat 233 by installing the bearing 234 and can rotate around the axis of the third bearing seat 233. The potentiometer 235 is used to measure the rotation angle of the output shaft 232 so that the control system can perform closed-loop control. The potentiometer 235 is fixed on the third bearing seat 233 by the potentiometer bracket 236, and the potentiometer 235 and the output shaft 232 are coaxially plugged and installed, so as to realize a compact and reliable connection between the potentiometer 235 and the output shaft 232. Specifically, as shown in FIG. Fig.13 As shown, the potentiometer 235 includes a potentiometer shaft 2351, on which an insertion pin 2352 perpendicular to its axial direction is installed, and a hole structure 41 corresponding to the potentiometer shaft 2351 is provided at the butt end between the output shaft 232 and the potentiometer 235, and a groove structure 42 corresponding to the insertion pin 2352 is provided at this butt end, and threaded holes 43 and second through holes 44 are respectively provided on both side walls of the groove structure 42; in the assembled state, the potentiometer 235 is coaxially plugged and installed with the output shaft 232, the potentiometer shaft 2351 cooperates with the hole structure 41 of the output shaft 232, and the insertion pin 2352 of the potentiometer 235 cooperates with the groove structure 42 of the output shaft 232, and a bolt structure is inserted into the second through hole 44, the groove structure 42 and the threaded hole 43 to lock and fix them, so that the groove structure 42 is deformed to clamp the insertion pin 2352.

[0108] In this embodiment, the insertion pin 2352 is a cylindrical pin, the hole structure 41 at the butt end of the output shaft 232 is a through hole with the same diameter as the potentiometer shaft 2351, and the groove structure 42 at the butt end of the output shaft 232 is a square groove, and the width of the square groove is the same as the diameter of the cylindrical pin. During installation, the potentiometer shaft 2351 is inserted into the hole structure 41, and the cylindrical pin of the potentiometer shaft 2351 is located in the square groove, and a screw is screwed into the side of the square groove to deform the square groove to clamp the cylindrical pin on the potentiometer shaft 2351, thereby realizing a compact and reliable connection between the potentiometer 235 and the output shaft 232.

[0109] To sum up, in a transmission device 200 and a four-channel electric servo mechanism thereof of the present invention, a frame structure is formed by combining a screw shaft 2121 and a parallel guide rod 216 and installed on the inner wall of the cabin 100, which has the effect of high rigidity and lightweight. Based on the transmission device 200 of the present invention, a better transmission effect can be achieved. At the same time, based on this structure, the fork 231 mechanism can have a specific transmission ratio curve or a constant transmission ratio to meet the power output characteristic requirements of the servo, which solves the problem that the transmission ratio of the traditional servo lead screw fork 231 transmission mechanism only depends on the size of the component, and the transmission ratio fluctuates within a certain range and cannot be corrected and adjusted.

[0110] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A transmission device for a four-channel electric steering gear mechanism, characterized in that: Include: A motor screw assembly, comprising a ball screw assembly, a lever and a guide rod, the ball screw assembly comprising a screw shaft and a screw nut, the screw shaft being rotatably connected to a first bearing seat and a second bearing seat respectively, the first bearing seat and the second bearing seat being fixedly arranged, one end of the screw shaft being connected to a motor; the lever is connected to the screw nut and the screw shaft is arranged through the two, the lever and the screw nut are located between the first bearing seat and the second bearing seat, the lever is provided with an insertion column in a direction perpendicular to the axis of the screw shaft, the guide rod is arranged parallel to the screw shaft, the lever is provided with a first through hole for the guide rod to pass through, so that the lever can slide along the guide rod; A shift fork output shaft assembly comprises a shift fork, an output shaft and a potentiometer, wherein the shift fork is provided with a shift fork groove of a specific shape, the insertion column of the shift rod is inserted into the shift fork groove and cooperates with it, the shift fork is connected to the output shaft, the output shaft is rotatably connected to a third bearing seat, the potentiometer is used to measure the rotation angle of the output shaft, and the potentiometer is fixedly arranged on the third bearing seat.

2. The transmission device for a four-channel electric steering gear mechanism according to claim 1, characterized in that: The rotation center of the shift fork is set as the coordinate origin. According to the spatial layout, the deviation distance between the ball screw assembly and the rotation center of the shift fork is determined to be y0. When the screw nut is at zero position, the position coordinate of the insertion column center of the shift rod is (x0, y0). The range of the shift fork rotation angle θ is: θ1≤θ≤θ2. The transmission ratio curve function i=f(θ) is set. The shape function of the shift fork groove is y=g(x). The lead of the screw shaft is p. According to the kinematic relationship of the shift fork pair, the shape function of the shift fork groove satisfies: Solving formula (1), we can get the parametric equation of the shape function of the fork groove:

3. The transmission device for a four-channel electric steering gear mechanism according to claim 1, characterized in that: The shape function of the fork slot can be adjusted based on different transmission ratio requirements.

4. The transmission device for a four-channel electric steering gear mechanism according to claim 1, characterized in that: The insertion column of the lever is a cylindrical structure.

5. The transmission device for a four-channel electric steering gear mechanism according to claim 1, characterized in that: The shift rod is connected to the lead screw nut via a mounting flange.

6. The transmission device for a four-channel electric steering gear mechanism according to claim 1, characterized in that: The potentiometer is coaxially plugged and installed with the output shaft, the potentiometer includes a potentiometer shaft, an insertion pin perpendicular to the axial direction of the potentiometer shaft is installed on the potentiometer shaft, a hole structure corresponding to the potentiometer shaft is provided at the butt end of the output shaft and the potentiometer, and a groove structure corresponding to the insertion pin is provided at the butt end, and a threaded hole and a second through hole are provided on both side walls of the groove structure respectively; in the assembled state, the potentiometer is coaxially plugged and installed with the output shaft, the potentiometer shaft cooperates with the hole structure of the output shaft, the insertion pin of the potentiometer cooperates with the groove structure of the output shaft, a bolt structure is inserted into the second through hole, the groove structure and the threaded hole, and locked and fixed, so that the groove structure is deformed to clamp the insertion pin; The potentiometer is fixed on the third bearing seat via a potentiometer bracket.

7. The transmission device for a four-channel electric steering gear mechanism according to claim 1, characterized in that: The first bearing seat and the second bearing seat are fixedly arranged on the inner wall of the cabin of the servo mechanism, the first bearing seat includes a first fan-shaped flange conforming to the inner wall of the cabin, the second bearing seat includes a second fan-shaped flange conforming to the inner wall of the cabin, and radial threaded holes are provided at the contact positions of the first fan-shaped flange and the second fan-shaped flange with the inner wall of the cabin.

8. The transmission device for a four-channel electric steering gear mechanism according to claim 1, characterized in that: The first bearing seat and the second bearing seat are respectively provided with a first seat hole and a second seat hole at a position parallel to the axis of the screw shaft at a preset distance, the first seat hole and the second seat hole are coaxially arranged, the first seat hole is provided with a first waist-shaped groove with a width smaller than the width of the first seat hole in the extending direction of the axes of the two, a first screw through hole is provided in a direction perpendicular to the plane of the first waist-shaped groove, and the second seat hole is correspondingly provided with a second waist-shaped groove and a second screw through hole; The guide rod comprises a first connection structure and a second connection structure respectively fitted with the first waist-shaped groove and the second waist-shaped groove, the first connection structure is provided with a first threaded hole corresponding to the first screw through hole, and the second connection structure is provided with a second threaded hole corresponding to the second screw through hole; In the assembled state, the first connection structure and the second connection structure of the guide rod are respectively placed in the first waist-shaped groove and the second waist-shaped groove, the first connection structure and the first bearing seat are connected by screwing the screw structure into the first screw through hole and the first threaded hole and tightening them, and the second connection structure and the second bearing seat are connected by screwing the screw structure into the second screw through hole and the second threaded hole and tightening them; In the assembled state, the shifting rod is located between the first connecting structure and the second connecting structure.

9. The transmission device for a four-channel electric steering gear mechanism according to claim 1, characterized in that: The screw shaft is connected to the first bearing seat via a double-row angular contact ball bearing; The screw shaft is connected to the second bearing seat through a deep groove ball bearing.

10. A four-channel electric servo mechanism, characterized in that: Include: A cabin body, wherein four sets of transmission devices according to any one of claims 1 to 9 are arranged in the cabin body, and the first bearing seat and the second bearing seat of the transmission device are fixedly arranged on the inner wall of the cabin body.

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