Reducing mechanism and rotary electric steering engine

Abstract

The invention relates to the technical field of aircraft airborne equipment, and provides a speed reducing mechanism and a rotary electric steering engine, the speed reducing mechanism comprises a needle pin gear, a cycloid gear ring and an output shaft, the cycloid gear ring adopts a hypocycloid gear, and an epicycloid gear is arranged on the output shaft; the tooth profile of the needle pin gear and the tooth profile of the hypocycloid gear are conjugated to form a small-tooth-difference internal meshing gear pair. The tooth profile of the pin gear and the tooth profile of the epicycloid gear are conjugated to form a small-tooth-difference internal meshing gear pair, transmission of power and motion is achieved through conjugate motion between the tooth profiles, and N-N type small-tooth-difference planetary gear transmission is formed by forming two-stage cycloid pin gear tooth profile internal meshing. High bearing performance and stability of cycloid tooth profile multi-tooth meshing are reserved, a larger reduction ratio is achieved through superposition of two-stage inner meshing, and meanwhile an intermediate output mechanism needed by traditional two-stage transmission is simplified.

Description

Technical Field

[0001] This invention relates to the technical field of airborne equipment for aircraft, and in particular to a deceleration mechanism and a rotary electric servo motor. Background Technology

[0002] In rotary electric steering gears, due to the high speed of the drive motor, the matching reducer needs to have a large reduction ratio to meet the operational requirements. Planetary gear transmissions with small tooth difference have become one of the preferred solutions in this field due to their compact structure and large transmission ratio.

[0003] In the prior art, the intelligent drive device disclosed in Chinese patent CN103410918B uses a two-stage internal meshing gear pair with a small tooth difference to form an NN-type reduction transmission, which does not require an output mechanism and has a simple structure; however, this transmission uses an involute tooth profile, which has the problem of a small number of teeth working at the same time, resulting in weak load-bearing capacity and poor transmission smoothness.

[0004] Compared to involute gear profiles, cycloidal pinwheel drives with fewer tooth differences offer the advantage of a larger number of teeth meshing simultaneously, resulting in higher load-bearing capacity and better transmission smoothness. Based on this principle, cycloidal pinwheel reducers are widely used. However, because the external gear in a cycloidal pinwheel drive uses a pinwheel structure, it is difficult to achieve a two-stage, low-tooth-difference NN-type planetary transmission. Conventional cycloidal pinwheel drives are mostly single-stage low-tooth-difference planetary gear transmission mechanisms, requiring a pin mechanism to transmit the low-speed rotation of the planetary gears to the output component, making the structure relatively complex.

[0005] To achieve two-stage cycloidal transmission, Korean Patent 10-2-15-001204 replaces the pinwheel in the cycloidal pinwheel transmission with a cycloidal wheel, and uses two planetary gear transmission mechanisms with small tooth difference meshing between the inner and outer cycloidal wheels to form an NN-type transmission reduction device. However, this solution requires the machining of four cycloidal gears, which is more difficult to machine and more expensive to manufacture compared to the pinwheel structure of the cycloidal transmission. For example, Chinese Patent CN108869641B proposes a two-stage cycloidal transmission reducer, which uses two sets of cycloidal pinwheel transmissions and eliminates the output mechanism on the planetary gears, but there is a problem that the two pinwheels are of different sizes, and the structure is still relatively complex.

[0006] In summary, existing reducers for rotary electric servos still have room for improvement in terms of balancing large reduction ratios, compact structures, high load-bearing capacity, and smooth transmission. There is an urgent need for a transmission solution with a simpler structure, lower manufacturing difficulty, and better performance. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a speed reduction mechanism, comprising a pin pin gear, a cycloidal gear ring, and an output shaft. The cycloidal gear ring is an internal cycloidal gear, and an external cycloidal gear is mounted on the output shaft. A planetary bearing is fitted between the pin pin gear and the output shaft. The planetary bearing supports the rotation of the pin pin gear relative to the output shaft during eccentric motion, reducing frictional losses in meshing transmission. The tooth profiles of the pin pin gear and the internal cycloidal gear are conjugate to form a small-tooth-difference internal meshing gear pair; the tooth profiles of the pin pin gear and the external cycloidal gear are conjugate to form a small-tooth-difference internal meshing gear pair. Power and motion transmission are achieved through the conjugate motion between the tooth profiles. This system achieves first-stage reduction through the meshing of a pin pin gear and a cycloidal gear ring with a small tooth difference. Simultaneously, it completes motion reversal and power output through meshing with the output shaft. The synergistic effect of these two meshing stages allows for a large reduction ratio within a compact space, meeting the low-speed, high-torque requirements of electric servos. The simultaneous multi-tooth meshing characteristics of the cycloidal gear profile and the pin pin enhance load-bearing capacity and transmission smoothness, reducing impact vibration. The integrated meshing structure eliminates the need for additional output mechanisms (such as pins, cranks, etc.), simplifying the overall reducer layout, reducing the number of parts and machining complexity. Furthermore, through the matching design of tooth pattern parameters, it can flexibly adapt to different transmission ratio requirements, making it suitable for power transmission scenarios in various rotary electric servos. Alternatively, an NN-type planetary gear transmission with a small tooth difference is constructed using the internal meshing of two-stage cycloidal pin gear profiles. This retains the high load-bearing capacity and smoothness of the multi-tooth meshing of the cycloidal gear profile while achieving a larger reduction ratio through the superposition of the two-stage internal meshing, and simplifies the intermediate output mechanism required by traditional two-stage transmissions.

[0008] Furthermore, the pin gear includes a pin holder and a pin, and the height of the pin is the same as the height of the pin holder, that is, the horizontal plane where the center of all pin holes is located coincides with the horizontal plane where the center of the inner hole of the pin holder body is located.

[0009] Furthermore, the number of teeth on the inner cycloidal gear is 1-3 more than the number of pins; the number of teeth on the outer cycloidal gear is 1-3 fewer than the number of pins.

[0010] Furthermore, the pin holder includes a pin holder body, which is a hollow cylinder. A first protrusion is provided on the outer side of the pin holder body, extending along the outer side wall of the pin holder body. A hollow frustum is provided on one end face of the pin holder body. The hollow frustum and the pin holder body are arranged concentrically, with their centers coinciding and their axes collinear. The outer edge of the hollow frustum contacts the first protrusion, and the inner diameter of the hollow frustum is smaller than the inner diameter of the pin holder body. The pin holder body, the first protrusion, and the hollow frustum are integrally formed.

[0011] The first boss and the pin seat body are provided with pin holes, which extend to the outer edge of the hollow truncated cone, forming a circumferentially distributed hole structure that simultaneously passes through the edge of the first boss and the hollow truncated cone. The pin is placed in the pin hole.

[0012] Preferably, the first protrusion is provided with first connecting holes evenly distributed for connecting and fixing with the pin cap.

[0013] Preferably, the pin seat body is provided with a first annular groove for installing a shaft retaining ring to fix the planetary bearing;

[0014] Furthermore, a first plane is provided on the pin seat body above the pin hole;

[0015] The pin hole located at the outer edge of the hollow frustum has a first opening, and the outer edges of the hollow frustum on both sides of the first opening form a second plane.

[0016] Furthermore, one end of the pin is provided with a first concave surface, and the other end of the pin is provided with a second concave surface. The concave directions of the first and second concave surfaces are opposite. The first and second concave surfaces are cut by a plane along the axis of the pin. The first concave surface includes a third plane and a first arcuate surface. The first arcuate surface is perpendicular to the axis of the pin, and the third plane and the first arcuate surface are arranged perpendicularly. The second concave surface includes a fourth plane and a second arcuate surface. The second arcuate surface is perpendicular to the axis of the pin, and the fourth plane and the second arcuate surface are arranged perpendicularly.

[0017] The third plane is aligned with the first plane; the fourth plane is flush with the second plane.

[0018] Furthermore, the output shaft has a hollow structure and includes a first journal, a boss portion, and a second journal. The boss portion is located between the first journal and the second journal. The epicycloid gear is located on the boss portion. The second journal has a second annular groove for installing a shaft retaining ring to fix the output shaft bearing. The center of the inner hole of the first journal and the center of the inner hole of the second journal are eccentrically positioned.

[0019] Preferably, the end face of the second journal is provided with a connecting hole for connecting the flange of the external output component.

[0020] Furthermore, the pin gear is sleeved on the outer ring of the first journal of the output shaft, and the hollow frustum of the pin gear is placed on the boss portion of the output shaft, with one end of the pin near the hollow frustum meshing with the tooth profile of the epicycloid gear on the boss portion.

[0021] The cycloidal gear ring is fitted onto the outer ring of the pin gear, and the tooth profile of the cycloidal gear ring meshes with the end of the pin pin away from the hollow frustum.

[0022] Furthermore, a pin cap is fitted onto one end of the pin near the hollow frustum. The pin cap fits against the fourth plane and the first boss of the pin, thereby fixing the axial position of the pin. Specifically, the pin cap includes a first fitting part and a second fitting part. The first fitting part fits against the first boss, and the second fitting part fits against the fourth plane of the pin. A second connecting hole is provided on the first fitting part, and the pin cap and the pin gear are fixedly connected by fasteners inserted into the first and second connecting holes.

[0023] Furthermore, the deceleration mechanism also includes a deceleration cover. The deceleration cover has a first through hole at its center and a third annular groove on its inner wall. A first retaining ring is located within the third annular groove. The second journal of the output shaft is disposed within the first through hole. An output shaft bearing and an output shaft seal are located between the second journal and the deceleration cover. The output shaft bearing and the output shaft seal are respectively located on both sides of the first retaining ring. Preferably, the deceleration cover is a disc-shaped part. The deceleration cover has a boss with an axial second through hole. The deceleration cover is placed on the rear end face of the servo housing. The deceleration cover is fixed to the servo housing by screws passing through the second through hole and being screwed into threaded holes on the rear end face of the servo housing. The deceleration cover has a flange with several threaded holes for installing and fixing the servo.

[0024] On the other hand, the present invention also provides a rotary electric servo motor, including a reduction mechanism, a servo motor housing, a motor stator, a motor cover, a motor bearing, a motor shaft, a motor rotor, and a controller box; the motor shaft is sleeved on the outer ring of the output shaft in the reduction mechanism and the inner ring of the pin gear in the reduction mechanism, and a sliding bearing is provided between the motor shaft and the output shaft. The sliding bearing is used as the front support, which has a simple structure, strong load-bearing capacity, and high support rigidity; a planetary bearing is provided between the motor shaft and the pin gear, and a motor rotor is also sleeved on the motor shaft. A motor bearing is provided on both sides of the motor rotor. The motor stator is fixed in the servo motor housing, and the servo motor housing is fixedly connected to the reduction gear cover and the motor cover of the reduction mechanism. The controller box is set on the servo motor housing, and the interior of the controller box is connected to the interior space of the servo motor housing, which facilitates the arrangement of the motor control cable.

[0025] Furthermore, the motor shaft has a third through hole at its center. The motor shaft includes a first motor journal and a second motor journal. The inner centers of the first and second motor journals are eccentrically positioned. The first motor journal has a fourth annular groove and a fifth annular groove, with a keyway between the fourth and fifth annular grooves. Shaft retaining rings are installed within the fourth and fifth annular grooves. A motor rotor is fitted between the fourth and fifth annular grooves. The second motor journal is fitted onto the outer ring of the output shaft. The second motor journal has a countersunk hole, and a sliding bearing is installed within the countersunk hole.

[0026] The present invention has the following beneficial effects:

[0027] (1) The tooth profile of the pin pin gear in this invention is conjugate with the tooth profile of the external cycloidal gear to form a small tooth difference internal meshing gear pair. The transmission of power and motion is realized through the conjugate motion between the tooth profiles, forming a two-stage cycloidal pin gear tooth profile internal meshing to form an NN-type small tooth difference planetary gear transmission. This not only retains the high load-bearing capacity and stability of the multi-tooth meshing of the cycloidal tooth profile, but also achieves a larger reduction ratio through the superposition of the two-stage internal meshing, while simplifying the intermediate output mechanism required by the traditional two-stage transmission.

[0028] (2) The pin gear in this invention can participate in two stages of internal meshing transmission simultaneously, simplifying the mechanical structure and reducing manufacturing costs.

[0029] (3) The present invention provides a sliding bearing between the motor shaft and the output shaft. By using the sliding bearing as the front support, the structure is simple, the load-bearing capacity is strong, and the support stiffness is large.

[0030] (4) All the structures in this invention are hollow structures, which can realize the precise measurement of dual-end power output and output shaft movement;

[0031] (5) The controller box in this invention is connected to the internal space of the servo housing, which facilitates the arrangement of the motor control cable. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of the deceleration mechanism in Example 1.

[0033] Figure 2 This is a cross-sectional view of the deceleration mechanism in Example 1.

[0034] Figure 3 This is a schematic diagram of the cycloidal gear ring in Example 1.

[0035] Figure 4 This is a schematic diagram of the pin gear in Example 1.

[0036] Figure 5 This is a schematic diagram of the pin holder in Example 1.

[0037] Figure 6 This is a schematic diagram of the pin seat from another perspective in Embodiment 1.

[0038] Figure 7 This is a schematic diagram of the pin in Example 1.

[0039] Figure 8 This is a schematic diagram of the output shaft in Example 1.

[0040] Figure 9 This is a schematic diagram of the pin cap in Example 1.

[0041] Figure 10 This is a schematic diagram of the deceleration cover in Example 1.

[0042] Figure 11 This is a schematic diagram of the rotary electric servo motor in Example 2.

[0043] Figure 12 This is an internal cross-sectional view of the rotary electric servo motor in Example 2.

[0044] Figure 13 This is a schematic diagram of the servo housing in Example 2.

[0045] Figure 14 This is a diagram of the gear meshing transmission structure of the rotary electric servo motor in Example 2.

[0046] Figure 15 This is a schematic diagram of the motor cover in Example 2.

[0047] Figure 16 This is a schematic diagram of the motor shaft in Example 2. Detailed Implementation

[0048] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. However, these embodiments are not intended to limit the present invention. Any similar structures and similar variations of the present invention should be included in the protection scope of the present invention. The commas in the present invention all indicate the relationship between and. The English letters in the present invention are case-sensitive.

[0049] Example 1

[0050] like Figures 1-2As shown, this embodiment provides a reduction mechanism, including a pin pin gear 1, a cycloidal gear ring 2, and an output shaft 3. The cycloidal gear ring 2 is an internal cycloidal gear 21, and the output shaft 3 is provided with an external cycloidal gear 30. A planetary bearing 74 is sleeved between the pin pin gear 1 and the output shaft 3. The planetary bearing 74 is used to support the rotation of the pin pin gear 1 relative to the output shaft 3 during eccentric motion, reducing frictional losses in meshing transmission. The tooth profile of the pin pin gear 1 is conjugate with the tooth profile of the internal cycloidal gear 21 to form a small tooth difference internal meshing gear pair; the tooth profile of the pin pin gear 1 is conjugate with the tooth profile of the external cycloidal gear 30 to form a small tooth difference internal meshing gear pair. The speed reduction is achieved through the conjugate motion between the tooth profiles. The transmission of force and motion utilizes the low-tooth-difference meshing of pin gears and cycloidal gear rings to achieve first-stage reduction. Simultaneously, meshing with the output shaft completes motion reversal and power output. The synergistic effect of these two stages of meshing allows for a large reduction ratio within a compact space, meeting the low-speed, high-torque requirements of electric servos. The simultaneous multi-tooth meshing characteristics of the cycloidal gear profile and pins enhance load-bearing capacity and transmission smoothness, reducing impact vibration. The integrated meshing structure eliminates the need for additional output mechanisms (such as pins, cranks, etc.), simplifying the overall reducer layout, reducing the number of parts and machining complexity. Furthermore, through matching tooth pattern parameters, it can flexibly adapt to different transmission ratio requirements, making it suitable for power transmission scenarios in various rotary electric servos. The NN-type low-tooth-difference planetary gear transmission, consisting of two stages of cycloidal pin gear internal meshing, retains the high load-bearing capacity and smoothness of the multi-tooth meshing of the cycloidal gear profile while achieving a larger reduction ratio through the superposition of the two stages of internal meshing, while simplifying the intermediate output mechanism required by traditional two-stage transmissions.

[0051] like Figure 3 As shown, the cycloidal gear ring 2 has a hollow structure, and the number of teeth of the inner cycloidal gear 21 is 1-3 more than the number of pins; the number of teeth of the outer cycloidal gear 30 is 1-3 fewer than the number of pins.

[0052] like Figure 4 As shown, the pin gear 1 includes a pin seat 11 and a pin 12. The height of the pin 12 is the same as the height of the pin seat 11, that is, the horizontal plane where the center of all the pin holes is located coincides with the horizontal plane where the center of the inner hole of the pin seat body is located.

[0053] like Figures 5-6As shown, the pin seat 11 includes a pin seat body 111, which is a hollow cylinder. A first protrusion 112 is provided on the outer side of the pin seat body 111, extending along the outer side wall of the pin seat body 111. A hollow frustum 113 is provided on one end face of the pin seat body 111, and the hollow frustum 113 and the pin seat body 111 are concentric circles, with their centers coinciding and their axes collinear. The outer edge of the hollow frustum 113 is adjacent to the first protrusion. The hollow frustum 113 is in contact with the pin holder body 111, and its inner diameter is smaller than that of the pin holder body 111. The pin holder body 111, the first boss 112, and the hollow frustum 113 are integrally formed. Pin holes 114 are evenly distributed at the connection between the first boss 112 and the pin holder body 111. The pin holes 114 penetrate to the outer edge of the hollow frustum 113, forming a circumferentially distributed hole structure that simultaneously penetrates the edges of the first boss 112 and the hollow frustum 113. The pin 12 is placed in the pin hole 114. All pin holes 114 are the same size, and the center of all pin holes 114 is located on a distributed circumference, the center of which coincides with the center of the inner hole of the pin holder body. The diameter of this distributed circumference is larger than the inner diameter of the pin holder body. A pin 12 is inserted into each pin hole 114, forming a pin-gear structure. Preferably, the first boss 112 is provided with first connecting holes 1121 evenly distributed for connection and fixation with the pin cap 4. The pin seat body 111 is provided with a first annular groove 1110 for installing a shaft retaining ring to fix the planetary bearing; the pin seat body 111 above the pin hole is provided with a corresponding first plane 1111; the pin hole located at the outer edge of the hollow frustum 113 is provided with a first opening 1141, and the outer edges of the hollow frustum 113 on both sides of the first opening 1141 form a second plane 1131.

[0054] like Figure 7 As shown, the pin 12 is cylindrical in shape. To fix the working position of the pin 12 and ensure its mechanical strength, one end of the pin 12 is provided with a first concave surface 121, and the other end of the pin 12 is provided with a second concave surface 122. The concave directions of the first concave surface 121 and the second concave surface 122 are opposite. The first concave surface 121 and the second concave surface 122 are cut by cutting a plane along the axis of the pin. The first concave surface 121 includes a third plane 1211 and a first arcuate surface 1212. The first arc-shaped surface 1212 is perpendicular to the axis of the pin 12, and the third plane 1211 is perpendicular to the first arc-shaped surface 1212; the second concave surface 122 includes a fourth plane 1221 and a second arc-shaped surface 1222, the second arc-shaped surface 1222 is perpendicular to the axis of the pin 12, and the fourth plane 1221 and the second arc-shaped surface 1222 are perpendicular to each other; the third plane 1211 fits against the first plane 1111; the fourth plane 1221 is flush with the second plane 1131.

[0055] like Figure 8 As shown, the output shaft 3 has a hollow structure and includes a first journal 31, a boss 32, and a second journal 33. The boss 32 is located between the first journal 31 and the second journal 33. The cycloidal gear 30 is located on the boss 32. The outer ring of the second journal 33 has a second annular groove 331 for installing a shaft retaining ring to fix the output shaft bearing. The inner center of the first journal 31 and the inner center of the second journal 33 are eccentrically positioned. The first journal 31 is an eccentric section connected to a pin gear. By rotating, the pin gear is driven to oscillate eccentrically, thereby achieving alternating meshing transmission with the cycloidal gear ring and the output shaft.

[0056] The end face of the second journal 33 is provided with a connecting hole for connecting the flange of the external output component.

[0057] The pin gear 1 is sleeved on the outer ring of the first journal 31 of the output shaft 3, and the hollow frustum 113 of the pin gear 1 is placed on the boss portion 32 of the output shaft 3. The pin end near the hollow frustum 113 meshes with the tooth profile of the cycloidal gear 30 on the boss portion 32. The cycloidal gear ring 2 is sleeved on the outer ring of the pin gear 1, and the tooth profile of the cycloidal gear ring 2 meshes with the pin end away from the hollow frustum 113.

[0058] like Figure 9 As shown, a pin cap 4 is fitted around one end of the pin near the hollow frustum. The pin cap 4 is hollow and fits against the fourth plane of the pin and the first boss 112, thereby fixing the axial position of the pin. Specifically, the pin cap 4 includes a first fitting part 41 and a second fitting part 42. The first fitting part 41 fits against the first boss 112, and the second fitting part 42 fits against the fourth plane of the pin; both the first fitting part 41 and the second fitting part 42 are planar. The first fitting part 41 has a second connecting hole 411, and the pin cap 4 and the pin gear 1 are fixedly connected by fasteners inserted into the first connecting hole 1121 and the second connecting hole 411. The second fitting part 42 has a notch 421, which corresponds to the second connecting hole 411, and the notch is used to place the fastener.

[0059] like Figure 10As shown, the deceleration mechanism also includes a deceleration cover 5, which is a hollow structure. A first through hole 51 is provided at the center of the deceleration cover 5. A third annular groove 511 is provided on the inner wall of the deceleration cover 5. A first retaining ring is provided in the third annular groove 511. The second journal 33 of the output shaft 3 is disposed within the first through hole 51. An output shaft bearing 332 and an output shaft sealing ring 333 are provided between the second journal 33 and the deceleration cover 5 to ensure that the lubricating oil inside the servo motor does not leak during operation. Preferably, the deceleration cover 5 is a disc-shaped part. A second boss 52 is provided on the deceleration cover 5, and an axial second through hole 521 is provided on the second boss 52. The deceleration cover 5 is placed on the rear end face of the servo motor housing. The deceleration cover screws pass through the second through hole and are screwed into the threaded holes on the rear end face of the servo motor housing to fix the deceleration cover to the servo motor housing. The deceleration cover 5 has a flange 53 with several first threaded holes 531 for installing and fixing the servo motor.

[0060] Example 2

[0061] like Figures 11-12 As shown, this embodiment provides a rotary electric servo motor, including a reduction gear mechanism, a servo motor housing 6, a motor stator 71, a motor cover 7, a motor bearing 72, a motor shaft 8, a motor rotor 73, and a controller box 9.

[0062] like Figure 13 As shown, the servo housing 6 is a hollow structure. Four evenly distributed axial bosses 61 are provided on the outer side of the servo housing 6. Each end of the axial boss 61 has a second threaded hole 611, which is fixedly connected to the reducer cover 5 and the motor cover 7, respectively. A partition is provided inside the servo housing 6, dividing it into a motor cavity and a reducer cavity. The reduction mechanism is located inside the reducer cavity. The motor stator 71, motor cover 7, motor bearing 72, motor shaft 8, and motor rotor 73 are all located inside the motor cavity. The outer diameter of the cycloidal gear ring 2 is the same as the inner diameter of the reducer cavity, and it is fixed inside the reducer cavity by its outer diameter. The meshing center distance between the cycloidal gear ring 2 and the pin gear 1 is equal to the eccentricity between the first motor journal and the second motor journal.

[0063] like Figure 14 As shown, when the motor shaft 8 of the servo motor rotates, it drives the pin gear on the pin seat to rotate through the eccentric shaft diameter on the motor shaft 8. The pin gear meshes with both the cycloidal gear ring and the cycloidal gear on the output shaft, forming an NN-type planetary gear transmission with a small tooth difference. This transmission drives the external working mechanism through the output shaft, and its transmission ratio i is:

[0064]

[0065] In the formula, Z1 is the number of teeth of the cycloidal gear ring, and Z3 is the number of teeth of the external cycloidal gear on the output shaft;

[0066] For example, the number of teeth Z1 of the cycloidal gear ring is 42, and its center is O1; the number of pins Z2 is 41, and the center of the distribution circle of the pins is O2; the number of teeth Z3 of the exocycloidal gear on the output shaft is 40, and its center is also O1. The pins mesh with two cycloidal gears at the same time, and the center distance of the meshing is the same, forming an NN-type planetary gear transmission with a small tooth difference, and the reduction ratio of the transmission is 20.

[0067] The servo housing 6 is provided with a controller placement position 62, and the controller placement position 62 is provided with a second opening 621. The controller box 8 is fixed in the controller placement position 62, and the controller box 8 is provided with a third opening. The second opening 621 and the third opening are arranged correspondingly to connect the interior of the controller box with the interior space of the servo housing, which facilitates the arrangement of the motor control cable. The control cable on the motor stator 71 can enter the controller box through the second opening and the third opening to connect the electrical control components installed inside the controller box.

[0068] like Figure 15 As shown, the motor cover 7 is a hollow structure made of aviation aluminum alloy. The motor cover 7 has a third boss 701 with an axial through hole 702 for fixed connection with the servo housing 6. The inner side of the motor cover 7 has an annular boss 703 for mounting the motor bearing 72 and the motor shaft seal ring 75. The motor shaft seal ring 75 fits snugly against the inner wall of the motor cover 7, ensuring that the lubricating oil inside the servo does not leak during operation.

[0069] like Figure 16 As shown, the motor shaft 8 is a hollow structure with a third through hole 80 at its center. The motor shaft 8 includes a first motor journal 81 and a second motor journal 82. The inner centers of the first and second motor journals are eccentrically positioned. The first motor journal 81 has a fourth annular groove 811 and a fifth annular groove 812, with a keyway 813 between them. Shaft retaining rings are installed within the fourth and fifth annular grooves 811 and 812. A motor rotor 73 is fitted between the fourth and fifth annular grooves 811 and 812. The second motor journal 82 is fitted onto the outer ring of the output shaft 3. The second motor journal 82 has a countersunk hole 821, and a sliding bearing 820 is installed within the countersunk hole 821.

[0070] The second motor journal 82 is provided with a sixth annular groove 822, and a shaft retaining ring is provided in the sixth annular groove 822. The second motor journal 82 of the motor shaft 8 is sleeved on the outer ring of the first journal 31 of the output shaft in the reduction mechanism, and the inner ring of the pin gear 1 provided in the reduction mechanism. A sliding bearing 820 is provided between the second motor journal 82 and the first journal 31 of the output shaft. The first journal 31 and the inner ring of the sliding bearing 820 are clearance-fitted. The sliding bearing supports the output shaft. Using the sliding bearing 820 as the front support has a simple structure, strong load-bearing capacity, and rigid support. The sliding bearing 820 is made of tin bronze to reduce friction. An output shaft bearing 332 and an output shaft seal 333 are provided between the second journal 33 of the output shaft 3 and the reduction cover 5. The outer ring of the output shaft bearing 332 is supported in the center hole of the reduction cover 5. The axis of the output shaft 3 coincides with the axis of the motor shaft 8, allowing the output shaft 3 to rotate relative to the servo housing 6. The output shaft 3 is connected to the reduction cover 5 via the output shaft bearing 332 to achieve stable rotation (e.g., deep groove ball bearing or cylindrical roller bearing), bearing radial force and part of the axial force, avoiding wobbling due to eccentric rotation, and ensuring smooth transmission.

[0071] Two planetary bearings 74 are provided between the second motor journal 82 and the pin gear 1 or between the pin gear 1 and the first journal 31. The planetary bearings 74 are deep groove ball bearings. The two planetary bearings 74 are mounted side by side on the second motor journal 82 and are located on both sides of the sixth annular groove 822.

[0072] The motor shaft 8 is also fitted with a motor rotor 73, and a motor bearing 72 is provided on each side of the motor rotor 73. The motor stator 71 is fixed inside the servo housing 6.

[0073] Since both the motor shaft 8 and the output shaft 3 are hollow structures, the power of the output shaft 3 can be transmitted to the front of the servo motor through an additional drive shaft to achieve dual-axis output; it can also drive the position sensor installed at the front of the servo motor through the drive shaft to achieve precise measurement of the output shaft movement.

[0074] The rotary electric servo of this invention adopts an integrated structure of motor, controller and reducer. The reduction transmission adopts NN-type planetary gear transmission with small tooth difference formed by the internal meshing of cycloidal pinwheel teeth, which has a large reduction ratio, high load capacity and smooth operation. The specially structured pin gear can participate in two stages of internal meshing transmission at the same time, simplifying the mechanical structure of the servo and reducing manufacturing costs. The output shaft uses a sliding bearing as the front support, which has a simple structure, strong load capacity and high support rigidity. The rotary electric actuator has a hollow structure, which can realize the precise measurement of dual-end power output or output shaft movement. The internal space of the servo controller box is connected to the internal space of the servo housing, which facilitates the arrangement of motor control cable.

[0075] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

Claims

1. A speed reduction mechanism, characterized in that, The device includes a pin pin gear, a cycloidal gear ring, and an output shaft. The cycloidal gear ring is an internal cycloidal gear, and the output shaft is equipped with an external cycloidal gear. A planetary bearing is fitted between the pin pin gear and the output shaft to support the rotation of the pin pin gear relative to the output shaft during eccentric motion. The tooth profile of the pin pin gear is conjugate with the tooth profile of the internal cycloidal gear to form a small tooth difference internal meshing gear pair. The tooth profile of the pin pin gear is conjugate with the tooth profile of the external cycloidal gear to form a small tooth difference internal meshing gear pair.

2. The speed reduction mechanism according to claim 1, characterized in that, The pin gear includes a pin holder and a pin, and the height of the pin is the same as the height of the pin holder.

3. A speed reduction mechanism according to claim 2, characterized in that, The number of teeth on the internal cycloidal gear is 1-3 more than the number of pins; the number of teeth on the external cycloidal gear is 1-3 fewer than the number of pins.

4. A speed reduction mechanism according to claim 2, characterized in that, The pin holder includes a pin holder body, which is a hollow cylinder. A first protrusion is provided on the outer side of the pin holder body, which extends along the outer side wall of the pin holder body. A hollow frustum is provided on one end face of the pin holder body. The hollow frustum and the pin holder body are arranged in concentric circles, with their centers coinciding and their axes collinear. The outer edge of the hollow frustum contacts the first protrusion, and the inner diameter of the hollow frustum is smaller than the inner diameter of the pin holder body. The first boss and the pin seat body are provided with pin holes, which extend to the outer edge of the hollow truncated cone, forming a circumferentially distributed hole structure that simultaneously passes through the edge of the first boss and the hollow truncated cone. The pin is placed in the pin hole.

5. A speed reduction mechanism according to claim 2, characterized in that, A first plane is provided on the body of the pin seat above the pin hole; The pin hole located at the outer edge of the hollow frustum has a first opening, and the outer edges of the hollow frustum on both sides of the first opening form a second plane.

6. A speed reduction mechanism according to claim 4, characterized in that, One end of the pin has a first concave surface, and the other end of the pin has a second concave surface. The concave directions of the first and second concave surfaces are opposite. The first concave surface includes a third plane and a first arcuate surface. The first arcuate surface is perpendicular to the axis of the pin, and the third plane and the first arcuate surface are perpendicularly arranged. The second concave surface includes a fourth plane and a second arcuate surface. The second arcuate surface is perpendicular to the axis of the pin, and the fourth plane and the second arcuate surface are perpendicularly arranged. The third plane fits against the first plane. The fourth plane is flush with the second plane.

7. A speed reduction mechanism according to claim 4, characterized in that, The output shaft has a hollow structure and includes a first journal, a boss, and a second journal. The boss is located between the first journal and the second journal. The cycloidal gear is located on the boss. The center of the inner hole of the first journal and the center of the inner hole of the second journal are eccentrically positioned.

8. A speed reduction mechanism according to claim 7, characterized in that, The pin gear is sleeved on the outer ring of the first journal of the output shaft, and the hollow truncated cone of the pin gear is placed on the boss of the output shaft. The pin end near the hollow truncated cone meshes with the tooth profile of the cycloidal gear on the boss. The cycloidal gear ring is fitted onto the outer ring of the pin gear, and the tooth profile of the cycloidal gear ring meshes with the end of the pin pin away from the hollow frustum.

9. A speed reduction mechanism according to claim 6, characterized in that, A pin cap is provided on one end of the pin near the hollow truncated cone side. The pin cap fits against the fourth plane and the first boss of the pin to fix the axial position of the pin.

10. A speed reduction mechanism according to claim 7, characterized in that, The deceleration mechanism also includes a deceleration cover, a first through hole is provided in the center of the deceleration cover, a third annular groove is provided on the inner wall of the deceleration cover, a first hole retaining ring is provided in the third annular groove, a second journal of the output shaft is provided in the first through hole, an output shaft bearing and an output shaft sealing ring are provided between the second journal and the deceleration cover, and the output shaft bearing and the output shaft sealing ring are respectively provided on both sides of the first hole retaining ring.

11. A rotary electric servo motor, characterized in that, The device includes a reduction mechanism as described in any one of claims 1-10, a servo housing, a motor stator, a motor cover, a motor bearing, a motor shaft, a motor rotor, and a controller box. The motor shaft is sleeved on the outer ring of the output shaft in the reduction mechanism and on the inner ring of the pin gear in the reduction mechanism. A sliding bearing is provided between the motor shaft and the output shaft, and a planetary bearing is also provided between the motor shaft and the pin gear. A motor rotor is also sleeved on the motor shaft, and a motor bearing is provided on each side of the motor rotor. The motor stator is fixed inside the servo housing. The servo housing is fixedly connected to the reducer cover and the motor cover of the reduction mechanism. The controller box is disposed on the servo housing.

12. A rotary electric servo motor according to claim 11, characterized in that, The motor shaft has a third through hole at its center. The motor shaft includes a first motor journal and a second motor journal. The inner center of the first motor journal and the inner center of the second motor journal are eccentrically positioned.

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