Ultrasonic motor

Abstract

The utility model relates to the technical field of motors, in particular to an ultrasonic motor which comprises a shell, a motor body and a planetary reducer assembly, the motor body comprises a stator assembly, a rotor and a motor rotating shaft, the motor rotating shaft is a hollow shaft, and one end of the motor rotating shaft is provided with a first sun gear. The input end of the planetary reducer assembly is connected to the first sun gear, and the output end drives load equipment. According to the ultrasonic motor, the planetary reducer assembly is arranged in the motor, the output of the rotating shaft of the motor is transmitted to the planetary reducer assembly through the first sun gear, the high reduction ratio is achieved, the output torque is increased, the ultrasonic motor is integrated with the planetary reducer assembly, and the overall structure of the ultrasonic motor is more compact; and the motion precision is improved. And the rotating shaft of the motor is arranged to be the hollow shaft, and the central shaft of the load equipment moving back and forth can penetrate through the hollow shaft, so that the application range of the ultrasonic motor is wider.

Description

TECHNICAL FIELD

[0001] The utility model relates to motor technical field especially relates to an ultrasonic motor. BACKGROUND

[0002] The ultrasonic motor is a new type of motor which utilizes the inverse piezoelectric effect of piezoelectric materials to achieve driving through mechanical vibration.

[0003] The ultrasonic motor can be well used in a non-magnetic environment and has high rotation precision, but the output torque of the ultrasonic motor itself is small, so when driving a large load, it is necessary to reduce the speed and increase the torque through an externally added multi-stage gear speed change, but such an externally added speed reduction and torque increase structure will make the overall structure of the ultrasonic motor larger, thereby reducing the motion precision and increasing the control difficulty.

[0004] Therefore, there is an urgent need for an ultrasonic motor to solve the above problems. SUMMARY

[0005] The utility model discloses a kind of ultrasonic motors, increase output torque, and make the overall structure of ultrasonic motor compact, improve motion precision.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] The ultrasonic motor comprises:

[0008] A housing;

[0009] A motor body comprising a stator assembly, a rotor and a motor shaft, the stator assembly is arranged on the housing, the motor shaft is arranged in the housing, the motor shaft is a hollow shaft, one end of the motor shaft is provided with a first sun gear, the rotor is coupled to the stator assembly, the rotor is fixedly sleeved on the motor shaft and arranged coaxially with the motor shaft.

[0010] A planetary reducer assembly, the input end of the planetary reducer assembly is connected to the first sun gear, and the output end of the planetary reducer assembly is used to drive a load device.

[0011] Further, the planetary reducer assembly comprises a ring gear, a first planetary carrier, a second planetary carrier, a first planetary gear and a second planetary gear, the ring gear is fixed in the shell, the first planetary carrier (32) and the second planetary carrier are coaxially arranged with the ring gear, a second sun gear is arranged on the first planetary carrier, the first planetary gear is rotatably arranged on the first planetary carrier, the first planetary gear is engaged with the first sun gear and the ring gear respectively, the second planetary gear is rotatably arranged on the second planetary carrier, the second planetary gear is engaged with the second sun gear and the ring gear respectively, and the output end of the second planetary carrier is used for driving a load device.

[0012] Further, the output shaft of the first planetary carrier and the output shaft of the second planetary carrier are hollow shafts.

[0013] Further, the stator assembly comprises a stator support and a piezoelectric element, the stator support is fixed on the shell, the piezoelectric element is arranged on the side of the stator support close to the rotor, and the piezoelectric element is frictionally coupled with the rotor.

[0014] Further, the motor body further comprises a friction assembly arranged between the piezoelectric element and the rotor, and the friction assembly is used for frictionally coupling the piezoelectric element with the rotor.

[0015] Further, the friction assembly comprises a first friction plate and a second friction plate, the first friction plate is arranged on the piezoelectric element, and the second friction plate is arranged on the rotor.

[0016] Further, a guide groove is arranged on the motor rotating shaft, a guide boss is arranged on the rotor, and the groove wall of the guide groove abuts against the guide boss.

[0017] Further, the ultrasonic motor further comprises an elastic element, and the two ends of the elastic element are elastically abutted against the motor rotating shaft and the rotor respectively.

[0018] Further, the shell comprises a base, a shell body and an end cover, one end of the shell body is arranged on the base, the other end is connected to the end cover, the stator assembly is arranged on the base, the peripheral wall of the ring gear abuts against the inner wall of the shell body, one end of the ring gear is arranged on the shell body, and the other end of the ring gear is connected to the end cover.

[0019] Further, a limiting groove is arranged on the ring gear, a limiting boss is arranged on the end cover, and the limiting boss abuts against the groove wall of the limiting groove.

[0020] The beneficial effects of the utility model are as follows:

[0021] This invention provides an ultrasonic motor, comprising a housing, a motor body, and a planetary reducer assembly. The motor body includes a stator assembly, a rotor, and a motor shaft. The motor shaft is hollow, with a first sun gear at one end. The input end of the planetary reducer assembly is connected to the first sun gear, and the output end of the planetary reducer assembly drives the load device. This ultrasonic motor achieves a high reduction ratio and increases output torque by incorporating a planetary reducer assembly within the motor, transmitting the output from the motor shaft to the planetary reducer assembly via the first sun gear. Furthermore, the integrated planetary reducer assembly makes the overall structure of the ultrasonic motor more compact and improves motion accuracy. Moreover, the hollow motor shaft allows the central axis of the moving load device to pass through it, broadening the application range of this ultrasonic motor. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the ultrasonic motor provided in this embodiment of the utility model;

[0023] Figure 2 This is a cross-sectional view of the ultrasonic motor provided in an embodiment of the present utility model;

[0024] Figure 3 This is a schematic diagram of the structure of the first planetary carrier provided in this embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of the structure of the first planetary gear shaft provided in an embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the structure of the second planetary gear shaft provided in an embodiment of the present invention;

[0027] Figure 6 This is a schematic diagram of the structure of the base provided in an embodiment of the present utility model;

[0028] Figure 7 This is a schematic diagram of the structure of the shell body provided in this embodiment of the utility model;

[0029] Figure 8 This is a schematic diagram of the gear ring provided in an embodiment of the present invention;

[0030] Figure 9 This is a schematic diagram of the structure of the motor shaft provided in this embodiment of the utility model;

[0031] Figure 10 This is a schematic diagram of the rotor provided in an embodiment of the present invention.

[0032] In the picture:

[0033] 1, housing; 11, base; 111, first through hole; 12, housing body; 121, second through hole; 122, support plate; 123, extension plate; 13, end cover; 131, limiting boss; 132, third through hole;

[0034] 21, stator assembly; 211, stator support; 212, piezoelectric element; 22, rotor; 221, guide boss; 23, motor rotating shaft; 231, rotating shaft body; 2311, first sun gear; 232, connecting part; 2321, guide groove; 2322, flange; 24, friction assembly; 241, first friction plate; 242, second friction plate;

[0035] 31, ring gear; 311, limiting groove; 32, first planetary carrier; 321, second sun gear; 33, second planetary carrier; 34, first planetary gear; 35, second planetary gear; 36, first planetary gear shaft; 361, first mounting groove; 37, second planetary gear shaft; 371, second mounting groove; 38, first circlip; 39, second circlip; 4, elastic element; 5, bearing. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0038] It should be noted that: similar reference numbers and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0039] In the description of the utility model, it needs to be explained that, the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly placed when the utility model product is used, and are only for the convenience of describing the utility model and simplifying the description, and thus cannot be understood as indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as limiting the utility model. In addition, the terms "first", "second", "third" and the like are only used for differentiation in description and cannot be understood as indicating or implying relative importance. In the description of the utility model, unless otherwise specified, the meaning of "a plurality of" is two or more than two.

[0040] In the description of the utility model, it also needs to be explained that, unless otherwise explicitly specified and limited, the terms "set", "connected" should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or integrally connected, can be mechanically connected, or can be electrically connected. For ordinary skilled persons in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0041] In the utility model, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include that the first and second features are in direct contact, or can include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "upper", "upper" and "upper" of the first feature to the second feature include that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "below", "below" and "below" of the first feature to the second feature include that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0042] The embodiments of the utility model are described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the utility model, and cannot be understood as limiting the utility model.

[0043] The technical scheme of the utility model is described in detail below in combination with Figures 1-10 The technical scheme of the utility model is described in detail below in combination with

[0044] In order to increase the output torque of the ultrasonic motor, improve the motion precision, and improve the application range of the ultrasonic motor, the utility model discloses an ultrasonic motor, which comprises a shell 1, a motor body and a planetary reducer assembly. Wherein, the motor body comprises a stator assembly 21, a rotor 22 and a motor shaft 23, the stator assembly 21 is arranged on the shell 1, the motor shaft 23 is arranged in the shell 1, and the motor shaft 23 is a hollow shaft, and one end of the motor shaft 23 is provided with a first sun gear 2311;The rotor 22 is coupled with the stator assembly 21, the rotor 22 is fixedly sleeved on the motor shaft 23, and is coaxially arranged with the motor shaft 23;The input end of the planetary reducer assembly is connected to the first sun gear 2311, and the output end of the planetary reducer assembly drives the load device. The ultrasonic motor sets the planetary reducer assembly in the motor, transmits the output of the motor shaft to the planetary reducer assembly through the first sun gear, realizes high reduction ratio, increases the output torque, and integrates the planetary reducer assembly into the ultrasonic motor, so that the overall structure of the ultrasonic motor is more compact, and the motion precision is improved. Moreover, the motor shaft is arranged as a hollow shaft, and the central shaft of the load device moving forward and backward can pass through the hollow shaft, so that the application range of the ultrasonic motor is wider.

[0045] Further, the stator assembly 21 comprises a stator support 211 and a piezoelectric element 212, the stator support 211 is fixedly arranged on the shell 1, the piezoelectric element 212 is arranged on the side of the stator support 211 close to the rotor 22, and the piezoelectric element 212 is frictionally coupled with the rotor 22. Specifically, the piezoelectric element 212 is bonded on the stator support 211, then the combination of the stator support 211 and the piezoelectric element 212 is arranged in the shell 1, and the stator support 211 is fixed with the shell 1 through screws, and the piezoelectric element 212 is frictionally coupled with the rotor 22.

[0046] Optionally, the piezoelectric element 212 is a piezoelectric ceramic, which has high sensitivity, good stability and is easy to process. The piezoelectric element 212 can also use piezoelectric crystal, high molecular piezoelectric material, etc., which is not limited here.

[0047] Further, the piezoelectric ceramic is bonded on the stator support 211 by epoxy glue, which has good wear resistance and strong fixing force, and can ensure that the piezoelectric ceramic and the stator support 211 are firmly and reliably bonded.

[0048] Furthermore, the planetary reducer assembly includes a ring gear 31, a first planetary carrier 32, a second planetary carrier 33, a first planetary gear 34, and a second planetary gear 35. The ring gear 31 is fixed inside the housing 1. The first planetary carrier 32 and the second planetary carrier 33 are both coaxially arranged with the ring gear 31. A second sun gear 321 is arranged on the first planetary carrier 32. The first planetary gear 34 is rotatably arranged on the first planetary carrier 32 and meshes with the first sun gear 2311 and the ring gear 31, respectively. The second planetary gear 35 is rotatably arranged on the second planetary carrier 33 and meshes with the second sun gear 321 and the ring gear 31, respectively. The output end of the second planetary carrier 33 is used to drive the load equipment.

[0049] In detail, such as Figures 2-3 As shown, when the piezoelectric element 212 is energized, the inverse piezoelectric effect of the piezoelectric element 212 converts electrical energy into mechanical energy, thereby causing the piezoelectric element 212 to vibrate. Through frictional coupling between the piezoelectric element 212 and the rotor 22, the vibration of the piezoelectric element 212 is converted into directional motion of the rotor 22, driving the rotor 22 to rotate. The rotor 22 then drives the motor shaft 23 to rotate. The first sun gear 2311 on the motor shaft 23 meshes with the first planetary gear 34, and the first planetary gear 34 revolves around the first sun gear 2311. The first planetary gear 34 rotates and rotates on its own axis, meshing with the ring gear 31. Since the ring gear 31 is stationary, the first planetary gear 34 drives the first planetary carrier 32 to rotate. The second sun gear 321 on the first planetary carrier 32 meshes with the second planetary gear 35, which rotates around the second sun gear 321 and on its own axis. The second planetary gear 35 meshes with the ring gear 31. Since the ring gear 31 is stationary, the second planetary gear 35 drives the second planetary carrier 33 to rotate. The output end of the second planetary carrier 33 is connected to the load device, transmitting power to the load device. The motor shaft 23 and the first sun gear 2311 are integrated into one unit, and the first planetary carrier 32 and the second sun gear 321 are integrated into one unit, simplifying the structure of the ultrasonic motor and ensuring the accuracy of power transmission. The planetary reducer assembly of this ultrasonic motor adopts a two-stage reduction structure: First-stage reduction: the first sun gear 2311 is the input, and the first planetary carrier 32 is the output; Second-stage reduction: the second sun gear 321 on the first planetary carrier 32 serves as the sun gear for the second-stage reduction, and the second planetary carrier 33 is the output. By setting up the first and second-stage reduction structures, a high reduction ratio is achieved, increasing the output torque. Furthermore, the ultrasonic motor integrates the planetary reducer assembly into one unit, making the overall structure of the ultrasonic motor more compact and improving motion accuracy. It should be noted that the inverse piezoelectric effect is existing technology and will not be detailed here.

[0050] Furthermore, the number of first planetary gears 34 is at least two, with at least two first planetary gears 34 meshing with the first sun gear 2311 along its axial direction and with the ring gear 31 along its circumference. The number of second planetary gears 35 is at least two, with at least two second planetary gears 35 meshing with the second sun gear 321 along its axial direction and with the ring gear 31 along its circumference. In this embodiment, based on the diameter of the first sun gear 2311, as many first planetary gears 34 as possible are arranged between the first sun gear 2311 and the ring gear 31, preferably three; based on the diameter of the second sun gear 321, as many second planetary gears 35 as possible are arranged between the second sun gear 321 and the ring gear 31, preferably three. This arrangement can improve the torque transmission capability of the planetary reduction structure.

[0051] Further, refer to Figure 4 A first planetary gear shaft 36 is provided on the first planetary carrier 32. The first planetary gear shaft 36 is fixedly mounted on the first planetary carrier 32, and the first planetary gear 34 is rotatably sleeved on the first planetary gear shaft 36. This configuration provides support for the rotation of the first planetary gear 34, ensuring the stability of power transmission. Specifically, each end of the first planetary gear shaft 36 has a first mounting groove 361. The first planetary gear shaft 36 passes through the first planetary carrier 32, and a first retaining ring 38 is engaged with the first mounting groove 361 and abuts against the first planetary carrier 32, thereby fixing the first planetary gear shaft 36 to the first planetary carrier 32. Furthermore, a bearing 5 is embedded between the inner hole of the first planetary gear 34 and the first planetary gear shaft 36, and the bearing 5 can effectively support the rotation of the first planetary gear 34.

[0052] Further, refer to Figure 5 A second planetary gear shaft 37 is provided on the second planetary carrier 33. The second planetary gear shaft 37 is fixedly mounted on the second planetary carrier 33, and the second planetary gear 35 is rotatably sleeved on the second planetary gear shaft 37. This configuration provides support for the rotation of the second planetary gear 35, ensuring the stability of power transmission. Specifically, each end of the second planetary gear shaft 37 is provided with a second mounting groove 371. The second planetary gear shaft 37 passes through the second planetary carrier 33, and a second snap ring 39 is engaged with the second mounting groove 371 and abuts against the second planetary carrier 33, thereby fixing the second planetary gear shaft 37 to the second planetary carrier 33. Furthermore, a bearing 5 is embedded between the inner hole of the second planetary gear 35 and the second planetary gear shaft 37, and the bearing 5 can effectively support the rotation of the second planetary gear 35.

[0053] Furthermore, such as Figures 6-8As shown, the housing 1 includes a base 11, a housing body 12, and an end cap 13. One end of the housing body 12 is disposed on the base 11, and the other end is connected to the end cap 13. The stator assembly 21 is disposed on the base 11. The peripheral wall of the gear ring 31 abuts against the inner wall of the housing body 12. One end of the gear ring 31 is disposed on the housing body 12, and the other end of the gear ring 31 is connected to the end cap 13. Specifically, in this embodiment, a receiving cavity is provided on the base 11, the stator assembly 21 is located in the receiving cavity, the stator support 211 is fixedly connected to the bottom wall of the receiving cavity by screws, a first through hole 111 is provided on the bottom wall of the receiving cavity, one end of the motor shaft 23 passes through the first through hole 111, the stator support 211 and the rotor 22 in sequence, thereby outputting power, and a bearing 5 is provided between the motor shaft 23 and the base 11; one end of the housing body 12 is provided on the base 11 and is fixedly connected to the base 11 by screws, a cylindrical cavity is provided inside the housing body 12, a support plate 122 is provided inside the cavity, a gear ring 31 is placed on the support plate 122, the outer wall of the gear ring 31 fits against the inner wall of the housing body 12, the support plate 122 supports the gear ring 31, a second through hole 121 is opened on the support plate 122, and the motor shaft 23 passes through the second through hole 121. An extension plate 123 is provided at the bottom of the support plate 122. The extension plate 123 is arranged around the second through hole 121 in the circumference. A bearing 5 is provided between the extension plate 123 and the motor shaft 23. The other end of the housing body 12 is connected to the end cover 13 and is fixedly connected to the end cover 13 by screws. A limit groove 311 is provided at the end of the gear ring 31 away from the support plate 122. A limit boss 131 is provided on the end cover 13. The limit boss 131 is located in the limit groove 311 and abuts against the groove wall of the limit groove 311. The gear ring 31 is fixed in the vertical direction and axial direction by the support plate 122 and the end cover 13, which ensures the stability of the power transmission of the planetary reducer assembly. A third through hole 132 is provided on the end cover 13. The output shaft of the second planetary carrier 33 passes through the third through hole 132. A bearing 5 is provided between the second planetary carrier 33 and the end cover 13 to output the power of the ultrasonic motor.

[0054] Furthermore, the output shafts of both the first planetary carrier 32 and the second planetary carrier 33 are hollow shafts. Specifically, by making the output shafts of the first planetary carrier 32 and the second planetary carrier 33 hollow shafts, the central shaft of the load equipment moving back and forth can pass through the hollow shaft and be coaxially aligned with the motor shaft 23, ensuring the stability of power transmission.

[0055] To reduce wear between the piezoelectric element 212 and the rotor 22, the motor body also includes a friction assembly 24. The friction assembly 24 is disposed between the piezoelectric element 212 and the rotor 22, and is used to frictionally couple the piezoelectric element 212 and the rotor 22. Specifically, in this embodiment, the friction assembly 24 includes a first friction plate 241 and a second friction plate 242. The first friction plate 241 is disposed on the piezoelectric element 212 and is bonded to the side of the piezoelectric element 212 away from the stator support 211. The second friction plate 242 is disposed on the rotor 22, which has a receiving groove. The second friction plate 242 is located in the receiving groove and is bonded to the rotor 22. When energized, the piezoelectric element 212 vibrates due to its inverse piezoelectric effect. This vibration is then transmitted to the first friction plate 241, and the second friction plate 242 transmits the vibration to the rotor 22, causing it to rotate. The rotor 22 then drives the motor shaft 23, thus transmitting power. The ultrasonic motor is driven by friction, has a fast response speed, and can achieve rapid start-up or stop.

[0056] In this embodiment, the first friction plate 241 and the piezoelectric element 212, as well as the second friction plate 242 and the rotor 22, are bonded together with epoxy adhesive. Epoxy adhesive has good wear resistance and strong fixing force, which can ensure that the bonding is firm and reliable.

[0057] Furthermore, such as Figures 9-10 As shown, a guide groove 2321 is provided on the motor shaft 23, and a guide boss 221 is provided on the rotor 22. The groove wall of the guide groove 2321 abuts against the guide boss 221. Specifically, the motor shaft 23 includes a shaft body 231 and a connecting part 232. A first sun gear 2311 is provided on the shaft body 231. The interior of the shaft body 231 is a hollow structure, and the connecting part 232 is a circular structure. The shaft body 231 passes through the center of the circular ring. A guide boss 221 is provided on the side of the rotor 22 near the circular ring. The guide boss 221 is located in the guide groove 2321, and the groove wall of the guide groove 2321 abuts against the guide boss 221. This arrangement can prevent the rotor 22 from rotating relative to the motor shaft 23, ensuring the stability of power transmission.

[0058] To ensure stable contact between the stator assembly 21 and the rotor 22, the ultrasonic motor also includes an elastic element 4. Both ends of the elastic element 4 elastically abut against the motor shaft 23 and the rotor 22, respectively. Specifically, a flange 2322 is provided on the connecting portion 232 of the motor shaft 23. One end of the elastic element 4 elastically abuts against the angle formed by the connecting portion 232 and the flange 2322, and the other end elastically abuts against the rotor 22. The elastic element 4 can apply preload between the stator assembly 21 and the rotor 22, ensuring stable contact between them and improving the output performance of the ultrasonic motor.

[0059] Furthermore, the elastic element 4 is a disc spring. Disc springs have high stiffness and strong load-bearing capacity, which can ensure stable contact between the stator assembly 21 and the rotor 22. The elastic element 4 can also be a wave spring, which is not specifically limited here.

[0060] The assembly process of the ultrasonic motor provided in this embodiment of the present invention is described in detail below:

[0061] First, the piezoelectric ceramic is bonded to the stator support 211 to form the stator assembly 21. The first friction plate 241 is bonded to the piezoelectric ceramic, and the second friction plate 242 is bonded to the rotor 22. Next, the stator assembly 21 is placed in the receiving cavity of the base 11, and the stator support 211 is fixedly connected to the base 11 using screws. The assembly of the rotor 22 and the second friction plate 242 is placed on the first friction plate 241. One end of the disc spring is installed on the rotor 22, at which point the disc spring is in a free state. Then, the motor shaft 23 is installed, with one end of the motor shaft 23 sequentially passing through the first through hole 111 on the base 11, the stator assembly 21, and the rotor 22. The guide groove 2321 on the motor shaft 23 is engaged with the guide boss 221 on the rotor 22, and the other end of the disc spring elastically abuts against the motor shaft 23. The housing body 12 is placed on the base 11, and screws are used to fix the housing body 12 to the base 11. At this time, the disc spring is in a compressed state to ensure the contact pressure between the stator assembly 21 and the rotor 22. The gear ring 31 is installed in the cavity of the housing body 12, with the outer wall of the gear ring 31 fitting against the inner wall of the cavity. Then, the planetary reducer assembly is installed, so that the first planetary gear 34 and the second planetary gear 35 mesh with the gear ring 31 respectively, and the first planetary carrier 32 and the second planetary carrier 33 are coaxial with the motor shaft 23. Finally, the end cover 13 is installed on the housing body 12, and the output shaft of the second planetary carrier 33 passes through the third through hole 132 on the end cover 13, so that the limiting boss 131 on the end cover 13 and the limiting groove 311 on the gear ring 31 are fitted together. Screws are used to fix the end cover 13 to the housing body 12, thus completing the assembly of the ultrasonic motor.

[0062] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. An ultrasonic motor, characterized in that, include: Shell (1); The motor body includes a stator assembly (21), a rotor (22), and a motor shaft (23). The stator assembly (21) is disposed on the housing (1). The motor shaft (23) passes through the housing (1). The motor shaft (23) is a hollow shaft. A first sun gear (2311) is provided at one end of the motor shaft (23). The rotor (22) is coupled to the stator assembly (21). The rotor (22) is fixedly sleeved on the motor shaft (23) and is coaxial with the motor shaft (23). A planetary reducer assembly, wherein the input end of the planetary reducer assembly is connected to the first sun gear (2311), and the output end of the planetary reducer assembly is used to drive the load device.

2. The ultrasonic motor according to claim 1, characterized in that, The planetary reducer assembly includes a gear ring (31), a first planet carrier (32), a second planet carrier (33), a first planet gear (34), and a second planet gear (35). The gear ring (31) is fixed inside the housing (1). The first planet carrier (32) and the second planet carrier (33) are both coaxially arranged with the gear ring (31). A second sun gear (321) is arranged on the first planet carrier (32). The first planet gear (34) is rotatably arranged on the first planet carrier (32). The first planet gear (34) meshes with the first sun gear (2311) and the gear ring (31) respectively. The second planet gear (35) is rotatably arranged on the second planet carrier (33). The second planet gear (35) meshes with the second sun gear (321) and the gear ring (31) respectively. The output end of the second planet carrier (33) is used to drive the load device.

3. The ultrasonic motor according to claim 2, characterized in that, The output shafts of the first planetary carrier (32) and the second planetary carrier (33) are both hollow shafts.

4. The ultrasonic motor according to claim 1, characterized in that, The stator assembly (21) includes a stator support (211) and a piezoelectric element (212). The stator support (211) is fixed on the housing (1), and the piezoelectric element (212) is disposed on the side of the stator support (211) close to the rotor (22). The piezoelectric element (212) is frictionally coupled to the rotor (22).

5. The ultrasonic motor according to claim 4, characterized in that, The motor body also includes a friction assembly (24), which is disposed between the piezoelectric element (212) and the rotor (22). The friction assembly (24) is used to frictionally couple the piezoelectric element (212) and the rotor (22).

6. The ultrasonic motor according to claim 5, characterized in that, The friction assembly (24) includes a first friction plate (241) and a second friction plate (242), the first friction plate (241) being disposed on the piezoelectric element (212) and the second friction plate (242) being disposed on the rotor (22).

7. The ultrasonic motor according to any one of claims 1-6, characterized in that, The motor shaft (23) is provided with a guide groove (2321), and the rotor (22) is provided with a guide boss (221). The groove wall of the guide groove (2321) abuts against the guide boss (221).

8. The ultrasonic motor according to any one of claims 1-6, characterized in that, The ultrasonic motor also includes an elastic element (4), the two ends of which are elastically abutted against the motor shaft (23) and the rotor (22) respectively.

9. The ultrasonic motor according to claim 2, characterized in that, The housing (1) includes a base (11), a housing body (12), and an end cap (13). One end of the housing body (12) is disposed on the base (11), and the other end is connected to the end cap (13). The stator assembly (21) is disposed on the base (11). The peripheral wall of the gear ring (31) abuts against the inner wall of the housing body (12). One end of the gear ring (31) is disposed on the housing body (12), and the other end of the gear ring (31) is connected to the end cap (13).

10. The ultrasonic motor according to claim 9, characterized in that, The gear ring (31) is provided with a limiting groove (311), and the end cap (13) is provided with a limiting boss (131). The limiting boss (131) abuts against the groove wall of the limiting groove (311).

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