A direct drive motor

Abstract

The utility model provides a kind of direct drive motor, including shell, stator, rotor, rotating shaft, the stator is fixed on the inner wall of shell, the rotor is located inside stator, the rotating shaft is fixed on rotor and coaxially with rotor setting, the both ends of shell are respectively connected with front end cover and rear end cover, one end of the rotating shaft passes through front end cover, still include magnet, circuit board, hall sensor, the magnet is fixed on the one end of rotating shaft away from front end cover and with rotating shaft eccentric setting, the rear end cover is opened with the mounting hole corresponding with the one end of rotating shaft away from front end cover, the circuit board is fixed in mounting hole, the hall sensor is electrically connected on circuit board and is used to correspond with magnet, the outer wall of rear end cover is connected with the wiring end for being electrically connected with circuit board, with the function of rotational speed detection.

Description

Technical Field

[0001] This utility model relates to electric motors, and more particularly to a direct drive motor. Background Technology

[0002] Currently, direct-drive servo motors are widely used in various precision automation equipment due to their advantages such as high precision, high torque density, and compact structure. To meet the demands of special working environments, such as humid, dusty, or high-vibration environments, waterproofing, dustproofing, and shockproofing of the motor body becomes particularly important.

[0003] Several related solutions already exist in the prior art. For example, Chinese patent CN212114998U discloses a direct-drive servo motor, whose structure includes a motor body, a front cover, a main housing, and a rear cover. This motor effectively improves its waterproof performance through innovative designs such as fitting a hydrophobic shell on the outside of the main housing, creating a hydrophobic channel between the outer wall of the rear cover and the outer wall of the hydrophobic shell, and incorporating a slotted heat dissipation structure between the hydrophobic shell and the main housing. Furthermore, by mounting the hydrophobic shell on an anti-vibration base, the motor also exhibits excellent shock resistance. These technological improvements enable the motor to adapt to harsher working environments, enhancing its environmental tolerance.

[0004] However, existing technologies, including the solution disclosed in the aforementioned patent CN212114998U, have a critical flaw: they cannot effectively detect the rotational speed of the motor rotor. In many practical applications, rotational speed is a core parameter for controlling and monitoring motor operation. For example, in the drive systems of electric or hybrid vehicles, motor speed information is crucial for the electronic control unit (ECU) to perform torque control, energy recovery, and shifting strategy formulation. The lack of speed feedback will severely impact vehicle power performance, energy efficiency, and driving experience. Therefore, the practicality and application scope of this technology are greatly limited due to the lack of effective speed detection functionality. Utility Model Content

[0005] In view of this, the purpose of this utility model is to provide a direct drive motor with a speed detection function, thereby improving its practicality and application range.

[0006] To solve the above-mentioned technical problems, the technical solution of this utility model is: a direct drive motor, including a housing, a stator, a rotor, and a shaft. The stator is fixed to the inner wall of the housing, the rotor is located inside the stator, and the shaft is fixed to the rotor and coaxially arranged with the rotor. A front cover and a rear cover are respectively connected to both ends of the housing. One end of the shaft passes through the front cover. The motor also includes a magnet, a circuit board, and a Hall sensor. The magnet is fixed to the end of the shaft away from the front cover and is eccentrically arranged with respect to the shaft. The rear cover has a mounting hole corresponding to the end of the shaft away from the front cover. The circuit board is fixed in the mounting hole. The Hall sensor is electrically connected to the circuit board and is used to correspond to the magnet. The outer wall of the rear cover has a terminal for electrical connection with the circuit board.

[0007] To achieve the above technical solution, when the motor is running, the rotor drives the shaft to rotate synchronously. Since the magnet is eccentrically fixed to the end of the shaft, it periodically sweeps across the Hall sensor fixed to the rear end cover during rotation. The Hall sensor converts each sensed magnetic field change into an electrical pulse signal, the frequency of which is proportional to the shaft's rotational speed. The signal is processed by the circuit board and output through the terminals. This design, by introducing a non-contact sensing structure, achieves accurate and real-time detection and feedback of the direct-drive motor's rotor speed, effectively solving the problem of missing speed monitoring in the background technology, and significantly improving the motor's controllability and application value.

[0008] In a preferred embodiment of this utility model, a positioning seat is connected to the end of the stator, and a magnetic shielding ring is connected to the positioning seat.

[0009] To achieve the above technical solution, positioning seats are added to both ends of the stator, and the magnetic shielding ring is fixed using these seats, forming a static shielding structure surrounding the stator windings. This structure remains stationary during motor operation. The magnetic shielding ring effectively suppresses the leakage of electromagnetic fields generated by the stator, preventing interference with surrounding electronic equipment. It also prevents external electromagnetic fields from interfering with the motor's internal control components, thereby improving the overall electromagnetic compatibility and operational stability of the motor.

[0010] In a preferred embodiment of this utility model, the positioning seat includes a ring body, fixing posts, fixing holes, an extension plate, an upper clamping plate, and a lower clamping plate. Multiple fixing holes are opened at the ends of the stator and are evenly distributed along the axis of the stator. Multiple fixing posts are fixedly connected to the sidewalls of the ring body and are used to be embedded in the fixing holes. One end of the extension plate is fixed to the inner wall of the ring body, and the other end of the extension plate extends towards the axis of the ring body. Multiple extension plates are evenly distributed along the axis of the ring body. Multiple upper clamping plates are fixed to the side of the ring body opposite to the fixing posts and are evenly distributed along the axis of the ring body. The lower clamping plate is fixed to the side of the extension plate opposite to the stator. A receiving cavity for positioning the magnetic shielding ring is formed between the upper clamping plate, the lower clamping plate, and the extension plate.

[0011] To achieve the above technical solution, the positioning seat uses its fixed posts to engage with the fixed holes at the end of the stator, enabling precise positioning and stable installation. Its ring body, extension plate, upper clamping plate, and lower clamping plate together form a structured receiving cavity. During assembly, the magnetic shielding ring is placed within this cavity. Through the integrated structural design, screwless and rapid positioning and fastening of the magnetic shielding ring are achieved, simplifying the assembly process and ensuring the precise positional relationship between the magnetic shielding ring and the stator, thus guaranteeing the stability and reliability of the shielding effect.

[0012] As a preferred embodiment of this utility model, the side of the extension plate facing the receiving cavity is connected to a protruding rib for abutting against the side wall of the magnetic shielding ring. The length direction of the protruding rib is parallel to the length direction of the extension plate, and the two ends of the protruding rib are respectively connected to the upper clamping plate and the lower clamping plate.

[0013] To achieve the above technical solution, during the process of installing the magnetic shielding ring into the receiving cavity, its sidewall will come into contact with the protrusions on the extension plate. By setting protrusions on the extension plate, the local structural rigidity of the extension plate is significantly improved, enhancing the overall seismic resistance of the positioning seat. In addition, the gap formed between adjacent protrusions can serve as an airflow channel, which helps to assist in heat dissipation during motor operation.

[0014] As a preferred embodiment of the present invention, a protrusion for contacting the side wall of the magnetic shielding ring is connected between the extension plate and the lower clamping plate, and the protrusion is located on the side of the extension plate opposite to the stator.

[0015] To achieve the above technical solution, during the process of inserting the magnetic shielding ring into the receiving cavity, its sidewall will come into contact with the protrusion. By setting protruding ridges on the extension plate, the structural rigidity between the extension plate and the lower clamping plate is significantly improved, enhancing the overall seismic performance of the positioning seat.

[0016] As a preferred embodiment of this utility model, a fixing ring is connected to the inner wall of the mounting hole, the fixing ring has a threaded hole, the circuit board has a connecting hole corresponding to the threaded hole, a locking bolt passes through the connecting hole, the locking bolt passes through the connecting hole and is threaded to the threaded hole, and the head of the locking bolt abuts against the circuit board.

[0017] To achieve the above technical solution, the circuit board is first placed into the mounting hole of the rear end cover, aligning its connecting hole with the threaded hole on the retaining ring. Then, the locking bolt is passed through the connecting hole and screwed into the threaded hole until its head presses against the circuit board. This provides a robust and removable circuit board mounting solution. It ensures high stability and consistency in the spatial position of the circuit board and Hall sensor, a prerequisite for accurate speed measurement, and also facilitates subsequent maintenance or replacement.

[0018] As a preferred embodiment of this utility model, the rear end cover has an installation ring groove on the side facing away from the outer shell, the installation hole is located inside the installation ring groove, a sealing ring is provided in the installation ring groove, a cover plate is connected to the rear end cover, and a protruding ring is connected to the cover plate for fitting into the installation ring groove and abutting against the sealing ring.

[0019] To achieve the above technical solution, during assembly, the sealing ring is first placed in the mounting ring groove of the rear end cover. When the cover plate is installed on the rear end cover, the protruding ring on the cover plate will embed into the mounting ring groove and effectively compress the sealing ring radially and axially. This constructs a reliable waterproof and dustproof barrier, effectively protecting the circuit board, Hall sensor, and wiring terminals inside the mounting hole from external environmental corrosion such as moisture and dust, significantly improving the environmental tolerance and operational reliability of the motor speed detection module under harsh operating conditions.

[0020] As a preferred embodiment of this utility model, the rear end cover is provided with a connecting groove for threading a wire. The connecting groove is located inside the mounting ring groove. A limiting ring is connected to the rear end cover. The mounting hole is located inside the limiting ring. A limiting groove for limiting the wire is provided on the rear end cover. One end of the limiting groove is connected to the connecting groove, and the other end of the limiting groove passes through the limiting ring and is connected to the mounting hole.

[0021] To achieve the above technical solution, after the wire is led out from the circuit board, it first enters one end of the limiting groove. Then, the wire passes through the limiting ring along the limiting groove and enters the connecting groove located inside the mounting ring groove from the other end of the limiting groove, finally exiting from there. The combination of the limiting ring, limiting groove, and connecting groove constructs a complete and protected guiding channel for the wire. This not only achieves standardized management of the wire, effectively preventing interference with other components during assembly or operation, but also ensures the neatness and consistency of the wiring path, thereby significantly improving the long-term reliability and safety of the electrical connection.

[0022] In a preferred embodiment of this utility model, a fixed frame is fixedly connected to the cover plate, a pressure plate is slidably connected inside the fixed frame, an elastic element is connected between the inner wall of the fixed frame and the pressure plate, the fixed frame and the pressure plate are both located in a communicating groove, and the pressure plate is used to contact the wire.

[0023] To achieve the above technical solution, during the wiring process, the wire is placed in the connecting groove and passes under the pressure plate. The elastic element within the fixed frame applies a continuous pushing force to the pressure plate, allowing the pressure plate to automatically press down and clamp the wire. This achieves reliable and self-adaptive clamping and fixing of the wire. It not only effectively prevents the wire from loosening or coming off due to vibration, but also accommodates wires of different diameters, simplifies assembly operations, and further enhances the stability of the wiring and the reliability of the electrical connection. Attached Figure Description

[0024] Figure 1 The external structure diagram of this utility model is shown below; Figure 2 The external structure diagram of this utility model is shown below; Figure 3 This is a schematic diagram of the exploded structure of this utility model; Figure 4 This is a schematic diagram of the exploded structure of this utility model; Figure 5 To illustrate the position of the positioning seat; Figure 6 To illustrate the exploded view between the stator and the positioning seat; Figure 7 To illustrate the structure of the positioning seat; Figure 8 To illustrate the structural diagram of the rear end cover; Figure 9 To illustrate the structural diagram of the rear end cover; Figure 10 This is a diagram illustrating the position of the fixed frame; Figure 11 for Figure 10 Enlarged view of point A.

[0025] Reference numerals: 1. Housing; 2. Stator; 3. Rotor; 4. Shaft; 5. Front cover; 6. Rear cover; 7. Magnet; 8. Mounting hole; 9. Circuit board; 10. Hall sensor; 11. Terminal; 12. Fixing ring; 13. Magnetic shielding ring; 14. Positioning seat; 15. Ring body; 16. Fixing post; 17. Fixing hole; 18. Extension plate; 19. Upper clamping plate; 20. Lower clamping plate; 21. Raised ridge; 22. Protrusion; 23. Mounting ring groove; 24. Sealing ring; 25. Cover plate; 26. Raised ring; 27. Communicating groove; 28. Limiting ring; 29. ​​Limiting groove; 30. Fixing frame; 31. Pressure plate; 32. Cylinder; 33. Elastic element. Detailed Implementation

[0026] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings, so that the technical solution of this utility model can be more easily understood and mastered.

[0027] A direct-drive motor includes a housing 1, a stator 2, a rotor 3, and a shaft 4. The stator 2 is fixed to the inner wall of the housing 1, the rotor 3 is located inside the rotor 3, and the shaft 4 is fixed to the rotor 3 and coaxially arranged with the rotor 3.

[0028] A front cover 5 and a rear cover 6 are bolted to both ends of the outer casing 1. One end of the rotating shaft 4 passes through the front cover 5. Bearings are provided between the rotating shaft 4 and the front cover 5, and between the rotating shaft 4 and the rear cover 6, to make the rotation of the rotating shaft 4 more stable.

[0029] Magnet 7 is fixed to the end of the rotating shaft 4 away from the front end cover 5 and is eccentrically positioned relative to the rotating shaft 4. A mounting hole 8 is provided on the rear end cover 6, corresponding to the end of the rotating shaft 4 away from the front end cover 5, and the aforementioned bearing is located in the mounting hole 8. Circuit board 9 is fixed within the mounting hole 8; Hall sensor 10 is electrically connected to circuit board 9 and is used to correspond with magnet 7.

[0030] The chip is integrated on circuit board 9.

[0031] A terminal 11 for electrical connection to the circuit board 9 is connected to the outer wall of the rear cover 6.

[0032] A coaxial retaining ring 12 is integrally connected to the inner wall of the mounting hole 8. Threaded holes are formed on the retaining ring 12, with three threaded holes evenly distributed along its axis. A connecting hole corresponding to the threaded hole is formed on the circuit board 9. A locking bolt passes through the connecting hole and is threaded onto the threaded hole, with its head abutting against the circuit board 9. The Hall sensor 10 is positioned close to the end of the rotating shaft 4.

[0033] Positioning seats 14 are connected to both ends of the stator 2, and magnetic shielding rings 13 are connected to the positioning seats 14. The positioning seats 14 are made of engineering plastic. The magnetic shielding rings 13 are made of silicon steel sheets.

[0034] The positioning base 14 includes an integrally formed ring 15, fixing posts 16, fixing holes 17, an extension plate 18, an upper clamping plate 19, and a lower clamping plate 20. Multiple fixing holes 17 are formed at the ends of the stator 2 and are evenly distributed along the axis of the stator 2. Multiple fixing posts 16 are fixedly connected to the sidewalls of the ring 15 and are used to be embedded in the fixing holes 17. One fixing post 16 is embedded in one fixing hole 17.

[0035] One end of the extension plate 18 is fixed to the inner wall of the ring 15, and the other end of the extension plate 18 extends towards the axis of the ring 15; multiple extension plates 18 are evenly distributed along the axis of the ring 15. Multiple upper clamping plates 19 are fixed to the side of the ring 15 opposite to the fixing post 16 and are evenly distributed along the axis of the ring 15, with the length direction of the upper clamping plates 19 parallel to the axis of the ring 15. A lower clamping plate 20 is fixed to the side of the extension plate 18 opposite to the stator 2, with the length direction of the lower clamping plate 20 parallel to the length direction of the upper clamping plates 19. A receiving cavity for positioning the magnetic shielding ring 13 is formed between the upper clamping plates 19, the lower clamping plates 20, and the extension plates 18.

[0036] Each extension plate 18 corresponds to two upper clamping plates 19, and each extension plate 18 is connected to two lower clamping plates 20.

[0037] An integrally formed ridge 21 for abutting against the sidewall of the magnetic shielding ring 13 is provided on the side of the extension plate 18 facing the receiving cavity. Each extension plate 18 has two ridges 21. The length direction of the ridge 21 is parallel to the length direction of the extension plate 18. The two ends of each ridge 21 are connected to an upper clamping plate 19 and a lower clamping plate 20, respectively.

[0038] A protrusion 22 is connected between the extension plate 18 and the lower clamping plate 20 for contacting the side wall of the magnetic shielding ring 13. The protrusion 22 is located on the side of the extension plate 18 opposite to the stator 2.

[0039] A mounting ring groove 23 is provided on the side of the rear end cover 6 facing away from the outer casing 1. The mounting hole 8 is located inside the mounting ring groove 23, and the mounting ring groove 23 and the mounting hole 8 are coaxially arranged. A rubber sealing ring 24 is provided inside the mounting ring groove 23.

[0040] A cover plate 25 is connected to the rear cover 6, and a protruding ring 26 is integrally connected to the cover plate 25 for embedding into the mounting ring groove 23 and abutting against the sealing ring 24.

[0041] A connecting groove 27 for threading wires is provided on the rear end cover 6. The connecting groove 27 is located inside the mounting ring groove 23. A limiting ring 28 is connected to the rear end cover 6. The connecting groove 27 is located outside the limiting ring 28, and the mounting hole 8 is located inside the limiting ring 28.

[0042] A limiting groove 29 for limiting the wire is provided on the rear cover 6; one end of the limiting groove 29 is connected to the connecting groove 27, and the other end of the limiting groove 29 passes through the limiting ring 28 and is connected to the mounting hole 8.

[0043] A fixing frame 30 is fixedly connected to the cover plate 25, and a pressure plate 31 is slidably connected inside the fixing frame 30. An elastic element 33 is connected between the inner wall of the fixing frame 30 and the pressure plate 31. A cylinder 32 is integrally connected to the side of the pressure plate 31 facing the fixing frame 30, and the elastic element 33 is a spring sleeved on the cylinder 32. The two ends of the elastic element 33 are fixedly connected to the inner wall of the fixing frame 30 and the pressure plate 31, respectively.

[0044] Both the fixed frame 30 and the pressure plate 31 are located in the connecting groove 27, and the pressure plate 31 is used to contact the wire.

[0045] Of course, the above are just typical examples of this utility model. In addition, this utility model may have many other specific implementation methods. All technical solutions formed by equivalent substitution or equivalent transformation fall within the scope of protection claimed by this utility model.

Claims

1. A direct-drive motor, comprising a housing (1), a stator (2), a rotor (3), and a shaft (4), wherein the stator (2) is fixed to the inner wall of the housing (1), the rotor (3) is located inside the stator (2), the shaft (4) is fixed to the rotor (3) and coaxially arranged with the rotor (3), a front end cover (5) and a rear end cover (6) are respectively connected to both ends of the housing (1), and one end of the shaft (4) passes through the front end cover (5), characterized in that: It also includes a magnet (7), a circuit board (9), and a Hall sensor (10). The magnet (7) is fixed to the end of the rotating shaft (4) away from the front end cover (5) and is eccentrically set with respect to the rotating shaft (4). The rear end cover (6) has a mounting hole (8) corresponding to the end of the rotating shaft (4) away from the front end cover (5). The circuit board (9) is fixed in the mounting hole (8). The Hall sensor (10) is electrically connected to the circuit board (9) and is used to correspond to the magnet (7). The outer wall of the rear end cover (6) is connected to a terminal (11) for electrical connection with the circuit board (9).

2. A direct-drive motor according to claim 1, characterized in that: Both ends of the stator (2) are connected to positioning seats (14), and magnetic shielding rings (13) are connected to the positioning seats (14).

3. A direct-drive motor according to claim 2, characterized in that: The positioning seat (14) includes a ring (15), fixing posts (16), fixing holes (17), an extension plate (18), an upper clamping plate (19), and a lower clamping plate (20). Multiple fixing holes (17) are located at the ends of the stator (2) and are evenly distributed along the axis of the stator (2). Multiple fixing posts (16) are fixedly connected to the sidewalls of the ring (15) and are used to embed into the fixing holes (17). One end of the extension plate (18) is fixed to the inner wall of the ring (15). The other end extends along the axis of the ring body (15), and a plurality of the extension plates (18) are evenly distributed along the axis of the ring body (15). A plurality of the upper clamping plates (19) are fixed to the side of the ring body (15) opposite to the fixed column (16) and are evenly distributed along the axis of the ring body (15). The lower clamping plate (20) is fixed to the side of the extension plate (18) opposite to the stator (2). The upper clamping plate (19), the lower clamping plate (20), and the extension plate (18) form a receiving cavity for positioning the magnetic shielding ring (13).

4. A direct-drive motor according to claim 3, characterized in that: The extension plate (18) is connected to a protruding rib (21) on the side facing the receiving cavity for contacting the side wall of the magnetic shielding ring (13). The length direction of the protruding rib (21) is parallel to the length direction of the extension plate (18), and the two ends of the protruding rib (21) are connected to the upper clamping plate (19) and the lower clamping plate (20) respectively.

5. A direct-drive motor according to claim 3, characterized in that: A protrusion (22) for contacting the sidewall of the magnetic shielding ring (13) is connected between the extension plate (18) and the lower clamping plate (20). The protrusion (22) is located on the side of the extension plate (18) facing away from the stator (2).

6. A direct-drive motor according to claim 1, characterized in that: A fixing ring (12) is connected to the inner wall of the mounting hole (8). A threaded hole is provided on the fixing ring (12). A connecting hole corresponding to the threaded hole is provided on the circuit board (9). A locking bolt is inserted into the connecting hole. The locking bolt passes through the connecting hole and is threaded onto the threaded hole. The head of the locking bolt abuts against the circuit board (9).

7. A direct-drive motor according to claim 1, characterized in that: The rear end cover (6) has an installation ring groove (23) on the side facing away from the outer shell (1). The installation hole (8) is located inside the installation ring groove (23). A sealing ring (24) is provided in the installation ring groove (23). A cover plate (25) is connected to the rear end cover (6). A protruding ring (26) is connected to the cover plate (25) for inserting into the installation ring groove (23) and abutting against the sealing ring (24).

8. A direct-drive motor according to claim 7, characterized in that: The rear end cover (6) has a connecting groove (27) for threading wires. The connecting groove (27) is located inside the mounting ring groove (23). A limiting ring (28) is connected to the rear end cover (6). The mounting hole (8) is located inside the limiting ring (28). The rear end cover (6) has a limiting groove (29) for limiting the wires. One end of the limiting groove (29) is connected to the connecting groove (27), and the other end of the limiting groove (29) passes through the limiting ring (28) and is connected to the mounting hole (8).

9. A direct-drive motor according to claim 8, characterized in that: A fixed frame (30) is fixedly connected to the cover plate (25), and a pressure plate (31) is slidably connected inside the fixed frame (30). An elastic element (33) is connected between the inner wall of the fixed frame (30) and the pressure plate (31). The fixed frame (30) and the pressure plate (31) are both located in the communicating groove (27). The pressure plate (31) is used to contact the wire.

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