A direct drive motor

Abstract

The application discloses a direct drive motor, which comprises a base, a rotating disc arranged opposite to the base, a support bearing arranged between the rotating disc and the base, the support bearing comprising an inner ring connected with the base and an outer ring connected with the rotating disc, a driving assembly arranged on the radial inner side of the support bearing, the driving assembly comprising a stator connected with the base and a rotor connected with the rotating disc, the stator generating a magnetic field to drive the rotor to rotate the rotating disc after being electrified, and a position feedback assembly comprising a scale and a reading head, the scale being arranged on the outer circumferential surface of the rotating disc, and the reading head being arranged on the base and facing the scale. The application can release the internal space to install a larger specification bearing by integrating the external support bearing and the external position feedback assembly, can significantly improve the overall structural rigidity and the anti-unbalance load capacity, and simultaneously simplifies the assembly and maintenance process, and is suitable for high-precision and precise automatic equipment.

Description

Technical Field

[0001] This application relates to the technical field of electric motors, and more particularly to a direct-drive motor. Background Technology

[0002] In precision automated equipment, direct-drive motors are widely used due to their high torque density and fast response speed. Existing direct-drive motors typically employ a structure with an inner ring bearing supporting the rotor and an outer ring rotating. Because the radial space inside the motor is limited, the bearings are small and have a weak ability to withstand eccentric loads and lateral torques, making them prone to deformation after long-term use and leading to accuracy degradation. Furthermore, the position feedback components of existing motors are mostly built into the housing, which not only occupies valuable internal space and limits further improvements in bearing specifications, but also results in complex internal wiring, difficult assembly, and extremely inconvenient maintenance and replacement. In addition, traditional motor frames are mostly made of aluminum alloy, which has a high coefficient of thermal expansion, making them prone to thermal deformation when the motor heats up or when the ambient temperature changes, further affecting rotational accuracy and structural rigidity. Summary of the Invention

[0003] The purpose of this invention is to provide a direct-drive motor that can solve the aforementioned problems existing in the prior art.

[0004] To achieve the above objectives, this application adopts the following technical solution: On the one hand, a direct drive motor is provided, comprising: Base; A turntable is positioned opposite to the base. A support bearing is located between the turntable and the base. The support bearing includes an inner ring and an outer ring. The inner ring is connected to the base, and the outer ring is connected to the turntable. A drive assembly, disposed radially inside the support bearing, includes a stator and a rotor. The stator is connected to the base, and the rotor is connected to the turntable. The stator is configured to generate a magnetic field when energized to drive the rotor to rotate the turntable. The position feedback component includes a scale and a reading head, the scale being disposed on the outer peripheral surface of the turntable, and the reading head being disposed on the base and facing the scale.

[0005] Preferably, the support bearing is a crossed roller bearing, in which the rollers are arranged at 90° to simultaneously withstand radial loads, bidirectional axial loads, and overturning moments, thereby achieving multi-directional constraint support.

[0006] Preferably, the inner ring of the support bearing is interference-fitted with the base, and the outer ring of the support bearing is interference-fitted with the turntable.

[0007] Preferably, it also includes a first pressure ring and a second pressure ring; The first pressure ring is disposed at one axial end of the inner ring of the support bearing, the bottom surface of the first pressure ring abuts against the end face of the inner ring, and the first pressure ring is fixedly connected to the base by a plurality of first fasteners distributed along the circumferential direction. The second pressure ring is disposed at one axial end of the outer ring of the support bearing, the top surface of the second pressure ring abuts against the end face of the outer ring of the support bearing, and the second pressure ring is fixedly connected to the turntable by a plurality of second fasteners distributed along the circumferential direction.

[0008] Preferably, the turntable is provided with an inner ring and an outer ring, and the base is provided with a connecting ring, which is located between the inner ring and the outer ring; The inner ring is circumferentially positioned with respect to the rotor by a first flat key, and the connecting ring is circumferentially positioned with respect to the stator by a second flat key.

[0009] Preferably, it also includes a rotor pressure plate and a stator pressure plate; The rotor pressure plate is disposed on the side of the rotor near the base, the surface of the rotor pressure plate abuts against the end face of the rotor, and the rotor pressure plate is fixedly connected to the turntable by a plurality of third fasteners distributed along the circumferential direction. The stator pressure plate is disposed on the side of the stator facing the base, the surface of the stator pressure plate abuts against the end face of the stator, and the stator pressure plate is fixedly connected to the base by a plurality of fourth fasteners distributed along the circumferential direction.

[0010] Preferably, the scale is a grating scale, which is attached to the outer cylindrical surface of the turntable; and the reading head is a grating reading head; The grating reading head is fixedly mounted on the side of the base via a bracket, with the sensing end of the grating reading head facing the grating ruler; and There is a preset gap between the sensing end and the grating ruler, so as to read the grating lines on the grating ruler in a non-contact manner.

[0011] Preferably, the grating ruler is an arc-shaped grating ruler that extends along the circumferential direction of the outer cylindrical surface of the turntable, and the arc diameter of the arc-shaped grating ruler matches the outer diameter of the turntable; The bracket is L-shaped, with one end fixed to the side of the base, and the grating reading head is mounted on the cantilever end of the bracket, with the grating reading head suspended on the outside of the base.

[0012] Preferably, the arc-shaped grating ruler is an arc-shaped segment arranged circumferentially along the outer cylindrical surface of the turntable, and the central angle corresponding to the arc-shaped segment is less than or equal to 360°.

[0013] Preferably, the top surface of the turntable has a plurality of waist-shaped weight-reducing grooves along the circumferential direction, and the waist-shaped weight-reducing grooves extend through the wall thickness of the turntable.

[0014] The beneficial effects of this application are as follows: By placing the support bearing radially outside the drive assembly and combining it with an interference fit and a double-ring axial locking structure, the problems of limited bearing size and rapid accuracy degradation in traditional external rotor motors can be effectively solved. Simultaneously, the external position feedback component frees up internal space, simplifies assembly and maintenance processes, and reduces the impact of heat sources on measurement accuracy. Combined with keyway drive, pressure plate fixing, and targeted weight reduction features, the dynamic response performance and engineering applicability of the motor can be effectively improved while ensuring structural strength and rotational accuracy. This makes it particularly suitable for precision automation scenarios with stringent requirements for accuracy, rigidity, and reliability, such as Micro LED mass transfer equipment. Attached Figure Description

[0015] The present application will now be described in further detail with reference to the accompanying drawings and embodiments.

[0016] Figure 1 This is a schematic diagram of a direct drive motor structure according to an embodiment of this application; Figure 2 This is a cross-sectional structural schematic diagram of a direct drive motor according to an embodiment of this application.

[0017] In the picture: 100. Base; 110. Connecting ring; 200. Turntable; 210. Inner ring; 220. Outer ring; 230. Waist-shaped weight reduction groove; 300. Support bearing; 400. Drive assembly; 410. Stator; 420. Rotor; 500. Position feedback assembly; 510. Scale; 520. Reading head; 530. Bracket; 610. First pressure ring; 620. Second pressure ring; 710. Rotor pressure plate; 720. Stator pressure plate; 800. Oil nozzle. Detailed Implementation

[0018] To make the technical problems solved by this application, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of this application are further described in detail below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] In the description of this application, unless otherwise expressly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0021] like Figure 1 and Figure 2 As shown, this embodiment provides a direct-drive motor, including a base 100, a turntable 200, a support bearing 300, a drive assembly 400, and a position feedback assembly 500. The base 100 and the turntable 200 are connected by the support bearing 300, so that the turntable 200 is rotatably connected to the base 100. The drive assembly 400 is located between the base 100 and the turntable 200 and is used to provide power for the rotation of the turntable 200.

[0022] Specifically, the base 100 is disc-shaped and is used to fix it to an external support surface. The bottom of the base 100 may have multiple mounting holes, and the base 100 can be fixed to the equipment body or other external support surface by means of fasteners such as bolts.

[0023] Furthermore, with Figure 2 The orientation shown is for reference only. The turntable 200 is positioned opposite the base 100, and the turntable 200 is located above the base 100. The turntable 200 also has a disc-shaped or ring-shaped structure, and its top surface is used to mount the load and drive the load to rotate. A receiving space is formed between the turntable 200 and the base 100 to accommodate components such as the support bearing 300 and the drive assembly 400.

[0024] Furthermore, the support bearing 300 is disposed radially outside the drive assembly 400 and located between the turntable 200 and the base 100. Specifically, the support bearing 300 is located in the radially outer region of the accommodating space between the turntable 200 and the base 100.

[0025] Specifically, the support bearing 300 includes an inner ring and an outer ring, wherein the inner ring is connected to the base 100 and the outer ring is connected to the turntable 200. Through this connection method, the turntable 200 is rotatably supported on the base 100 via the support bearing 300. Since the support bearing 300 is located radially outward of the drive assembly 400, the bearing's support diameter can be significantly increased, thereby significantly improving the device's resistance to eccentric loads and its rigidity.

[0026] Furthermore, the drive assembly 400 is disposed radially inside the support bearing 300, that is, the drive assembly 400 is located within the space enclosed by the inner ring of the support bearing 300.

[0027] Specifically, the drive assembly 400 includes a stator 410 and a rotor 420. The stator 410 is fixedly connected to the base 100, and the rotor 420 is fixedly connected to the turntable 200. The stator 410 generates a magnetic field after being energized to drive the rotor 420 to rotate, and the rotor 420 in turn drives the turntable 200 fixedly connected to it to rotate.

[0028] In this embodiment, the stator 410 is an energized coil winding, and the rotor 420 is a permanent magnet. The magnetic field generated by the stator 410 after being energized interacts with the magnetic field of the rotor 420, driving the rotor 420 to rotate. Since the rotor 420 is fixed to the turntable 200, the turntable 200 rotates accordingly, thereby driving the load mounted on the turntable 200 to rotate.

[0029] Furthermore, the position feedback component 500 includes a scale 510 and a reading head 520, with the scale 510 disposed on the outer peripheral surface of the turntable 200 and the reading head 520 disposed on the base 100 and facing the scale 510. The position feedback component 500 is used to detect the rotational position of the turntable 200 relative to the base 100 and feeds the position signal back to the control system to achieve closed-loop control.

[0030] In this embodiment, the scale 510 is preferably a grating scale, and the reading head 520 is preferably a grating reading head. The grating scale is attached to the outer cylindrical surface of the turntable 200, while the grating reading head is fixedly mounted on the side of the base 100, with its sensing end facing the grating scale. It is understood that the grating scale rotates together with the turntable 200, and the position data on the grating scale is read by the grating reading head to obtain the rotation angle information of the turntable 200.

[0031] In this embodiment, by placing the support bearing 300 on the radially outer side of the drive assembly 400, the support bearing 300 is externally mounted while the drive assembly 400 is internally mounted. This significantly increases the support diameter of the support bearing 300, thereby significantly improving the anti-eccentric load capacity and radial and axial rigidity of the direct drive motor. Simultaneously, the scale 510 of the position feedback assembly 500 is mounted on the outer circumferential surface of the turntable 200, and the reading head 520 is mounted on the base 100, further realizing an external encoder. This makes installation and maintenance more convenient and also makes the direct drive motor structure of this disclosure simpler and more compact.

[0032] However, this is not the only one. In other embodiments, the shape of the base 100 and the turntable 200 is not limited to a circle, and can also be designed into other shapes according to actual application requirements.

[0033] Please see Figure 2 In one embodiment, the support bearing 300 is a crossed roller bearing, which includes an inner ring, an outer ring, and a plurality of rollers disposed between the inner ring and the outer ring. Adjacent rollers are arranged at 90° in the annular space of the bearing, that is, the axes of two adjacent rollers are perpendicular to each other.

[0034] Specifically, a crossed roller bearing has a 90° V-shaped raceway between its inner and outer rings, and several cylindrical rollers are arranged within the raceway by a retainer. The rollers are arranged in a spatially orthogonal, cross-shaped configuration, with adjacent roller axes perpendicular to each other at 90° and alternating circumferentially. For example, one roller axis may be parallel to the bearing's central axis, while the axes of adjacent rollers may be perpendicular to the bearing's central axis.

[0035] Crossed roller bearings can simultaneously withstand radial loads, bidirectional axial loads, and overturning moments, forming a bidirectional constraint support structure in both the axial and radial directions, which can meet the precision rotation support requirements under multi-directional composite loads.

[0036] Specifically, when the turntable 200 is subjected to an axial load, the axially arranged rollers bear the axial force; when the turntable 200 is subjected to a radial load or a lateral moment generated by an eccentric load, the radially arranged rollers bear the radial force and moment. Because the rollers are arranged in a 90°90° cross pattern, the crossed roller bearing can simultaneously bear axial load, radial load, and moment load.

[0037] In this embodiment, the inner ring of the crossed roller bearing is fixedly connected to the base 100, and the outer ring of the crossed roller bearing is fixedly connected to the turntable 200. Because the rollers of the crossed roller bearing are arranged in a crossed pattern, the bearing itself has high rigidity, which can effectively prevent the turntable 200 from shifting or shaking during rotation, and can effectively ensure the rotational accuracy and stability of the turntable 200.

[0038] However, this is not the only option. In other embodiments, the support bearing 300 may also be a four-point contact ball bearing or a three-point contact ball bearing or other types of bearings that can simultaneously bear axial and radial loads. The specific structural form of the support bearing 300 can be determined according to actual needs.

[0039] like Figure 2 As shown, in one embodiment, the inner ring of the support bearing 300 is interference-fitted with the base 100, and the outer ring of the support bearing 300 is interference-fitted with the turntable 200.

[0040] Specifically, the inner diameter of the inner ring of the support bearing 300 is slightly smaller than the outer diameter of the boss on the base 100 that mates with the inner ring. The inner ring is installed into the base 100 by heat fitting or press fitting, forming an interference fit between the inner ring and the base 100. Similarly, the outer diameter of the outer ring of the support bearing 300 is slightly larger than the diameter of the mounting hole on the turntable 200 for installing the outer ring. The outer ring is installed into the turntable 200 by heat fitting or press fitting, forming an interference fit between the outer ring and the turntable 200.

[0041] Understandably, the interference fit ensures a firm connection between the inner ring of the support bearing 300 and the base 100, and between the outer ring and the turntable 200, eliminating the possibility of relative movement or loosening, thus further enhancing the overall rigidity and transmission accuracy of the direct drive motor.

[0042] However, this is not the only option. In other embodiments, the inner ring of the support bearing 300 can be fixedly connected to the base 100, and the outer ring can be fixedly connected to the turntable 200 by means of key connection and fasteners, or by other fixed connection methods such as bonding, which can be determined according to actual needs.

[0043] Please see Figure 2 In one embodiment, the direct drive motor provided in this disclosure further includes a first pressure ring 610 and a second pressure ring 620 for axially pressing the support bearing 300.

[0044] Specifically, the first pressure ring 610 is located on the inner side of the support bearing 300.

[0045] In this embodiment, the first pressure ring 610 is the bearing inner ring pressure ring, located above the inner ring of the supporting bearing 300 (within the bearing inner ring). Figure 2 (The orientation shown is for reference only). The bottom surface of the first pressure ring 610 abuts against the end face of the inner ring of the support bearing 300, and the first pressure ring 610 is fixedly connected to the base 100 by a plurality of first fasteners distributed along the circumferential direction. The first fasteners are preferably screws or bolts, evenly distributed along the circumferential direction, to fix the first pressure ring 610 to the base 100. Through the pressing action of the first pressure ring 610, the inner ring of the support bearing 300 is axially pressed against the base 100, preventing axial movement of the inner ring.

[0046] Furthermore, the second pressure ring 620 is disposed on the outer side of the support bearing 300.

[0047] In this embodiment, the second pressure ring 620 is a bearing outer ring pressure ring, located below the outer ring of the supporting bearing 300 (within the range of...). Figure 2 (The orientation shown is for reference only). The top surface of the second pressure ring 620 abuts against the outer ring end face of the support bearing 300, and the second pressure ring 620 is fixedly connected to the turntable 200 by a plurality of second fasteners distributed along the circumferential direction. The second fasteners are preferably screws or bolts, evenly distributed along the circumferential direction, fixing the second pressure ring 620 to the turntable 200. Through the pressing action of the second pressure ring 620, the outer ring of the support bearing 300 is axially pressed against the turntable 200, preventing axial movement of the outer ring.

[0048] It is understandable that the first pressure ring 610 and the second pressure ring 620 axially press the support bearing 300 from both ends of the bearing, forming a double anti-loosening structure. The pressing direction of the first pressure ring 610 and the second pressure ring 620 can be adjusted according to the actual installation position, as long as the inner ring is pressed against the base 100 and the outer ring is pressed against the turntable 200 respectively.

[0049] In this embodiment, the inner and outer rings of the support bearing 300 are axially pressed together by the first pressure ring 610 and the second pressure ring 620, forming a double anti-loosening structure. This effectively prevents axial movement of the bearing due to vibration or thermal expansion and contraction during operation. The first and second fasteners are evenly distributed along the circumference, ensuring that the clamping force is evenly applied to the entire circumference of the bearing, avoiding local stress concentration, and guaranteeing stable operation and long service life of the bearing.

[0050] However, this is not the only possibility. In other embodiments, the first pressure ring 610 and the second pressure ring 620 may also adopt other shapes and structures, as long as they can respectively press the inner ring of the support bearing 300 against the base 100 and the outer ring against the turntable 200. The number of the first fastener and the second fastener can be determined according to actual needs and is not limited to uniform distribution.

[0051] Please see Figure 2 In one embodiment, the turntable 200 is provided with an inner ring 210 and an outer ring 220, and the base 100 is provided with a connecting ring 110, which is located between the inner ring 210 and the outer ring 220.

[0052] Specifically, the turntable 200 includes an inner ring 210 extending radially inward, an outer ring 220 extending radially outward, and a top wall connecting the inner ring 210 and the outer ring 220. The inner ring 210 extends axially downward, and the outer ring 220 also extends axially downward, forming a space between the inner ring 210 and the outer ring 220 for accommodating the drive assembly 400. A connecting ring 110 is provided on the base 100, extending axially upward and located between the inner ring 210 and the outer ring 220 of the turntable 200.

[0053] Furthermore, the inner ring 210 and the rotor 420 are circumferentially limited by the first flat key.

[0054] Specifically, a keyway can be provided on the inner circumferential surface of the inner ring 210 and / or the outer circumferential surface of the rotor 420, with a first flat key disposed in the keyway to achieve circumferential transmission connection between the rotor 420 and the turntable 200. When the rotor 420 rotates, it drives the turntable 200 to rotate together via the first flat key.

[0055] Furthermore, the connecting ring 110 and the stator 410 are circumferentially positioned by a second flat key.

[0056] Specifically, a keyway can be provided on the inner circumferential surface of the connecting ring 110 and / or the outer circumferential surface of the stator 410, and a second flat key is provided in the keyway to achieve circumferential positioning between the stator 410 and the base 100, and to prevent the stator 410 from rotating circumferentially during operation.

[0057] Understandably, the flat key connection method has a compact structure and strong torque-bearing capacity, making it suitable for high-torque applications of direct-drive motors. Meanwhile, the inner ring 210 and outer ring 220 of the turntable 200 cooperate with the connecting ring 110 of the base 100 to form a clear radial hierarchical structure: the outermost ring 220 connects to the outer ring of the support bearing 300; the middle ring is the connecting ring 110, with its outer side connecting to the inner ring of the support bearing 300 and its inner side connecting to the stator 410; and the innermost ring 210 connects to the rotor 420, resulting in a reasonable and compact overall structural layout.

[0058] However, this is not the only option. In other embodiments, the rotor 420 and the turntable 200, and the stator 410 and the base 100 can also be connected by spline, pin, or other circumferential limiting methods, which can be determined according to actual needs.

[0059] Please see Figure 2 In one embodiment, the direct drive motor of this disclosure further includes a rotor pressure plate 710 and a stator pressure plate 720 for axially pressing / locking the rotor 420 and the stator 410.

[0060] Specifically, the rotor pressure plate 710 is located on the side of the rotor 420 near the base 100, that is, below the rotor 420 (within the plane of the base 100). Figure 2 (The orientation shown is for reference only). The surface of the rotor pressure plate 710 abuts against the end face of the rotor 420, and the rotor pressure plate 710 is fixedly connected to the turntable 200 by a plurality of third fasteners distributed along the circumferential direction. The third fasteners are preferably screws or bolts, evenly distributed along the circumferential direction, to fix the rotor pressure plate 710 to the turntable 200. Through the pressing action of the rotor pressure plate 710, the rotor 420 is axially pressed against the turntable 200, preventing the rotor 420 from moving axially.

[0061] Furthermore, the stator pressure plate 720 is disposed on the side of the stator 410 facing the base 100, that is, below the stator 410 (to... Figure 2 (The orientation shown is for reference only). The surface of the stator pressure plate 720 abuts against the end face of the stator 410, and the stator pressure plate 720 is fixedly connected to the base 100 by a plurality of fourth fasteners distributed along the circumferential direction. The fourth fasteners are preferably screws or bolts, evenly distributed along the circumferential direction, to fix the stator pressure plate 720 to the base 100. Through the pressing action of the stator pressure plate 720, the stator 410 is axially locked to the base 100, preventing the stator 410 from moving axially.

[0062] Understandably, by using the rotor pressure plate 710 to axially press the rotor 420 against the turntable 200, and by using the stator pressure plate 720 to axially lock the stator 410 against the base 100, axial movement of the rotor 420 and stator 410 during operation due to vibration or thermal expansion and contraction can be effectively prevented. The third and fourth fasteners are evenly distributed along the circumference, resulting in a uniform distribution of clamping force and effectively avoiding localized stress concentration.

[0063] Furthermore, by combining the first and second parallel keys in the above embodiments, the rotor 420 and stator 410 of the drive assembly 400 are reliably positioned and fixed in the circumferential and axial directions, respectively, which can effectively ensure the long-term operational stability and transmission accuracy of the direct drive motor.

[0064] Please see Figure 1 In one embodiment, the scale 510 is a grating scale, and the reading head 520 is a grating reading head. The grating scale is attached to the outer cylindrical surface of the turntable 200.

[0065] Specifically, the grating ruler is a precision-scaled grating scale 510 that extends circumferentially along the outer cylindrical surface of the turntable 200 and rotates together with the turntable 200. The grating reading head is fixedly mounted to the side of the base 100 via a bracket 530, with its sensing end facing the grating ruler. The grating reading head is used to read the grating lines on the grating ruler, thereby obtaining the rotational position information of the turntable 200.

[0066] It is important to note that there is a preset gap between the sensing end of the grating reading head and the grating ruler, allowing the grating reading head to read the grating lines on the grating ruler in a non-contact manner. The size of the preset gap is determined based on the model of the grating ruler and the grating reading head, and is typically between 0.1mm and 1mm. This non-contact reading method effectively avoids friction and wear, thus ensuring long-term accuracy stability.

[0067] Furthermore, since the grating ruler is set on the outer peripheral surface of the turntable 200 and the grating reading head is set on the side of the base 100, the entire position feedback component 500 is located outside the direct drive motor, which can effectively realize the external encoder.

[0068] Understandably, because the encoder is external, the direct drive motor no longer needs to reserve space for the encoder, making the internal structure simpler and more compact, and leaving space for the installation of larger bearings.

[0069] In one embodiment, the grating ruler is an arc-shaped grating ruler that extends circumferentially along the outer cylindrical surface of the turntable 200, and the diameter of the arc surface of the arc-shaped grating ruler matches the outer diameter of the turntable 200. That is, the radius of curvature of the arc-shaped grating ruler is equal to (or slightly larger than) the outer diameter of the turntable 200, so that the arc-shaped grating ruler can be tightly attached to the outer cylindrical surface of the turntable 200.

[0070] Specifically, the arc-shaped grating ruler reads the arc position data (i.e., displacement along the arc), which can be converted to obtain the rotation angle data of the turntable 200. Specifically, based on the arc diameter (i.e., the outer diameter of the turntable 200) and the arc position data, the rotation angle of the turntable 200 can be calculated using the conversion formula between arc length and angle (angle = arc length / radius).

[0071] Furthermore, the bracket 530 is L-shaped, and one end of the bracket 530 is fixed to the side of the base 100. The grating reading head is mounted on the cantilever end of the bracket 530. The bracket 530 allows the grating reading head to be suspended outside the base 100, with the sensing end of the grating reading head facing the scale line surface of the arc-shaped grating ruler.

[0072] Furthermore, in one embodiment, the arc-shaped grating ruler is an arc-shaped segment arranged circumferentially along the outer cylindrical surface of the turntable 200, and the central angle corresponding to the arc-shaped segment is less than or equal to 360°.

[0073] For example, the arc-shaped grating ruler is attached to the outer cylindrical surface at a position corresponding to the preset rotation angle range of the turntable 200. Specifically, different application scenarios have different requirements for the rotation angle range of the turntable 200: in scenarios requiring small-angle reciprocating rotation, the central angle corresponding to the arc segment is small, only covering the preset small angle range; in scenarios requiring full-circumference rotation, the central angle corresponding to the arc segment is equal to 360°, that is, the arc-shaped grating ruler extends along the entire outer circumference of the turntable 200 to form an annular grating ruler.

[0074] Please see Figure 1 In one embodiment, both the base 100 and the turntable 200 are steel shells made of 45 steel. Meanwhile, the top surface of the turntable 200 has multiple waist-shaped weight-reducing grooves 230 formed along the circumferential direction, and these grooves extend along the wall thickness of the turntable 200.

[0075] Understandably, the waist-shaped weight-reduction groove 230 can reduce the overall weight of the turntable 200 without affecting its structural rigidity. Specifically, the waist-shaped weight-reduction groove 230 is formed on the top surface of the turntable 200, avoiding the area connected to key components such as the support bearing 300 and the drive assembly 400, thus having minimal impact on structural rigidity. Simultaneously, the lighter turntable 200 has a smaller moment of inertia, which is beneficial for improving the dynamic response performance of the direct drive motor disclosed herein and also enhances its load capacity.

[0076] However, this is not the only option. In other embodiments, the base 100 and the turntable 200 can also be made of other high-rigidity steels, such as 40Cr, 42CrMo, and other alloy steels. Meanwhile, the number, size, and distribution of the waist-shaped weight-reducing grooves 230 can be adjusted according to actual needs, and other shapes of weight-reducing holes, such as circular holes or elliptical holes, can also be used.

[0077] Please see Figure 1 and Figure 2 In one embodiment, an oil injection nozzle 800 is provided on the side wall of the base 100. The oil outlet of the oil injection nozzle 800 is connected to the lubrication channel of the support bearing 300 through a lubrication channel provided inside the base 100. It can be understood that when maintenance is required, the operator can inject an appropriate amount of lubricating oil into the support bearing 300 through the oil injection nozzle 800 to complete the lubrication maintenance of the bearing.

[0078] On the other hand, the direct drive motor provided in this disclosure can be applied to an automated device, and the automated device also includes a control system, which is electrically connected to the stator 410 of the direct drive motor and the position feedback component 500.

[0079] Furthermore, the specific working process of automated equipment includes: The control system energizes the stator 410, which generates a magnetic field that drives the rotor 420 to rotate. The rotor 420 then drives the turntable 200 and the load mounted on it to rotate. During rotation, the grating ruler rotates with the turntable 200, and the grating reading head reads the position data on the grating ruler and feeds it back to the control system. The control system compares the feedback position data with the target position and adjusts the energizing state of the stator 410 in real time to achieve closed-loop control, ultimately bringing the turntable 200 to a precise stop at the target angular position.

[0080] In this embodiment, the automated equipment is a Micro LED mass transfer device, machine tool, or robot.

[0081] For example, taking a Micro LED mass transfer device as an example, this device needs to accurately transfer a massive number of Micro LED chips to designated positions on a substrate, requiring extremely high positioning accuracy and stability of the turntable. The direct-drive motor of this invention, with its external bearing and internal drive layout, combined with crossed roller bearings and 45 steel material, possesses extremely high rigidity and resistance to off-center loads, thus meeting the accuracy requirements of the Micro LED mass transfer device.

[0082] However, this is not the only one. In other embodiments, the automated equipment may also be semiconductor wafer positioning equipment, lithography machine, optical alignment system, precision CNC machine tool, automobile assembly / testing equipment, liquid crystal manufacturing equipment, screen bonding equipment, medical device and other micro-precision high-end manufacturing equipment.

[0083] In summary, this disclosure provides a direct-drive motor that, by placing the support bearing 300 radially outside the drive assembly 400 and combining it with an interference fit and a double-ring axial locking structure, constructs a high-rigidity, anti-eccentric load support system. This effectively solves the problems of limited bearing size and rapid accuracy degradation in traditional external rotor 420 motors. Simultaneously, the external position feedback assembly 500 frees up internal space, simplifies assembly and maintenance processes, and reduces the impact of heat sources on measurement accuracy. Combined with keyway transmission, pressure plate fixing, and targeted weight reduction design, while ensuring structural strength and rotational accuracy, it effectively improves the motor's dynamic response performance and engineering applicability, making it particularly suitable for precision automation scenarios with stringent requirements for accuracy, rigidity, and reliability, such as Micro LED mass transfer equipment.

[0084] In the description herein, it should be understood that the terms "upper," "lower," "left," "right," and other orientations or positional relationships are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used merely for descriptive distinction and have no special meaning.

[0085] In the description of this specification, references to terms such as "an embodiment," "example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0086] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0087] The technical principles of this application have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of this application and should not be construed as limiting the scope of protection of this application in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of this application without inventive effort, and these embodiments will all fall within the scope of protection of this application.

Claims

1. A direct-drive motor, characterized in that, include: Base (100); A turntable (200) is disposed opposite to the base (100); A support bearing (300) is located between the turntable (200) and the base (100). The support bearing (300) includes an inner ring and an outer ring. The inner ring is connected to the base (100), and the outer ring is connected to the turntable (200). A drive assembly (400) is disposed radially inside the support bearing (300). The drive assembly (400) includes a stator (410) and a rotor (420). The stator (410) is connected to the base (100), and the rotor (420) is connected to the turntable (200). as well as The position feedback component (500) includes a scale (510) and a reading head (520), the scale (510) being disposed on the outer peripheral surface of the turntable (200), and the reading head (520) being disposed on the base (100) and facing the scale (510).

2. The direct-drive motor according to claim 1, characterized in that, The support bearing (300) is a crossed roller bearing, in which the rollers are arranged in a 90° cross pattern to simultaneously withstand radial loads, bidirectional axial loads, and overturning moments, thereby achieving multi-directional constraint support.

3. The direct-drive motor according to claim 1, characterized in that, The inner ring of the support bearing (300) is interference-fitted with the base (100), and the outer ring of the support bearing (300) is interference-fitted with the turntable (200).

4. The direct-drive motor according to claim 3, characterized in that, It also includes a first pressure ring (610) and a second pressure ring (620); The first pressure ring (610) is disposed at one axial end of the inner ring of the support bearing (300), the bottom surface of the first pressure ring (610) abuts against the end face of the inner ring, and the first pressure ring (610) is fixedly connected to the base (100) by a plurality of first fasteners distributed along the circumferential direction. The second pressure ring (620) is disposed at one axial end of the outer ring of the support bearing (300). The top surface of the second pressure ring (620) abuts against the end face of the outer ring of the support bearing (300), and the second pressure ring (620) is fixedly connected to the turntable (200) by a plurality of second fasteners distributed along the circumferential direction.

5. The direct-drive motor according to claim 1, characterized in that, The turntable (200) is provided with an inner ring (210) and an outer ring (220), and the base (100) is provided with a connecting ring (110), which is located between the inner ring (210) and the outer ring (220); The inner ring (210) and the rotor (420) are circumferentially limited by a first flat key, and the connecting ring (110) and the stator (410) are circumferentially positioned by a second flat key.

6. The direct-drive motor according to claim 5, characterized in that, It also includes a rotor pressure plate (710) and a stator pressure plate (720); The rotor pressure plate (710) is disposed on the side of the rotor (420) near the base (100), the surface of the rotor pressure plate (710) abuts against the end face of the rotor (420), and the rotor pressure plate (710) is fixedly connected to the turntable (200) by a plurality of third fasteners distributed along the circumferential direction. The stator pressure plate (720) is disposed on the side of the stator (410) facing the base (100), the surface of the stator pressure plate (720) abuts against the end face of the stator (410), and the stator pressure plate (720) is fixedly connected to the base (100) by a plurality of fourth fasteners distributed along the circumferential direction.

7. The direct-drive motor according to claim 6, characterized in that, The scale (510) is a grating scale, which is attached to the outer cylindrical surface of the turntable (200); and the reading head (520) is a grating reading head; The grating reading head is fixedly mounted on the side of the base (100) via a bracket (530), with the sensing end of the grating reading head facing the grating ruler; and There is a preset gap between the sensing end and the grating ruler, so as to read the grating lines on the grating ruler in a non-contact manner.

8. The direct-drive motor according to claim 7, characterized in that, The grating ruler is an arc-shaped grating ruler that extends along the circumferential direction of the outer cylindrical surface of the turntable (200), and the arc diameter of the arc-shaped grating ruler matches the outer diameter of the turntable (200). The bracket (530) is L-shaped, one end of the bracket (530) is fixed to the side of the base (100), the grating reading head is installed on the cantilever end of the bracket (530), and the grating reading head is suspended on the outside of the base (100).

9. The direct-drive motor according to claim 8, characterized in that, The arc-shaped grating ruler is an arc-shaped segment arranged circumferentially along the outer cylindrical surface of the turntable (200), and the central angle corresponding to the arc segment is less than or equal to 360°.

10. The direct-drive motor according to claim 1, characterized in that, The top surface of the turntable (200) is provided with a plurality of waist-shaped weight-reducing grooves (230) along the circumferential direction, and the waist-shaped weight-reducing grooves (230) penetrate along the wall thickness direction of the turntable (200).

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