Permanent-magnet semi-direct-drive low-speed driving device
By adopting a permanent magnet semi-direct drive slow drive device, the problems of large footprint, difficult maintenance, and high energy consumption of cement ball mill slow drive systems have been solved, achieving compact design, flexible maintenance, and efficient operation of the equipment, and reducing energy consumption and maintenance costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-15
- Publication Date
- 2026-03-31
AI Technical Summary
Traditional cement ball mills have slow-drive systems that occupy a large area, are difficult to maintain, and have high energy consumption and poor stability.
The equipment adopts a permanent magnet semi-direct drive slow drive device, including a permanent magnet motor, a variable frequency reduction unit and a spline clutch, to achieve a compact design and bidirectional rotation. The spline clutch and variable frequency control enable efficient and flexible power transmission and maintenance.
It significantly reduces the equipment footprint, improves maintenance efficiency, reduces energy consumption, enhances equipment stability and lifespan, and lowers maintenance costs.
Smart Images
Figure CN224068487U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of cement industry equipment technology, specifically to a permanent magnet semi-direct drive slow drive device. Background Technology
[0002] In the dry process of cement clinker production, the cement ball mill is an indispensable key piece of equipment. Thanks to its unique working mechanism, the cement ball mill can efficiently produce cement clinker with a high saturation ratio, demonstrating significant advantages in environmental protection, energy conservation, and product quality, thus possessing a very broad market prospect in the cement production field.
[0003] A cement ball mill mainly consists of core components such as a main motor, main reducer, coupling, slow drive device, and large and small gears. Among them, the slow drive device plays a crucial role in the operation of the ball mill. Its main functions are to adjust the balance position of the ball mill and to flexibly adjust the direction of the cylinder during equipment maintenance, providing necessary support for the stable operation and maintenance of the ball mill.
[0004] However, traditional slow-drive systems employ a combination of a parallel-shaft universal gearbox and a claw clutch, which has several drawbacks. Firstly, the parallel-shaft universal gearbox is bulky and has a relatively small speed ratio, directly resulting in a large footprint for the entire slow-drive system. In production sites with limited space, this not only increases the difficulty of equipment layout but also reduces space utilization. Secondly, the claw clutch at the output end is severely out of sync with the bidirectional rotation requirements of actual on-site maintenance, greatly limiting the flexibility and efficiency of maintenance work and failing to meet the demands of modern cement production enterprises for efficient and convenient equipment maintenance. Utility Model Content
[0005] The present invention aims to provide a permanent magnet semi-direct drive slow drive device to solve the problems of large footprint and high maintenance difficulty of existing cement ball mill drive devices.
[0006] To achieve the above objectives, the present invention adopts the following technical solution: a permanent magnet semi-direct drive slow drive device, comprising a base, wherein a brake, a permanent magnet drive system and a spline clutch are provided on the base, the spline clutch and the brake are respectively connected to both ends of the permanent magnet drive system and the three are coaxially designed; the permanent magnet drive system includes a permanent magnet motor and a frequency conversion reduction unit, and the spline clutch is used to realize the bidirectional rotation of the drive device.
[0007] The principles and advantages of this scheme are:
[0008] 1. Reduced equipment space occupancy:
[0009] Traditional parallel-shaft universal gearboxes in slow-drive systems, due to their large size, significantly increase the difficulty of equipment layout within limited production spaces. In this solution, the core permanent magnet drive system consists of a permanent magnet motor and a variable frequency reduction unit, resulting in an extremely compact overall structure. The permanent magnet motor itself is characterized by its small size and excellent power density. Combined with an optimized variable frequency reduction unit, it successfully achieves a significant reduction in device size while ensuring sufficient driving force, freeing up more usable space in the production area and significantly improving the flexibility of site layout.
[0010] 2. Reduced equipment maintenance difficulty and increased maintenance efficiency:
[0011] In ball mill maintenance scenarios, operators often faced challenging situations when using older slow-drive systems. For example, adjusting the position of the mill cylinder, especially if reverse operation was involved, became extremely cumbersome. Conventional procedures often required a series of complex auxiliary tools such as manual chain hoists and specially designed steering linkages, necessitating significant manpower and resulting in lengthy operations that greatly impacted maintenance progress. However, the permanent magnet semi-direct drive slow-speed device, equipped with a spline clutch, exhibits unique flexibility in its drive logic thanks to its spline tooth structure. Operators can easily switch drive directions simply by controlling the spline clutch, allowing the ball mill cylinder to rotate smoothly or in reverse as needed. The entire operation is seamless and efficient, significantly improving the maintenance experience.
[0012] 3. Stable equipment operation and reduced maintenance costs:
[0013] Traditional slow-drive systems, due to their relatively small speed ratio, require the motor to continuously output high torque during operation. This not only leads to high energy consumption but also makes the system prone to vibration and impact during startup and operation, subjecting various components to additional stress and negatively impacting the equipment's lifespan in the long run. In contrast, the permanent magnet motor in the permanent magnet semi-direct drive slow-speed device boasts highly efficient operating characteristics. Combined with a variable frequency reduction unit, it can precisely regulate speed and torque according to the actual operating conditions of the ball mill. During slow-drive operation of the ball mill, this device can operate smoothly with lower energy consumption, significantly reducing energy consumption. Simultaneously, thanks to the system's precise control strategy, the impact during equipment startup and operation is effectively suppressed, significantly reducing wear on various components and extending the overall service life of the equipment, further reducing long-term maintenance costs.
[0014] Furthermore, the variable frequency reduction unit includes a frequency converter and a planetary reducer, and the frequency converter, planetary reducer and permanent magnet motor are integrated into a single structure.
[0015] Beneficial effects: The integrated structural design compactly combines the frequency converter, planetary gearbox, and permanent magnet motor, significantly reducing the overall size of the device and saving considerable space in the production area. This allows for more flexible equipment layout and better adaptability to the spatial constraints of different production sites. Furthermore, the integrated structure greatly shortens the power transmission distance, effectively reducing energy loss during transmission. Simultaneously, the centralized integrated design ensures that the permanent magnet drive system is precisely assembled and debugged before leaving the factory. On-site installation personnel only need to install the entire device on the base and connect the necessary wiring and piping, greatly shortening the installation cycle.
[0016] Furthermore, the spline clutch includes a passive external spline half-coupling, an active external spline half-coupling, and an inner spline sleeve connecting the two. The passive external spline half-coupling is connected to the cement ball mill, and the active external spline half-coupling is connected to the planetary reducer.
[0017] Beneficial effects: The passive external spline half-coupling connects to the cement ball mill, while the active external spline half-coupling connects to the planetary reducer. The internal spline sleeve serves as an intermediate connecting component, with its internal splines tightly engaging with the external splines of both the active and passive external spline half-couplings. This effectively prevents power transmission instability caused by gaps or looseness during power transmission. During ball mill operation, when uneven material distribution generates instantaneous impact loads, the spline clutch, with its tight meshing structure, smoothly transmits the power output from the planetary reducer to the cement ball mill cylinder, reducing the impact of power fluctuations on equipment operational stability and ensuring continuous and stable ball mill operation.
[0018] Secondly, the sliding connection between the internal spline sleeve and the driven and driven external spline half-couplings allows for smooth power transmission in both directions, perfectly meeting the practical needs of ball mills during maintenance and daily operation, which require bidirectional adjustment of the cylinder direction. When maintenance is required on the clutch itself, the cement ball mill, or the planetary reducer, simply separating the internal spline sleeve from the driven and driven external spline half-couplings allows for convenient individual inspection or replacement of each component. Compared to some highly integrated or complex clutches, this structural design significantly reduces maintenance time.
[0019] Furthermore, the permanent magnet motor includes a front axle extension and a rear axle extension, with the front axle extension connected to a planetary reducer and the rear axle extension connected to a brake.
[0020] Beneficial Effects: The permanent magnet motor adopts a design where the planetary reducer is connected to the front shaft extension and the brake is connected to the rear shaft extension. This integrates the originally scattered components at both ends of the motor, achieving a more compact equipment layout. Furthermore, since the front and rear shaft extensions connect to different components, a certain degree of fault isolation can be achieved when one connection fails. If the planetary reducer fails, the brake connected to the rear shaft extension and the rear shaft extension of the motor can still operate normally, and the braking function of the brake on the motor will not be affected by the planetary reducer failure. Conversely, when the brake fails, it will not affect the transmission of power from the motor to the planetary reducer through the front shaft extension, thereby reducing the impact of the fault on the overall equipment operation and improving the reliability and availability of the equipment.
[0021] Meanwhile, during equipment maintenance, the clear connections between components allow maintenance personnel to more easily inspect, repair, and replace each part. When the brake needs to be replaced, only the connecting parts on the rear axle extension need to be disassembled, eliminating the need for large-scale disassembly of the entire drive system, thus improving maintenance efficiency and reducing maintenance costs.
[0022] Furthermore, the outer periphery of the inner spline sleeve is provided with an annular shift fork groove, the shift fork groove contains a shift fork, the shift fork is used to control the axial movement of the inner spline sleeve; a support shaft is connected to the bottom of the shift fork.
[0023] Beneficial effects: The addition of a shift fork groove on the outer circumference of the inner spline sleeve, and the control of the shift fork to move the inner spline sleeve axially, significantly improves the accuracy and efficiency of power transmission switching. This greatly satisfies the need for bidirectional rotation during maintenance, reduces maintenance difficulty, and increases efficiency. Furthermore, the support shaft connected to the bottom of the shift fork provides stable support for the entire power transmission switching system. During equipment operation, especially during high-speed rotation of the rotary kiln and frequent switching of power transmission directions, the shift fork and inner spline sleeve are subjected to significant impact forces and vibrations. The support shaft effectively disperses these external forces, reducing the swaying and displacement of the shift fork and inner spline sleeve, thereby ensuring the stability of the spline clutch system.
[0024] Furthermore, the planetary reducer has at least one planetary gear.
[0025] Beneficial effects: The planetary gear system structure of the planetary gear set described above can significantly improve torque transmission efficiency. In the planetary gear set, multiple planetary gears are evenly distributed and rotate around the sun gear. Compared with traditional single-stage gear transmission, it can distribute and transmit the torque from the permanent magnet motor more efficiently. In addition, the planetary gear can provide a more precise reduction ratio, which can accurately control the output speed and perfectly match the actual working speed requirements of the ball mill.
[0026] The uniform distribution and symmetrical structure of planetary gears can effectively balance centrifugal force and inertial force during operation, significantly reducing equipment vibration and noise. Furthermore, due to their efficient transmission and good load adaptability, the failure rate of the equipment is reduced, and the corresponding maintenance costs are also reduced.
[0027] Furthermore, the spline clutch adopts a module gear system with a module less than or equal to 1.
[0028] Beneficial effects: The small module gear system, where the tooth module is less than or equal to 1, is adopted in this solution. Firstly, alignment becomes simpler and faster during equipment installation and commissioning. Compared to the traditional large module gear system, the small module gear has a smaller tooth pitch and more teeth per unit length. This allows for more precise position adjustment and rapid alignment when assembling the internal spline sleeve and external spline half-coupling. In practice, installers can accurately align the components of the spline clutch using only visual inspection and simple tools, shortening installation and commissioning time.
[0029] On the other hand, small-module tooth splines perform better during engagement and disengagement. When the inner spline sleeve moves between the driven and driving external spline half-couplings, the fine structure of the small-module teeth provides a smoother transition. Due to the small tooth pitch, the engagement and disengagement of the inner spline sleeve with the external spline half-coupling are smoother during axial movement, reducing power transmission interruptions or instability caused by tooth collisions and jamming. Attached Figure Description
[0030] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model. Detailed Implementation
[0031] The following detailed description illustrates the specific implementation method:
[0032] The reference numerals in the accompanying drawings include: brake 1, permanent magnet drive system 2, planetary reducer 21, frequency converter 22, permanent magnet motor 23, spline clutch 3, passive external spline half coupling 31, internal spline sleeve 32, active external spline half coupling 33, base 4, shift fork groove 5, shift fork 6, support shaft 7.
[0033] The basic implementation examples are as follows: Figure 1 As shown:
[0034] A permanent magnet semi-direct drive slow drive device includes a base 4, on which a brake 1, a permanent magnet drive system 2 and a spline clutch 3 are provided. The spline clutch 3 and the brake 1 are respectively connected to both ends of the permanent magnet drive system 2 and the three are designed to be coaxial. The permanent magnet drive system 2 includes a permanent magnet motor 23 and a frequency conversion reduction unit. The spline clutch 3 is used to realize the bidirectional rotation of the drive device.
[0035] The variable frequency reduction unit includes a frequency converter 22 and a planetary reducer 21. The frequency converter 22, the planetary reducer 21 and the permanent magnet motor 23 are integrated into a single structure. The permanent magnet motor 23 includes a front shaft extension and a rear shaft extension. The front shaft extension is connected to the planetary reducer 21 and the rear shaft extension is connected to the brake 1. The frequency converter 22 is fixed on the top of the planetary reducer 21. The frequency converter 22 can accurately regulate the speed and torque according to the actual working conditions of the ball mill.
[0036] During the slow-drive operation of the ball mill, a permanent magnet motor 23 is used as the power source, in conjunction with a frequency converter reduction unit. This device can operate smoothly with low energy consumption, greatly reducing energy consumption. The permanent magnet motor 23 has high transmission performance, a small speed ratio requirement, and can be coaxially designed with the spline clutch 3. At the same time, the integrated design of the permanent magnet drive system 2 makes the structure more compact and significantly reduces the overall size of the device, saving a lot of space in the production site and making the equipment layout more flexible, better adapting to the space constraints of different production sites. Moreover, the integrated structure significantly shortens the power transmission distance, effectively reducing energy loss during transmission. Secondly, the integrated centralized design allows the permanent magnet drive system 2 to be precisely assembled and debugged before leaving the factory. On-site installation personnel only need to install the entire device on the base 4 and connect the necessary lines and pipes, greatly shortening the installation cycle.
[0037] Preferably, the planetary reducer 21 has at least one planetary gear. The planetary gear system structure can significantly improve torque transmission efficiency. In the planetary gear set, multiple planetary gears are evenly distributed and rotate around the sun gear, which can distribute and transmit the torque from the permanent magnet motor 23 more efficiently. In addition, the planetary gear can provide a more precise reduction ratio, which can accurately control the output speed and perfectly match the actual working speed requirements of the ball mill.
[0038] The spline clutch 3 includes a driven external spline half-coupling 31, an active external spline half-coupling 33, and an inner spline sleeve 32 connecting the two. The active external spline half-coupling 33 is connected to the planetary reducer 21 to receive input power, and the driven external spline half-coupling 31 is connected to the cement ball mill to output power. The driven external spline half-coupling 31 and the active external spline half-coupling 33 have spline structures at opposite ends, and the axial lengths of the spline structures of the two are the same. In the initial state, the inner spline sleeve 32 is located in the middle position between the driven external spline half-coupling 31 and the active external spline half-coupling 33.
[0039] With consistent spline lengths, the inner spline sleeve 32 achieves more precise alignment when switching power transmission paths, avoiding power transmission disruptions or jamming caused by spline structure differences. Furthermore, when the inner spline sleeve 32 is initially positioned between the passive and active external spline half-couplings 33, the distance the inner spline sleeve 32 needs to move is minimized, whether power needs to be transmitted from the active external spline half-coupling 33 to the passive external spline half-coupling 31 or in the reverse direction, resulting in the shortest switching response time.
[0040] The inner spline sleeve 32 has an annular fork groove 5 on its outer periphery, which houses a fork 6. The fork 6 controls the axial movement of the inner spline sleeve 32. The inner spline sleeve 32 extends forward under the control of the fork 6 to connect with the cement ball mill, and moves backward to separate from the cement ball mill. A support shaft 7 is connected to the bottom of the fork 6. The fork 6 can be driven to move by an electric or pneumatic control system. The operator only needs to control the connection between the inner spline sleeve 32 and the passive outer spline half coupling 31 to easily switch the drive direction, allowing the ball mill cylinder to easily rotate in the forward or reverse direction according to actual needs. The entire operation process is smooth and efficient, greatly improving the work experience during maintenance.
[0041] During equipment operation, especially when the rotary kiln rotates at high speed and frequently changes the power transmission direction, the shift fork 6 and the inner spline sleeve 32 are subjected to significant impact and vibration. At this time, the support shaft 7 can effectively disperse these external forces, reducing the swaying and displacement of the shift fork 6 and the inner spline sleeve 32, thereby ensuring the stability of the spline clutch 3 system. Furthermore, when the electric or pneumatic system is under maintenance or experiencing a malfunction, workers can move the shift fork 6 on the ground via the support shaft 7, ensuring the continuity of equipment operation.
[0042] The spline clutch 3 adopts a small module gear system, where the gear module is less than or equal to 1. On one hand, this makes alignment during equipment installation and commissioning simpler and faster. Compared to the traditional large module gear system, the small module gear has a smaller tooth pitch and more teeth per unit length. This allows for more precise positioning and rapid alignment when assembling the inner spline sleeve 32 with the driven external spline half-coupling 31 and the driving external spline half-coupling 33, shortening installation and commissioning time. On the other hand, the fine structure of the small module teeth provides a smoother transition when the inner spline sleeve 32 moves between the driven external spline half-coupling 31 and the driving external spline half-coupling 33. Due to the small tooth pitch, the engagement and disengagement of the inner spline sleeve 32 with the external spline half-coupling is smoother during axial movement, reducing power transmission interruptions or instability caused by tooth collisions and jamming.
[0043] During specific maintenance, the movable fork 6 moves the inner spline sleeve 32 toward the permanent magnet motor 23, disengaging it from the passive external spline coupling 31, thus disconnecting the power transmission between the drive system and the cement ball mill, facilitating bidirectional rotational maintenance.
[0044] In this embodiment, the permanent magnet motor 23 is integrated with the planetary reducer 21 and the frequency converter 22, resulting in higher integration, greater space utilization, a more compact overall system, and a smaller footprint, making it adaptable to more complex process environments. The frequency converter control allows for on-demand adjustment of the output speed, and the permanent magnet motor 23 offers better energy efficiency. The output uses a spline clutch 3, which provides better bidirectional rotation and engagement / disengagement performance, making on-site operation more convenient.
[0045] The above descriptions are merely embodiments of this utility model. Commonly known technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solution of this utility model. These modifications and improvements should also be considered within the scope of protection of this utility model, and will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.
Claims
1. A permanent magnet semi-direct drive slow speed drive apparatus comprising a base, characterized in that: The base is provided with a brake, a permanent magnet driving system and a spline clutch, the spline clutch and the brake are respectively connected at two ends of the permanent magnet driving system and coaxially designed; the permanent magnet driving system comprises a permanent magnet motor and a variable frequency speed reduction unit, and the spline clutch is used for realizing bidirectional rotation of the driving device.
2. The permanent magnet semi-direct drive slow speed drive device according to claim 1, characterized in that: The variable frequency speed reduction unit comprises a frequency converter and a planetary reducer, and the frequency converter, the planetary reducer and the permanent magnet motor are integrated into an integrated structure.
3. The permanent magnet semi-direct drive slow speed drive device according to claim 1, characterized in that: The spline clutch comprises a passive outer spline half-coupling, an active outer spline half-coupling and an inner spline sleeve connecting the two, the passive outer spline half-coupling is connected to the cement ball mill, and the active outer spline half-coupling is connected to the planetary reducer.
4. The permanent magnet semi-direct drive slow speed drive device according to claim 2, characterized in that: The permanent magnet motor comprises a front shaft extension and a rear shaft extension, the front shaft extension is connected to the planetary reducer, and the rear shaft extension is connected to the brake.
5. The permanent magnet semi-direct drive slow speed drive device according to claim 3, characterized in that: An annular shift fork groove is arranged on the outer periphery of the inner spline sleeve, the shift fork groove contains a shift fork, the shift fork is used for controlling the axial movement of the inner spline sleeve, and the bottom of the shift fork is connected with a supporting shaft.
6. A permanent magnet semi-direct drive slow speed drive apparatus according to claim 5, characterized in that: The planetary reducer comprises at least one planetary gear.
7. The permanent magnet semi-direct drive slow speed drive device according to claim 6, characterized in that: The spline clutch adopts a module gear with a module less than or equal to 1.