Dual-redundancy modular cascade motor and redundant fault-tolerant propulsion system

Abstract

The invention provides a dual-redundancy modular cascade motor and a redundant fault-tolerant propulsion system, the dual-redundancy modular cascade motor is composed of a plurality of cascade motors with the same structure, and a stator winding outgoing line is led out from a wiring board assembly through a casing; the rotor is fastened on the long shaft, the magnetic steel is adhered to the rotor, and the two ends of the long shaft are of the same internal spline structure; two ends of the elastic shaft respectively extend out of the casings of the two cascade motors and are connected with the long shaft; the other end of the long shaft is connected with the same elastic shaft which extends out of the machine shell and is connected with an external load through a spline. The bearings are installed at the two ends of the long shaft and support each section of the long shaft in a segmented mode. The front end cover and the rear end cover adopt the same flange plate structure, the end cover at one end is provided with a connecting bulge, the end cover at the other end is provided with a connecting groove, and the connecting bulge of the front-stage motor end cover is inserted into the connecting groove of the rear-stage motor end cover; the rotary transformer is mounted at the tail end of the long shaft; impact and vibration generated by starting and stopping of the motor and sudden load change can be absorbed, mechanical reliability is provided, and power output is more flexible.

Description

Technical Field

[0001] This invention belongs to the field of drive motor structure design technology, and particularly relates to a dual-redundant modular cascaded motor and a redundant fault-tolerant propulsion system. Background Technology

[0002] With the development of electrification, the application scenarios of multi-electric and all-electric propulsion technologies are gradually increasing, placing increasingly higher demands on the power level and safety of electric drive systems. Cascaded motor systems can increase power levels by increasing the number of motors and flexibly disconnect faulty individual modules using control strategies. They have excellent fault tolerance and low maintenance costs, and have broad application prospects in electric vehicles, underwater exploration, and other fields.

[0003] Currently, existing cascaded motor systems such as Figure 1 As shown, the system consists of multiple identical motors connected in series and cascaded through multiple long shafts. This multi-stage rigid cascade structure is sensitive to vibration and shock, and is prone to torsional vibration during start-up, shutdown, or sudden load changes, leading to a risk of shaft breakage and low mechanical reliability. Furthermore, the system's electrical redundancy can only be achieved by disconnecting the faulty motor using control strategies. When a shaft or any bearing experiences a mechanical failure, the electrical redundancy fails, and a single point of failure causes the entire system to shut down. Therefore, this cascade structure has low safety margins and insufficient redundancy design. The multi-shaft structure also complicates system installation, as coaxiality errors between shaft segments accumulate, requiring extremely high alignment accuracy and making installation difficult. Summary of the Invention

[0004] To address the problems of low mechanical reliability in existing cascaded motor systems, such as sensitivity to vibration and shock, susceptibility to torsional vibration leading to shaft breakage during start-up, shutdown, or sudden load changes, low electrical redundancy (where a single mechanical failure can cause the entire system to fail), low safety margin, insufficient redundancy design, and high installation difficulty, this invention provides a dual-redundant modular cascaded motor and redundant fault-tolerant propulsion system. The technical solution is as follows: Firstly, a dual-redundant modular cascaded motor is provided, which consists of multiple cascaded motors with the same structure. Each cascaded motor includes a stator assembly, rotor assembly, bearings, fastening structure, end cover, rotary transformer, baffle cover, and terminal block assembly. The stator assembly includes a stator core and a stator winding, with the stator winding leads extending from the terminal block assembly through the housing; The rotor assembly includes a long shaft, a rotor, and magnets. The rotor is fastened to the long shaft, and the magnets are bonded to the rotor and protected by a sheath. Both ends of the long shaft have the same internal spline structure. Both ends of the elastic shaft extend out of the housings of the two cascaded motors and are connected to the long shaft to achieve torque transmission. To achieve torque output, the other end of the long shaft is connected to the same elastic shaft, which extends out of the housing and is connected to the external load via a spline. The bearings are installed at both ends of the long shaft to support each section of the long shaft, and the fastening structure is installed on the long shaft to achieve its axial fixation; The end cover includes a front end cover and a rear end cover. The front and rear end covers adopt the same flange structure. One end cover has a connecting protrusion and the other end cover has a connecting groove. The connecting protrusion of the front motor end cover is inserted into the connecting groove of the rear motor end cover and is locked by the flange thread. The rotary transformer is mounted on the tail end of the long shaft and is clamped with a cover.

[0005] Optionally, each motor employs the same structure, enabling a dual-redundancy design for both the number of motors and the motor windings. Each cascaded motor has a symmetrical structure, with two bearings, two fastening structures, two end covers, two rotary transformers, two cover plates, and two terminal block assemblies. The stator windings use a dual-winding design, with each winding forming a modular unit that outputs half the motor power. The stator winding leads are drawn from two terminal block assemblies. If two motors are cascaded, half, one, three, or two times the motor power output can be achieved, broadening the power output range of the cascaded system.

[0006] Optionally, the motor adopts a flat structure to reduce the impact of imbalance caused by the motor span.

[0007] Optionally, the long shaft can be hollow to reduce the weight of the motor.

[0008] Optionally, the sheath can be made of carbon fiber or glass fiber composite material to reduce the weight of the motor.

[0009] Optionally, the flexible shaft has identical external spline structures at both ends, extending out of the housings of the two cascaded motors and splinedly connected to the long shaft to achieve torque transmission, and is secured with a fixing pin. The flexible shaft and long shaft of the front motor are connected and driven by splines, and secured with a fixing pin.

[0010] Optionally, the motor can be flexibly cooled by either air or liquid cooling, depending on the heat dissipation requirements. When the motor is designed for liquid cooling, inlet and outlet connectors are connected to the housing or end cover, and appropriate sealing designs are implemented at the end cover and housing locations.

[0011] Secondly, a redundant fault-tolerant propulsion system is provided, comprising a dual-redundant modular cascaded motor as described in any of the first aspects, and multiple first controllers and second controllers. Multiple first controllers are electrically connected to cascaded motors, and the first controllers are used to control individual module motors; Alternatively, multiple second controllers can be electrically connected to a single motor, with the second controllers used to implement dual-winding control of the motor; Alternatively, multiple first controllers and multiple second controllers are electrically connected to a single motor. The first controller is used to control the single motor, and the second controller is used to control the two sets of windings of the motor respectively, thereby realizing flexible power output of the electric drive system.

[0012] The beneficial effects of this invention are at least as follows: 1. By cascading motors through flexible shafts, the impact and vibration caused by motor start-up and shutdown and sudden load changes can be absorbed, thereby increasing mechanical reliability.

[0013] 2. By using the flexible shaft to break the shaft, mechanical faults such as overload impact and bearing failure can be isolated, protecting downstream equipment, thereby avoiding the downtime of the entire system and improving the system's fault tolerance and safety margin.

[0014] 3. The flexible shaft allows for a certain angular or positional deviation between the two ends of the connector, which can reduce installation difficulty and installation cost.

[0015] 4. Conventional cascaded single motors have relatively low power. If the number of cascaded motors is two, they can only output one or two times the motor power. When adopting a dual-redundancy design for the number of motors and motor windings, this motor can output one-half, one, three-half, or two times the motor power, making the power output more flexible. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the existing technology.

[0017] Figure 2 This is a cross-sectional view of the cascaded motor system.

[0018] Figure 3 This is a cross-sectional view of the motor structure in a single-machine application scenario using a dual-redundancy design.

[0019] Figure 4 for Figure 3 A schematic diagram of the stator winding in the structure shown.

[0020] Figure 5 To adopt Figure 3 The diagram shows a cross-sectional view of the motor structure in a cascaded motor application scenario.

[0021] Among them, 1 is the housing, 2 is the rear end cover, 2-1 is the rear end cover flange, 2-2 is the rear end cover connecting groove, 3 is the bearing, 4 is the dynamic sealing structure, 5 is the rotary transformer, 6 is the long shaft, 6-1 is the long shaft output end, 6-2 is the long shaft connecting end, 7 is the terminal block assembly, 8 is the front end cover, 8-1 is the front end cover flange, 8-2 is the front end cover connecting protrusion, 9 is the elastic shaft, 10 is the fixing pin, 11 is the fastening structure, 12 is the baffle, 13 is the rotor assembly, 13-1 is the rotor, 13-2 is the magnet, 13-3 is the sheath, 14 is the stator assembly, 12-1 is the A1 phase winding, 12-2 is the A2 phase winding, and 15 is the water jacket. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] The features and illustrative embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific setups and methods set forth below, but covers any improvements, substitutions, and modifications to structures, methods, and devices without departing from the spirit of the invention. Well-known structures and techniques are not shown in the drawings and the following description to avoid unnecessarily obscuring the invention.

[0024] It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other, and the various embodiments can be referenced and cited from each other.

[0025] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0026] This invention incorporates an additional flexible shaft on the long shaft, enabling cascading of motors. When a motor experiences a sudden torque impact (motor start-up / stop, sudden load change, etc.), the flexible shaft can buffer the speed of the impact transmission, reducing peak load and mitigating the risk of shaft breakage. Furthermore, in the event of a fault, the system can disconnect the faulty motor through control strategies, achieving electrical fault isolation; it can also isolate mechanical faults such as overload impacts and bearing failures by breaking the flexible shaft, protecting downstream equipment and preventing system downtime, thus improving the system's fault tolerance and safety margin. Moreover, because adjacent motors are connected via flexible shafts, a certain angular or positional deviation between the connecting parts at both ends is permissible, reducing installation difficulty and costs.

[0027] See Figure 2 The present invention provides a dual-redundant modular cascaded motor, which consists of multiple cascaded motors with the same structure. Each cascaded motor includes a stator assembly 14, a rotor assembly 13, bearings 3, a fastening structure 11, end covers, a rotary transformer 5, a baffle cover 12, and a terminal block assembly 7. The stator assembly 14 includes a stator core and a stator winding, with the stator winding leads extending out from the terminal block assembly 7 through the housing; The rotor assembly 13 includes a long shaft 6, a rotor 13-1, and a magnet 13-2. The rotor 13-1 is fastened to the long shaft 6, and the magnet 13-2 is bonded to the rotor 13-1 and protected by a sleeve 13-3. Both ends of the long shaft 6 have the same internal spline structure. The two ends of the elastic shaft 9 extend out of the housings 1 of the two cascaded motors and are connected to the long shaft 6 to realize torque transmission. To realize torque output, the other end of the long shaft 6 is connected to the same elastic shaft 9. The elastic shaft 9 extends out of the housing 1 and is connected to the external load through a spline. The output end of the long shaft is 6-1, and the connection end of the long shaft is 6-2.

[0028] Bearings 3 are installed at both ends of the long shaft 6 to provide segmental support for each section of the long shaft 6, and fastening structure 11 is installed on the long shaft to achieve its axial fixation; The end cover includes a front end cover 8 and a rear end cover 2. The front and rear end covers adopt the same flange structure. One end cover has a connecting protrusion and the other end cover has a connecting groove. The connecting protrusion of the front motor end cover is inserted into the connecting groove of the rear motor end cover and is locked by the flange thread. The rotary transformer 5 is installed at the end of the long shaft and is pressed down with the cover 12.

[0029] The modular cascaded motor and redundant fault-tolerant electric drive system provided by this invention can be applied to single-machine application scenarios or cascaded application scenarios.

[0030] Example 1: For standalone usage scenarios, such as Figure 3 , Figure 4As shown, a modular cascaded motor with a dual-winding scheme is provided, including a stator assembly 12, a rotor assembly 11, a bearing 3, a fastening structure 11, a front end cover 8, a rear end cover 2, a rotary transformer 5, a baffle 12, and a terminal block assembly 7.

[0031] The motor has a symmetrical structure, and there are two of each of the following components: bearing 3, fastening structure 11, rotary transformer 5, cover 12, and terminal block assembly 7.

[0032] The stator assembly 12 includes a stator core and stator windings. The stator windings have a dual-winding structure, with two sets of windings 12-1 and 12-2 each forming a three-phase Y-type structure. Each set of windings does not affect the others. Two rotary transformers 5 are used to monitor the winding status separately, and they are connected to the power supply through two independent terminal block assemblies 7. The rotor assembly 11 includes a long shaft 6, a rotor 13-1, a magnet 13-2, and a sheath 13-3.

[0033] Rotor 13-1 is fastened to long shaft 6, magnet 13-2 is bonded to rotor 13-1 and protected by sheath 13-3, and both ends of long shaft 6 have internal spline structure; Both ends of the elastic shaft 9 have external spline structures. The elastic shaft 9 extends out of the housing 1 and is connected to the external load through splines to achieve torque output. Bearings 3 are installed at both ends of the long shaft 6 to provide segmental support for each section of the long shaft 6; The rotary transformer 5 is installed at the tail end of the long shaft 6 and is pressed tightly with the cover 12.

[0034] In this embodiment, the motor adopts liquid cooling. A water jacket 15 is installed on the outer circle of the stator core, a dynamic sealing structure 4 is designed at the bearing 3, and a fastening structure 11 is installed on the long shaft 6 to achieve axial fixation. At the same time, a sealing ring is installed in places where leakage is likely.

[0035] Example 2: For cascading application scenarios, such as Figure 5 As shown, a modular cascaded motor system with dual redundancy design is provided, which consists of multiple cascaded motors with the same structure. Each cascaded motor includes a stator assembly 12, a rotor assembly 11, an elastic shaft 9, a bearing 3, a fastening structure 11, a front cover 8, a rear cover 2, a rotary transformer 5, a baffle 12, and a terminal block assembly 7.

[0036] The motor has a symmetrical structure, and there are two of each of the following components: bearing 3, fastening structure 11, rotary transformer 5, cover 12, and terminal block assembly 7.

[0037] The stator assembly 12 includes a stator core and stator windings. The stator windings have a dual-winding structure, with two sets of windings 12-1 and 12-2 each forming a three-phase Y-type structure. Each set of windings does not affect the others. Two rotary transformers 5 are used to monitor the winding status separately, and they are connected to the power supply through two independent terminal block assemblies 7. The rotor assembly 11 includes a long shaft 6, a rotor 13-1, a magnet 13-2, and a sheath 13-3.

[0038] Rotor 13-1 is fastened to long shaft 6, magnet 13-2 is bonded to rotor 13-1 and protected by sheath 13-3, long shaft 6 is a hollow shaft with the same internal spline structure at both ends; The elastic shaft 9 has the same external spline structure at both ends, and both ends extend out of the housings 1 of the two cascaded motors and are splined to the long shaft 6 to realize torque transmission, and are fastened with fixing pins 10. To achieve torque output, the other end of the long shaft 6 is connected to the same elastic shaft 9, which extends out of the housing 1 and is connected to the external load via a spline; bearings 3 are installed at both ends of the long shaft 6 to provide segmental support for each section of the long shaft 6; The front end cover flange 8-1 and the rear end cover flange 2-1 have the same structure. One end cover has a connecting protrusion 8-2 and the other end cover has a connecting groove 2-2. The connecting protrusion 8-2 of the front motor end cover is inserted into the connecting groove 2-2 of the rear motor end cover and is locked by threads through the flange. The rotary transformer 5 is installed at the tail end of the long shaft 6 and is pressed tightly with the cover 12.

[0039] In this embodiment, the motor adopts liquid cooling. A water jacket 15 is installed on the outer circle of the stator core, a dynamic sealing structure 4 is designed at the bearing 3, and a fastening structure 11 is installed on the long shaft 6 to achieve axial fixation. At the same time, a sealing ring is installed in places where leakage is likely.

[0040] The above description merely illustrates embodiments of the present invention and is quite specific and detailed; however, it should not be construed as limiting the scope of the patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Furthermore, any parts of the present invention not described in detail are conventional techniques.

Claims

1. A dual-redundancy modular cascaded electric machine, characterized in that, The motor is composed of a plurality of same-structure cascade motors, Each of the cascade motors comprises a stator assembly, a rotor assembly, a bearing, a fastening structure, an end cover, a rotary transformer, a cover and a terminal block assembly, The stator assembly comprises a stator core and a stator winding, and the stator winding leads are led out from the terminal block assembly through a casing; The rotor assembly comprises a long shaft, a rotor and a magnetic steel, the rotor is fastened on the long shaft, the magnetic steel is bonded on the rotor and protected by a sheath, and the long shaft has the same internal spline structure at both ends; elastic shafts are respectively extended into the casings of the two cascade motors to connect with the long shaft, so as to realize torque transmission; in order to realize torque output, the other end of the long shaft is connected with the same elastic shaft, and the elastic shaft is extended out of the casing to be connected with an external load through a spline; The bearing is installed at both ends of the long shaft to support each section of the long shaft, and the fastening structure is installed on the long shaft to realize axial fixation; The end cover comprises a front end cover and a rear end cover, the front and rear end covers have the same flange plate structure, one end cover has a connecting protrusion, and the other end cover has a connecting groove, the connecting protrusion of the front end cover of the front motor is inserted into the connecting groove of the rear end cover of the rear motor, and the flange plate is screwed and locked; The rotary transformer is installed at the tail end of the long shaft and is pressed by the cover.

2. The dual-redundancy modular cascaded electric machine of claim 1, wherein, Each of the cascade motors has a left-right symmetrical structure, and the number of the bearing, the fastening structure, the end cover, the rotary transformer, the cover and the terminal block assembly is two; the stator winding adopts a double-winding design, each set of winding is a module unit, and outputs one-half of the motor power, and the stator winding leads are respectively led out from the two terminal block assemblies.

3. The dual-redundancy modular cascaded electric machine of claim 1, wherein, The motor adopts a flat structure.

4. The dual-redundancy modular cascaded electric machine of claim 1, wherein, The long shaft adopts a hollow shaft structure.

5. The dual-redundancy modular cascaded electric machine of claim 1, wherein, The sheath is made of carbon fiber or glass fiber composite material.

6. The dual-redundancy modular cascaded electric machine of claim 1, wherein, The elastic shafts have the same external spline structure at both ends, and are respectively extended into the casings of the two cascade motors to be spline-connected with the long shaft, so as to realize torque transmission and be fastened and matched by a fixing pin.

7. The dual-redundancy modular cascaded electric machine of claim 1, wherein, When the motor adopts liquid cooling design, inlet and outlet connectors are connected on the casing or the end cover, and corresponding sealing design is made at the positions of the end cover and the casing.

8. A redundant fault tolerant propulsion system characterized by, The dual-redundancy modular cascade motor comprises a plurality of first controllers and a plurality of second controllers, The plurality of first controllers are electrically connected with the cascade motor, and the first controller is used to control a single module motor; Alternatively, the plurality of second controllers are electrically connected with the single motor, and the second controller is used to control the double winding of the motor; Alternatively, the plurality of first controllers and the plurality of second controllers are electrically connected with the single motor, the first controller is used to control the single motor, and the second controller is used to control the two sets of windings of the motor, so as to realize flexible output of the power of the electric drive system.

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