CN111641308A

CN111641308A - Annular electric propeller driven by axial magnetic motor

Info

Publication number: CN111641308A
Application number: CN202010489204.1A
Authority: CN
Inventors: 郑锐聪; 邱湘瑶; 刘福超; 邵志江
Original assignee: Zhuhai Hantuda Technology Co ltd
Current assignee: Zhuhai Hantuda Technology Co ltd
Priority date: 2020-06-02
Filing date: 2020-06-02
Publication date: 2020-09-08

Abstract

The invention relates to an annular electric thruster driven by an axial magnetic motor, which comprises: a housing, an axial-flux motor, a propeller, and a bearing assembly. The annular electric propeller directly drives the propeller to rotate by adopting the axial flux motor placed in water, so that a transmission device in the middle is omitted, and the rotor and propeller assembly is supported by the bearing placed in the water and transmits thrust to the motor and the ship body; the intermediate transmission loss between the motor and the propeller is reduced, the efficiency is improved, the structure of a propulsion system is simplified, and noise, vibration and the like are reduced.

Description

Annular electric propeller driven by axial magnetic motor

Technical Field

The invention belongs to the technical field of ship turbine propellers, and particularly relates to an annular electric propeller driven by an axial magnetic flux motor.

Background

With the development of electric propulsion technology, electric propulsion systems are increasingly used on ships. Common electric propulsion systems include change-speed gearboxes, shafting (including shafts, couplings, various bearings and bearing blocks, stern tube seals), propellers, etc.; the electric propulsion system adopts a propulsion mode that after a speed change gear box is driven by a motor to decelerate, a shaft system and a propeller are driven to rotate to generate the forward or backward thrust of the ship. This propulsion method has the following problems: the structure is complex, the number of parts is large, the failure rate is high, the occupied space is large, and the weight is heavy; the propulsion efficiency is low: the motor and the propeller are driven by components such as a gear, a shaft system and the like, the gear is meshed to generate energy loss, and meanwhile, the bearing is usually a sliding bearing, so that the friction force is large and the friction power consumption is large; the transmission links generate intermediate transmission loss, and the propulsion efficiency of the system is reduced; the transmission gear is meshed to generate vibration and cause noise, then, water flow generates turbulent flow after flowing through the shafting and the underwater appendage, the propeller rotates in the turbulent flow to generate excitation and cavitation, and the cavitation bursts to generate noise.

Disclosure of Invention

In order to reduce the intermediate transmission loss between the motor and the propeller, improve the efficiency, simplify the structure of the propulsion system, reduce noise and vibration and the like. The invention provides an annular electric propeller driven by an axial magnetic flux motor, which directly drives a propeller to rotate by adopting the axial magnetic flux motor arranged in water, saves a transmission device in the middle, and a rotor and propeller assembly is supported by a bearing arranged in water and transmits thrust to the motor and a ship body.

In order to solve at least one of the above technical problems, the technical solution adopted by the present invention is:

an axial flux motor driven annular electric thruster, comprising: a housing, an axial-flux motor, a propeller, and a bearing assembly, wherein,

the axial-flux electric machine includes: the end face flange is arranged at each of two ends of the shell, the stator component is fixed on the end face flange, the rotor component and the stator component are arranged in parallel, and the direction of an air gap magnetic field generated by the rotor component and the stator component is axial;

the propeller is connected with the rotor assembly through a blade tip flange, and the blade tip flange is positioned on the outer side of the end face flange;

the bearing assembly includes: the thrust disc and wear-resisting cover, the both ends of blade tip flange are fixed with respectively the thrust disc, just the thrust disc is located the outside of end flange, wear-resisting cover set up respectively in between thrust disc and the end flange and between blade tip flange and the end flange.

Further, the rotor assembly includes: the permanent magnet is embedded in the support frame, the support frame and the stator assembly are arranged in parallel, and one end of the support frame is connected with the blade tip flange.

Furthermore, a first axial wear-resistant sleeve is arranged on the outer wall of the end face flange, a second axial wear-resistant sleeve is arranged on the inner wall of the thrust disc, and the second axial wear-resistant sleeve and the first axial wear-resistant sleeve form a thrust bearing pair for bearing forward and reverse thrust of the propeller.

Furthermore, the outer wall of the end face flange is also provided with a radial wear-resistant sleeve, and the radial wear-resistant sleeve and the outer circular surface of the blade tip flange form a radial bearing pair for bearing the weight of the rotor assembly and the propeller and the centrifugal force formed by eccentricity in the rotating process.

Furthermore, the surfaces of the radial bearing pair and the thrust bearing pair are provided with water grooves for containing silt in water, and the radial bearing pair and the thrust bearing pair are cooled by water flow.

Furthermore, the wear-resistant sleeves of the thrust bearing pair and the radial bearing pair are made of corrosion-resistant and wear-resistant metal or nonmetal materials, or polymer materials, or hard wear-resistant coatings.

Furthermore, the thrust bearing pair adopts paired permanent magnets or electromagnetic coils with like poles repelling each other to form a magnetic thrust bearing pair.

Further, the propeller is an integral propeller or a split propeller.

Furthermore, two ends of the shell are respectively provided with a protective cover for protecting the axial flux motor and the bearing assembly.

Furthermore, the number of the stator assemblies is two, and the number of the rotor assemblies is one and is arranged between the two stator assemblies.

Furthermore, the number of the stator assemblies and the number of the rotor assemblies are multiple, and the rotor assemblies and the stator assemblies are alternately inserted into the shell.

The beneficial effects of the invention at least comprise:

1) the axial flux permanent magnet brushless motor (disc type motor) with the double-stator and single-rotor structure is adopted, axial forces on two sides of the rotor are balanced, and the motor is high in efficiency and compact in structure; the permanent magnet is adopted to replace a coil, so that compared with a separately excited motor, the current loss is reduced, and the motor efficiency and the power factor are further improved; secondly, the inner circle of the rotor of the motor directly fixes the propeller, and the rotor directly drives the propeller to rotate, so that any intermediate transmission link is not needed;

2) the invention adopts a double-stator single-rotor structure, magnetic fields at two sides of the rotor generate electromagnetic force to drive the rotor, and simultaneously output power and high power density, or more stators and rotors are integrated to improve the power density;

3) because the rotor directly drives the propeller, the vibration and noise caused by the meshing of gears of a gear box in the traditional propulsion mode are eliminated;

4) the structure is simplified, the weight is lightened, the reliability is improved, and the occupied space in the cabin is less: the invention cancels the middle transmission components such as a coupler, a gear box, a shafting, a sliding bearing, a bearing seat, a stern tube stern sealing system and the like which are inherent in the traditional electric propulsion type, only remains the motor, the propeller and the bearing group, has simpler structure and higher reliability, greatly reduces the weight, and saves the space in the cabin because the motor is arranged under water.

Drawings

Fig. 1 is a schematic structural view of an annular electric thruster of the present invention.

Fig. 2 is a schematic view of the structure of the integrated propeller of the present invention.

Fig. 3 is a schematic structural view of the split propeller of the present invention.

Fig. 4 is a cross-sectional view taken along line C-C of the first embodiment of fig. 1.

Fig. 5 is a partially enlarged view of fig. 4.

Fig. 6 is a cross-sectional view taken along line C-C of the second embodiment of fig. 1.

Fig. 7 is a partially enlarged view of fig. 6.

Fig. 8 is a cross-sectional view taken along line C-C of the third embodiment of fig. 1.

Fig. 9 is a partially enlarged view of fig. 8.

The blade comprises a shell 1, a propeller 2, blades 201, a blade tip flange 202, an end face flange 3, a rotor assembly 4, a permanent magnet 401, a support frame 402, a stator assembly 5, a thrust disc 6, a first axial wear-resistant sleeve 7, a second axial wear-resistant sleeve 8, a radial wear-resistant sleeve 9 and a protective cover 10.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

Example 1: as shown in fig. 1, 4 and 5, the annular electric propeller of this embodiment is of a double-stator single-rotor assembly structure, and mainly includes: a housing, an axial-flux motor, a propeller, and a bearing assembly.

The axial flux motor adopts an axial flux permanent magnet brushless motor (a disc type motor), is different from a common motor, has a plane air gap, an axial air gap magnetic field direction, a radial current-carrying conductor system and a disc type structure of a stator and a rotor. The motor consists of a stator component, a rotor component, a machine shell and an end face flange. The left stator component and the right stator component are respectively fixed on the left end face flange and the right end face flange of the motor, and the middle part is a single rotor component. Motor stator module is axial iron core and coil constitution, also can design for no iron core structure, and stator module wholly encapsulates the packing protective material of multilayer sealed insulation, and isolated with water and play insulating effect. The rotor assembly is clamped between the two stator assemblies and is parallel to the stator assemblies, and the structure of the rotor assembly is not radially concentric with the stator like a common motor. The rotor assembly comprises a permanent magnet and a support frame, the permanent magnet is embedded in the support frame, and a sealing filling material is filled in the support frame in a sealing mode, so that water is prevented from entering the interior of the support frame to corrode the permanent magnet. The casing is the propeller casing, and both ends are connected the terminal surface flange and the protection casing of motor about the casing.

The rotor internal diameter is big, can hold the screw, and the screw is fixed on the blade tip flange, and the blade tip flange is connected with rotor support frame internal diameter, and the rotor directly drives the screw and rotates, and motor speed is the screw rotational speed, does not need intermediate transmission links such as gear. The left and right stator components of the motor generate a rotating magnetic field after a three-phase power supply is switched on, the permanent magnet in the middle rotor component generates electromagnetic force under the action of the rotating magnetic field, and the rotor rotates and outputs torque to drive the propeller to rotate in water to generate thrust for pushing a ship.

The propeller is a metal propeller and can also be a composite propeller. The number of propeller blades is determined from hydrodynamic performance calculations and the number of blades may be 2, 3, 4, 5, 6 or more.

As shown in fig. 2, the propeller may be a single-piece type, and each blade tip is connected to a common blade tip flange as a single piece, and then connected to the rotor support frame through the blade tip flange.

As shown in figure 3, the propeller blades can be split, each blade is fixed on the inner circle of the rotor support frame through a blade tip flange, and is supported by the rotor and directly driven, and meanwhile, the propeller is split, so that the propeller is convenient to disassemble and replace.

It can be understood that the integral propeller or the split propeller is a propeller without a propeller hub, each blade is fixed on the rotor through a propeller flange and is directly driven by the rotor, and the rotating speed of the motor, namely the rotating speed of the propeller, does not need a shafting and the propeller hub for supporting and driving, and does not need intermediate transmission links such as a transmission gear and the like.

The bearing assembly is a water lubricated bearing. Bearing the weight of the rotor assembly and the propeller, and bearing the forward and reverse thrust of the propeller. The bearing assembly consists of a left thrust disc, a right thrust disc, a thrust bearing pair and a radial bearing pair.

Specifically, the method comprises the following steps: the left radial wear-resistant sleeve and the right radial wear-resistant sleeve and the outer circular surface of the blade tip flange form a radial bearing pair: the left radial wear-resistant sleeve and the outer circular surface on the left side of the propeller flange form a left radial bearing pair, the right radial wear-resistant sleeve and the outer circular surface on the right side of the propeller flange form a right radial bearing pair, the left radial bearing pair and the right radial bearing pair are concentric, the weights of the rotor assembly and the propeller are supported together, and the centrifugal force formed by eccentricity in the rotating process of the rotor assembly and the propeller is borne.

The left thrust disc and the right thrust disc are connected with the two ends of the blade tip flange, a second wear-resistant sleeve on the left thrust disc and a first wear-resistant sleeve mounted on the left end face flange of the motor form a left thrust bearing pair, and a second wear-resistant sleeve on the right thrust disc and a first wear-resistant sleeve mounted on the right end face flange of the motor form a right thrust bearing pair respectively bearing forward and reverse thrust of the propeller.

The wear-resistant sleeves of the thrust bearing pair and the radial bearing pair are made of corrosion-resistant and wear-resistant metal or nonmetal materials, or polymer materials, or hard wear-resistant coatings and the like. The surfaces of the radial bearing pair and the thrust bearing pair can be provided with water grooves for containing silt in water and cooling the bearing pair through water flow.

The front and rear protective covers are arranged at the front and rear ends of the motor shell and play a role in protecting the motor and the rotating thrust disc, and the front and rear protective covers can be made into a circular arc shape or a streamline shape, so that resistance is reduced, and hydrodynamic performance is improved.

In many cases, the radial dimensions of the propeller and the propeller are limited due to limited draught of the ship or limited space dimensions of the stern, the diameters of the propeller and the propeller cannot be further increased, and in order to increase the power under the condition of limited radial dimensions, the power can be increased by increasing the number of the stator assemblies and the rotor assemblies. Under the condition that the radial size is limited, the number of the stator assemblies and the rotor assemblies of the motor integrated by the propeller is increased, and the power density are improved; the number of integrated motor stator and rotor assemblies of the impeller is reduced and the power and power density is reduced.

Example 2: when the requirement on power density is not high, the power and the power density can be reduced by adopting a single-stator single-rotor type, as shown in fig. 6 and 7, the annular electric propeller of the embodiment is in a single-stator single-rotor assembly structure, different from embodiment 1, the number of the stator assemblies is set as one group, the rotor assembly is driven by only one single-stator assembly on one side, and by adopting the single stator and the single rotor, the power is reduced, the power density is reduced, but the structure is simple, the cost is low, and the annular electric propeller is suitable for the propellers with lower power and low requirement on the power density.

Example 3: when the power needs to be larger and the diameter is not changed, that is, the power density needs to be improved, the method can be realized by increasing the number of the stator assemblies and the rotor assemblies, that is, a plurality of stator assemblies simultaneously drive a plurality of rotor assemblies, and a plurality of rotor assemblies simultaneously drive a propeller. As shown in fig. 8 and 9, the annular electric thruster of this embodiment is of a three-stator and two-rotor assembly structure, and unlike

embodiments

1 and 2, three stator assemblies drive two rotor assemblies, and two rotor assemblies simultaneously drive one propeller.

The motor adopts a multi-disc structure with three stators and double rotors, the front stator component and the rear stator component are respectively fixed on the front end face flange and the rear end face flange of the motor, and the middle stator component is embedded in the shell. The middle of each two stator components is provided with a rotor component, the middle of the front stator component and the middle stator component is provided with a front rotor component, and the middle of the middle stator component and the rear stator component is provided with a rear rotor component. The support frames of the two rotor assemblies are fastened with the blade tip flange of the propeller together to push the propeller to rotate together, the power of the motor is higher, and the power density is improved.

In a similar way, more stator assemblies and more rotor assemblies can be integrated on the propeller simultaneously, a propeller is driven simultaneously, the power and the power density of the propeller are continuously improved, and the propeller is enabled to send larger thrust by improving the power density and the power under the condition that the radial size is limited.

Example 4: different from the above embodiments 1-3, the thrust bearing pair may even adopt paired permanent magnets or electromagnetic coils with like poles repelling each other to form a magnetic thrust bearing pair, and the magnetic thrust force formed by repelling each other bears the weight of the rotor assembly and the propeller, and simultaneously bears the forward thrust and the reverse thrust of the propeller.

In conclusion, the axial flux motor of a double-stator single-rotor structure or a multi-stator multi-rotor structure is adopted, so that the power density and the efficiency are improved, and the operation noise is reduced. In addition, the elimination of the intermediate transmission link also reduces the weight, improves the reliability, reduces the occupied space in the cabin and improves the utilization rate of the space in the cabin. The electric ship is suitable for being used on various electric ships.

In the description of the present invention, it is to be understood that the terms "first", "second" and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

Although embodiments of the present invention have been shown and described, it is understood that the embodiments are illustrative and not restrictive, that various changes, modifications, substitutions and alterations may be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. An axial flux motor-driven annular electric thruster, comprising: a housing, an axial-flux motor, a propeller, and a bearing assembly, wherein,

2. The annular electric thruster of claim 1, wherein the rotor assembly comprises: the permanent magnet is embedded in the support frame, the support frame and the stator assembly are arranged in parallel, and one end of the support frame is connected with the blade tip flange.

3. The annular electric thruster of claim 1, wherein the outer wall of the end face flange is provided with a first axial wear-resistant sleeve, the inner wall of the thrust disc is provided with a second axial wear-resistant sleeve, and the second axial wear-resistant sleeve and the first axial wear-resistant sleeve form a thrust bearing pair for bearing forward and reverse thrust of the propeller.

4. The annular electric thruster of claim 3, wherein the outer wall of the end face flange is further provided with a radial wear-resistant sleeve, and the radial wear-resistant sleeve and the outer circular surface of the blade tip flange form a radial bearing pair for bearing the weight of the rotor assembly and the propeller and the centrifugal force generated by eccentricity during rotation.

5. The annular electric thruster of claim 4, wherein the surfaces of the radial bearing pair and the thrust bearing pair are provided with water grooves for containing silt in the water and cooling the radial bearing pair and the thrust bearing pair by the water flow.

6. The annular electric thruster of claim 5, wherein the wear-resistant sleeves of the thrust bearing pair and the radial bearing pair are made of corrosion-resistant and wear-resistant metal or nonmetal materials, or polymer materials, or hard wear-resistant coatings.

7. The annular electric thruster of claim 5, wherein the thrust bearing pair uses pairs of permanent magnets or electromagnetic coils with like poles repelling each other to form a magnetic thrust bearing pair.

8. The annular electric thruster of claim 1, wherein the propeller is an integral propeller or a split propeller.

9. An annular electric thruster according to claim 1, wherein the casing is further provided at each end with a protective shield for protecting the axial flux motor and the bearing assembly.

10. Annular electric thruster according to any of claims 1-9, characterized in that said stator assemblies are two, said rotor assembly being one and being arranged between two of said stator assemblies.

11. The toroidal electric thruster of any one of claims 1 to 9, wherein said stator assembly and rotor assembly are each plural, said rotor assembly and stator assembly being reciprocally interleaved within said housing.