RU2722873C1 - Propulsion system with annular electric motor for underwater vehicles of large autonomy - Google Patents

Abstract

FIELD: shipbuilding.SUBSTANCE: invention relates to ship building, namely, to propulsion devices. Propulsion complex with annular electric motor for underwater vehicles of large autonomy comprises attachment, which is attached to stern cowl by means of pylons and straightening apparatus. In the nozzle there is a synchronous multi-pole motor stator. Monolithic stator filled with rigid compound with inverter power switches integrated therein. Stator has sectioning in longitudinal direction into two identical parts not connected by common magnetic flux. In the propulsion complex, a screw with a hub is used, in which a thrust bearing is installed. On rotor outer annular part rotor assembled of detachable magnetic units is arranged.EFFECT: higher efficiency in modes of underwater vehicle full stroke.1 cl, 4 dwg

Description

The invention relates to underwater shipbuilding, in particular to the movement of underwater objects, mainly to non-nuclear underwater vehicles of great autonomy, by forming a jet and creating a driving longitudinal force.

Known submersible ring ship propulsion (patent No. 2526303 RU, priority dated 05.03.2013), consisting of an annular stator, an annular rotor equipped with a blade system.

Other motor-propulsion systems are also known (RU patent No. 2204502, priority of July 18, 2001; RU patent No. 2585207, priority of December 22, 2014).

Known propulsion system with a built-in engine for watercraft with several electric motors that drive one propeller (US patent 5252875, priority from 03/28/1991, this patent is adopted as a prototype). The submersible mover is a cylindrical nozzle, inside which two identical windings of the synchronous drive stator are installed, a propeller with a hub, in which a thrust bearing is installed, two identical rotors mounted on the periphery of the propeller, the magnetization of which is ensured by permanent magnets.

The action of the device is to convert electrical energy into mechanical energy through hydrodynamic transmission. The thrust is formed due to the reaction of the discarded jet. The change in traction is achieved by changing the power (speed) of the propeller. The hydrodynamic emphasis is perceived by a thrust bearing, which is cooled and lubricated by sea water.

The disadvantages of the prototype include:

- the impossibility of achieving a given high efficiency (0.95) of the engine in the economic running mode when the power is hundreds of times lower than the power in full speed when using a synchronous electric motor (EDMS) with permanent magnets in the rotor, with a diameter of more than one meter and engine limitation by weight;

- the complexity of using low-voltage ring motors with large diameters of the bore of the rotor, the small thickness of the rotor and stator and significant power, requiring the splitting of the winding into parallel sections, leading to the appearance of equalizing connections or a large number of sealed current leads;

- the need to use the temperature control system of the inverter power switches installed in a sturdy housing of the device.

The problem solved by this invention is the creation of a propulsion device for an underwater vehicle (PA) having a long range, the possibility of afterburning and thereby expanding the functionality of the device, as well as increasing its reliability. For this, the propulsion device must have high efficiency in all operating modes, a simple design with a minimum number of systems.

The task to achieve high efficiency in full speed and economic stroke is achieved due to the variable induction of the magnetic field of the rotor of the ring motor with permanent magnets.

The solution to the problem of using underwater low-voltage engines is achieved by placing inverter power switches in the stator (nozzle). Parallel-working inverters are connected to independent sections of the winding, in this case there is no need for equalizing connections.

All sections of the winding are powered by their sectional inverter bridge, which controls and equalizes the current in a group of coils located in diametrically opposite sectors of the motor. To power the motor, only two wires (busbars), designed for direct current voltage, are needed, which reduces the number of current leads to the rugged PA housing and increases the utilization of conductors in the absence of skin effects.

Also, installing an inverter overboard the PA solves the problem of cooling it. An additional temperature control (cooling) system, installed in a robust housing (PC) PA, is not required, which increases reliability, improves overall dimensions and simplifies the design of the apparatus.

In FIG. 1 shows a General view of the ring mover, consisting of:

- nozzles 1 into which the stator 2 of a synchronous multi-pole motor with longitudinal and tangential sectioning is integrated;

- stator 2 monolithic, filled with a rigid compound, with integrated power keys 3;

- a screw 4 with a hub in which a thrust bearing 5 is installed;

- the rotor 6, integrated into the shell of the screw, with a mechanism 7 for changing the induction of the magnetic field of the rotor;

- pylons 8 and straightening apparatus 9, performing the function of rigidly attaching the nozzle to the feed fairing 10.

In FIG. 2 presents a three-dimensional image of a propulsion system with a ring electric motor.

In FIG. 3 shows a three-dimensional image of the mover in cross section.

In FIG. 4 shows a mechanism 7 for changing the induction of the magnetic field of the rotor.

The stator 2 consists of a core, a winding, pressure rings. The engine has no retaining rings. The stator 2 of the engine has a partitioning, in the longitudinal direction it is divided into two identical parts that are not connected by a common magnetic flux, which increases the reliability of the EDMS and allows you to flexibly organize the partial load modes.

The stator core 2 is assembled from stamped segments of anisotropic electrical steel, pressed between the pressure rings and fixed from movement by means of dowels. The core is assembled directly in the stator housing.

The stator housing 2 is a steel shell with axial connectors, allowing to assemble the winding in a limited space. In the sheets of the stator core, rectangular grooves are made in which the winding is laid. The stator winding consists of a three-phase “star” with a shortened pitch. The winding circuit contains one coil and is made of a litcended rectangular conductor. All phase coils are connected in series.

In each cross section of the motor, no more than three connections are designed for a full phase current. In the housing of the stator 2 built-in power switches 3 inverter. In this case, there is no need for equalizing compounds. All sections of the winding are powered by their sectional inverter bridge.

The inverter bridge controls and equalizes the current in a group of coils located diametrically opposite. To power the motor, only two wires (busbars), designed for DC current, are needed. To maximize the groove fill factor (in order to increase efficiency and reduce losses in the motor), the coils are wound directly at the stator pole.

The poles are installed in the stator housing 2, are fixed with screws to the keys and are wedged by insulating non-magnetic wedges in the interpolar gap. A guaranteed minimum spurious clearance is maintained between the magnetic cores of the poles. To control the temperature in the winding, the installation of resistance thermal converters is provided, which are stacked in the frontal zones with a uniform distribution around the circumference.

The rotor 6, like the stator 2 is axially sectioned, concentrically located in the inner bore of the stator 2. It is equipped with a mechanism 7 for changing the induction of the magnetic field of the rotor and is a prefabricated structure consisting of a screw 4 made as a unit with the shell and hub, the magnetic circuit assembled on the shell of the screw, permanent magnets in the form of magnetic blocks 11, which are installed in the magnetic circuit and can be made cylindrical. The magnetic circuit is fastened to the rotor screw 4 by the fixing screws through the rods pressed into the magnetic circuit, which are simultaneously pins that ensure the strength of the magnetic circuit. Holes are made in the magnetic circuit in which removable magnetized magnetic blocks 11 with permanent magnets of at least N45SH brand are installed. The rotor magnetic circuit is sealed, on the outer surface the magnetic circuit is protected by a shell made of 12X18H10T steel welded with the cheeks of the rotor magnetic circuit with a tendril seam. The cylindrical shells in the tunnels under the magnetic blocks 11 are expanded with a rubber ring seal.

The mechanism 7 for changing the magnetic field induction (see Fig. 1 and, in more detail, Fig. 4) of the rotor is configured to rotate the magnetic blocks 11. The rotation of the magnetic blocks 11 can be implemented using a drive 14 connected to the magnetic blocks via a gear 13 , gears 12 or pivotally connected rods. As the drive 14 can be used:

- own moment of the electric motor;

- electric actuator mounted on the rotor;

- a hydraulic servo drive mounted in the rotor design.

The inverter unit is an inverter housed in sealed enclosures based on IGBT transistors and control system drivers.

The rotor position sensor (DPR) is located in the hub of the screw 4 and is a resolver with sine-cosine windings on the stator and a magnetic circuit of a special profile that provides the minimum number of harmonics in the signal installed on the rotor (in the screw hub). DPR does not have a dedicated excitation winding, the sensor windings are connected in a bridge circuit, with the excitation being applied to one of the bridge diagonals and picking up a useful signal from the other diagonal.

Axial thrust bearing 5 is a plain bearing lubricated by seawater. This support is located in the hub of the screw 4 and is a steel sleeve, pressed into the hub of the screw. The axis of the thrust bearing 5 is mounted on the aft end of the PA. Ceramic or polymer liners of a thrust bearing are installed on the axis, which ensure the perception of radial and axial loads with a minimum coefficient of friction. The supply of lubricating water occurs through holes in the axis of the thrust bearing 5 and through the lubricating grooves in the liner of the thrust bearing.

The engine is cooled from the outer surface of the stator 2 (and through the working clearance of the rotor) by an incoming flow of water.

A propulsion system with a ring electric motor for underwater vehicles of great autonomy works as follows.

During the movement of the PA, depending on the situation, a change in the modes of full or economic progress by a change in traction is required. The change in traction is achieved by changing the power (speed) of the propeller. The hydrodynamic emphasis is perceived by a thrust bearing, which is cooled and lubricated by sea water.

At the same time, a direct current source installed in a solid PA housing through two pressure glands through two cables supplies power to the inverter bridge sections, which feed the stator winding sections, controlling and equalizing the current in the group of coils located in diametrically opposite sectors of the motor.

When reducing the speed of the PA and power consumption by more than a hundred times the nominal, to increase the efficiency of the engine, the mechanism for changing the induction of the magnetic field of the rotor is switched on.

In this case, power is supplied to the electric motor, the rotor rotates, the drive of the mechanism for changing the induction of the magnetic field of the rotor is turned on.

The drive mechanism for changing the induction of the magnetic field of the rotor acts on the magnetic blocks connected to it by turning them. Under the influence of the drive, the magnetic blocks rotate to a predetermined position, which is determined by the rotor position sensor, setting the optimal magnetic field to increase the motor efficiency.

A propulsion system with a ring electric motor for underwater vehicles of great autonomy expands the functionality of the PA, provides a greater range of underwater travel due to various modes of its operation with high efficiency. Eliminates a large number of current leads into the robust housing of the underwater vehicle, thereby simplifying the design and increasing the reliability of the device. It also solves the problem of cooling the inverter and eliminates the installation of additional thermostatic systems in a rugged housing.

Claims (1)

A propulsion system with a ring motor for large autonomous underwater vehicles, containing a nozzle that is attached to the aft cowl using pylons and a straightening device, a two-section stator, a screw with a hub, in which a thrust bearing is installed, a two-section rotor with permanent magnets mounted on the outer the annular part of the screw, characterized in that in the stator, filled with a rigid compound, the inverter power keys are integrated; the rotor is equipped with a mechanism for changing the induction of the magnetic field of the rotor by rotating the magnetic blocks of the rotor.

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