RU220232U1 - Axleless screw propulsion - Google Patents

Abstract

The utility model relates to the field of underwater technology, in particular to the propulsion units of surface and underwater vehicles. An axleless screw propulsion unit has been created, containing a stator mounted in a housing-frame and a movably placed solid-cast annular rotor, a hubless fixed-pitch propeller, consisting of profiled propeller impellers made along the circumference of the inner side of the solid-cast annular rotor. Moreover, along the geometric axis of the solid-cast annular rotor there is free space between the inner ends of the impellers. The stator has a three-phase stator winding placed on a magnetic core installed in the housing-frame, and liners pressed into bearing shields attached with screws to the housing-frame. A solid-cast annular rotor containing permanent magnets is installed inside the stator with its support-thrust end journals in liners pressed into bearing shields, while the contacting surfaces of the support-thrust end journals and liners form two corresponding pairs of angular contact plain bearings, providing a solid-cast annular rotor possibility of rotation. Also, the solid-cast annular rotor is made with the ability to lubricate the contacting surfaces of the support-thrust end journals and liners with surrounding water through profiled hydrodynamic grooves made on the inner ends of the liners. The technical result of the claimed utility model is to minimize periodic lubrication of an axleless screw propeller.

Description

The technical field to which the utility model belongs.

The utility model relates to the field of underwater technology, in particular to the propulsion units of surface and underwater vehicles.

State of the art.

To propel surface and underwater carriers (ships or underwater vehicles), various propellers are used [Propulsors: elements of a propeller. Found on the Internet 04/27/2023 at: https://mirmarine.net/component/content/article/48-dvizhiteli?layout=blog&Itemid=&catid=29]. Propellers are used to provide the required thrust vector (thrust) at the point of installation on the carrier with the ability to regulate its magnitude and reverse direction. Propulsors based on electric motor and propeller units of various sizes, power, and type of electric motor have become widespread. The electric motor in such propulsors is connected to the propeller either directly or through a reduction gearbox. Their common properties are ease of arrangement on the carrier, ease of supplying power to them and controlling them, ease of replacement when repairing the carrier (F.A. Gelver, I.V. Belousov, V.F. Samoseiko, Electrical propulsion installations for high-power ships, Electrical engineering, information technology, control systems, 2019, N 30, pp. 7-27).

Traditionally, the propulsion unit is a propeller and an electric motor connected to each other, possibly through a gearbox. The propeller is a streamlined shaft rotating in a bearing with propeller impellers mounted on it around its circumference. As a rule, the propeller is located coaxially inside a streamlined annular hydrodynamic nozzle, which provides optimal conditions for the movement of water through the propulsion unit.

All elements of the propeller are made underwater. In this regard, rotor bearings require special attention. These can be rolling or sliding bearings. To minimize friction in them and have a long service life, various lubricants are used. The use of various lubricants in underwater bearings is associated with their washing out with water, the formation of water-oil emulsions, corrosion of friction or rolling surfaces, which leads to an increase in the friction torque, an increase in clearances, or even jamming. This is especially acute in ball bearings, which sharply reduces the service life of propellers based on them (Classification of bearings: types and their names. Published February 04, 2019. Found on the Internet 04/27/2023 at: https://podshipnik.mobi/klientam/blog /klassifikatsiya-podshipnikov-vidy-i-ih-nazvaniya.html).

A serious operational disadvantage of traditional screw propellers is the danger of various ropes, pieces of fishing nets, seaweed and other objects that are quite often found in real bodies of water being wound around the screw axis. This can cause the propeller to stop, which means loss of speed or mobility of the carrier, inability to perform work, and even danger to the lives of people if they are on board the carrier. In addition, the use of a gearbox leads to increased acoustic noise of the propulsion unit.

A combined propulsion-propulsion complex (CPPC) of a vessel is known, having a body in the form of an axisymmetric ship ring nozzle, which houses a reversible submersible electric motor, consisting of a stator mounted in the body and a reversible electric motor movably placed in the rotor housing. Inside the annular nozzle there is a hubless impeller, consisting of blades mounted on the inner side of a circular ring suspended on support structures. The circular ring is fixed inside the rotor of the mentioned electric motor, with which the circular ring is made as a single unit. Downstream of the impeller, coaxially with it, there is a bladed propeller, which is located on the propeller shaft, cantilevered out from the drive motor located in the hull of the vessel, and passing along with the deadwood through the gap between the inner ends of the impeller blades. The propeller is installed with a minimum gap between the ends of its blades and the inner surface of the nozzle body, amounting to 0.01-0.015 of the blade radius. The propeller and impeller are equipped with drives to ensure their counter-rotation and autonomous stoppers to stop their rotation. The number of propeller blades and impeller is selected from the condition of meeting the requirements for obtaining the highest efficiency (RU 2617310, 04/24/2017). However, this does not exclude the possibility of foreign extended objects wrapping around the screw axis.

The closest technical solution to the claimed device is an open-type electric propulsion unit (GEM), including a propeller built into a hollow cylindrical rotor, a stator with windings and bearing shields combined into a single structure; an asynchronous electric motor with a hollow three-layer rotor is used, which is made in in the form of an assembly of three concentric cylinders of various thicknesses from various materials with predetermined electromagnetic properties, and the hollow cylindrical rotor includes an active working part with a propeller located inside it. The propeller blades are fixed in the upper part in the rotor bore, and in the central part - on the rotor neck with a key and rotate together with the shaft in two thrust bearings made of special materials intended for operation in sea water (RU 2306656, 20.09.2007). However, the presence of sliding bearings requires various lubricants associated with their washing out with water, the formation of water-oil emulsions, corrosion of friction surfaces, which leads to an increase in the friction torque, an increase in gaps or even jamming. This is especially acute in ball bearings, which sharply reduces the service life of propulsors based on them.

The essence of the invention.

The technical result of the claimed utility model is the minimization of periodic lubrication of an axleless screw propeller.

The technical result is achieved by creating an axleless screw propulsion device containing a stator mounted in the body-frame, a movably placed solid-cast annular rotor and a hubless fixed-pitch propeller, consisting of profiled propeller impellers made along the circumference of the inner side of the solid-cast annular rotor, and along the geometric axis a solid-cast annular rotor has free space between the inner ends of the impellers, the stator has a three-phase stator winding placed on a magnetic core installed in the housing-frame, and liners pressed into bearing shields attached with screws to the housing-frame, a solid-cast annular rotor containing permanent magnets, installed inside the stator with its support-thrust end journals in liners pressed into bearing shields, while the contacting surfaces of the support-thrust end journals and liners form two corresponding pairs of angular contact sliding bearings, providing the solid-cast ring rotor with the possibility of rotation, as well as the solid-cast ring rotor made with the ability to lubricate the contacting surfaces of the support-thrust end journals and liners with ambient water through profiled hydrodynamic grooves made on the inner ends of the liners.

In a preferred embodiment, the geometry of the profiled hydrodynamic grooves is designed to allow ambient water to be sucked into the rubbing end pair of liners when the sliding bearing rotates.

In the preferred embodiment, the stator is placed in a conveniently streamlined annular hydrodynamic nozzle, inside of which a solid-cast annular rotor rotates on sliding bearings, formed by an annular profiled cage with profiled impellers and a magnetic system on permanent magnets located inside it along the circumference.

Brief description of drawings

The essence of the utility model is illustrated by drawings.

In fig. Figure 1 shows a general view of an axleless screw propulsion unit with a control unit.

In fig. 2, 3 show sections of an axleless screw propeller.

In fig. Figure 4 shows a general view of a solid-cast annular rotor.

In fig. Figure 5 shows a cross-section of a solid-cast annular rotor.

In fig. Figure 6 shows a general view of the magnetic circuit.

In fig. Figure 7 shows a general view of an axleless screw propeller with a conventionally not shown solid-cast ring rotor.

In fig. Figure 8 shows a cross-section of a profiled hydrodynamic groove on the liners.

In fig. Figure 9 shows the position of the rotor when creating traction (thrust) force.

The axleless propulsion unit is a unit of a submersible electric motor and a hubless fixed-pitch propeller (see Fig. 1-9). In this case, the axleless propulsion device contains a stator 1, a frame housing 2, a magnetic circuit 3, a three-phase stator winding 4, liners 5, bearing shields 6, a solid-cast ring rotor 7, profiled impellers 8, permanent magnets 9, support-thrust end journals 10, profiled hydrodynamic grooves 13, screws 14. A stator 1 is mounted in the body-frame 2, a solid-cast ring rotor 7 and a hubless fixed-pitch propeller, consisting of profiled propeller impellers 8, are movably placed. Stator 1 has a three-phase stator winding 4 placed on a magnetic core 3 installed in the body-frame 2, and liners 5, pressed into bearing shields 6, attached with screws 14 to the body-frame 2.

A solid-cast annular rotor 7, containing permanent magnets 9 and support-thrust end journals 10, is installed inside the stator 1 with its support-thrust end journals 10 in liners 5, pressed into bearing shields 6. At the same time, the contacting surfaces of the support-thrust end journals 10 and liners 5 form two corresponding pairs of angular contact sliding bearings, providing the solid-cast annular rotor 7 with the ability to rotate due to radial and axial clearances. Moreover, the stator 1 is located in a conveniently streamlined annular hydrodynamic nozzle, inside of which a solid-cast annular rotor 7 rotates on sliding bearings, formed by an annular profiled cage with profiled impellers 8 and a magnetic system on permanent magnets 9 located inside it along the circumference. Also, the solid-cast annular rotor 7 is designed with the possibility lubrication of the contacting surfaces of the support-thrust end journals 10 and liners 5 with ambient water through profiled hydrodynamic grooves 13 made on the inner ends of the liners 5. The geometry of the profiled hydrodynamic grooves 13 ensures, when the sliding bearing rotates, hydrodynamic suction of surrounding water into the rubbing end pair. An angular contact sliding bearing consists of two coaxial cylindrical rings with two mating pairs of surfaces: a pair of concentric surfaces with a gap ensures free rotation of one ring inside the other with the transmission of radial loads, a pair of end surfaces provides axial support of one ring to the other to transfer the required axial force between rings. Ambient water freely enters the corresponding radial and axial clearances of the bearings, ensuring their lubrication. This ensures the maintenance of the required water film in the rubbing pair of concentric surfaces of the sliding bearing (not shown in the figures) during operation of the propulsion device and its forced water cooling.

A hubless fixed-pitch propeller, consisting of profiled propeller impellers 8, is made along the circumference of the inner side of the solid-cast annular rotor 7, and there is free space along the geometric axis of the solid-cast annular rotor 7 between the inner ends of the profiled propeller impellers 8.

Stator 1, solid-cast annular rotor 7, support-thrust end journals 10, liners 5, screws 14 are made in underwater design.

Detailed description of the implementation of the utility model.

The axleless screw propulsion system functions as follows (see Fig. 3, 4, 7, 9). An axleless screw propeller is installed on the carrier and placed together with it in water. The solid-cast annular rotor 7, located inside the stator 1, rotates due to the axial clearances in the liners 5, the axial movement is limited by the size of the axial clearance in the structure. The first, second and third inputs of the three-phase stator winding 4 are connected by wires 12, respectively, to the first, second and third outputs of the control unit 11. When a control signal is applied to rotate the solid-cast ring rotor 7 in a given direction, the control unit 11 supplies the three-phase stator winding 4 with a three-phase current, forming a rotating electric field with which permanent magnets 9 interact in the solid-cast annular rotor 7, which causes its rotation, and hence the rotation of the profiled impellers 8, which gives the traction force (thrust) of the screw propeller. The magnitude and direction of the thrust force (thrust) P is determined by the direction and speed of rotation of the solid-cast ring rotor 7, which is determined by the direction, frequency and strength of the three-phase current specified by the control unit 11. The solid-cast annular rotor 7 with profiled impellers 8 rotates, while the traction force (thrust) from it is transmitted through one of the support-thrust end journals 10 to the stator 1 and ultimately to the body-frame 2, from which it is transmitted to the carrier. The surrounding water enters the radial and axial gaps and profiled hydrodynamic grooves 13 on the liners 5, providing effective water lubrication and cooling of the contacting rubbing surfaces of the angular contact sliding bearing.

During friction on the support-thrust end journal 10 of the solid-cast annular rotor 7 (see Fig. 9), loaded by traction force P, intense squeezing out of lubricating water occurs, but it is constantly sucked into it by the loaded rotating support-thrust end journal 10 through profiled hydrodynamic grooves 13 at the current direction of rotation of the solid-cast annular rotor 7. The opposite support-thrust end journal 10 of the solid-cast annular rotor 7 rotates without contacting the end surface of the corresponding liner 5.

When changing the direction of rotation of the solid-cast annular rotor 7, the direction of the thrust force (thrust) changes. Accordingly, the support-thrust end pin 10, opposite to the previously loaded one, becomes loaded. There is intense squeezing out of lubricating water on it, but it is constantly sucked into it by the loaded rotating support-thrust end pin 10 through profiled hydrodynamic grooves 13 at the current direction of rotation of the solid-cast annular rotor 7.

In addition, the water pumped through the axleless screw propulsion effectively cools the magnetic circuit 3 with the three-phase stator winding 4 and the permanent magnets 9 in the solid-cast ring rotor 7.

Also, in an axleless propulsion unit, the axis of rotation of the propeller is purely geometric, without a physically axial rotating shaft as such, since the profiled impellers 8 with their outer ends are fixed inside the annular profiled race, rotating in a plain bearing, and between the inner ends of the profiled impellers 8 near the geometric axis of rotation of the annular race there is free space. Thus, a hubless propeller of a fixed pitch is obtained in a rotating annular profiled cage. This makes it possible to eliminate the winding of foreign extended objects around the screw axis due to the absence of a physical axis as such.

The rotation of the annular profiled cage of the axleless screw propeller is carried out without a gearbox by a low-speed contactless DC electric motor, the main elements of which are stator 1 with a three-phase stator winding 4 and a solid-cast ring rotor 7 on permanent magnets 9.

Thus, the created axleless screw propeller is an effective device for creating the required traction force (thrust) for surface or underwater carriers with increased resistance to the winding of foreign objects on the propeller and water-lubricated sliding bearings with an increased service life. The mover is easy to operate and reliable.

Claims (3)

1. An axleless screw propulsion device containing a stator mounted in the housing-frame, a movably placed solid-cast ring rotor and a hubless fixed-pitch propeller, consisting of profiled propeller impellers made around the circumference of the inner side of the solid-cast ring rotor, and along the geometric axis of the solid-cast ring rotor between the inner there is free space at the ends of the impellers, the stator has a three-phase stator winding placed on a magnetic core installed in the housing-frame, and liners are pressed into bearing shields attached with screws to the housing-frame; a solid-cast ring rotor containing permanent magnets is installed inside the stator with its supporting -thrust end journals into liners pressed into bearing shields, while the contacting surfaces of the support-thrust end journals and liners form two corresponding pairs of angular contact sliding bearings, providing the solid-cast ring rotor with the ability to rotate, and also the solid-cast ring rotor is made with the possibility of lubrication of the surrounding water of the contacting surfaces of the support-thrust end journals and liners through profiled hydrodynamic grooves made on the inner ends of the liners. 2. An axleless screw propeller according to claim 1, characterized in that the geometry of the profiled hydrodynamic grooves is designed to allow ambient water to be sucked into the rubbing end pair of liners when the sliding bearing rotates. 3. An axleless screw propulsion device according to claim 1, characterized in that the stator is placed in a streamlined annular hydrodynamic nozzle, inside of which a solid-cast annular rotor rotates on sliding bearings, formed by an annular profiled cage with profiled impellers and a magnetic system on permanent magnets located inside it along the circumference .