Ship propeller shafting device with annular magnetorheological damper

Abstract

The invention discloses a ship propeller shafting device with a circular magnetorheological damper. The propeller vibration absorption device is mainly suitable for propeller vibration absorption, and the influence of exciting force generated by a propeller on a hull and equipment thereof is reduced. When the magnetorheological damper works, the magnetorheological fluid in the damping channel generates a magnetorheological effect, shear stress is increased, when exciting force is transmitted to the annular piston rod of the magnetorheological damper along the stern shaft, the annular piston rod begins to displace and drives the annular piston to displace, due to the fact that the shear stress is increased, large damping force is generated, and the damping effect is improved. The annular piston rod and the annular piston are prevented from moving, and the vibration absorption effect is achieved. A piston of the magnetorheological damper is divided into two parts, namely an annular piston outer ring part and an annular piston inner ring part; two annular damping channels with different radiuses are respectively formed between the piston outer ring and the lower surface of the cylinder body outer ring and between the piston inner ring and the upper surface of the cylinder body inner ring; the adjustable range of the output damping force can be improved through the two magnetic fields which operate independently.

Description

Technical Field

[0001] The invention relates to the technical field of longitudinal vibration reduction of a ship propeller shaft system, in particular to a ship propeller shaft system device with a circular magnetorheological damper. Background Art

[0002] In the shipbuilding field, when the ship is operating, the propeller will generate pulsating loads in the uneven wake field. The exciting force will cause vibration failures along the propeller, main engine, and transmission shaft system. In addition, the propeller pulsation frequency components are complex and can easily match the natural frequencies of various mechanical equipment on the ship, thereby causing resonance and aggravating the vibration of the mechanical equipment.

[0003] At present, propeller dampers mostly adopt the traditional single column shape, and can only be placed on one side of the propeller drive shaft during installation and need to be fixed with the help of external suspension without direct contact with the shaft system. First of all, the traditional structure only has a strong vibration absorption ability in the installation area, and the farther the area is, the weaker the absorption ability of the exciting force is, which indirectly weakens the overall vibration absorption ability of the device. In addition, the traditional installation method of the damper also makes it impossible to directly absorb the exciting force in the first time, further reducing its performance.

[0004] Based on this, the present invention proposes an annular magnetorheological damper, which increases the effective damping gap by changing the traditional single column shape to an annular column shape, thereby ensuring uniform and maximum absorption of the exciting force generated by the propeller during operation. Summary of the invention

[0005] In view of the problems and shortcomings generated during the operation of the magnetorheological damper in the above background, the present invention proposes a ship propeller shafting device with a circular magnetorheological damper. The piston of the magnetorheological damper is divided into two parts, namely, an annular piston outer ring part and an annular piston inner ring part; two annular gaps are formed between the piston outer ring and the lower surface of the cylinder outer ring, and between the piston inner ring and the upper surface of the cylinder inner ring, thereby forming two annular damping channels with different radii; the piston is made of magnetic conductive material as a whole, and in order to avoid the mutual influence of the magnetic fields of the inner and outer rings of the piston, the annular piston rod is made of magnetic isolation material, and the annular piston rod is tightly fitted with the inner circumference of the annular piston outer ring and the partial outer circumference of the annular piston inner ring, respectively, to guide the two magnetic fields to operate independently, wherein a magnetic conductive ring is installed between the annular piston rod and the annular piston inner ring; on the basis of ensuring that the original size of the damper remains unchanged, the total length of the effective liquid flow channel is increased, the output damping force is increased, and the two independently operating magnetic fields can also effectively increase the adjustable range of the output damping force; the magnetic conductive material is made of silicon steel, and the magnetic isolation material is made of stainless steel, which can ensure the structural strength while ensuring the magnetic isolation effect. When the excitation coil is energized, the magnetic lines of force generated by electromagnetic induction pass through the left side of the piston head and the axial annular damping gap to reach the cylinder body, and then pass through the axial annular damping gap on the right side of the winding frame to reach the piston head to form a closed loop. The magnetorheological fluid in the damping gap quickly produces a magnetorheological effect under the action of the magnetic field, and the magnetorheological fluid becomes semi-solid. The corresponding shear yield stress increases to produce the damping force required for vibration absorption, hindering the movement of the piston; changing the current of the excitation coil can obtain the corresponding output damping force required for external excitation in real time.

[0006] The technical problem solved by the present invention adopts a technical solution comprising: a left annular piston rod (1), a screw (2), an end cover outer ring (3), an annular piston outer ring (4), an excitation coil (5), a cylinder (6), a floating annular piston (7), a right annular piston rod (8), a magnetic conductive ring (9), an annular piston inner ring (10), a magnetorheological fluid (11), an end cover inner ring (12), and a sealing ring (13); the left annular piston rod (1) is processed into a stepped shape; the damper end cover outer ring (3) and the end cover inner ring (12) are fixedly connected to the cylinder (6) by means of screws (2) and are sealed by means of a sealing ring (11); the left annular piston rod (1) is gap-matched with the inner surface of the damper annular piston outer ring (4) and the outer surface of the annular piston inner ring (10) and are sealed by means of a sealing ring; a transition fit is formed between the inner surface of the annular piston outer ring (4) and the outer surface of the annular piston inner ring (10) and the left annular piston rod (1); The inner surface of the rightmost end of the piston rod (1) is transitionally matched with the outer surface of the magnetic ring (9); the right annular piston rod (7) is processed into a concave shape and is interference-fitted with the rightmost end of the left annular piston rod (1) to clamp the piston and limit the movement of the piston; the inner surface of the damper cylinder (6) forms a damping channel with the outer surface of the annular piston outer ring (4) and the outer circular channel of the inner surface of the annular piston inner ring (10); the excitation coil (5) is evenly wound on the annular piston outer ring (4), and the same operation is taken on the annular piston inner ring (10); the left side of the left annular piston rod (1), the annular piston outer ring (4), and the annular piston inner ring (10) are all processed with right lead holes, and the lead of the excitation coil (5) is led out through the lead hole, and the same operation is taken on the annular piston inner ring (10); the annular piston outer ring (4), the magnetic ring (9), the annular piston inner ring (10) and the damper cylinder (6) are made of magnetic silicon steel, and the remaining parts are made of non-magnetic stainless steel.

[0007] Compared with the background technology, the present invention has the following characteristics: (1) The magnetorheological damper of the present invention effectively increases the total length of the effective liquid flow channel by dividing the piston head into two parts, an inner ring and an outer ring, and further improves the adjustable damping range of the damper.

[0008] (2) There is an annular piston ring made of magnetic isolation material between the inner ring and the outer ring of the piston head of the magnetorheological damper of the present invention. The two rings do not affect each other in their operation. The two rings can adjust the current inside the excitation coil separately or simultaneously. The damping change is more precise and has stronger adaptability to external exciting force.

[0009] (3) The magnetorheological damper of the present invention is designed to have an overall structure in a circular ring shape, which can better fit the rotating shaft system during installation and more comprehensively absorb external exciting forces.

[0010] (4) The present invention has a simple and compact structure, which improves the reliability of the magnetorheological damper. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of a ship propeller shafting device with a circular magnetorheological damper.

[0012] Figure 2 It is a schematic diagram of the structure of a circular magnetorheological damper.

[0013] Figure 3 It is a cross-sectional view of a circular magnetorheological damper.

[0014] Description of reference numerals: Figure 1 :1-engine motor, 2-thrust shaft spring, 3-flexible coupling, 4-thrust bearing, 5-intermediate shaft, 6-magnetorheological damper, 7-intermediate bearing, 8-stern shaft, 9-stern bearing, 10-propeller, 11-foundation.

[0015] Figure 3 :1-left annular piston rod, 2-screw, 3-end cover outer ring, 4-annular piston outer ring, 5-excitation coil, 6-cylinder, 7-floating annular piston, 8-right annular piston rod, 9-magnetic ring, 10-annular piston inner ring, 11-magnetorheological fluid, 12-end cover inner ring, 13-sealing ring. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings and examples: Figure 1 Schematic diagram of the application scenario of the present invention. From left to right, there are an engine motor (1), a thrust shaft (2), an elastic coupling (3), a thrust bearing (4), an intermediate shaft (5), a magnetorheological damper (6), an intermediate bearing (7), a stern shaft (8), a stern bearing (9), a propeller (10), and a base (11). The magnetorheological damper is installed at the intermediate shaft (5), and the two ends of the damper are connected to the support platforms at the thrust bearing (4) and the intermediate bearing (7) respectively by means of fixed lifting rings, so as to achieve installation.

[0017] Figure 2 The overall shape is cylindrical, and the end cover and the cylinder are fixedly connected by installing multiple screws (2). The left end threaded hole of the left annular piston rod and the threaded hole at the right end of the cylinder are prepared for the subsequent installation of the fixing ring.

[0018] Figure 3The schematic diagram of the structure of the present invention includes a left annular piston rod (1), a screw (2), an end cover outer ring (3), an annular piston outer ring (4), an excitation coil (5), a cylinder (6), a floating annular piston (7), a right annular piston rod (8), a magnetic conductive ring (9), an annular piston inner ring (10), a magnetorheological fluid (11), an end cover inner ring (12), and a sealing ring (13).

[0019] The working principle of the present invention is as follows: Two annular gaps are formed between the piston outer ring and the lower surface of the cylinder outer ring, and between the piston inner ring and the upper surface of the cylinder inner ring, respectively, to form two annular damping channels with different radii. The piston head, cylinder barrel, and damping channel form a closed magnetic circuit. When current is passed through the excitation coil, a magnetic field perpendicular to the damping channel is generated, and the magnetorheological fluid along the channel produces a magnetorheological effect in the damping channel, and the shear stress increases. At this time, under the action of the external excitation force, the left annular piston rod (1) begins to move, driving the annular piston outer ring (4), the annular piston inner ring (10), and the right annular piston rod (8) to move. Due to the increase in shear stress, a larger damping force is generated, which hinders the left annular piston rod (1), the annular piston outer ring (4), the annular piston inner ring (10), and the right annular piston rod (8) from moving to the right, thereby achieving a vibration absorption effect. By changing the current in the excitation coil (5) and performing the same operation on the excitation coil on the annular piston inner ring (10), the optimal damping size corresponding to the external excitation force can be matched.

[0020] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, the technical solution described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. These modifications or replacements will not cause the essence of the corresponding technical solution to deviate from the scope of the technical solution of the present invention.

Claims

1. A ship propeller shafting device with an annular magnetorheological damper, characterized in that include: An engine motor (1), a thrust shaft (2), an elastic coupling (3), a thrust bearing (4), an intermediate shaft (5), a magnetorheological damper (6), an intermediate bearing (7), a stern shaft (8), a stern bearing (9), a propeller (10), and a base (11); the magnetorheological damper (6) is installed on the intermediate shaft (5), located between the thrust bearing (4) and the intermediate bearing (7), and its two ends are respectively connected to the support platforms at the thrust bearing (4) and the intermediate bearing (7) by means of fixed lifting rings, so as to achieve installation; when the ship is working, the engine motor (1) transmits the generated power to the propeller (10) through the thrust shaft system, and at the same time, the propeller (10) transmits the thrust generated by the rotation to the ship, thereby driving the ship to move forward, and the propeller (10) generates pulsation during the working process. Dynamic load, the exciting force will be transmitted from the propeller (10) along the stern shaft (8), the intermediate bearing (7), and the thrust shaft (2) back to the ship itself; when the magnetorheological damper (6) is working, the excitation coil is connected with current to generate a magnetic field perpendicular to the damping channel, and the magnetorheological fluid along the channel produces a magnetorheological effect in the damping channel, and the shear stress increases. When the exciting force is transmitted along the stern shaft (8) to the support platform at the intermediate bearing (7), it will be further transmitted along the fixed lifting ring to the annular piston rod of the magnetorheological damper (6), and the annular piston rod begins to move, driving the annular piston outer ring and the annular piston inner ring to move. As the shear stress increases, a larger damping force is generated, which hinders the movement of the annular piston rod, the annular piston outer ring, and the annular piston inner ring, thereby achieving a vibration absorption effect.

2. The annular magnetorheological damper according to claim 1, characterized in that The overall structure is cylindrical, the piston rod is annular, and the internal piston is divided into an annular piston outer ring part and an annular piston inner ring part.

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