A sensor for measuring the clearance of ship outboard bearings based on eddy current

Abstract

The present invention discloses a sensor for measuring the clearance of outboard bearings on ships based on eddy currents. The sensor comprises a protective housing, an eddy current sensing probe, a signal amplifier, a signal adapter cable, a sensor base, and fastening bolts. The protective housing is pressure-resistant and watertight. The eddy current sensing probe is connected to the input of the signal amplifier via a signal line and is placed within the protective housing. The lower portion of the eddy current sensing probe extends beyond the sensor probe outlet on the lower surface of the protective housing and is aligned with the measured shaft section or surface to acquire the sensing signal. The signal amplifier is placed within the protective housing and connected to a signal acquisition device via a signal adapter cable. The sensor base is integrally formed with the protective housing and is located on the side of the protective housing. The fastening bolts pass through screw holes around the sensor base and are then connected to the ship. The present invention can be applied to measuring the clearance of outboard bearings on ships and has the advantages of a compact structure, small size, and pressure-resistant and watertightness.

Description

Technical Field

[0001] The invention belongs to the field of sensors, and in particular relates to a ship outboard bearing clearance measuring sensor based on eddy current. Background Art

[0002] Water-lubricated bearings in ship shafting, a crucial component of a vessel's power take-off system, are typically located outboard in the water, making bearing clearance difficult to monitor. Due to the vibration, pressure, and biofouling that can occur during operation, there are currently no mature eddy current sensors suitable for practical shipboard applications.

[0003] Currently, eddy current sensors used for bearing clearance measurement on land in China cannot be directly applied underwater due to limitations such as watertightness, space dimensions, vibration, and signal attenuation. The underwater bearing clearance measurement module used by a foreign company is bulky and technically difficult to install.

[0004] Therefore, we urgently need a new sensor to measure the clearance of ship outboard bearings. Summary of the Invention

[0005] The object of the present invention is to provide a ship outboard bearing clearance measurement sensor based on eddy current, which can be used to measure the ship outboard bearing clearance and has the advantages of compact structure, small size, pressure resistance and watertightness.

[0006] The technical solution adopted in the present invention is:

[0007] A ship outboard bearing clearance measurement sensor based on eddy current, comprising a protective housing, an eddy current sensing probe, a signal amplifier, a signal transfer cable, a sensor base, and fastening bolts;

[0008] The protective shell adopts a pressure-resistant and watertight shell;

[0009] The eddy current sensing probe is connected to the input end of the signal amplifier through a signal line, placed in a protective housing, and sealed and fastened to the protective housing; the lower part of the eddy current sensing probe extends out of the sensor probe outlet on the lower surface of the protective housing, is aligned with the measured surface of the measured shaft section, and obtains the induction signal;

[0010] The signal amplifier is encapsulated in a protective housing, and its output end is connected to one end of a signal adapter cable encapsulated in the protective housing, and is used to amplify the induction signal transmitted from the eddy current sensing probe;

[0011] The other end of the signal transfer cable extends out of the cable outlet on the side of the protective housing and is connected to the signal acquisition device. The signal transfer cable outputs the amplified signal to the signal acquisition device.

[0012] The sensor base is integrally formed with the protective housing and is located on the side of the protective housing; the sensor base extends out of the protective housing on all sides; the fastening bolts pass through the screw holes on the four sides of the sensor base and are connected to the ship via nuts to fix the entire sensor on the ship; the nuts and fastening bolts work together to prevent the protective housing from loosening;

[0013] The sensor probe outlet and cable outlet are equipped with watertight and pressure-resistant seals.

[0014] According to the above solution, the radius of the eddy current sensing probe is R, the radius of the sensing area of ​​the measured surface of the measured shaft section is R2, and R2 is not less than 1.4×R to ensure measurement accuracy.

[0015] According to the above scheme, the angle between the edge of the sensing area of ​​the measured surface of the measured shaft section and the edge of the eddy current sensing probe is 45°, and there are no other sensed objects within the 45° range to ensure measurement accuracy.

[0016] According to the above scheme, the distance between the eddy current sensing probe and the measured surface of the measured shaft section is d4, d4 = the distance from the eddy current sensing probe measurement point 0 to the lower end face of the eddy current sensing probe + the distance from the lower end face of the eddy current sensing probe to the measured surface of the measured shaft section, to ensure measurement accuracy.

[0017] According to the above solution, the sensor height d5 + the distance between the eddy current sensing probe measurement 0 point and the lower end face of the eddy current sensing probe ≤ the distance d2 between the top dead center of the shaft system and the lower flange of the shroud base.

[0018] According to the above scheme, the radius of the eddy current sensing probe is 10 mm to ensure small size and high precision.

[0019] According to the above scheme, the protective shell is made of anti-corrosion and anti-fouling material, and its surface is coated with anti-corrosion and anti-fouling paint, which enhances the anti-corrosion and anti-fouling ability of the protective shell; the protective shell is made of anti-corrosion and anti-fouling metal material, and its surface is coated with anti-corrosion and anti-fouling paint; the protective shell includes 4 side surfaces, 1 lower surface, and 1 upper surface; the side surfaces and the lower surface are integrally formed, and the lower surface is provided with a sensor probe outlet with a watertight and pressure-resistant seal; one of the side surfaces is provided with a cable outlet with a watertight and pressure-resistant seal; the upper surface is tightened to the side surfaces by threads.

[0020] According to the above solution, the signal transfer cable includes a signal line, a shielding layer, a sealing layer, a protective layer, etc. from the inside to the outside, and has functions such as pressure resistance, longitudinal watertightness, and low noise.

[0021] According to the above scheme, the eddy current-based ship outboard bearing clearance measurement sensor is placed in an annular space surrounded by the deflector, bearing sleeve, copper sleeve, and shaft section, and the eddy current sensing probe is facing the measured surface of the shaft section.

[0022] According to the above scheme, the measured dimension of the shaft section to be measured is the length of the bearing sleeve extending out of the bearing.

[0023] According to the above scheme, the eddy current sensing probe and the protective shell are connected by a thread + sealant process, the internal circuit board adopts a glue injection process, and the signal transfer cable adopts a waterproof sealed plug.

[0024] The beneficial effects of the present invention are:

[0025] By adopting a pressure-resistant watertight housing, the watertight limitation of existing eddy current sensors that cannot be directly used underwater is resolved, allowing the sensor to be used to measure the clearance of outboard bearings in water.

[0026] By placing the signal amplifier in the protective housing, integrating the sensor base with the protective housing, and extending the signal adapter cable from the cable outlet on the side of the protective housing, the existing eddy current sensor can be used to measure the clearance of outboard underwater bearings.

[0027] The eddy current sensing probe, signal amplifier, and signal adapter cable are positioned through a protective housing, thereby overcoming the vibration limitation of existing eddy current sensors that cannot be directly used underwater, and enabling the sensor to be used for measuring outboard bearing clearance in water.

[0028] By placing the signal amplifier in the protective housing, the data collected by the eddy current sensing probe is directly amplified, thereby increasing the signal transmission distance to 30-40 meters. This overcomes the signal attenuation limitation of existing eddy current sensors that cannot be directly used underwater (the signal transmission distance of existing eddy current sensors is about 9 meters), enabling the sensor to be used for measuring outboard bearing clearance in water.

[0029] The integrated design of the protective shell and sensor base enhances the structural strength of the sensor and simplifies installation conditions;

[0030] The protective shell encapsulates part of the eddy current sensing probe, signal amplifier, and part of the signal transfer cable; it has the functions of corrosion resistance, pressure resistance, and sealing;

[0031] The structure is compact, simple, small in size, pressure-resistant and watertight, which can realize the measurement of the outboard bearing clearance of ships in water medium, simplify the installation technical requirements, and meet the conditions for actual ship application for easy implementation;

[0032] The eddy current sensing probe, signal amplifier, and signal transfer cable connector are structurally encapsulated (the probe is connected using a threaded + sealant process, the internal circuit board is glue-injected, and the rear-end outlet is a waterproof sealed plug). This ensures watertightness and pressure resistance, reduces size, avoids signal attenuation, and improves measurement accuracy.

[0033] The invention can be used outside the ship and can operate safely and reliably in the space. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0035] Figure 1 This is a schematic diagram of the main structure of a ship outboard bearing clearance measurement sensor based on eddy current;

[0036] Figure 2 This is a side view schematic diagram of the structure of a ship outboard bearing clearance measurement sensor based on eddy current (without signal adapter cable);

[0037] Figure 3 This is a schematic diagram of the upward-looking structure of a ship outboard bearing clearance measurement sensor based on eddy current;

[0038] Figure 4 This is a schematic diagram of the technical parameters of the eddy current sensing probe and the measured surface;

[0039] Figure 5 This is a schematic diagram of the installation of a sensor for measuring the clearance of a ship's outboard bearing based on eddy current;

[0040] In the figure: 1. Protective shell, 1.1. Upper surface, 1.2. Lower surface, 1.3. Side, 2. Eddy current sensing probe, 3. Signal transfer cable, 4. Sensor base, 5. Fastening bolts, 7. Cable outlet, 8. Measured surface of measured shaft section, 10. Bearing sleeve, 11. Fairing, 12. Bearing sleeve, 13. Ship outboard bearing clearance measurement sensor based on eddy current, 14. Shaft section, 15. Screw hole. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0042] When selecting parameters for sensors based on the eddy current principle, the following relationships apply: probe size is directly proportional to the effective range, the size of the measured surface, the height of the probe center from the base, and the installation space. In measuring ship shafting clearances, the measured surface size is the primary factor affecting sensor probe size, which in turn influences the effective range of the sensor assembly. To achieve measurements within a specific range, factors such as the available space, the size of the measured surface, and the effective range must be considered.

[0043] Sensor modules used in watertight environments adopt pressure-resistant watertight housings, and the installation space is further reduced. Factors such as vibration and fluid impact near the rotating shaft system need to be comprehensively considered in terms of corrosion resistance, safety, and reliability.

[0044] See also Figure 1-Figure 5 A sensor 13 for measuring the clearance of a ship's outboard bearing based on eddy currents is placed in the annular space enclosed by a fairing 11, a bearing sleeve 12, a bearing sleeve 10, and a shaft section 14. The eddy current sensing probe 2 faces the measured surface 8 of the shaft section 14. The measured surface 8 is the length of the shaft section 14 extending beyond the bearing sleeve 10.

[0045] The ship outboard bearing clearance measurement sensor 13 based on eddy current includes a protective shell 1, an eddy current sensing probe 2, a signal amplifier, a signal transfer cable 3, a sensor base 4, and a fastening bolt 5.

[0046] The protective shell 1 adopts a pressure-resistant and watertight shell; it is made of anti-corrosion and anti-fouling stainless steel material, and its surface is coated with anti-corrosion and anti-fouling paint, which enhances the anti-corrosion and anti-fouling ability of the protective shell; the protective shell is made of anti-corrosion and anti-fouling metal material, and its surface is coated with anti-corrosion and anti-fouling paint; the protective shell includes four side surfaces 1.3, a lower surface 1.2, and an upper surface 1.1; the side surfaces 1.3 and the lower surface 1.2 are integrally formed, and the lower surface 1.2 is provided with a sensor probe outlet with a watertight and pressure-resistant seal; one of the side surfaces 1.3 is provided with a cable outlet 7 with a watertight and pressure-resistant seal; the upper surface 1.1 is tightened to the side surface 1.3 by a thread.

[0047] The eddy current sensing probe 2 is connected to the input end of the signal amplifier through a signal line, placed in the protective shell 1, and sealed and fastened to the protective shell 1; the lower part of the eddy current sensing probe 2 extends out of the sensor probe outlet 1.2 of the lower surface of the protective shell 1, and is aligned with the measured surface 8 of the measured shaft section to obtain the induction signal.

[0048] The signal amplifier is enclosed within the protective housing 1. Its output end is connected to one end of a signal adapter cable 3, also enclosed within the protective housing 1, to amplify the induced signal transmitted from the eddy current sensing probe 2. The other end of the signal adapter cable 3 extends through a cable outlet 7 on the side 1.3 of the protective housing 1 and is connected to a signal acquisition device. The signal adapter cable 3 outputs the amplified signal to the signal acquisition device. In this embodiment, the signal adapter cable 3 includes, from the inside out, a signal line, a shielding layer, a sealing layer, and a protective layer.

[0049] The sensor base 4 is integrally formed with the lower surface 1.2 and side surface 1.3 of the protective housing 1 and is located on the side surface 1.3 of the protective housing 1. The sensor base 4 extends out of the protective housing 1 on all sides. Fastening bolts 5 pass through screw holes 15 around the sensor base 4 and connect to the vessel. Nuts then secure the entire sensor to the vessel. The nuts and fastening bolts 5 work together to prevent the protective housing 1 from becoming loose.

[0050] In this embodiment, in order to achieve a good watertight effect, the sensor probe outlet and the cable outlet 7 are provided with watertight and pressure-resistant seals.

[0051] See also Figure 1-Figure 3 Part of the eddy current sensing probe 2, the signal amplifier, and part of the signal transfer cable 3 are encapsulated in the protective shell 1, thereby reducing the volume of the sensor.

[0052] See also Figure 4 The radius of the eddy current sensing probe 2 is R, the encapsulated coil is located in the annular area with a radius of R3~R, the radius of the sensing area of ​​the measured surface 8 of the measured shaft segment is R2, and the sensing area of ​​the measured surface 8 of the measured shaft segment of the shaft segment 14 is an annular area with a radius of R1~R2, and R2 is not less than 1.4×R. The angle between the edge of the sensing area of ​​the measured surface 8 of the measured shaft segment of the shaft segment 14 and the edge of the eddy current sensing probe 2 is generally 45°, so it is necessary to ensure that there are no other sensed objects within the 45° range.

[0053] See also Figure 5 In this embodiment, the diameter of the eddy current sensing probe 2 is 20 mm. The distance between the eddy current sensing probe 2 and the measured surface 8 of the measured shaft section is d4, where d4 = the distance from the eddy current sensing probe 2's measurement point 0 to the lower end face of the eddy current sensing probe 2 + the distance from the lower end face of the eddy current sensing probe 2 to the measured surface 8 of the measured shaft section. The effective measurement distance d4 between the eddy current sensing probe 2 and the measured surface 8 of the measured shaft section is 1 mm to 10 mm. The 0-point distance is 2 mm, so the range of d4 is 3 mm to 12 mm.

[0054] The present invention is installed at the end face of the bearing by fastening bolts, and the eddy current sensing probe 2 is facing the measured surface 8 of the measured shaft segment. The measured dimension of the measured shaft segment is the length of the bearing sleeve extending out of the bearing. The area dimension of the measured surface 8 of the measured shaft segment is the length of the shaft segment 14 extending out of the bearing sleeve 10. The width of the measured surface 8 of the measured shaft segment is d1. The width of d1 limits the sensing area of ​​the eddy current sensing probe 2, which also limits the maximum measuring range and also limits the size of the eddy current sensing probe 2. In this embodiment, d1 is 50 mm. When the maximum measuring range is 10 mm (d4 = 12 mm), the width of the sensing area of ​​the measured surface 8 of the measured shaft segment is 44 mm.

[0055] The sensor height d5 + the distance between the measurement 0 point of the eddy current sensing probe 2 and the lower end face of the eddy current sensing probe 2 ≤ the distance d2 between the top dead center of the shaft system and the lower end face of the shroud base flange. In this embodiment, d2 is 94 mm and d5 is 90 mm.

[0056] The distance d3 between the center line of the eddy current sensing probe 2 and the mounting surface of the bearing sleeve 12 is such that, in order to ensure that there are no other sensed objects within the 45° range, the center line height needs to be raised to prevent the bearing sleeve 12 from entering the eddy current magnetic field area. d3 is selected as 20 mm, and an effective sensing area can be guaranteed when d4 = 1 mm to 10 mm.

[0057] Furthermore, in this embodiment, the protective housing and base are integrated into a stainless steel housing with a surface coating of corrosion-resistant paint. This integrated design allows the sensor to be used for outboard bearing clearance measurements on general vessels, requiring only the width of the sensing area to be selected, simplifying installation.

[0058] The present invention adopts the eddy current principle and designs and manufactures the sensor based on the measured surface width, effective range requirements, space size requirements, pressure-resistant seal, etc., so that the sensor meets the requirements for measuring the clearance of the ship's outboard bearing.

[0059] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A ship outboard bearing clearance measurement sensor based on eddy current, characterized by: Including protective shell, eddy current sensing probe, signal amplifier, signal transfer cable, sensor base, fastening bolts; The protective shell adopts a pressure-resistant watertight shell; The eddy current sensing probe is connected to the input end of the signal amplifier through a signal line and is placed in the protective shell. The lower part of the eddy current sensing probe extends out of the sensor probe outlet on the lower surface of the protective shell and is aimed at the measured surface of the measured shaft section to obtain the sensing signal. The signal amplifier is placed in the protective housing, and its output end is connected to one end of the signal adapter cable, and is used to amplify the induction signal transmitted from the eddy current sensing probe; The other end of the signal transfer cable extends out of the cable outlet on the side of the protective housing and is connected to the signal acquisition device. The signal transfer cable outputs the amplified signal to the signal acquisition device. The sensor base is integrally formed with the protective housing and is located on the side of the protective housing; the periphery of the sensor base extends out of the protective housing; the fastening bolts pass through the screw holes on the periphery of the sensor base and are connected to the ship to fix the entire sensor on the ship; The sensor probe outlet and cable outlet are equipped with watertight and pressure-resistant seals.

2. The eddy current-based ship outboard bearing clearance measurement sensor according to claim 1, characterized in that: The radius of the eddy current sensing probe is R, the radius of the sensing area of ​​the measured surface of the measured shaft section is R2, and R2 is not less than 1.4×R.

3. The eddy current-based ship outboard bearing clearance measurement sensor according to claim 2, characterized in that: The angle between the edge of the sensing area of ​​the measured surface of the measured shaft section and the edge of the eddy current sensing probe is 45°, and there are no other sensed objects within the 45° range.

4. The eddy current-based ship outboard bearing clearance measurement sensor according to claim 1 or 2, characterized in that: The distance between the eddy current sensing probe and the measured surface of the measured shaft section is d4, d4=the distance from the measurement 0 point of the eddy current sensing probe to the lower end face of the eddy current sensing probe + the distance from the lower end face of the eddy current sensing probe to the measured surface of the measured shaft section.

5. The eddy current-based ship outboard bearing clearance measurement sensor according to claim 4, characterized in that: The sensor height d5 + the distance between the eddy current sensing probe measurement 0 point and the lower end face of the eddy current sensing probe ≤ the distance d2 between the top dead center of the shaft system and the lower end face of the shroud base flange.

6. The eddy current-based ship outboard bearing clearance measurement sensor according to claim 1, characterized in that: The radius of the eddy current sensing probe is 10 mm.

7. The eddy current-based ship outboard bearing clearance measurement sensor according to claim 1, characterized in that: The protective shell is made of anti-corrosion and anti-fouling stainless steel material, and the surface is coated with anti-corrosion and anti-fouling paint; the protective shell includes 4 side surfaces, 1 lower surface, and 1 upper surface; the side surfaces and the lower surface are integrally formed, and the lower surface is provided with a sensor probe outlet with a watertight and pressure-resistant seal; one of the side surfaces is provided with a cable outlet with a watertight and pressure-resistant seal; the upper surface is tightened to the side surfaces by threads.

8. The eddy current-based ship outboard bearing clearance measurement sensor according to claim 1, characterized in that: The signal transfer cable comprises a signal line, a shielding layer, a sealing layer and a protective layer from the inside to the outside.

9. The eddy current-based ship outboard bearing clearance measurement sensor according to any one of claims 1 to 3, characterized in that: The eddy current-based ship outboard bearing clearance measurement sensor is placed in an annular space surrounded by a fairing, a bearing sleeve, a copper sleeve, and a shaft section, and the eddy current sensing probe faces the measured surface of the shaft section.

10. The eddy current-based ship outboard bearing clearance measurement sensor according to claim 1, characterized in that: The eddy current sensing probe and the protective shell are connected using a thread + sealant process, the internal circuit board uses a glue injection process, and the signal transfer cable uses a waterproof sealed plug.

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