JP7213870B2 - Machine element monitoring system for slewing ship propulsion system - Google Patents

Description

The present invention relates to a machine element monitoring system that is provided in a slewing type ship propulsion device in which a slewing section housing a machine element for driving a propeller is rotatably attached to a ship, and that monitors the machine elements in the slewing section. More particularly, the present invention relates to a machine element monitoring system for a slewing type ship propulsion device capable of reliably remotely monitoring machine elements with a compact configuration.

Patent Document 1 discloses an invention in which wireless communication is performed between the fixed portion and the movable portion in a ship propulsion device having a fixed portion installed on the hull and a turning-type movable portion to which a propeller is attached. ing. A vibration sensor (401c) is provided near the bearing provided below the inside of the movable portion, and a transmitter (401a) is provided near the upper end inside the movable portion. 401a) is connected by wire. Then, wireless communication is performed between this transmitter (401a) and a receiver (401b) provided in the fixed part.

Patent Document 2 discloses an invention of a vibration monitoring device used for vibration monitoring of a vertical shaft pump. This vibration monitoring device has a structure in which a vibration sensor, a transmitter, and a vibration power generator are housed inside a waterproof unit case. Since radio waves do not propagate through water, the vibration monitor, when installed underwater, uses a transmitting antenna (41 ) or a relay (65) floating on the liquid surface is provided.

European Patent Publication No. 2960147 JP 2016-205869 A

2. Description of the Related Art As a ship propulsion means, there is known a turning type ship propulsion device in which a turning section containing a mechanical element for driving a propeller is rotatably attached to a fixed part of the ship. In this slewing type ship propulsion device, the slewing part containing the mechanical elements is usually submerged under water, and the internal space is filled with lubricating oil. , it is necessary to constantly monitor the state of machine elements to prepare for the occurrence of an unexpected event.

In general, a slip ring is used as a means for electrically connecting the revolving part and the fixed part. Regular maintenance is required for wear. Furthermore, there is a concern that electrical noise may be generated from the contact surface of the conductive part due to vibrations mainly generated by the engine and propeller, so noise countermeasures are necessary.

Therefore, in the monitoring and measurement of the mechanical elements of the turning-type ship propulsion device immersed in oil, as in the invention described in Patent Document 1, a sensor module for monitoring the mechanical elements is installed in the turning section. In some cases, a configuration is adopted in which communication is performed between the fixed side equipment of the ship propulsion device and the sensor module, but in this case, a stable communication state is secured and the sensor module Reliable power supply to

The invention described in Patent Document 1 uses wireless communication for communication between the swivel part and the fixed part. They are connected by wires to ensure compatibility. In this case, it is necessary to provide wiring inside the swivel portion, which is a movable part, and there are problems of complicated assembly and soundness and airtightness of the wiring in the oil that fills the swivel portion.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and provides a slewing-type ship propulsion device in which a slewing section housing a mechanical element for driving a propeller is rotatably attached to a ship, and which has a compact configuration. It is an object of the present invention to provide a machine element monitoring system capable of reliably performing remote monitoring of machine elements.

A machine element monitoring system for a turning type ship propulsion device according to claim 1,
Provided in a turning type ship propulsion device comprising: a fixed part fixed to a ship; a turning part provided with a propeller for propelling the ship and a mechanical element for driving the propeller; A machine element monitoring system comprising:
a wireless sensor device provided inside the revolving unit that detects the state of the mechanical element and wirelessly transmits data based on the state;
a receiving device that is installed in the fixed part and receives the data transmitted from the wireless sensor device;
A machine element monitoring system for a turning type ship propulsion device, comprising: a radio wave path provided between the wireless sensor device and the receiving device inside the turning type ship propulsion device,
The turning part is
a vertical shaft that transmits power to the propeller, a bearing that rotatably supports the vertical shaft, and a support portion that supports the bearing inside the revolving portion;
A radio wave transmission hole included in the radio wave path is provided in the support portion .

A mechanical element monitoring system for a turning type ship propulsion device according to claim 2,
Provided in a turning type ship propulsion device comprising: a fixed part fixed to a ship; a turning part provided with a propeller for propelling the ship and a mechanical element for driving the propeller; A machine element monitoring system comprising:
a wireless sensor device provided inside the revolving unit that detects the state of the mechanical element and wirelessly transmits data based on the state;
a receiving device that is installed in the fixed part and receives the data transmitted from the wireless sensor device;
A machine element monitoring system for a turning type ship propulsion device, comprising: a radio wave path provided between the wireless sensor device and the receiving device inside the turning type ship propulsion device,
The wireless sensor device is
a first sensor that detects the state of the mechanical element;
When the state detected by the first sensor does not exceed the reference value for a predetermined period of time, the state shifts to a power saving state, and when the state detected by the first sensor exceeds the reference value. a second sensor that transitions to an operating state to obtain primary data indicating the state of the mechanical element;
It is characterized by having

A machine element monitoring system for a turning type ship propulsion device according to claim 3 is the machine element monitoring system for a turning type ship propulsion device according to claim 1, wherein:
The wireless sensor device is
It is characterized in that it operates only within a predetermined operation period, obtains primary data indicating the state of the mechanical element, calculates secondary data from the primary data, and transmits the data wirelessly.

A machine element monitoring system for a turning type ship propulsion device according to claim 4 is a machine element monitoring system for a turning type ship propulsion device according to claim 3 , wherein:
The wireless sensor device is
a first sensor that detects the state of the mechanical element;
When the state detected by the first sensor does not exceed the reference value for a predetermined period of time, the state shifts to a power saving state, and when the state detected by the first sensor exceeds the reference value. and a second sensor that is activated to obtain the primary data.

A machine element monitoring system for a turning type ship propulsion device according to claim 5 is the machine element monitoring system for a turning type ship propulsion device according to claim 3 , wherein:
The wireless sensor device is
The secondary data is calculated by performing frequency analysis on the primary data.

A machine element monitoring system for a turning type ship propulsion device according to claim 6 is the machine element monitoring system for a turning type ship propulsion device according to claim 2 or 3 , wherein:
The wireless sensor device is
a power supply;
a capacitor connected to the power supply to provide temporary high power;
It is characterized by having

A machine element monitoring system for a turning type ship propulsion device according to claim 7 is the machine element monitoring system for a turning type ship propulsion device according to any one of claims 1 to 6 , comprising:
The wireless sensor device is
It is characterized by having a sealed housing with radio wave transmission and oil resistance.

According to the machine element monitoring system for a turning type ship propulsion device described in claims 1 and 2 , the wireless sensor device provided inside the turning section wirelessly transmits data based on the state of the machine elements detected. , the radio waves reliably reach the receiving device through the radio wave path provided between the wireless sensor device and the receiving device, and are received. Therefore, it is possible to reliably detect the state of the mechanical elements in the revolving section remotely.

According to the machine element monitoring system for a slewing type ship propulsion device described in claim 1 , the vertical shaft that transmits power to the propeller, the bearing that rotatably supports the vertical shaft, and the bearing that is supported inside the slewing portion The radio wave transmitted from the wireless sensor device is not blocked by the supporting portion of the housing, which is the main body of the rotating portion, and passes through the radio wave transmission hole provided in this supporting portion. It can pass through and reliably reach the receiver.
Further, according to the mechanical element monitoring system for a swing-type ship propulsion device described in claim 2, the second sensor for acquiring the primary data is such that the state of the mechanical element detected by the first sensor exceeds the reference value. If it does not exceed the reference value, it is in the power saving state, but only when the first sensor detects that it exceeds the reference value, it will switch to the operating state and acquire the primary data, so if the second sensor is always operating power consumption can be saved. Here, the reference value of the first sensor can be set to a large value that cannot normally be measured for a predetermined period of time, and can be changed to a suitable value as the reference value after the predetermined period of time has elapsed. By doing so, even when the swing-type vessel propulsion device is in an operating state, the operation of the second sensor becomes intermittent, and power consumption can be saved.

According to the mechanical element monitoring system for a swing-type ship propulsion device described in claim 3 , the wireless sensor device operates only within a required predetermined operation period to obtain primary data indicating the state of the mechanical elements. Therefore, power consumption can be saved compared to the case of constant operation. Moreover, by making the size of the secondary data calculated from the primary data by the wireless sensor device smaller than that of the temporary data, power consumption required for transmission can be saved. Therefore, if the power source of the wireless sensor device is a battery, the service life of the device can be extended, and it is also possible to use a configuration that operates using a small amount of power, such as an energy harvesting power source.

According to the mechanical element monitoring system for a swing-type ship propulsion device described in claim 4 , the second sensor for obtaining the primary data is such that the state of the mechanical element detected by the first sensor does not exceed the reference value. When the first sensor detects a state exceeding the reference value, it is in a power saving state, but only when the first sensor detects a state exceeding the reference value, it shifts to the operating state and acquires the primary data. power consumption can be saved. Here, the reference value of the first sensor can be set to a large value that cannot normally be measured for a predetermined period of time, and can be changed to a suitable value as the reference value after the predetermined period of time has elapsed. By doing so, even when the swing-type vessel propulsion device is in an operating state, the operation of the second sensor becomes intermittent, and power consumption can be saved.

According to the machine element monitoring system for a swing-type ship propulsion device described in claim 5 , the wireless sensor device calculates the secondary data by performing frequency analysis (FFT analysis) on the primary data. It is possible to reduce the size of the secondary data stored in the primary data to, for example, 1/16 or less of the primary data, thereby reducing power consumption and extending battery life.

According to the mechanical element monitoring system for a swing-type ship propulsion device described in claim 6 , by connecting the capacitor to the power source of the wireless sensor device and performing necessary charging, the operation of acquiring the primary data and the , this capacitor can supply a large amount of power temporarily when the operation of calculating secondary data from primary data is required.

According to the mechanical element monitoring system for a turning type ship propulsion device described in claim 7 , the parts constituting the wireless sensor device are housed in a hermetically sealed housing having radio wave permeability and oil resistance, and are independent of each other. It can be a sensor module. Therefore, even if the inside of the revolving part of the revolving ship propulsion device is filled with lubricating oil, this modularized compact wireless sensor device can be placed anywhere in the space completely immersed in this oil. It can be installed and can withstand an environment in oil and operate reliably. Also, no wiring is required to connect with devices on the oil surface.

1 is a cross-sectional view of a turning type vessel propulsion device provided with a machine element monitoring system according to an embodiment; FIG. FIG. 2 is a cross-sectional view along the ZZ cutting line of FIG. 1; FIG. 4 is a diagram showing the relationship between radio wave transmission distance in lubricating oil and radio wave quality; FIG. 5 is a diagram showing the relationship between the distance of the receiving antenna from the base and the quality of radio waves in the wireless sensor device of the machine element monitoring system of the embodiment; 1 is a longitudinal sectional view of a wireless sensor device of a machine element monitoring system according to an embodiment; FIG. It is a block diagram of the wireless sensor device of the machine element monitoring system of the embodiment. 4 is a circuit diagram of a main power supply including a capacitor provided in the wireless sensor device of the machine element monitoring system of the embodiment; FIG. 4 is a flowchart showing the order of operations such as activation and sleep of the wireless sensor device of the machine element monitoring system of the embodiment;

1 to 8, a mechanical element monitoring system for a turning type ship propulsion device according to an embodiment of the present invention will be described below.
1. Revolving Vessel Propulsion Apparatus First, the configuration of a revolving vessel propulsion apparatus 1 provided with a mechanical element monitoring system according to an embodiment will be described.

In the turning type ship propulsion device 1 of the embodiment shown in FIG. is rotatably mounted.

A speed reducer 5 having a gear case is installed on the upper surface of a bed 4 inside the ship 2 . A horizontal input shaft 6 that transmits driving force and an upper bevel gear 8 that transmits the rotational force of the input shaft 6 to the vertical shaft 7 are provided inside the speed reducer 5 . A drive shaft of the main engine is connected via a slip clutch 9 to the end of the input shaft 6 protruding outside the speed reducer 5 .

A hollow strut 10 and a casing 11 are integrally attached to the base 4 so as to protrude below the base 4, which is the exterior of the ship 2, and turnable. The upper portion of the strut 10 has a conical portion and is pivotally supported inside the bed. The strut 10 and the casing 11 constitute the main body of the revolving section 3 . The strut 10 and casing 11 can be turned by a turning drive mechanism (not shown). A vertical shaft 7 as a mechanical element extends substantially vertically inside the strut 10 and the casing 11 . The vertical shaft 7 is rotatably supported by bearings B1, B2, and B3, which are mechanical elements arranged at three locations, namely, the upper end, the central portion, and the lower end. The bearing B1 at the upper end is attached to a support S1 that is integral with the base 4, while the two bearings B2 and B3 at the central and lower ends are attached to the support S2 that is an integral component of the strut 10 or the casing 11. , S3. The upper end of the vertical shaft 7 passes through the base 4 and is connected to the upper bevel gear 8 inside the speed reducer 5 . A lower end portion of the vertical shaft 7 is connected to one end side of a propeller shaft 13 as a mechanical element extending in the horizontal direction via a lower bevel gear 12 as a mechanical element provided in a casing 11 . Both ends of the propeller shaft 13 are rotatably supported by bearings B4 and B5 as mechanical elements. These bearings B4 and B5 are attached to supporting portions S4 and S5, which are components integral with the casing 11, respectively. The other end of propeller shaft 13 is connected to propeller 14 outside casing 11 . This propeller 14 is arranged in a substantially cylindrical duct 15 connected to the casing 11 .

As described above, inside the strut 10 and casing 11, various mechanical elements (vertical shaft 7, propeller shaft 13, bearings B1 to B5, lower bevel gear 12, etc.) are attached for power transmission and the like. However, the interiors of the strut 10 and the casing 11 are filled with lubricating oil, and these mechanical elements are in a state of being immersed in the lubricating oil.

This slewing type vessel propulsion device 1 detects vibration as an index indicating the state of various mechanical elements (vertical shaft 7, propeller shaft 13, bearings B1 to B5, lower bevel gear 12, etc.) provided inside the slewing section 3. It is equipped with a machine element monitoring system that can transmit this by radio waves and remotely monitor it on board.

2. Outline of Machine Element Monitoring System Next, the overall configuration of the machine element monitoring system and the stability of transmission and reception of radio waves will be described with reference to FIGS. 1 to 4. FIG.
As shown in FIG. 1, this machine element monitoring system has wireless sensor devices T1 to T4 provided inside the swivel section 3. As shown in FIG. The wireless sensor devices T1 to T4, whose structure will be described in detail later, have a function of acquiring primary data indicating vibration of a mechanical element, calculating secondary data from the primary data, and transmitting the data wirelessly. The wireless sensor devices T1-T4 are fixed to supports S2-S5 near the bearings B2-B5 in the strut 10 or casing 11, respectively. In the example shown in FIG. 1, two support portions S2 and S3 are attached to the two bearings B2 and B3 supporting the central portion and the lower end portion of the vertical shaft 7, respectively, and one end portion of the propeller shaft 13. Wireless sensor devices T1 to T4 are attached to two support portions S4 and S5 to which two bearings B4 and B5 supporting the other end are respectively attached.

Inside the revolving part 3 of the revolving ship propulsion device 1, there is provided a mechanism for ensuring the propagation of radio waves so that the radio waves transmitted from the wireless sensor devices T1 to T4 reliably reach the receiving device R, which will be described later. radio wave passage is secured. The strut 10 or casing 11, which is the main body of the swivel part 3, is a hollow housing, and as described above, the bearings B2 to B5 for rotatably supporting the vertical shaft 7 and the propeller shaft 13 are fixed inside. As parts, there are supports S2-S5 that are integral with the strut 10 or the casing 11. FIG. The support parts S2 to S5 are rib-like or partition wall-like members that partition the inner space of the strut 10 or the casing 11. If no treatment is given, these support parts S2 to S3 act as barriers to the propagation of radio waves. Become.

As shown in FIG. 1, the supporting portions S2 to S3 inside the swivel portion 3 are provided with radio wave transmitting holes H1 to H3 for easily passing radio waves. First, as shown in FIGS. 1 and 2, the supporting portion S2 of the bearing B2 that supports the central portion of the vertical shaft 7 is provided with four rectangular radio wave transmission holes H1 at intervals of 90 degrees in the rotational direction. . The longitudinal direction of the rectangle is along the direction of rotation. This radio wave transmission hole H1 is useful as part of the radio wave path for radio waves coming from all the wireless sensor devices T1 to T4 located below.

Here, the length of the rectangular radio wave transmission hole H1 in the longitudinal direction is equal to, half the wavelength, or larger than the wavelength of the radio wave emitted by the wireless sensor devices T1 to T4 in consideration of radio wave permeability. is preferred. For example, if the wavelength of the radio wave to be used is 12 cm, the long side of the radio wave transmission hole H1 is set to 12 cm, 6 cm, or a dimension close to these values, or a large opening of 12 cm or more. In this way, the radio waves coming from the wireless sensor devices T1 to T4 can pass through the radio wave transmitting hole H1 in a state where they are difficult to attenuate. Due to the effect of this radio wave transmission hole H1, the radio waves of the wireless sensors T1 to T4 transmitted in the revolving section 3 of the revolving vessel propulsion device 1 filled with lubricating oil are transmitted to the radio waves exceeding 100 LQI at the position directly below the platform 4. It was confirmed by experiment that it can be received with good quality. If the length of the short side of the radio wave transmitting hole H1 is too short compared to the long side, the directionality of radio waves may be biased, but the effect is limited. Note that LQI is a reference value for displaying radio wave quality indicated by radio wave intensity, and is represented by a numerical value from 0 to 255. Generally, less than 50 (bad), 50-100 (slightly bad), 100-150 (good), 150 or more (very good).

As shown in FIG. 1 again, the support portion S3 of the bearing B3 that supports the lower end portion of the vertical shaft 7 is also provided with a radio wave transmission hole H2. This radio wave transmission hole H2 is useful as part of the radio wave path for radio waves coming from the wireless sensor device T3 located below. A larger radio wave transmission hole H3 is provided on the opposite side of the vertical axis 7 from the radio wave transmission hole H2. This radio wave transmission hole H3 is useful as part of the radio wave path for radio waves coming from the wireless sensor device T4 located below. The relationship between the shape and size of these radio wave transmission holes H2 and H3 and the wavelength of radio waves is the same as that of the radio wave transmission holes.

FIG. 3 is a graph showing the relationship between radio wave transmission distance in lubricating oil and radio wave quality (LQI). The penetration depth D, which is the distance at which the radio wave intensity is halved, is expressed by the following equation (1).
D=3.32×10 7 /f×√ε×tan δ (m) (1)
(However, f is the frequency, ε is the dielectric constant, and tan δ is the dielectric loss tangent.)
As shown in this graph, radio waves transmitted through lubricating oil are attenuated. Since the attenuation is only about 90 LQI, there is no problem in practical use. Moreover, in the present embodiment, since the radio wave path having the radio wave transmission holes H1 to H3 is provided in the swivel portion 3, the radio wave propagation condition is maintained well.

As shown in FIG. 1, this machine element monitoring system has a receiver R. As shown in FIG. The receiving device R is installed on the upper surface of the base 4, which is a fixed part, and has a receiving antenna 16 protruding below the upper surface of the base 4. Receive data.

The radio waves transmitted from the wireless sensor devices T1 to T4 arrive at the receiving antenna 16 while being reflected in a complicated manner inside the metallic turning section 3 . Radio waves have the property that their intensity increases when radio waves with the same phase wavelength overlap, and the intensity decreases when radio waves with a phase difference of half a wavelength overlap. Therefore, the receiving antenna 16 installed on the base 4 can arbitrarily adjust the length projecting downward from the upper surface of the base 4 so that radio waves can be received at a position where the strength is high.

Specifically, a cylindrical support member having an open upper end is prepared, the receiving antenna 16 is inserted into the supporting member, and the supporting member with the receiving antenna 16 inserted is inserted downward through a hole provided in the base 4 to obtain the desired amount. It should be fixed at the position of As a result, the downward projection length of the receiving antenna 16 can be arbitrarily set. The support member of the reception antenna 16 may be a mechanism that slides on the base 4 and is fixed at an arbitrary position, or may be set to an appropriate length in advance.

FIG. 4 is a graph showing the results of an experiment conducted to investigate the relationship between the length of the receiving antenna 16 projecting downward from the base 4 and the quality of received radio waves. As can be seen from this figure, the radio waves transmitted from the two wireless sensor devices T2 and T4 have the highest quality when the receiving antenna 16 projects downward from the base 4 by about 0.1 m. It was confirmed that the LQI ratio was improved by about 30% compared to that directly under the bed 4 . This length of 10 cm is a value close to the wavelength of 12 cm in the example of the radio waves used above.

3. Configuration of wireless sensor device (generally denoted by the symbol T) Next, the specific configuration of the wireless sensor device T, which is the transmitter of the machine element monitoring system, will be described with reference to FIGS. explain.
As shown in FIG. 5, the wireless sensor device T has a control board 21, a battery 22 as a main power supply, and a second vibration sensor with an analysis function on a bottom plate 20 made of stainless steel. , and a cover 24 is placed on the bottom plate 20 so as to cover these components, fixed and sealed. A transmission antenna 25 connected to the control board 21 is provided on the inner surface of the cover 24 . This wireless sensor device T is installed by fixing a bottom plate 20 to support portions S2 to S4 (generally denoted by the symbol S) inside the swivel portion 3 with bolts or the like.

As shown in FIG. 6, the control board 21 is mounted with a control section 30 and a starting sensor 31 . The control unit 30 is a microcomputer that controls the entire wireless sensor device T, and has a data transmission antenna 25 . The activation sensor 31 is a first sensor that detects vibration, which is a criterion for determining whether or not to activate the control unit 30 . Also, the battery 22 provided outside the control board 21 supplies a very small current of, for example, about 20 mA, and is connected to the power supply line 32 arranged on the control board 21 via a reverse connection protection element 33 to prevent sleep. It is used to drive the control unit 30, the starting sensor 31, etc., including the inside. A capacitor 34 is provided in the feeder line 32 . The capacitor 34 is an electric double layer capacitor, charged by the battery 22, and capable of instantaneously supplying a large current (for example, 40 mA for one second) when the measurement sensor 23 operates. The capacitor is selected to have a capacity that allows charging to be completed in about 1/3 of the sampling interval time. Further, the power supply line 32 is connected to the control unit 30 downstream of the capacitor 34 and is also connected to the sensor power source 35 . A sensor power supply 35 is connected to a connector 37 via a power switch 36 . An external sensor 38 outside the control board 21 is connected to the connector 37 , and the power switch 36 is turned ON/OFF by the control of the control section 30 . The external sensor 38 is an analog sensor that detects temperature and pressure. Analog data sent from the external sensor 38 is converted into digital data by a converter 39 connected to the connector 37 and sent to the controller 30 . Further, the power supply line 32 is also connected to another connector 41 via another power switch 40 . Another connector 41 is connected to a measurement sensor 23 as a second sensor that is provided outside the control board 21 and detects vibrations of mechanical elements. turned off. The two power switches 36 and 40 can be composed of semiconductor switches such as transistors. Moreover, the control part 30 is equipped with LED42 for a display.

A determination value (1G in FIG. 8, G: gravitational acceleration) is set in the starting sensor 31 at each predetermined sampling period, as will be described later. is transmitted to activate the control unit 30 . A very large value (255G in FIG. 8) is set as the judgment value so that the interrupt signal of the activation sensor 31 is not generated until the next sampling timing. The activated control unit 30 turns on the two power switches 36 and 40 to supply power to the measurement sensor 23 and the external sensor 38 .

The measurement sensor 23 is a sensor that is activated from a sleep state by an interrupt signal from the activation sensor 31 and detects vibration of a mechanical element. When the start sensor 31 does not send an interrupt signal to the control unit 30 for a predetermined time, the measurement sensor 23 turns off the power switch 40 under the control of the control unit 30 and shifts to a power saving state. When the activation sensor 31 transmits an interrupt signal to the control unit 30, the power switch 40 is turned ON under the control of the control unit 30 to shift to an operating state, and acquire primary data regarding the vibration of the mechanical element. do.

The measurement sensor 23 has a function of calculating secondary data based on primary data. The calculated secondary data is wirelessly transmitted from the transmitting antenna 25 via the control unit 30 . Here, the measurement sensor 23 is a sensor with an FFT (Fast Fourier Transform) function, performs FFT analysis of vibration data, which is primary data, and reduces the wireless transmission power when transmitting by reducing the size of the data to be transmitted. can do.

For example, when transmitting vibration data up to 1 KHz as it is, generally four times the frequency or more, that is, 4000 samplings (data at four locations in one cycle) are required, and a large amount of power is required for wireless transmission. Become. However, if FFT analysis (accuracy 4 Hz) is performed with sufficient accuracy as in the measurement sensor 23, it is possible to reduce the data size to 1/16 (256 pieces of data), resulting in a significant reduction in wireless transmission power. becomes possible.

In remote data sampling by a general vibration sensor, the vibration level detected by the vibration sensor is converted into a voltage and the vibration data is transmitted to the receiver. A huge amount of vibration data is required to perform the analysis. As a result, power consumption required for transmission increases, and since the amount of communication data is large, transmission data tends to be lost, and the lost data cannot be used for FFT analysis. In this embodiment, there is no such problem, and processed data can be sent with low power consumption.

As described above, in the present embodiment, the measurement sensor 23 not only acquires primary data, but also has a function of performing FFT analysis on the primary data to acquire secondary data. However, the function of the measurement sensor 23 may be until it acquires the primary data, and the control unit 30 may have the function of FFT-analyzing the primary data and calculating the secondary data. Even with such a configuration, the same effect as that of the present embodiment can be obtained.

FIG. 7 is a simplified circuit diagram of a power supply system including a capacitor 34 provided in the wireless sensor device T. As shown in FIG. The battery 22 corresponds to the main power supply shown in FIG. The main function of the main power source (battery 22) is to charge the capacitor 34 when the wireless sensor device T is not in operation. As a power supply other than 22, a low-power power supply such as an energy harvest can also be used. When the control unit 30 is activated, the measurement sensor 23 starts operating to detect vibration, and the detected primary data is subjected to FFT analysis to calculate secondary data, a momentarily large current is required. The discharge from the capacitor 34 compensates for this.

The cover 24 shown in FIG. 5 is a sealed housing having radio wave transmission properties and oil resistance. Specifically, for example, PTFE (polytetrafluoroethylene) is preferably used.
With respect to radio wave transmission, PTFE has a relative dielectric constant ε as low as 2.1 and a dielectric loss tangent tan δ as low as 0.0012 compared to other resins. As can be seen from the above formula (1), the smaller these values are, the larger the penetration depth D becomes, and the easier it is for radio waves to pass. In addition, the radio wave half-life depth is 7.79m, which is much larger than water (0.1m), lubricating oil (0.5m), ABS resin (0.46m), and acrylic resin (0.25m). I know it's easy.

Regarding oil resistance, PTFE exhibits high resistance to lubricating oil, gasoline, and petroleum, so it is suitable as a material for the outer housing of the wireless sensor device T installed inside the revolving part 3 filled with lubricating oil. is. In addition, PTFE is highly resistant to seawater, so it is suitable as a material for the outer casing of the wireless sensor device T provided in the revolving ship propulsion device 1 .

4. Operation of Wireless Sensor Device T Next, the operation of the wireless sensor device T, which is the transmitter of the mechanical element monitoring system, will be described with reference to FIGS. 8 and 1. FIG.
When the wireless sensor device T starts to operate (start), the control unit 30 determines whether or not the sampling cycle time has passed (S1). The control unit 30 sets the judgment value of the sensor 31 (S2). The determination value at this time is a condition for transitioning to the state of detecting vibrations of the mechanical elements in the revolving section 3, so it is set to a relatively small value such as 1 G, for example. When the activation sensor 31 detects vibration exceeding the determination value (S3, YES), the activation sensor 31 outputs an interrupt signal to the control section 30 (S4), and the control section 30 is activated (S5).

The control unit 30 turns on the two power switches 36 and 40 to start supplying power to the measurement sensor 23 and the external sensor 38 (S6). The measurement sensor 23 performs vibration measurement to obtain vibration data (primary data), and further performs FFT analysis to obtain analyzed vibration data (secondary data) (S7). Further, the external sensor 38 measures state quantities such as temperature and pressure and acquires analog data (S7).

The FFT-analyzed vibration data (secondary data) output by the measurement sensor 23 and the digital data obtained by converting the analog data output by the external sensor 38 are input to the control unit 30 and transmitted from the transmission antenna 25 of the control unit 30. It is wirelessly transmitted (S8).

When the transmission is completed, the controller 30 sets the determination value of the activation sensor 31 (S9). The determination value at this time is a condition for preventing transition to the state of detecting vibration of the mechanical elements in the revolving section 3 in the middle of the sampling cycle time, so a relatively large value such as 255 G is set. By the control unit 30 setting the determination value of the start-up sensor 31, the operation of one cycle of sampling for vibration detection is completed, and the control unit 30 determines whether or not the sampling cycle time has elapsed, returning to step 1. (S1).

After the next sampling cycle time has passed (S1, YES), when the determination value of the start sensor 31 is set to a small value (S2), if the start sensor 31 does not detect vibration exceeding the determination value, (S3, NO), and the interrupt signal of the activation sensor 31 is turned OFF (S10). As a result, the control unit 30 shifts to the sleep mode, and by turning off the two power switches 36 and 40, the control unit 30 cuts off the power supply to the measurement sensor 23 and the external sensor 38 (S11). .

5. Mechanical Element Monitoring System for Slewing Type Vessel Propulsion Apparatus 1 According to Embodiment Next, the configuration, operation, and effects of the embodiment described above will be described again, and modifications thereof, etc. will also be described.
According to the slewing type vessel propulsion device 1 of the embodiment, a propeller shaft 13, which is a mechanical element for driving the propeller 14, a vertical shaft 7, and bearings that rotatably support them are installed inside the slewing section 3 having the propeller 14. B2 to B5 are arranged, and lubricating oil is stored inside the revolving portion 3 for lubricating and cooling the mechanical elements. In order to monitor the soundness of these machine elements, especially the bearings B2 to B5, a wireless sensor device T is attached to a position close to the target machine element of a structure physically continuous with the target machine element. Further, a receiving device R is installed on the side of a fixed portion (bed 4) fixed to the ship. Between the wireless sensor device T and the receiving device R, a radio wave path that is not blocked by a metal member is secured.

The inventors of the present application have confirmed that radio communication is possible at a practical level, although most of the radio wave path is filled with lubricating oil inside the revolving portion 3 . By adopting the above configuration, wireless data communication can be performed in the air or in the oil inside the turning type ship propulsion device 1 without requiring a wiring structure. Remote monitoring is now possible.

It should be noted that the receiving device R may be provided with a transmitting function to perform two-way communication with the wireless sensor device T. FIG. The receiving device R is typically composed of a receiving antenna 16 and a radio device to which the receiving antenna 16 is connected. A computer for signal processing may be provided as necessary. The receiving antenna 16 is provided facing the inner space of the revolving part 3 , and preferably protrudes downward from the lower surface of the base floor 4 , which is the ceiling portion of the inner space of the revolving part 3 .

The slewing type ship propulsion device 1 typically has a structure in which a vertical shaft 7 for transmitting power to a propeller 14 is provided inside the slewing section 3 . In such a case, in order to rotatably support the vertical shaft 7 inside the swivel portion 3, the swivel portion 3 is provided with support portions S2 to S5, and the support portions S2 to S5 are provided with bearings B2 to B5. is installed. Typically, the support portions S2 to S5 are iron members that are continuous with the outer shell of the swivel portion 3 and have a plate shape that partitions the inside of the swivel portion 3 . Here, radio wave transmission holes H1 to H3 are provided in the support portions S2 and S3 to form part of the radio wave passage. The radio wave transmission holes H1 to H3 may be formed by opening the plate-shaped support portions S2 and S3 like the radio wave transmission holes H1 and H2, or they may be formed by forming plate-like support portions in advance like the radio wave transmission hole H3. A space may be provided so as not to block the entire internal cross section of the turning portion 3, and this space may be used as a radio wave transmission hole. As can be understood from the structure of the support portions S2 to S5 of the present embodiment, there is no particular limitation on the shape and structure of the support portions, and they are large enough to support the bearings B2 to B5 of the vertical shaft 7 and the propeller shaft 13. Any member may be used as long as it has a hollow shape, and whether or not to provide a radio wave transmitting hole depends on whether or not the supporting portion interferes with the propagation of radio waves.

When the measurement data such as the vibration data measured by the measurement sensor 23 is wirelessly transmitted as it is, the size of the data increases, resulting in data loss and increased power consumption. In particular, when the wireless sensor device T is an independent unit that does not receive power supply from the outside as in this embodiment, reducing power consumption is an important issue. Therefore, in the present embodiment, the FFT calculation is performed inside the wireless sensor device T, that is, in the measurement sensor 23 or the control unit 30, and the result is wirelessly transmitted. We decided to reduce it to Even if the increase in power required for the FFT calculation is taken into account, the power consumption of the wireless sensor device T can be reduced and the battery life can be extended.

In addition, the 2.4 GHz band of the IEEE802.15.4 standard is adopted as the wireless communication method, and the applicant has confirmed that good wireless communication is possible at the frequency of the 2.4 GHz band. there is

In this embodiment, a control unit 30 (microcomputer), a start-up sensor 31, a measurement sensor 23, a battery 22, a wireless communication circuit, a transmission antenna 25, etc. A self-contained, modular, wireless sensor device T that does not require an external power supply was used. According to the independent modularized wireless sensor device T in this way, it can be installed in a place completely submerged in oil, and requires wiring to connect with equipment above the oil surface. Not at all.

When the wireless sensor device T detects from the measurement value of the activation sensor 31 that the machine element to be monitored is in a stopped state for a certain period of time, it pauses part of its functions and shifts to a power saving state. Therefore, the battery life can be extended.

When the wireless sensor device T is in the power saving state, the control unit 30 (microcomputer) including the wireless communication function is placed in the sleep state, and the power to the elements other than the control unit 30, that is, the measurement sensor 23 and the external sensor 38 is turned off. The supply of power is stopped, and only the starting sensor 31 is kept in a starting state so as to consume only the minimum amount of electric power.

The wireless sensor device T is provided with an electric double layer capacitor 34 in the power supply system so as to be compatible with low power sources such as energy harvesting power sources (vibration power generation, temperature difference power generation, photovoltaic power generation, etc.), and temporarily generates large power. can be supplied from the capacitor 34.

The receiving device R installed on the base 4 (fixed part) is composed of a receiving antenna 16 and an antenna support member, and the receiving antenna 16 is supported at a predetermined position inside the swivel part 3 from below the base 4 . be. The position of the receiving antenna 16 can be adjusted by the antenna support member so that the receiving antenna 16 can receive signals at a position where the radio wave intensity is high.

REFERENCE SIGNS LIST 1 slewing type vessel propulsion device 2 vessel 3 slewing section 4 base as fixed section 7 vertical shaft as mechanical element 12 lower bevel gear as mechanical element 13 propeller shaft as mechanical element 14 propeller 22 Battery as power supply 23 Measurement sensor as second sensor 24 Cover as sealed housing 31 Starting sensor as first sensor 34 Capacitor B1 to B5 Bearing as mechanical element S1 to S5 Support Part T1 to T4... Wireless sensor device R... Receiving device H1 to H3... Radio wave transmission hole provided in the radio wave passage

Claims (7)

Provided in a turning type ship propulsion device comprising: a fixed part fixed to a ship; a turning part provided with a propeller for propelling the ship and a mechanical element for driving the propeller; A machine element monitoring system comprising:
a wireless sensor device provided inside the revolving unit that detects the state of the mechanical element and wirelessly transmits data based on the state;
a receiving device that is installed in the fixed part and receives the data transmitted from the wireless sensor device;
A machine element monitoring system for a turning type ship propulsion device, comprising: a radio wave path provided between the wireless sensor device and the receiving device inside the turning type ship propulsion device,
The turning part is
a vertical shaft that transmits power to the propeller, a bearing that rotatably supports the vertical shaft, and a support portion that supports the bearing inside the revolving portion;
A machine element monitoring system for a swing-type ship propulsion device, wherein a radio wave transmission hole included in the radio wave path is provided in the support portion. Provided in a turning type ship propulsion device comprising: a fixed part fixed to a ship; a turning part provided with a propeller for propelling the ship and a mechanical element for driving the propeller; A machine element monitoring system comprising:
a wireless sensor device provided inside the revolving unit that detects the state of the mechanical element and wirelessly transmits data based on the state;
a receiving device that is installed in the fixed part and receives the data transmitted from the wireless sensor device;
A machine element monitoring system for a turning type ship propulsion device, comprising: a radio wave path provided between the wireless sensor device and the receiving device inside the turning type ship propulsion device,
The wireless sensor device is
a first sensor that detects the state of the mechanical element;
When the state detected by the first sensor does not exceed the reference value for a predetermined period of time, the state shifts to a power saving state, and when the state detected by the first sensor exceeds the reference value. a second sensor that transitions to an operating state to obtain primary data indicating the state of the mechanical element;
A machine element monitoring system for a turning type ship propulsion device, comprising: The wireless sensor device is
2. The apparatus according to claim 1, wherein the apparatus operates only within a predetermined operation period to obtain primary data indicating the state of the mechanical element, calculates secondary data from the primary data, and transmits the data wirelessly. Machine element monitoring system for slewing type ship propulsion equipment. The wireless sensor device is
a first sensor that detects the state of the mechanical element;
When the state detected by the first sensor does not exceed the reference value for a predetermined period of time, the state shifts to a power saving state, and when the state detected by the first sensor exceeds the reference value. a second sensor that transitions to an operating state to acquire the primary data;
4. A machine element monitoring system for a turning type ship propulsion device according to claim 3, characterized by comprising: The wireless sensor device is
4. A mechanical element monitoring system for a turning type ship propulsion device according to claim 3 , wherein said secondary data is calculated by performing frequency analysis on said primary data. The wireless sensor device is
a power supply;
a capacitor connected to the power supply to provide temporary high power;
4. A machine element monitoring system for a turning type ship propulsion device according to claim 2 or 3, characterized by comprising: The wireless sensor device is
7. A machine element monitoring system for a turning type ship propulsion device according to claim 1, wherein the machine element monitoring system has a sealed housing having radio wave permeability and oil resistance.

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