Bearing temperature monitoring device

Abstract

To provide a bearing temperature monitoring device capable of monitoring, with a simple constitution, a bearing temperature as a monitoring object.SOLUTION: A bearing temperature monitoring device for monitoring a temperature of a bearing portion rotatably supporting a crank pin of a crank rotating around a shaft center of a crank shaft of an internal combustion engine includes: an oil receiving portion disposed on an inner wall surface of the internal combustion engine with an inlet portion opened at an upper part, and receiving, via the inlet portion, a lubricant scattering from the bearing portion revolving around the shaft center of the crank shaft along with the rotation of the crank shaft; and a temperature measuring portion for measuring a temperature of the lubricant received by the oil receiving portion.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a bearing temperature monitoring device for an internal combustion engine. [Background technology]

[0002] In internal combustion engines such as marine diesel engines installed on ships, the temperature of the crankpin bearing has been monitored as a means of early detection of abnormalities in the crankpin bearing, which rotatably supports the crankpin of the crank that converts the reciprocating motion of the piston in the cylinder into the rotational motion of the crankshaft.

[0003] Normally, lubricating oil is supplied between the sliding surface (inner peripheral surface) of the crankpin bearing and the crankpin, and a film of the lubricating oil ensures smooth sliding between the crankpin bearing and the crankpin. However, the sliding surface of the crankpin bearing may be damaged, such as by scratches or cracks, due to the intrusion of foreign matter between the crankpin bearing and the sliding surface, or fatigue failure of the crankpin bearing. In this case, the formation of the lubricating oil film is hindered, resulting in metal-to-metal contact between the sliding surface of the crankpin bearing and the crankpin journal, causing an excessive rise in the temperature of the crankpin bearing (hereinafter referred to as the bearing temperature).

[0004] If the above-mentioned bearing temperature is monitored and an excessive rise in bearing temperature is detected at an early stage, an abnormality in the crankpin bearing can be discovered early. Based on this, for example, the load on the internal combustion engine (engine load) can be reduced to suppress the progression of damage to the crankpin bearing, or the internal combustion engine can be stopped to perform maintenance such as inspection or replacement of the crankpin bearing, thereby preventing serious damage to the internal combustion engine, such as burning of the sliding surface or journal of the crankpin bearing.

[0005] As a conventional temperature measurement technology for monitoring such bearing temperatures, for example, a technology has been proposed in which a temperature sensor is attached to the crank pin bearing portion and the temperature sensor detects an increase in the bearing temperature (see Patent Document 1). In particular, in the conventional technology described in Patent Document 1, the temperature sensor is made of a shape memory alloy that changes shape with an increase in temperature, and the movement of the temperature sensor when the bearing temperature rises excessively is detected in a non-contact manner using a proximity switch such as a magnetic sensor. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Utility Model Application Publication No. 59-121520 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the above-mentioned conventional technology, the crankpin bearing with the temperature sensor attached revolves around the axis of the crankshaft together with the crankpin as the crankshaft rotates, so there is a risk that the temperature sensor will fall off the crankpin bearing during the revolving movement due to centrifugal force, etc., which may result in the bearing temperature not being able to be measured.

[0008] Furthermore, because the temperature sensor revolves together with the crankpin bearing, it is difficult to fix the proximity switch, which detects bearing temperature rises without contact from the temperature sensor, in a position where it can be brought close to the temperature sensor without coming into contact with it. That is, there is a risk that the temperature sensor and proximity switch will come into contact with each other and be damaged during the orbital movement of the crankpin bearing, making it impossible to measure the bearing temperature. Alternatively, if the separation distance between the temperature sensor and proximity switch is increased to avoid contact between them, there is a risk that the proximity switch will not detect the movement of the temperature sensor, making it difficult to stably detect bearing temperature rises.

[0009] The present invention has been made in view of the above circumstances, and has an object to provide a bearing temperature monitoring device that can monitor the temperature of a bearing to be monitored with a simple configuration. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems and achieve the object, the bearing temperature monitoring device of the present invention is a bearing temperature monitoring device for monitoring the temperature of a bearing part that rotatably supports the crank pin of a crank that rotates around the axis of the crankshaft of an internal combustion engine, and is characterized in that it comprises: an oil receiving part that has an inlet part that opens upward and is provided on the inner wall surface of the internal combustion engine, and that receives, via the inlet part, lubricating oil scattered from the bearing part that revolves around the axis of the crankshaft as the crank rotates; and a temperature measuring part that measures the temperature of the lubricating oil received by the oil receiving part.

[0011] In addition, the bearing temperature monitoring device of the present invention is characterized in that, in the above invention, it is provided with a blocking section that is provided above the oil receiving section and blocks lubricating oil flowing down along the inner wall surface of the internal combustion engine.

[0012] Furthermore, in the bearing temperature monitoring device according to the present invention, in the above invention, a plurality of the oil receiving portions are provided vertically along the inner wall surface of the internal combustion engine.

[0013] In addition, the bearing temperature monitoring device of the present invention is characterized in that, in the above invention, the inlet portion of the oil receiving portion is configured to be narrower than the bearing portion in the axial direction of the crankshaft, and one or more inlet portions are provided corresponding to at least one end of the bearing portion in the axial direction of the crankshaft.

[0014] In addition, the bearing temperature monitoring device of the present invention is characterized in that, in the above invention, the inlet width of the oil receiving portion is equal to or greater than the width of the bearing portion in the axial direction of the crankshaft, and is less than the width of the crosshead pin bearing portion of the crosshead that interfaces with the bearing portion of the internal combustion engine.

[0015] In addition, the bearing temperature monitoring device of the present invention is characterized in that, in the above invention, the oil receiving portion is provided in an area between the uppermost position of the bearing portion when the piston corresponding to the crankpin of the internal combustion engine is located at top dead center, and the lowermost position of the bearing portion when the piston is located at bottom dead center.

[0016] In addition, the bearing temperature monitoring device of the present invention is characterized in that, in the above invention, it comprises a control unit that determines whether the temperature of the bearing unit is abnormal based on the temperature of the lubricating oil measured by the temperature measurement unit, and an output unit that outputs the determination result of the temperature of the bearing unit by the control unit. [Effects of the Invention]

[0017] The bearing temperature monitoring device according to the present invention has the advantage that the temperature of the bearing to be monitored can be monitored with a simple configuration. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic diagram showing an example of the configuration of an internal combustion engine to which a bearing temperature monitoring device according to a first embodiment of the present invention is applied. [Figure 2] FIG. 2 is a schematic diagram showing an example of the configuration of the bearing temperature monitoring device according to the first embodiment of the present invention. [Figure 3] FIG. 3 is a cross-sectional schematic view of the bearing temperature monitoring device shown in FIG. 2 taken along line AA. [Figure 4] FIG. 4 is a schematic diagram showing an example of the arrangement of the oil receiving portion in the height direction in the first embodiment of the present invention. [Figure 5] FIG. 5 is a schematic diagram showing an example of the configuration of a bearing temperature monitoring device according to a second embodiment of the present invention. [Figure 6] FIG. 6 is a schematic diagram for explaining the width of the interrupter of the bearing temperature monitoring device according to the second embodiment of the present invention. [Figure 7] FIG. 7 is a schematic diagram showing an example of a state in which the blocking section according to the second embodiment of the present invention blocks oil. [Figure 8] FIG. 8 is a schematic diagram showing an example of the configuration of a bearing temperature monitoring device according to a third embodiment of the present invention. [Figure 9] FIG. 9 is a schematic diagram for explaining the width of the oil receiving portion of the multi-stage structure in the third embodiment of the present invention. [Figure 10] FIG. 10 is a schematic diagram showing an example of the configuration of a bearing temperature monitoring device according to a fourth embodiment of the present invention. [Figure 11] FIG. 11 is a schematic cross-sectional view of the bearing temperature monitoring device shown in FIG. 10 taken along line BB. [Figure 12] FIG. 12 is a schematic diagram showing an example of the configuration of a bearing temperature monitoring device according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] A preferred embodiment of a bearing temperature monitoring device according to the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention is not limited to this embodiment. It should be noted that the drawings are schematic, and the dimensional relationships and ratios of each element may differ from those in reality. The drawings may also include parts with different dimensional relationships and ratios. In addition, the same components are designated by the same reference numerals in each drawing.

[0020] (Embodiment 1) First, the configuration of an internal combustion engine to which a bearing temperature monitoring device according to a first embodiment of the present invention is applied will be described. Fig. 1 is a schematic diagram showing an example of the configuration of an internal combustion engine to which a bearing temperature monitoring device according to a first embodiment of the present invention is applied. Fig. 1 schematically shows a marine diesel engine 10 mounted on a ship as an example of this internal combustion engine. For example, the marine diesel engine 10 is a two-stroke diesel engine such as a uniflow scavenging and exhausting crosshead type diesel engine, which rotates and drives a propeller (not shown) for propelling the ship.

[0021] 1 , the marine diesel engine 10 includes a bedplate 1 located on the lower side in a height direction D1, a frame 5 provided on the bedplate 1, and a cylinder jacket 11 provided on the frame 5. The bedplate 1, frame 5, and cylinder jacket 11 are fastened together and fixed by connecting members such as a plurality of tie bolts 22 extending in the height direction D1 (i.e., the up-down direction) of the marine diesel engine 10. The marine diesel engine 10 also includes a cylinder 12 provided in the cylinder jacket 11, a piston 15 provided inside the cylinder 12, and a crankshaft 2 that rotates in conjunction with the reciprocating motion of the piston 15.

[0022] The bed plate 1 constitutes a crankcase that houses the crankshaft 2 and other components of the marine diesel engine 10. As shown in FIG. 1, the bed plate 1 contains the crankshaft 2 having a crank 3 and a crankpin 4, and a bearing (not shown) for the crankshaft 2. The crankshaft 2 is an example of an output shaft that outputs the propulsive force of the vessel, and is rotatably supported by the bearing. The lower end of a connecting rod 6 is connected to the crankshaft 2 via the crankpin 4 of the crank 3. As shown in FIG. 1, the lower end of the connecting rod 6 forms a crankpin bearing 7 that rotatably supports the crankpin 4. The marine diesel engine 10 is also provided with a bearing temperature monitoring device 30 for monitoring the temperature (bearing temperature) of the crankpin bearing 7, as shown in FIG. 1. The configuration of the bearing temperature monitoring device 30 will be described in detail below.

[0023] As shown in FIG. 1 , a connecting rod 6 having the crankpin bearing 7, sliding plates 8, and a crosshead 9 are provided inside the frame 5. The frame 5 is arranged on the bedplate 1 so that the sliding plates 8, which are provided along the piston axis direction, form a pair spaced apart in the width direction D2 of the marine diesel engine 10. The connecting rod 6 is arranged between the pair of sliding plates 8 with its lower end (crankpin bearing 7) connected to the crankpin 4. A crosshead pin 9a connected to the lower end of the piston rod 16 and a crosshead pin bearing (not shown) connected to the upper end of the connecting rod 6 are rotatably connected to the crosshead 9 at the lower half of the crosshead pin 9a. The crosshead 9 is arranged between the pair of sliding plates 8 as shown in FIG. 1 and is supported so as to be reciprocatable along the pair of sliding plates 8.

[0024] As shown in FIG. 1, the cylinder jacket 11 is provided on top of the frame 5 and supports the cylinder 12. As shown in FIG. 1, the cylinder 12 is a cylindrical structure (cylinder) composed of a cylinder liner 13 and a cylinder cover 14, and has a combustion chamber 17 for burning fuel. The cylinder liner 13 is, for example, a cylindrical structure and is supported inside the cylinder jacket 11. The cylinder cover 14 is fixed to the top of the cylinder liner 13, thereby defining an internal space (combustion chamber 17, etc.) of the cylinder liner 13. A piston 15 is provided in the internal space of the cylinder liner 13 so as to be able to reciprocate freely in the piston axial direction (height direction D1 in FIG. 1). The upper end of the piston 15 is connected to the upper end of a piston rod 16 as shown in FIG. 1.

[0025] As shown in FIG. 1 , the cylinder cover 14 is provided with an exhaust valve 18 and an upper valve train 19. The exhaust valve 18 is a valve that opens and closes an exhaust port (exhaust port) of an exhaust pipe 21 that leads to a combustion chamber 17 in the cylinder 12. The upper valve train 19 is a device that drives the exhaust valve 18 to open and close. The combustion chamber 17 is a space surrounded by the exhaust valve 18, the cylinder liner 13, the cylinder cover 14, and the piston 15. The marine diesel engine 10 is also provided with an exhaust manifold 20 near the cylinder 12. The exhaust manifold 20 receives exhaust gas from the combustion chamber 17 of the cylinder 12 through the exhaust pipe 21, temporarily stores the received exhaust gas, and converts the dynamic pressure of the exhaust gas into static pressure.

[0026] In the marine diesel engine 10 configured as described above, combustion gas is supplied from a scavenging trunk to a combustion chamber 17 in the cylinder 12 through scavenging ports and the like (neither of which is shown). In this combustion chamber 17, the combustion gas is compressed by the piston 15, and fuel supplied from a fuel injection valve (not shown) is ignited and burned by the combustion gas. The piston 15 then reciprocates in the cylinder liner 13 in the piston axial direction due to the energy generated by the combustion of the fuel in the combustion chamber 17. At this time, when the exhaust valve 18 is actuated by the upper valve gear 19 to open the exhaust port of the cylinder 12, residual gas remaining in the cylinder liner 13 after the fuel combustion is discharged as exhaust gas to an exhaust pipe 21. At the same time, new combustion gas is introduced into the internal space of the cylinder liner 13 from the scavenging trunk through scavenging ports and the like.

[0027] Furthermore, when the piston 15 reciprocates in the piston axial direction as described above, the piston rod 16 reciprocates in the piston axial direction together with the piston 15. In conjunction with this, the crosshead 9 reciprocates in the piston axial direction along the sliding plate 8. As a result, the reciprocating motion of the piston 15 is transmitted to the connecting rod 6 via the crosshead 9 and converted into the rotational motion of the crank 3, whose crank pin 4 is journaled at the lower end (crank pin bearing portion 7) of the connecting rod 6. The crankshaft 2 rotates in conjunction with the rotational motion of the crank 3, and rotates the propeller shaft to propel the ship.

[0028] For ease of explanation, the present specification defines a height direction D1, a width direction D2, and an axial direction D3 for the marine diesel engine 10 as shown in FIG. 1 , but these directions do not limit the present invention. The height direction D1 of the marine diesel engine 10 is the up-down direction and is, for example, parallel to the direction of reciprocating motion of the piston 15. The width direction D2 of the marine diesel engine 10 is perpendicular to the height direction D1 and the axial direction D3. The axial direction D3 of the marine diesel engine 10 is the longitudinal direction (i.e., the axial direction) of the crankshaft 2. The height direction D1, width direction D2, and axial direction D3 are perpendicular to one another. The height direction D1, width direction D2, and axial direction D3 apply not only to the marine diesel engine 10 but also to each component of the marine diesel engine 10.

[0029] (Configuration of bearing temperature monitoring device) Next, the configuration of a bearing temperature monitoring device 30 according to the first embodiment of the present invention will be described. FIG. 2 is a schematic diagram showing an example of the configuration of a bearing temperature monitoring device according to the first embodiment of the present invention. FIG. 2 is a schematic diagram showing a main part of the marine diesel engine 10 shown in FIG. 1, including the bearing temperature monitoring device 30, as viewed from the axial direction D3. FIG. 3 is a schematic cross-sectional view of the bearing temperature monitoring device shown in FIG. 2, taken along line AA. The bearing temperature monitoring device 30 is a device for monitoring the temperature (bearing temperature) of a crankpin bearing 7 that supports a crankpin 4 of a crank 3 that rotates about the axis of a crankshaft 2 of the marine diesel engine 10. A bearing temperature monitoring device 30 is provided in the marine diesel engine 10 for each crankpin bearing 7 to be monitored. For example, the number of bearing temperature monitoring devices 30 is the same as the number of crankpin bearings 7 (i.e., the number of cylinders) provided in the marine diesel engine 10. In the first embodiment, the bearing temperature monitoring device 30 includes an oil receiving section 31 and a temperature measuring section 33, as shown in FIGS.

[0030] The oil receiving portion 31 receives lubricating oil scattered from the crankpin bearing 7 to be monitored. Specifically, as shown in FIGS. 2 and 3 , the oil receiving portion 31 is configured in a container shape having an inlet 31a that opens upward (upward in the height direction D1), and is provided on the inner wall surface 27 of the marine diesel engine 10 so as to extend from the inner wall surface 27 toward the crankshaft 2. Examples of the inner wall surface 27 on which the oil receiving portion 31 is provided include the inner wall surface (inner wall surface of the frame wall 25) of the frame 5 that houses the crosshead 9, the connecting rod 6, etc., and the inner wall surface (inner wall surface of the bed plate wall 26) of the bed plate that houses the crankshaft 2, etc. Note that FIG. 2 illustrates the oil receiving portion 31 provided on the inner wall surface 27 of the frame wall 25.

[0031] As described above, the crankpin bearing 7 rotatably supports the crankpin 4 of the crank 3, and is provided at the lower end of the connecting rod 6 connected to the crosshead 9. Although not shown, lubricating oil is supplied between the sliding surface of the crankpin bearing 7 and the outer circumferential surface of the crankpin 4. The lubrication between the crankpin bearing 7 and the crankpin 4 is ensured by an oil film of the lubricating oil. The crank 3 rotates about the axis 2a of the crankshaft 2 in accordance with the reciprocating motion of the crosshead 9 (i.e., the reciprocating motion of the piston 15), which is connected to the piston 15 (see FIG. 1) via the piston rod 16. As the crank 3 rotates, the crankpin bearing 7 revolves around the axis 2a of the crankshaft 2 together with the crankpin 4. 2, the orbital path K of the crankpin bearing 7 is a circular orbit centered on the axis 2a of the crankshaft 2 and having a radius equal to the distance between the axis 2a of the crankshaft 2 and the axis 4a of the crankpin 4. In conjunction with the reciprocating motion of the piston 15 described above, the crankpin bearing 7 performs an orbital motion along the orbital path K, repeating a downward movement from the uppermost position P1 side toward the lowermost position P2 side (see arrow Y1 in FIG. 2) and an upward movement from the lowermost position P2 side toward the uppermost position P1 side (see arrow Y2 in FIG. 2).

[0032] The uppermost position P1 is the uppermost position of the orbital path K of the crankpin bearing 7, and is the position of the crankpin bearing 7 when the piston 15 is at top dead center. The lowermost position P2 is the lowermost position of the orbital path K of the crankpin bearing 7, and is the position of the crankpin bearing 7 when the piston 15 is at bottom dead center.

[0033] As described above, lubricating oil 100 is scattered from the revolving crankpin bearing 7, as indicated by the dashed arrows in FIG. 2 . Specifically, as shown in FIG. 2 , the lubricating oil 100 is released from the revolving crankpin bearing 7 by a combined force of centrifugal force F1 due to the revolving motion of the crankpin bearing 7, tangential force F2 acting in the tangential direction of the orbital path K, and gravity F3. The lubricating oil 100 is then scattered parabolically by the continuing force of gravity F3 and air resistance. The oil receiving section 31 receives the lubricating oil 100 scattered from the revolving crankpin bearing 7 via the inlet 31a. The layout and dimensions of the oil receiving section 31 are set, for example, based on the results of experiments or simulations, so that the lubricating oil 100 scattered from the crankpin bearing 7 can be directly and efficiently collected without passing through the inner wall surface 27 of the marine diesel engine 10.

[0034] Specifically, the oil receiving portion 31 is disposed within an area of ​​the inner wall surface of the marine diesel engine 10 where the lubricating oil 100 may be scattered from the crankpin bearing 7 during orbital movement. For example, in the first embodiment, the oil receiving portion 31 is disposed on the inner wall surface of the frame 5, which is one of the base plate 1 and the frame 5 that surround the orbital path K of the crankpin bearing 7 in a direction intersecting the axis 2a of the crankshaft 2. In particular, from the viewpoint of facilitating the reception of the lubricating oil 100 from the crankpin bearing 7, it is preferable that the oil receiving portion 31 be disposed on the inner wall surface 27 of the frame wall 25 on the side of the inner wall surfaces on both sides of the frame 5 in the width direction D2 where the lubricating oil 100 is more likely to be scattered from the crankpin bearing 7, for example, on the side where the crankpin bearing 7 descends during orbital movement (to the right of the orbital path K in FIG. 2 ), as shown in FIG.

[0035] Furthermore, the lubricating oil 100 in the crankpin bearing 7 is released and scattered from gaps S1, S2 (see FIG. 3) between the crank 3 and the first end 7a and second end 7b of the crankpin bearing 7 in the axial direction of the crankpin 4 (longitudinal direction of the axis 4a). Therefore, as shown in FIG. 3, the oil receiving portion 31 is preferably arranged so that imaginary straight lines (not shown) extending from each of the first end 7a and second end 7b of the crankpin bearing 7 in a direction perpendicular to the axis 4a of the crankpin 4 are located inside the inlet portion 31a of the oil receiving portion 31.

[0036] FIG. 4 is a schematic diagram showing an example of an arrangement of an oil receiving portion in a height direction in the first embodiment of the present invention. As shown in FIG. 4, the oil receiving portion 31 is provided on the inner wall surface 27 of the frame wall 25 or the bedplate wall 26 (the inner wall surface 27 of the frame wall 25 in FIG. 4). From the viewpoint of allowing the oil receiving portion 31 to receive a larger amount of lubricating oil 100 scattered from the crankpin bearing portion 7, the oil receiving portion 31 is preferably provided in a region in the height direction D1 of the marine diesel engine 10 between an uppermost position P1 of the crankpin bearing portion 7 when the piston 15 (see FIG. 1) corresponding to the crankpin 4 is at top dead center and a lowermost position P2 of the crankpin bearing portion 7 when the piston 15 is at bottom dead center, as shown in FIG. 4. Furthermore, as shown in FIG. 4, it is even more preferable that the oil receiving portion 31 be provided in the region between the uppermost position P1 and the lowermost position P2, and above the position of the axis 2a of the crankshaft 2 in the height direction D1 (axis center position P3).

[0037] As shown in FIG. 3, the inlet width W1 of the oil receiving portion 31 is the opening dimension (opening width) of the inlet portion 31a in the axial direction of the crankshaft 2 (the longitudinal direction of the axis 2a). The inlet width W1 of the oil receiving portion 31 is preferably wider to reduce the loss of lubricating oil 100 scattered from the crankpin bearing 7, and is preferably narrower to reduce the likelihood of receiving excess oil other than the lubricating oil 100. In other words, the inlet width W1 of the oil receiving portion 31 is set, taking both of these considerations into account, so that the oil receiving portion 31 can efficiently receive the lubricating oil 100 from the crankpin bearing 7. As shown in FIG. 3, the inlet width W1 of the oil receiving portion 31 is preferably equal to or greater than the width W2 of the crankpin bearing 7. Furthermore, the inlet width W1 of the oil receiving portion 31 is preferably less than the width W3 of the crosshead 9.

[0038] The width W2 of the crankpin bearing portion 7 is the dimension of the crankpin bearing portion 7 in the axial direction of the crankshaft 2. The crosshead 9, as shown in FIG. 3, is composed of a crosshead pin 9a, a crosshead pin bearing portion 9b that rotatably supports the crosshead pin 9a, and a sliding metal 9c that is in sliding contact with the sliding plate 8 (see FIG. 1). The piston rod 16 is connected to the upper end of the crosshead pin 9a. The connecting rod 6 is connected to the lower end of the crosshead pin bearing portion 9b. The width W3 of the crosshead 9 is the dimension in the axial direction (longitudinal direction) of the crosshead pin 9a of the crosshead 9 that moves in conjunction with the crankpin bearing portion 7 in the marine diesel engine 10, and corresponds to the distance between the inner end faces of a pair of sliding metals 9c arranged on both sides in the axial direction, as shown in FIG. 3, for example. The axial direction of the crankshaft 2 is the same as the axial direction D3 of the marine diesel engine 10 and the axial direction of the crankpin 4.

[0039] The excess oil is oil other than the lubricating oil 100 scattered from the crank pin bearing 7. Examples of such excess oil include lubricating oil 101 (see FIGS. 3 and 4) on the crosshead pin bearing 9b and lubricating oil 102 (see FIGS. 3 and 4) between the crosshead 9 and the sliding plate 8 (see FIG. 1). These lubricating oils 101 and 102 are scattered from the gap between the crosshead pin bearing 9b and the sliding metal 9c or the gap between the sliding metal 9c and the sliding plate 8 due to the reciprocating motion or swinging motion of the crosshead 9, which is converted into the rotational motion of the crank 3, as shown in FIGS. 3 and 4, for example.

[0040] 4, the depth L1 of the oil receiving portion 31 is the extension dimension of the oil receiving portion 31 extending from the inner wall surface 27 of the marine diesel engine 10 in a direction intersecting the axis 2a of the crankshaft 2. In other words, the depth of the inlet portion 31a of the oil receiving portion 31 is the depth L1 of the oil receiving portion 31 minus the wall thickness of the oil receiving portion 31. From the viewpoint of facilitating the reception of lubricating oil 100 scattered from the crankpin bearing 7, it is preferable that the depth L1 of the oil receiving portion 31 be made longer as long as the crankpin bearing 7 and the oil receiving portion 31 do not come into contact with each other during orbital movement.

[0041] On the other hand, as shown in FIGS. 2 and 3, the oil receiving section 31 is provided with a discharge pipe 32. The discharge pipe 32 is a pipe for discharging the lubricating oil 100 stored inside the oil receiving section 31, and is provided at the bottom of the oil receiving section 31, for example, as shown in FIG. 2. The discharge pipe 32 communicates with the interior of the oil receiving section 31 and gradually discharges the lubricating oil 100 stored inside the oil receiving section 31 so that the lubricating oil 100 is replaced chronologically with newer lubricating oil. The internal dimensions, such as the inner diameter, of the discharge pipe 32 are set in consideration of the balance between the amount of lubricating oil 100 received and the amount of lubricating oil 100 discharged, so that the lubricating oil 100 can be stored inside the oil receiving section 31 to such an extent that a measurement terminal 33a of a temperature measuring section 33 (described later) is immersed in the lubricating oil 100 to be measured, as shown in FIG. 3. Although not specifically shown, the discharge pipe 32 is connected to an oil recovery section such as an oil pan, and the lubricating oil 100 discharged from the oil receiving section 31 is poured into the oil recovery section.

[0042] The temperature measurement unit 33 is a device for measuring the temperature of the bearing to be monitored. Specifically, as shown in FIG. 2, the temperature measurement unit 33 has a measurement terminal 33a and is configured to measure the temperature of the lubricating oil 100 in the oil receiving unit 31 using this measurement terminal 33a. More specifically, the measurement terminal 33a is disposed inside the oil receiving unit 31 through a through-hole formed in the housing wall of the marine diesel engine 10 (the frame wall 25 in FIG. 2). The main body of the temperature measurement unit 33 is attached to the outer wall surface of the marine diesel engine 10 while connected to this measurement terminal 33a. The temperature measurement unit 33 measures the temperature of the bearing to be monitored, i.e., the temperature of the lubricating oil 100 received by the oil receiving unit 31, using the measurement terminal 33a in contact with the lubricating oil 100 as shown in FIG. 3. In addition, the temperature measuring unit 33 has a display function for displaying the measured temperature of the lubricating oil 100, and for example, displays the temperature (measured value) of the lubricating oil 100 in the oil receiving unit 31 visibly using a scale or a numerical display.

[0043] By visually checking the temperature of the lubricating oil 100 measured by the temperature measurement unit 33, an operator can easily monitor the current bearing temperature of the crankpin bearing 7. For example, if the temperature measurement value (absolute value) of the lubricating oil 100 measured by the temperature measurement unit 33 exceeds a predetermined reference temperature, the operator can use this information to quickly detect an excessive rise in the bearing temperature of the crankpin bearing 7 that released the lubricating oil 100, and can also quickly determine and discover an abnormality in the crankpin bearing 7. Furthermore, if the marine diesel engine 10 has multiple crankpin bearings 7 (i.e., multiple cylinders), if the difference (relative value) between the temperature measurement value of the lubricating oil 100 measured by the temperature measurement unit 33 and the temperature measurement value of the lubricating oil scattered from other crankpin bearings 7 exceeds a predetermined reference value, the operator can use this information to quickly detect an excessive rise in the bearing temperature and quickly discover an abnormality in the crankpin bearing 7, just as in the case of the absolute value. Alternatively, if the difference between the temperature of the lubricating oil 100 measured by the temperature measuring unit 33 and the temperature of the lubricating oil 100 before being supplied to the crankpin bearing 7 exceeds a predetermined reference value, the operator can use this information to detect an excessive rise in the bearing temperature early on, as in the case of the absolute value described above, and discover an abnormality in the crankpin bearing 7 early on.

[0044] As described above, in the bearing temperature monitoring device 30 according to the first embodiment of the present invention, an oil receiving section 31 having an inlet section 31a that opens upward is provided on the inner wall surface 27 of the marine diesel engine 10, and the oil receiving section 31 receives the lubricating oil 100 scattered from the crankpin bearing section 7 that revolves around the axis of the crankshaft 2 via the inlet section 31a, and the temperature measuring section 33 measures the temperature of the lubricating oil 100 received by the oil receiving section 31.

[0045] With the above configuration, the bearing temperature of the crankpin bearing 7 can be measured indirectly based on the measured temperature of the lubricating oil 100 scattered from the crankpin bearing 7, without directly measuring the bearing temperature of the crankpin bearing 7. The temperature rise of the lubricating oil 100 associated with the temperature rise of the crankpin bearing 7 can be detected. Therefore, there is no need to provide a temperature measuring device such as a temperature sensor on the revolving crankpin bearing 7. Therefore, the temperature measuring device cannot fall off the crankpin bearing 7. This eliminates the need for a cumbersome structure, such as a groove or hole, for attaching the temperature measuring device to the crankpin bearing 7, and the need for strict positioning of a non-contact sensor that detects the temperature measurement results from the temperature measuring device without contact. Furthermore, an excessive temperature rise of the crankpin bearing 7 can be indirectly detected based on the detected temperature rise of the lubricating oil 100. Therefore, the bearing temperature to be monitored can be monitored with a simple configuration, and periodic or continuous monitoring of the bearing temperature enables early detection of abnormalities in the crankpin bearing 7.

[0046] Furthermore, in the bearing temperature monitoring device 30 according to the first embodiment of the present invention, the inlet width W1 of the oil receiving portion 31 is set, in the axial direction of the crankshaft 2, to be equal to or greater than the width W2 of the crankpin bearing portion 7 and less than the width W3 of the crosshead pin bearing portion of the crosshead 9 interlocked with the crankpin bearing portion 7. Therefore, the oil receiving portion 31 can reduce the loss of lubricating oil 100 scattered from the crankpin bearing portion 7 and make it difficult for excess oil other than the lubricating oil 100 to be collected. Therefore, the oil receiving portion 31 can suppress the intrusion of the excess oil and efficiently collect the desired lubricating oil 100 from the crankpin bearing portion 7. As a result, the accuracy of measuring the temperature of the lubricating oil 100 itself from the crankpin bearing portion 7 can be improved, and the temperature of the bearing to be monitored can be indirectly measured with high accuracy through the temperature measurement of the lubricating oil 100.

[0047] Furthermore, in the bearing temperature monitoring device 30 according to the first embodiment of the present invention, the oil receiving portion 31 is provided in a region between the uppermost position P1 of the crankpin bearing 7 when the piston 15 is at top dead center and the lowermost position P2 of the crankpin bearing 7 when the piston 15 is at bottom dead center. This allows the oil receiving portion 31 to receive a larger amount of the lubricating oil 100 scattered from the crankpin bearing 7. This ensures that the amount of lubricating oil 100 required for indirect measurement of the temperature of the bearing to be monitored is secured, and the temperature of the lubricating oil 100 can be measured efficiently.

[0048] (Embodiment 2) Next, a bearing temperature monitoring device according to a second embodiment of the present invention will be described. Fig. 5 is a schematic diagram showing an example of the configuration of a bearing temperature monitoring device according to the second embodiment of the present invention. As shown in Fig. 5, a bearing temperature monitoring device 30A according to the second embodiment further includes a blocking section 34 and a discharge pipe 35 in addition to the configuration of the bearing temperature monitoring device 30 according to the first embodiment described above. The other configuration is the same as that of the first embodiment, and the same components are assigned the same reference numerals.

[0049] The blocking portion 34 blocks lubricating oil flowing down the inner wall surface of the marine diesel engine 10 from flowing into the oil receiving portion 31. In detail, as shown in Fig. 5, the blocking portion 34 is configured, for example, in the shape of a canopy, and is provided above the oil receiving portion 31 so as to extend from the inner wall surface 27 of the marine diesel engine 10 toward the crankshaft 2. The inner wall surface 27 on which the blocking portion 34 is provided may be the inner wall surface of the frame wall 25 or the bed plate wall 26, as with the oil receiving portion 31. Note that Fig. 5 illustrates the blocking portion 34 provided on the inner wall surface 27 of the frame wall 25.

[0050] The location and dimensions of this blocking portion 34 are set, for example, based on the results of experiments or simulations, taking into consideration the direct receipt by the oil receiving portion 31 of the lubricating oil 100 scattered from the crankpin bearing portion 7 and the blocking of oil flowing down the inner wall surface 27 of the marine diesel engine 10. Specifically, the blocking portion 34 is provided on the inner wall surface 27 of the marine diesel engine 10 so as to be spaced above the oil receiving portion 31 and cover the inlet portion 31a of the oil receiving portion 31. In this case, the blocking portion 34 is placed above the oil receiving portion 31 with a sufficient distance from the oil receiving portion 31 so as not to block the trajectory (see the dashed arrow in FIG. 5 ) of the lubricating oil 100 scattered from the crankpin bearing portion 7 and directly received by the oil receiving portion 31.

[0051] 5, the depth L2 of the blocking portion 34 is the extension dimension of the blocking portion 34 extending from the inner wall surface 27 of the marine diesel engine 10 in a direction intersecting the axis 2a of the crankshaft 2. The depth L2 of the blocking portion 34 may be shorter than the depth L1 (see FIG. 4) of the oil receiving portion 31, as long as it is a dimension necessary to block oil flowing down the inner wall surface 27 of the marine diesel engine 10 toward the oil receiving portion 31. On the other hand, from the viewpoint of preventing oil from dripping from the blocking portion 34 into the oil receiving portion 31, it is preferable that the depth L2 of the blocking portion 34 be longer than the depth L1 of the oil receiving portion 31 as long as the crankpin bearing portion 7 and the blocking portion 34 do not come into contact with each other during orbital movement.

[0052] Fig. 6 is a schematic diagram for explaining the width of the blocking portion of the bearing temperature monitoring device in embodiment 2 of the present invention. Fig. 6 schematically shows the oil receiving portion 31 and the blocking portion 34 shown in Fig. 5 as viewed from the crankshaft 2 side. As shown in Fig. 6, the width W4 of the blocking portion 34 is the dimension in the same direction as the inlet width W1 of the oil receiving portion 31 (the axial direction of the crankshaft 2 shown in Fig. 5). The width W4 of the blocking portion 34 is set wider than the inlet width W1 of the oil receiving portion 31 to prevent oil that has flowed down the inner wall surface 27 of the marine diesel engine 10 from entering the oil receiving portion 31 through the inlet portion 31a.

[0053] The oil flowing down the inner wall surface 27 may be, for example, lubricating oil that has scattered from the crankpin bearing portion 7 and adhered to the inner wall surface 27, or oil that has scattered from somewhere other than the crankpin bearing portion 7 and adhered to the inner wall surface 27 (i.e., excess oil similar to that in embodiment 1).

[0054] On the other hand, as shown in Figures 5 and 6, the shutoff section 34 is provided with a discharge pipe 35. The discharge pipe 35 is a pipe for discharging oil such as lubricating oil that has been blocked by the shutoff section 34. For example, as shown in Figures 5 and 6, the discharge pipe 35 is provided at the edge of the shutoff section 34 via a gutter or the like, and is routed along the inner wall surface 27 of the marine diesel engine 10 so as to extend through an area spaced apart from the oil receiving section 31. The discharge pipe 35 sequentially discharges the oil received by the shutoff section 34 from the shutoff section 34 so as not to enter the oil receiving section 31. Although not particularly shown, the discharge pipe 35 leads to an oil recovery section such as an oil pan, and pours the oil discharged from the shutoff section 34 into the oil recovery section.

[0055] (Function of the interrupter) Next, the operation of the shutoff unit 34 in the second embodiment of the present invention will be described. Fig. 7 is a schematic diagram showing an example of a state in which the shutoff unit in the second embodiment of the present invention shuts off oil. The shutoff unit 34 described above shuts off lubricating oil flowing down along the inner wall surface of the marine diesel engine 10.

[0056] 7, the lubricating oil released from the crankpin bearing 7 during its orbital movement includes lubricating oil 100 that splashes directly from the crankpin bearing 7 toward the inlet 31a of the oil receiving portion 31, and lubricating oil 100a that splashes from the crankpin bearing 7 onto the inner wall surface of the marine diesel engine 10 (in FIG. 7, the inner wall surface 27 of the frame wall 25). Of the splashed lubricating oil, the blocking portion 34 catches the lubricating oil 100a that adheres to the inner wall surface 27 and then flows down the inner wall surface 27 toward the oil receiving portion 31, thereby blocking the downward flow of the lubricating oil 100a.

[0057] Here, since the interior of the marine diesel engine 10 is in a high temperature state during operation, the temperature of the lubricating oil between the crankpin 4 and the crankpin bearing 7 is unlikely to decrease even after it has scattered from the crankpin bearing 7, and it maintains approximately the same temperature as before it scattered from the crankpin bearing 7. On the other hand, the outer wall surfaces of the frame wall 25 and the bedplate wall 26 are in contact with the outside air (air outside the marine diesel engine 10). Therefore, the lubricating oil 100a scattered from the crankpin bearing 7 onto the inner wall surface 27 of the frame wall 25 or the like is cooled by the housing wall of the marine diesel engine 10, such as the frame wall 25, even though it is inside the marine diesel engine 10. As a result, the temperature of the lubricating oil 100a on the inner wall surface 27 is significantly lower than that before it scattered from the crankpin bearing 7.

[0058] 7, the blocking section 34 blocks the downward flow of the lubricating oil 100a whose temperature has dropped as described above, thereby preventing the lubricating oil 100a from entering the oil receiving section 31 through the inlet section 31a. As a result, the blocking section 34 can prevent the lubricating oil 100a whose temperature is significantly lower than that of the lubricating oil 100 in the oil receiving section 31 from mixing with the lubricating oil 100 whose temperature should be measured by the temperature measuring section 33 (see FIG. 5) in the oil receiving section 31.

[0059] 7, the blocking portion 34 catches lubricating oil 100b that has scattered from the crankpin bearing 7 during revolution and whose scattering trajectory has deviated toward the inner wall surface 27 from the inlet 31a of the oil receiving portion 31. This lubricating oil 100b would likely have scattered from the crankpin bearing 7 toward the inner wall surface 27 if the blocking portion 34 had not been provided on the inner wall surface 27 (hereinafter referred to as deviated lubricating oil). The blocking portion 34 blocks the scattering of such deviated lubricating oil 100b in the same manner as the lubricating oil 100a that flows down the inner wall surface 27. This prevents the lubricating oil 100b, which may adhere to the inner wall surface 27 and cause a temperature drop, from entering the oil receiving portion 31.

[0060] 7, the blocking section 34 blocks the lubricating oil 100a on the inner wall surface 27 and the deviated lubricating oil 100b, but does not hinder the scattering of the lubricating oil 100 from the crankpin bearing 7 directly toward the inlet 31a of the oil receiving section 31, i.e., the scattering of the lubricating oil 100 whose temperature is to be measured. As a result, the blocking section 34 can selectively scatter the lubricating oil 100 whose temperature is to be measured from the lubricating oil scattered from the crankpin bearing 7 toward the inlet 31a of the oil receiving section 31.

[0061] Although not specifically shown, the blocking section 34 also blocks excess oil scattered from places other than the crankpin bearing section 7, in the same manner as the lubricating oil 100a on the inner wall surface 27 and the stray lubricating oil 100b described above. The oil blocked by the blocking section 34 does not enter the oil receiving section 31, but is sequentially discharged from the blocking section 34 through the discharge pipe 35 shown in FIG. 5.

[0062] As described above, the bearing temperature monitoring device 30A according to the second embodiment of the present invention is configured similarly to the first embodiment, except that the blocking section 34 is provided above the oil receiving section 31 and blocks the lubricating oil flowing down the inner wall surface 27 of the marine diesel engine 10. Therefore, the same effects as those of the first embodiment can be obtained, and it is possible to prevent lubricating oil whose temperature has dropped significantly due to contact with the inner wall surface 27 from mixing with the lubricating oil whose temperature is to be measured in the oil receiving section 31. This makes it possible to prevent the temperature of the lubricating oil whose temperature is to be measured from dropping significantly below the temperature that should be measured, and therefore makes it possible to promptly detect an abnormal temperature rise in the lubricating oil due to an excessive rise in the temperature of the bearing to be monitored.

[0063] (Embodiment 3) Next, a bearing temperature monitoring device according to a third embodiment of the present invention will be described. Fig. 8 is a schematic diagram showing one configuration example of a bearing temperature monitoring device according to the third embodiment of the present invention. As shown in Fig. 8, a bearing temperature monitoring device 30B according to the third embodiment has an oil receiving section 41 with a multi-stage structure instead of the oil receiving section 31 of the bearing temperature monitoring device 30A according to the second embodiment described above. The other configuration is the same as that of the second embodiment, and the same components are assigned the same reference numerals.

[0064] The multi-stage oil receiving section 41 is made up of a plurality of oil receiving sections lined up one above the other, and each of these oil receiving sections receives the lubricating oil scattered from the crankpin bearing section 7 to be monitored. In detail, as shown in Fig. 8, the multi-stage oil receiving section 41 includes a first oil receiving section 42 and a second oil receiving section 43, which are examples of a plurality of oil receiving sections. The first oil receiving section 42 and the second oil receiving section 43 are configured in the shape of a container, each having an inlet section 42a, 43a that opens upward, and a plurality of them (two in Fig. 8) are provided vertically along the inner wall surface 27 of the marine diesel engine 10.

[0065] As shown in FIG. 8 , the first oil receiving section 42 is the lowest oil receiving section in the multi-stage oil receiving section 41 and is provided on the inner wall surface 27 of the marine diesel engine 10 so as to extend from the inner wall surface 27 toward the crankshaft 2. The first oil receiving section 42 directly receives the lubricating oil 100 scattered from the crankpin bearing 7 through the inlet portion 42a. The layout and dimensions of the first oil receiving section 42 are set, for example, based on the results of experiments or simulations, to be suitable for receiving the lubricating oil 100 from the crankpin bearing 7. Specifically, the layout and dimensions of the first oil receiving section 42 are preferably set similarly to the single oil receiving section 31 in the first and second embodiments, from the viewpoint of enabling direct and efficient reception of the lubricating oil 100. The first oil receiving section 42 is also provided with a discharge pipe 32, as in the first and second embodiments.

[0066] As shown in FIG. 8 , the second oil receiving portion 43 is the uppermost oil receiving portion in the multi-stage oil receiving portion 41. The second oil receiving portion 43 is located higher in the height direction D1 than the first oil receiving portion 42 described above, and, like the first oil receiving portion 42, is provided on the inner wall surface 27 so as to extend from the inner wall surface 27 toward the crankshaft 2. The second oil receiving portion 43 is located above the first oil receiving portion 42 and directly receives the lubricating oil 100 scattered from the crankpin bearing portion 7 via the inlet portion 43a. At this time, the second oil receiving portion 43 receives the lubricating oil 100 from the crankpin bearing portion 7 in parallel with the first oil receiving portion 42 without interfering with the reception of the lubricating oil 100 by the first oil receiving portion 42 described above. In particular, the lubricating oil 100 received by the second oil receiving portion 43 includes lubricating oil that would, if the second oil receiving portion 43 were not provided, scatter from the crankpin bearing portion 7 and adhere to the inner wall surface 27 above the first oil receiving portion 42. In other words, the second oil receiving portion 43 also functions as a blocking portion that blocks lubricating oil that would otherwise flow down the inner wall surface 27 between the first oil receiving portion 42 and the second oil receiving portion 43, preventing it from entering the first oil receiving portion 42.

[0067] 8, the second oil receiving section 43 is provided with a communication pipe 36 that connects the first oil receiving section 42 and the second oil receiving section 43, which are arranged vertically. The communication pipe 36 is provided at a predetermined location, such as the bottom of the second oil receiving section 43, so as to communicate with the inlet section 42a of the first oil receiving section 42. The communication pipe 36 sequentially delivers the lubricating oil 100 received in the upper second oil receiving section 43 to the lower first oil receiving section 42. As a result, the lubricating oil 100 from the second oil receiving section 43 is added to the lubricating oil 100 in the first oil receiving section 42, and as a result, the amount of lubricating oil 100 in the first oil receiving section 42 is increased.

[0068] In the third embodiment, the measurement terminal 33a of the temperature measurement unit 33 is disposed inside the first oil receiving portion 42 at the lowest stage, as shown in Fig. 8. This measurement terminal 33a is immersed in a mixture of the lubricating oil 100 that has directly splashed from the crankpin bearing portion 7 into the inside of the first oil receiving portion 42 and the lubricating oil 100 that has been added from the second oil receiving portion 43 to the first oil receiving portion 42 (i.e., the increased amount of lubricating oil 100). The temperature measurement unit 33 measures the temperature of the lubricating oil 100 that has been increased in amount in the first oil receiving portion 42.

[0069] The location and dimensions of the second oil receiving portion 43 are set, for example, based on the results of experiments or simulations, taking into consideration the direct receipt by each of the first oil receiving portion 42 and the second oil receiving portion 43 of the lubricating oil 100 scattered from the crankpin bearing portion 7. Specifically, the second oil receiving portion 43 is placed above the first oil receiving portion 42 at a sufficient distance from the first oil receiving portion 42 so as not to block the trajectory (see the dashed arrow in FIG. 8 ) of the lubricating oil 100 scattered from the crankpin bearing portion 7 and directly received by the first oil receiving portion 42. Furthermore, from the viewpoint of being able to directly and efficiently receive the lubricating oil 100 from the crankpin bearing portion 7, the location and dimensions of the second oil receiving portion 43 are preferably set similarly to the single oil receiving portion 31 in the first and second embodiments, provided that it is placed above the first oil receiving portion 42. In particular, the depth of the second oil receiving portion 43 and the vertical separation distance between the first oil receiving portion 42 and the second oil receiving portion 43 are preferably set so that the lubricating oil that would otherwise scatter from the crankpin bearing portion 7 and adhere to the inner wall surface 27 above the first oil receiving portion 42 can be received by the second oil receiving portion 43 without adhering to the inner wall surface 27. Although not specifically shown, the depth of the second oil receiving portion 43 is the extension dimension of the second oil receiving portion 43 that extends from the inner wall surface 27 of the marine diesel engine 10 in a direction intersecting the axis 2a of the crankshaft 2.

[0070] Fig. 9 is a schematic diagram for explaining the width of the multi-stage oil receiving portion in the third embodiment of the present invention. Fig. 9 shows a schematic view of the multi-stage oil receiving portion 41 and the cut-off portion 34 shown in Fig. 8 as viewed from the crankshaft 2 side.

[0071] 9, the inlet width W5 of the first oil receiving portion 42 is the opening dimension of the inlet portion 42a in the axial direction of the crankshaft 2 (see FIG. 8). From the viewpoint of being able to efficiently receive the lubricating oil 100 from the crankpin bearing 7, it is preferable that the inlet width W5 of the first oil receiving portion 42 be the same as the inlet width W1 (see FIG. 3) of the oil receiving portion 31 in the above-described first and second embodiments.

[0072] The inlet width W6 of the second oil receiving portion 43 is the opening dimension of the inlet portion 43a in the axial direction of the crankshaft 2, similar to the first oil receiving portion 42. From the viewpoint of efficiently receiving the lubricating oil 100 from the crankpin bearing portion 7, the inlet width W6 of the second oil receiving portion 43 is preferably set to the same as the inlet width W1 of the oil receiving portion 31 in the first and second embodiments. In particular, in order to prevent lubricating oil scattered from the crankpin bearing portion 7 from adhering to the inner wall surface 27 between the first oil receiving portion 42 and the second oil receiving portion 43 and flowing downward toward the inlet portion 42a of the first oil receiving portion 42, the inlet width W6 of the second oil receiving portion 43 is more preferably equal to or greater than the inlet width W5 of the first oil receiving portion 42.

[0073] In the third embodiment, the width W4 of the blocking portion 34 is the dimension in the same direction as the inlet widths W5 and W6 of the multi-stage oil receiving portion 41. The width W4 of the blocking portion 34 is set wider than the oil receiving portions (the first oil receiving portion 42 and the second oil receiving portion 43 in the third embodiment) of the multi-stage oil receiving portion 41 in order to prevent oil that has flowed down the inner wall surface 27 of the marine diesel engine 10 from entering the oil receiving portions. For example, as shown in FIG. 9 , the width W4 of the blocking portion 34 is larger than the inlet widths W5 and W6 of the first oil receiving portion 42 and the second oil receiving portion 43.

[0074] 8 and 9, the blocking section 34 is provided on the inner wall surface 27 of the marine diesel engine 10 so as to be spaced above the uppermost second oil receiving section 43 and cover each inlet of the multi-stage oil receiving section 41. In this case, the blocking section 34 is disposed above the multi-stage oil receiving section 41 at a sufficient distance from the second oil receiving section 43 so as not to block the trajectory (see the dashed arrow in FIG. 8) of the lubricating oil 100 that is scattered from the crankpin bearing section 7 and directly received in the uppermost second oil receiving section 43.

[0075] In this embodiment 3, the discharge pipe 35 of the shutoff section 34 is piped along the inner wall surface 27 of the marine diesel engine 10 so as to extend through an area spaced apart from the multi-stage oil receiving section 41, as shown in Figures 8 and 9, for example.

[0076] As described above, in the bearing temperature monitoring device 30B according to the third embodiment of the present invention, the oil receiving section has a multi-stage structure in which a plurality of oil receiving sections are provided vertically along the inner wall surface 27 of the marine diesel engine 10, constituting the oil receiving section 41, and the other sections are configured similarly to the second embodiment. Therefore, the same effects as those of the second embodiment can be obtained, and the lubricating oil to be measured can be efficiently received inside the oil receiving section (e.g., the first oil receiving section 42 at the lowest stage) in the multi-stage oil receiving section 41 in which the measurement terminal 33a of the temperature measuring section 33 is located. This makes it possible to collect lubricating oil whose temperature is closer to the temperature of the bearing to be monitored as the lubricating oil to be measured, and by measuring the temperature of such lubricating oil, the bearing temperature can be monitored with higher accuracy.

[0077] (Embodiment 4) Next, a bearing temperature monitoring device according to a fourth embodiment of the present invention will be described. Fig. 10 is a schematic diagram showing one configuration example of a bearing temperature monitoring device according to the fourth embodiment of the present invention. Fig. 11 is a schematic cross-sectional view of the bearing temperature monitoring device shown in Fig. 10, taken along line BB. As shown in Figs. 10 and 11, a bearing temperature monitoring device 30C according to the fourth embodiment has an oil receiving portion 51 with a narrow inlet structure instead of the oil receiving portion 31 of the bearing temperature monitoring device 30A according to the second embodiment described above. The other configuration is the same as that of the second embodiment, and the same components are designated by the same reference numerals.

[0078] The oil receiving portion 51 is configured in a container-like shape with a narrower inlet structure than the oil receiving portions in the first to third embodiments described above, and receives lubricating oil scattered from the crankpin bearing 7 to be monitored. This oil receiving portion 51 is provided with one or more narrow inlet structures corresponding to at least one of both ends of the crankpin bearing 7 in the axial direction of the crankshaft 2. For example, as shown in FIGS. 10 and 11 , the oil receiving portion 51 has, as the narrow inlet structure, a first inlet portion 52 corresponding to the first end 7a of the crankpin bearing 7 and a second inlet portion 53 corresponding to the second end 7b of the crankpin bearing 7. The upper portion of the oil receiving portion 51 is open at the first inlet portion 52 and the second inlet portion 53, and is configured like a closed lid in the areas other than these inlet portions. As shown in FIG. 10, the oil receiving portion 51 is provided on the inner wall surface 27 of the marine diesel engine 10 so as to extend from the inner wall surface 27 toward the crankshaft 2 side.

[0079] As shown in FIG. 11 , each of the first inlet portion 52 and the second inlet portion 53 of the oil receiving portion 51 is a box-shaped structure that opens upward and is narrower than the crankpin bearing portion 7 in the axial direction of the crankshaft 2. As shown in FIGS. 10 and 11 , the first inlet portion 52 and the second inlet portion 53 are provided in the upper part of the oil receiving portion 51 so as to extend from the inner wall surface 27 of the marine diesel engine 10 toward the crankshaft 2 and to be spaced apart from each other by a predetermined distance in the axial direction of the crankshaft 2. As shown in FIG. 11 , the first inlet portion 52 and the main body of the oil receiving portion 51 are communicated with each other via a communication hole 54. Similarly, the second inlet portion 53 and the main body of the oil receiving portion 51 are communicated with each other via a communication hole 55. The first inlet 52 receives the lubricating oil 100 scattered from the first end 7a of the crankpin bearing 7 and allows the lubricating oil 100 to flow into the main body of the oil receiving part 51 via a communication hole 54. The second inlet 53 receives the lubricating oil 100 scattered from the second end 7b of the crankpin bearing 7 and allows the lubricating oil 100 to flow into the main body of the oil receiving part 51 via a communication hole 55.

[0080] The arrangement and dimensions of each of the first inlet portion 52 and the second inlet portion 53 are set to be suitable for receiving the lubricating oil 100 from the crankpin bearing portion 7, for example, based on the results of an experiment or a simulation.

[0081] 11, the first inlet portion 52 is disposed on the first end 7a side of the crankpin bearing 7, out of both ends of the oil receiving portion 51 in the axial direction of the crankshaft 2. That is, an imaginary line (see the dashed line in FIG. 11) extending from the first end 7a of the crankpin bearing 7 in a direction perpendicular to the axis 4a of the crankpin 4 is located inside the first inlet portion 52. From the viewpoint of making it easier for the first inlet portion 52 to receive the lubricating oil 100 from the first end 7a of the crankpin bearing 7, it is preferable that the center position of the first inlet portion 52 in the axial direction of the crankpin 4 (axial direction D3) and the position of the first end 7a of the crankpin bearing 7 coincide with each other.

[0082] 11, the width W7 of the first inlet portion 52 is an example of the narrow inlet width of the oil receiving portion 51 in the third embodiment, and is the opening dimension of the first inlet portion 52 in the axial direction of the crankshaft 2. From the viewpoint of facilitating the reception of lubricating oil 100 from the first end portion 7a of the crankpin bearing portion 7, the width W7 of the first inlet portion 52 is preferably larger than the gap S1 between the first end portion 7a and the crank 3.

[0083] 11, the second inlet portion 53 is disposed on the second end 7b side of the crankpin bearing 7, out of both ends of the oil receiving portion 51 in the axial direction of the crankshaft 2. That is, an imaginary line (see the dashed dotted line in FIG. 11) extending from the second end 7b of the crankpin bearing 7 in a direction perpendicular to the axis 4a of the crankpin 4 is located inside the second inlet portion 53. From the viewpoint of making it easier for the second inlet portion 53 to receive the lubricating oil 100 from the second end 7b of the crankpin bearing 7, it is preferable that the center position of the second inlet portion 53 in the axial direction of the crankpin 4 and the position of the second end 7b of the crankpin bearing 7 coincide with each other.

[0084] 11, the width W8 of the second inlet portion 53 is an example of the narrow inlet width of the oil receiving portion 51 in the third embodiment, and is the opening dimension of the second inlet portion 53 in the axial direction of the crankshaft 2. From the viewpoint of facilitating the reception of lubricating oil 100 from the second end portion 7b of the crankpin bearing portion 7, the width W8 of the second inlet portion 53 is preferably larger than the gap S2 between the second end portion 7b and the crank 3.

[0085] Furthermore, from the viewpoint of making it difficult for the first inlet portion 52 and the second inlet portion 53 to receive excess oil other than the lubricating oil 100 in the crankpin bearing portion 7, the widths W7 and W8 of the first inlet portion 52 and the second inlet portion 53 are preferably less than the width W2 of the crankpin bearing portion 7, and more preferably less than half the width W2 of the crankpin bearing portion 7. Also, as shown in FIG. 11 , the width W9 between one end of the first inlet portion 52 and the other end of the second inlet portion 53 in the axial direction of the crankshaft 2 is greater than the width W2 of the crankpin bearing portion 7 and is preferably less than the width W3 (see FIG. 3) of the crosshead pin bearing portion of the crosshead 9. Meanwhile, the width W4 (see FIG. 6) of the blocking portion 34 is greater than the widths W7 and W8 of the first inlet portion 52 and the second inlet portion 53 and is also greater than the width W9 of the oil receiving portion 51.

[0086] Although not particularly shown, the depth of each of the first inlet portion 52 and the second inlet portion 53 may be greater than or less than the depth of the main body of the oil receiving portion 51. From the viewpoint of facilitating the reception of the lubricating oil 100 scattered from the crankpin bearing portion 7, it is preferable that the depth of each of the first inlet portion 52 and the second inlet portion 53 is greater.

[0087] In the fourth embodiment, the measurement terminal 33a of the temperature measurement unit 33 is disposed inside the main body of the oil receiving unit 51, as shown in Figures 10 and 11. This measurement terminal 33a is immersed in the lubricating oil 100 received into the main body of the oil receiving unit 51 from the crankpin bearing unit 7 via the first inlet 52 or the second inlet 53. In this way, the temperature measurement unit 33 measures the temperature of the lubricating oil 100 in the oil receiving unit 51. The main body of the oil receiving unit 51 is provided with a discharge pipe 32, as in the first to third embodiments described above.

[0088] As described above, in the bearing temperature monitoring device 30C according to the fourth embodiment of the present invention, the inlet of the oil receiving portion 51 is configured narrower in the axial direction of the crankshaft 2 than the crankpin bearing portion 7, and at least one inlet is provided corresponding to at least one of the two axial ends of the crankpin bearing portion 7. The remaining configuration is the same as that of the second embodiment. Therefore, while achieving the same effects as the second embodiment, the inlet of the oil receiving portion 51 for receiving the lubricating oil whose temperature is to be measured can be narrowed to at least one of the two axial ends of the crankpin bearing portion 7 from which the lubricating oil is discharged. This allows the lubricating oil whose temperature is to be measured to be efficiently received while minimizing the intrusion of excess oil from sources other than the crankpin bearing portion 7 into the oil receiving portion 51. As a result, the temperature of the lubricating oil whose temperature is to be measured becomes closer to the temperature of the bearing whose temperature is to be monitored. Therefore, by measuring the temperature of such lubricating oil, the bearing temperature can be monitored with higher accuracy.

[0089] (Embodiment 5) Next, a bearing temperature monitoring device according to a fifth embodiment of the present invention will be described. Fig. 12 is a schematic diagram showing an example of the configuration of a bearing temperature monitoring device according to the fifth embodiment of the present invention. As shown in Fig. 12, a bearing temperature monitoring device 30D according to the fifth embodiment further comprises an output unit 38 and a control unit 39 in addition to the configuration of the bearing temperature monitoring device 30 according to the first embodiment described above. The other configuration is the same as that of the first embodiment, and the same components are assigned the same reference numerals.

[0090] The output unit 38 outputs the result of the determination of the bearing temperature to be monitored. Specifically, the output unit 38 is configured by a device such as a display device or an audio output device, and is connected to the control unit 39 so as to be able to send and receive signals, as shown in FIG. 12 . The output unit 38 outputs the result of the determination of the temperature of the crankpin bearing 7 by the control unit 39, i.e., the result of the determination of whether the bearing temperature to be monitored is abnormal. For example, the output unit 38 may output the result of the determination of whether the bearing temperature is abnormal by displaying visually identifiable information such as light or text, or by audibly identifiable information such as sound. The bearing temperature determination result output by the output unit 38 may include, for example, a determination result indicating whether the bearing temperature to be monitored has risen excessively, a determination result indicating whether an abnormality has occurred in the crankpin bearing 7, etc. By outputting the bearing temperature determination result as described above, the output unit 38 can notify an external party (such as an operator) of an excessive temperature rise or the occurrence of an abnormality in the crankpin bearing 7.

[0091] The control unit 39 has both a control function for controlling the operation of the output unit 38 and a processing function as a determination unit for determining whether the temperature of the bearing to be monitored is abnormal. Specifically, the control unit 39 is configured with a CPU that executes a processing program, a memory, and the like, and is connected to the temperature measurement unit 33 and the output unit 38 so as to be able to send and receive signals, as shown in FIG. 12 . The control unit 39 acquires, continuously or intermittently in time series, an electrical signal indicating the temperature of the lubricating oil measured by the temperature measurement unit 33. The control unit 39 determines whether the temperature of the crankpin bearing 7 to be monitored is abnormal based on the temperature information indicated by the acquired electrical signal, i.e., the measured lubricating oil temperature.

[0092] Specifically, the control unit 39 has a preset reference value for the temperature of the lubricating oil in the crankpin bearing 7. The control unit 39 compares the measured lubricating oil temperature value obtained from the temperature measurement unit 33 with the reference value, and if the measured lubricating oil temperature value exceeds the reference value, it determines that the temperature of the lubricating oil from the crankpin bearing 7 has risen excessively and is in an abnormal state. Based on this, the control unit 39 determines that there has been an abnormal rise in the temperature of the bearing to be monitored, i.e., that an abnormality has occurred in the crankpin bearing 7. The control unit 39 then controls the output unit 38 to output information indicating the occurrence of an abnormality in the crankpin bearing 7 as the bearing temperature determination result. At this time, the control unit 39 may cause the output unit 38 to output information indicating the abnormal rise in bearing temperature together with the information indicating the occurrence of the abnormality in the crankpin bearing 7.

[0093] Furthermore, if the marine diesel engine 10 has multiple crankpin bearings 7 (i.e., multiple cylinders), the control unit 39 may compare the measured lubricant temperature value obtained from the temperature measurement unit 33 with the measured temperature value of lubricant scattered from other crankpin bearings within the marine diesel engine 10 to determine the bearing temperature to be monitored. For example, the control unit 39 calculates the temperature difference between the measured lubricant temperature value obtained from the temperature measurement unit 33 and the measured temperature value of lubricant scattered from other crankpin bearings, and if this calculated temperature difference exceeds the reference value, determines that the temperature of the lubricant from the crankpin bearing 7 has risen excessively and is in an abnormal state. In the case of determination processing based on this temperature difference, the control unit 39 determines that an abnormality has occurred in the crankpin bearing 7, as in the determination processing based on the comparison of the measured temperature value with the reference value described above, and controls the output unit 38 to output the determination result of the abnormality, etc., of the crankpin bearing 7.

[0094] Alternatively, the control unit 39 may determine the bearing temperature to be monitored based on the temperature difference between the lubricant temperature measured by the temperature measurement unit 33 and the lubricant temperature measured before being supplied to the crankpin bearing 7. For example, the control unit 39 calculates the temperature difference between the lubricant temperature measured by the temperature measurement unit 33 and the lubricant temperature measured before being supplied to the crankpin bearing 7, and if this calculated temperature difference exceeds the reference value, determines that the temperature of the lubricant from the crankpin bearing 7 has risen excessively and is in an abnormal state. In the case of determination processing based on this temperature difference, the control unit 39 determines that an abnormality has occurred in the crankpin bearing 7, as in the determination processing based on the comparison between the temperature measurement and the reference value described above, and controls the output unit 38 to output the determination result of the occurrence of an abnormality in the crankpin bearing 7, etc.

[0095] Furthermore, when the control unit 39 compares the measured lubricant temperature value acquired from the temperature measurement unit 33 with the reference value and the measured lubricant temperature value is equal to or lower than the reference value, the control unit 39 determines that the temperature of the lubricant from the crankpin bearing 7 is within an allowable range (normal state). Based on this, the control unit 39 determines that the bearing temperature to be monitored is normal, that is, that the crankpin bearing 7 is normal. When the control unit 39 performs the determination process based on the temperature difference described above, if the lubricant temperature difference is equal to or lower than the reference value, the control unit 39 determines that the crankpin bearing 7 is normal.

[0096] In any of the above determination processes, when the control unit 39 determines that the crankpin bearing 7 is in a normal state, it controls the output unit 38 to output information indicating the normal state of the crankpin bearing 7 as the determination result of the bearing temperature. At this time, the control unit 39 may cause the output unit 38 to output information indicating the normal state of the bearing temperature together with the information on the normal state of the crankpin bearing 7. Alternatively, the control unit 39 may stop the output unit 38 when the bearing temperature is in a normal state, and operate the output unit 38 only when the bearing temperature is in an abnormal state.

[0097] As described above, in the bearing temperature monitoring device 30D according to the fifth embodiment of the present invention, the control unit 39 determines whether the temperature of the crankpin bearing 7 is abnormal based on the temperature of the lubricating oil measured by the temperature measurement unit 33, and the output unit 38 outputs the bearing temperature determination result by the control unit 39. The rest of the configuration is the same as that of the first embodiment. Therefore, the same effects as those of the first embodiment described above can be obtained, and it is possible to automatically determine in chronological order whether the temperature of the bearing to be monitored has risen excessively, i.e., whether an abnormality has occurred in the crankpin bearing 7. This allows the bearing temperature to be automatically monitored without any hassle, and the occurrence of an abnormality in the crankpin bearing 7 can be detected easily and early.

[0098] In the above-described first to fifth embodiments, the oil receiving portion is disposed on the inner wall surface 27 of the frame wall 25 on the side where the crankpin bearing 7 moves downward during revolution, but the present invention is not limited to this. For example, the oil receiving portion of the bearing temperature monitoring device according to the present invention may be disposed on the inner wall surface of the frame wall on the side where the crankpin bearing 7 moves upward during revolution. Furthermore, the inner wall surface on which the oil receiving portion is disposed is not limited to the inner wall surface of the frame wall, and may also be the inner wall surface of the base plate wall.

[0099] Furthermore, in the above-described first to fifth embodiments, the oil receiving portion is inclined with respect to the width direction D2 of the marine diesel engine 10, but the present invention is not limited to this. For example, the oil receiving portion of the bearing temperature monitoring device according to the present invention may be configured to extend from the inner wall surface in a direction parallel to the width direction D2 of the marine diesel engine 10. Similarly, the blocking portion may also be configured to extend from the inner wall surface in a direction parallel to the width direction D2.

[0100] Furthermore, in the above-described first to fifth embodiments, a marine diesel engine has been described as an example of an internal combustion engine to which the bearing temperature monitoring device according to the present invention is applied, but the present invention is not limited to this. For example, the bearing temperature monitoring device according to the present invention may be applied to internal combustion engines other than marine diesel engines, such as vehicle engines.

[0101] In the third embodiment described above, as an example of a multi-stage oil receiving portion, a two-stage oil receiving portion configured with two oil receiving portions (first oil receiving portion 42 and second oil receiving portion 43) aligned vertically along the inner wall surface is shown, but the present invention is not limited to this. For example, the multi-stage oil receiving portion may be configured with three or more oil receiving portions aligned vertically along the inner wall surface.

[0102] In the third embodiment, the temperature measuring terminal is disposed inside the lowest oil receiving section of the multi-stage oil receiving section to measure the temperature of the lubricating oil collected in the lowest oil receiving section, but the present invention is not limited to this. For example, the temperature measuring terminal may be disposed inside any of the multi-stage oil receiving sections, or may be disposed inside all of the multi-stage oil receiving sections.

[0103] In addition, in the above-described fourth embodiment, the oil receiving portion is provided with two narrow inlet portions corresponding to both axial ends of the crankpin bearing portion, but the present invention is not limited to this. For example, one narrow inlet portion may be provided in the oil receiving portion corresponding to one of both axial ends of the crankpin bearing portion.

[0104] Furthermore, the present invention is not limited to the above-described first to fifth embodiments. Configurations in which the above-described components are appropriately combined are also included in the present invention. For example, a bearing temperature monitoring device according to the present invention may be a combination of at least two of the above-described first to fifth embodiments. In addition, all other embodiments, examples, operational techniques, etc. made by those skilled in the art based on the above-described first to fifth embodiments are included in the scope of the present invention. [Explanation of symbols]

[0105] 1 base plate 2 crankshaft 2a Axis center 3 Crank 4 crank pin 4a Axis center 5 Frame 6 connecting rod 7 Crank pin bearing 7a First end 7b Second end 8 Sliding plate 9 Crosshead 9a Crosshead pin 9b Crosshead pin bearing 9c Slide 10 Marine diesel engines 11 Cylinder jacket 12 cylinders 13 Cylinder liner 14 Cylinder cover 15 pistons 16 Piston rod 17 Combustion chamber 18 Exhaust valve 19 Upper valve train 20 Exhaust manifold 21 Exhaust pipe 22 Tie bolt 25 Frame wall 26 Base plate wall 27 Inner wall surface 30, 30A, 30B, 30C, 30D Bearing temperature monitoring device 31, 41, 51 Oil receiving section 31a, 42a, 43a entrance section 32, 35 Discharge pipe 33 Temperature measurement section 33a measurement terminal 34 Breaker 36 Communication pipe 38 Output section 39 Control Unit 42 No. 1 Oil Receptacle 43 Second Oil Receptacle 52 1st entrance section 53 2nd entrance section 54, 55 communication hole 100, 100a, 100b, 101, 102 Lubricating oil D1 Height direction D2 width direction D3 Axial direction F1 centrifugal force F2 Wiring direction force F3 Gravity K orbital track P1 top position P2 bottom position P3 axis position S1, S2 gap Y1, Y2 Yayin

Claims

1. A bearing temperature monitoring device for monitoring the temperature of a bearing portion that rotatably supports a crank pin of a crank that rotates around the axis of a crankshaft of an internal combustion engine, comprising: an oil receiving section that has an inlet portion that opens upward and is provided on an inner wall surface of the internal combustion engine, and that receives, via the inlet portion, lubricating oil scattered from the bearing portion that revolves around the axis of the crankshaft as the crank rotates; a temperature measuring unit for measuring the temperature of the lubricating oil received by the oil receiving unit; a blocking portion provided above the oil receiving portion and configured to block lubricating oil flowing down along an inner wall surface of the internal combustion engine toward the oil receiving portion; A bearing temperature monitoring device comprising:

2. The oil receiving portion is provided in plurality along the inner wall surface of the internal combustion engine, 2. The bearing temperature monitoring device according to claim 1.

3. The inlet portion of the oil receiving portion is configured to be narrower than the bearing portion in the axial direction of the crankshaft, and one or more inlet portions are provided corresponding to at least one end portion of the bearing portion in the axial direction of the crankshaft.

3. The bearing temperature monitoring device according to claim 1 or 2.

4. an inlet width of the oil receiving portion is equal to or greater than the width of the bearing portion in the axial direction of the crankshaft, and is less than the width of a crosshead pin bearing portion of a crosshead that interlocks with the bearing portion of the internal combustion engine; 3. The bearing temperature monitoring device according to claim 1 or 2.

5. the oil receiving portion is provided in a region between an uppermost position of the bearing portion when a piston corresponding to the crank pin of the internal combustion engine is positioned at a top dead center and a lowermost position of the bearing portion when the piston is positioned at a bottom dead center.

5. The bearing temperature monitoring device according to claim 1, wherein the temperature of the bearing is monitored by the temperature monitoring device.

6. a control unit that determines whether the temperature of the bearing unit is abnormal based on the temperature of the lubricating oil measured by the temperature measurement unit; and an output unit that outputs a result of the determination of the temperature of the bearing unit by the control unit; 6. The bearing temperature monitoring device according to claim 1, further comprising:

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