Gear reducer and construction machine

Abstract

To provide a gear reducer capable of efficiently diagnosing a state of lubricating oil while suppressing generation of bubbles without requiring a pump driven by an external driving force and a bubble removing device.SOLUTION: A gear speed reducer according to the present invention includes a housing that accommodates a planetary gear mechanism, a flat plate disposed between an oil surface of lubricating oil filled in the housing and the gear speed reducer, and a sensor that detects foreign matter in the lubricating oil.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a gear reducer and a construction machine equipped with the gear reducer. [Background technology]

[0002] Construction machinery, including hydraulic excavators, are often equipped with a reducer as a power transmission device that transmits the power of a prime mover, such as a hydraulic motor, via gears, etc. The reducer case is filled with lubricating oil that lubricates the gears, bearings, etc. Because reducers cannot prevent wear on the gears, etc., foreign matter such as metal chips and broken pieces resulting from wear can get mixed into the lubricating oil. If foreign matter gets mixed into the lubricating oil, it could damage the gears, bearings, oil seals, etc.

[0003] Although not related to construction machinery, Patent Document 1 describes a technology for diagnosing the condition of lubricant in rotating machinery. The document aims to "provide a highly reliable diagnostic technology for diagnosing the condition of lubricant in rotating machinery such as wind turbines using a condition monitoring sensor," and describes the following technology (see abstract): "A lubricant diagnostic system includes a lubricant-using device, a lubricant tank for storing lubricant to be supplied to the lubricant-using device, a circulation line through which the lubricant flows between the lubricant tank and the lubricant-using device, a pump installed in the circulation line for circulating the lubricant toward the lubricant-using device, a filter installed in the circulation line, and a sensor for measuring the characteristics of the lubricant. In this system, the sensor is located in the path of the lubricant flowing from the pump to the filter, at a point where the oil pressure is higher than the position immediately after the filter. Alternatively, the sensor is located at a point lower than half the depth of the lubricant in the lubricant tank."

[0004] Patent Document 2 describes a construction machine equipped with a gear reducer. The document addresses the issue of "providing a slewing device and a construction machine equipped with the same that can accurately diagnose the condition of the lubricating oil in the reducer without requiring a pump driven by an external driving force," and describes the following technology (see abstract): "A slewing device equipped with a hydraulic motor and a gear reducer having a carrier driven by the hydraulic motor, the device comprising: an impeller attached to the carrier within a housing of the gear reducer; an oil passage structure having an upper opening located outside the impeller in the radial direction of the carrier and constituting an oil passage for circulating the lubricating oil filled in the housing via the outside of the housing; and a contamination sensor provided in the oil passage structure for detecting foreign matter in the lubricating oil flowing through the oil passage structure." [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2020-084899 [Patent Document 2] Japanese Patent Publication No. 2023-096231 Summary of the Invention [Problem to be solved by the invention]

[0006] The lubricant diagnostic system in Patent Document 1 requires an externally driven pump to supply lubricant to the sensor. Furthermore, since air bubbles generated in the lubricant may be detected as foreign matter, the influence of air bubbles must be eliminated for accurate measurement. For example, this requires the incorporation of an air bubble removal device, such as an ultrasonic wave or heater, upstream of the sensor.

[0007] Furthermore, the construction machine described in Patent Document 2 supplies lubricating oil from within the slewing device to an externally installed sensor. Therefore, space is required to place the sensor outside the slewing device, so there is room for improvement from the perspective of space saving. There is also room for improvement from the perspective of suppressing the generation of air bubbles.

[0008] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a gear reducer that can efficiently diagnose the condition of lubricating oil while suppressing the generation of bubbles, without requiring a pump or bubble removal device driven by an external driving force, and a construction machine equipped with a gear reducer. [Means for solving the problem]

[0009] The gear reducer of the present invention comprises a housing that accommodates a planetary gear mechanism, a flat plate arranged between the gear reducer and the oil level of lubricating oil filled in the housing, and a sensor that detects foreign matter in the lubricating oil. [Effects of the Invention]

[0010] The gear reducer according to the present invention can efficiently diagnose the condition of lubricating oil while suppressing the generation of bubbles, without requiring an externally driven pump or bubble removal device. Problems, configurations, and effects other than those described above will become apparent from the following description of the preferred embodiment of the invention. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a side view schematically showing the appearance of a hydraulic excavator 1, which is an example of a construction machine according to a first embodiment. [Figure 2] 2 is a cross-sectional view of a slewing device 11 and a slewing ring 5 mounted on the hydraulic excavator 1. FIG. [Figure 3] FIG. 2 is a schematic cross-sectional view of a swivel device 11. [Figure 4] FIG. 10 is an enlarged view of the sensor 62 and its surroundings. [Figure 5] 10 is a side cross-sectional view of a swing device 11 provided in a hydraulic excavator 1 according to a second embodiment. FIG. [Figure 6] FIG. 10 is a side cross-sectional view of a swing device 11 provided in a hydraulic excavator 1 according to a third embodiment. [Figure 7] FIG. 10 is a side cross-sectional view of a swing device 11 provided in a hydraulic excavator 1 according to a fourth embodiment. [Figure 8] FIG. 10 is a network diagram showing the connection between a controller 30 provided in a construction machine according to a fifth embodiment and its communication destination. [Figure 9] 10 is an example showing the change over time in the number of foreign objects counted by the sensor 62. [Figure 10] 10 is a flowchart illustrating a procedure for the server 101 to diagnose a lubricant. DETAILED DESCRIPTION OF THE INVENTION

[0012] <First Embodiment> 1 is a side view schematically showing the appearance of a hydraulic excavator 1, which is an example of a construction machine according to a first embodiment of the present invention. The following describes a hydraulic excavator equipped with a bucket as an attachment located at the tip of a front working mechanism, but the attachment can be replaced with various other attachments such as a grapple, breaker, or lifting magnet in addition to the bucket.

[0013] The hydraulic excavator 1 comprises a self-propelled crawler-type lower track body 2 and an upper rotating body 3 rotatably mounted on the lower track body 2. A working device 4 is attached to the front side of the upper rotating body 3 so that it can be raised and lowered, and this working device 4 is operated by an operator to perform excavation work and the like. A slewing ring 5 is provided between the lower track body 2 and the upper rotating body 3, and the upper rotating body 3 is rotatably supported on the lower track body 2 via the slewing ring 5. A slewing device 11 that drives the upper rotating body 3 to swing left and right is mounted on a slewing frame 3A that forms the base of the upper rotating body 3.

[0014] The upper rotating body 3 is equipped with a controller 30 that performs processing to diagnose abnormalities in a reducer 44 (described below) included in the rotating device 11 based on the state of the lubricating oil, and a wireless communication device 33 for communicating data processed by the controller 30 with an external terminal. The controller 30 includes a processor (e.g., a CPU) and a storage device (e.g., a memory), and the processor executes various processes based on programs stored in the storage device.

[0015] Fig. 2 is a cross-sectional view of the slewing device 11 and slewing ring 5 mounted on the hydraulic excavator 1. First, the overall operation of the slewing device 11 will be explained using Fig. 2. It should be noted that some of the components will be explained again in Fig. 3, and are therefore not shown in Fig. 2.

[0016] (Slewing ring 5) The slewing ring 5 includes an inner ring 5A fixed onto the support cylinder 2A (see FIG. 1) of the lower running body 2, an outer ring 5B fixed to the underside of the slewing frame 3A, and a number of steel balls 5C (only one is shown in FIG. 2) disposed between the inner ring 5A and the outer ring 5B. Internal teeth 5D are formed around the entire inner circumference of the inner ring 5A. When the pinion 40B provided at the lower end of the output shaft 40 of the slewing device 11 is rotated by the operation of the slewing device 11, the outer ring 5B fixed to the slewing frame 3A rotates around the inner ring 5A, causing the upper slewing body 3 to perform a slewing operation on the lower running body 2.

[0017] (Swivel device 11) The slewing device 11 includes a hydraulic motor 16 that rotates the upper slewing body 3 left and right, a reducer 44 having a rotating shaft (for example, a second carrier 46D or an output shaft 40 described below) driven by the hydraulic motor 16, and a housing 12 that covers the reducer 44. The housing 12 is filled with lubricating oil (not shown) that lubricates the gears and bearings in the reducer 44.

[0018] (Reducer 44) The reducer 44 reduces the rotation speed input from the hydraulic motor 16 and outputs the reduced speed to the output shaft 40. The reducer 44 of this embodiment is a gear reducer, and includes a first planetary gear mechanism 45 located in the top stage (first stage) and a second planetary gear mechanism 46 located in the stage next to the top stage (second stage).

[0019] (First planetary gear mechanism 45) The first planetary gear mechanism 45 comprises a first sun gear 45A fixed to the output shaft (rotation shaft) of the hydraulic motor 16, a plurality of first planetary gears 45B (in this embodiment, three first planetary gears 45B are arranged) that mesh with the first sun gear 45A and can rotate while revolving and rotating around the first sun gear 45A, a first internal gear 45C that meshes with the plurality of first planetary gears 45B and is fixed to the housing 12 of the reducer 44, and a first carrier 45D that is fixed to a plurality of first planetary gear pins inserted into the rotation center of the first planetary gear 45B and can rotate at the orbital speed of the first planetary gear 45B.

[0020] (Second planetary gear mechanism 46) The second planetary gear mechanism 46 includes a second sun gear 46A fixed to the first carrier 45D, a plurality of second planetary gears 46B that mesh with the second sun gear 46A and can rotate while revolving and rotating around the second sun gear 46A, a second internal gear 46C that meshes with the plurality of second planetary gears 46B and is fixed to the housing 12, and a second carrier 46D that is fixed to a plurality of second planetary gear pins inserted into the rotation center of the second planetary gear 46B and can rotate at the orbital speed of the second planetary gear 46B.

[0021] The second carrier 46D is connected to the output shaft 40 of the reducer 44. A plurality of bearings 41, 42 that support the rotation of the output shaft 40 are provided around the output shaft 40. A pinion 40B is provided at the lower end of the output shaft 40. The pinion 40B rotates due to the driving force of the hydraulic motor 16, causing the upper rotating body 3 to rotate (turn). Note that the dashed dotted line 40C in the drawing is the central axis (rotational axis) of the output shaft 40.

[0022] 3 is a schematic cross-sectional view of the slewing device 11. The dotted line in FIG. 3 indicates the position of the oil level 50 filled in the housing 12. In addition to the configuration described in FIG. 2, the slewing device 11 in this embodiment is provided with a flat plate 51 between the hydraulic motor 16 and the first planetary gear mechanism 45. The flat plate 51 is located below the oil level 50, and there is a gap between the rotary shaft of the hydraulic motor 16 and the flat plate 51.

[0023] A sensor 62 is disposed below the reducer 44 and attached to the housing 12 to detect foreign matter (e.g., wear debris from the components of the reducer 44) in the lubricating oil. The sensor 62 is an oil contamination sensor that can detect the number and size of foreign matter in the lubricating oil passing through an internal sensor flow path 62A (shown in FIG. 4). The sensor 62 is attached to the housing 12 by an attachment part 65.

[0024] The sensor 62 is connected to the controller 30 wirelessly or by wire (not shown), and the detection data collected by the sensor 62 is stored in the controller 30. The sensor 62 can be, for example, an optical or eddy current type. If the sensor 62 is an optical type, it can measure foreign matter other than metal, but it will detect air bubbles as foreign matter, so it is preferable to perform measurement in a state where air bubbles have been removed as much as possible. The eddy current type cannot detect foreign matter other than metal, but for accurate measurement it is preferable to remove air bubbles as much as possible. Any type of contamination sensor can be used, but the sensor 62 is an eddy current type contamination sensor.

[0025] FIG. 4 is an enlarged view of the area around the sensor 62. A funnel-shaped member 63 is provided on the top of the sensor 62. The member 63 is a member for removing air bubbles contained in the lubricating oil and making it easier to collect foreign matter. The lubricating oil flows from the top to the bottom in FIG. 4. Therefore, the bottom in FIG. 4 is the downstream side. The member 63 is connected to the sensor 62, and thereby guides the lubricating oil toward the sensor 62.

[0026] A foreign matter collection unit 64 that collects foreign matter in the lubricating oil is connected to a flow path 67 located downstream of the sensor 62. The sensor 62 and the foreign matter collection unit 64 are connected via the flow path 67. By having the foreign matter collection unit 64 collect the foreign matter, it is possible to reduce damage to the meshing surfaces of the bearings and gears that would occur if lubricating oil containing foreign matter were to continue to be used within the housing 12. For example, a magnet or a filter can be used as the foreign matter collection unit 64, but of the two, a magnet is preferable because it is less likely to cause flow path resistance than a filter.

[0027] The sensor 62 and foreign matter collection unit 64 are fixed to mounting parts 65 with bolts or the like (not shown), and can be easily removed from the housing 12 during maintenance. Therefore, when performing maintenance (e.g., replacing) on ​​the sensor 62 or foreign matter collection unit 64, it is not necessary to remove the entire gear mechanism. The mounting parts 65 are fixed to the housing 12 with bolts or the like (not shown). Seal members 68 are sandwiched between each part and the housing 12 to prevent leakage of lubricating oil inside the housing. The holding part 66 is a member that holds the sensor 62 and foreign matter collection unit 64.

[0028] [Operation] The operation of the reducer 44 (slewing device 11) configured as described above will now be described. The flat plate 51 acts to suppress fluctuations in the lubricating oil level. This prevents air from being drawn in above the gears as they rotate. That is, when the gears in the reducer 44 rotate due to the rotation of the hydraulic motor 16, the flat plate 51 suppresses fluctuations in the oil level, significantly reducing the generation of air bubbles caused by air being drawn in between the hydraulic motor 16 and the gears. As the operation time of the slewing device 11 passes, the gears wear, and wear debris (metal particles) settles to the bottom of the reducer 44. The wear debris is introduced into the sensor 62 through a member 63, which serves as the upper opening of the sensor 62. After the size and quantity are detected and counted by the sensor 62, it passes through a flow path 67 and is collected in the foreign matter collection unit 64. The lubricating oil, purified after the wear debris is collected, is returned to the housing 12 through a lower opening 69 and used to lubricate the gears, etc.

[0029] The diagnosis of abnormalities in the reducer 44 based on the detection data of the sensor 62 may be performed by the controller 30 mounted on the hydraulic excavator 1, or may be performed by a terminal such as an external computer. In the latter case, the detection data may be transferred, for example, by sequentially transmitting the data to the external terminal via a wireless communication device 33 mounted on the hydraulic excavator 1, or by having a serviceman or the like periodically copy or transfer the detection data to a recording medium.

[0030] [effect] The reducer 44 (swing device 11) of this embodiment is provided with a flat plate 51 located below the oil surface between the hydraulic motor 16 and the reducer 44. This significantly reduces the generation of air bubbles, and measurement by the sensor 62 can be performed without installing an air bubble removal device such as an ultrasonic device, eliminating the influence of air bubbles. Therefore, according to this embodiment, the amount of wear debris in the lubricating oil can be determined without the influence of air bubbles, making it possible to detect early on whether or not there is damage to the gears that make up the reducer 44. Furthermore, the measurement results can be used to determine the appropriate time for inspection. Another advantage of this embodiment is that it can be easily introduced, as it can be configured by modifying an existing swing device.

[0031] <Embodiment 2> FIG. 5 is a side cross-sectional view of a swing device 11 provided in a hydraulic excavator 1 according to a second embodiment of the present invention. In the first embodiment, the flat plate 51 is installed with a gap between it and the rotating shaft of the hydraulic motor 16. In the second embodiment, an oil seal 70 is installed on the side of the rotating shaft of the flat plate 51. Furthermore, the flat plate 51 is provided in a part thereof with a hole 71 that connects the hydraulic motor 16 side with the reducer 44 side. The hole 71 may be a communicating hole, and there are no limitations on the size or number of the hole 71. The other configurations are the same as those of the first embodiment.

[0032] [Actions and Effects] In the slewing device 11 configured as described above, it is possible to suppress the generation of bubbles due to air being drawn in as the gears rotate. Furthermore, bubbles generated due to internal pressure changes or the like can be discharged out of the lubricating oil through the communication hole 71. Therefore, the sensor 62 can perform measurements with little influence from air bubbles, and the amount of wear powder in the lubricating oil can be determined.

[0033] Possible planar positions on the flat plate 51 for arranging the holes 71 include, for example, the following: (a) at both end portions of the flat plate 51, for example, a position closer to the outer periphery of the flat plate 51 than the rotation axis of the first planetary gear mechanism 45; and (b) on the rotational orbit of the rotation axis of the first planetary gear mechanism 45. In the case of (a), for example, when the slewing device 11 is tilted, air bubbles can escape through the holes 71 at the end portions of the flat plate 51. In the case of (b), the holes 71 are located at a position where the rotation speed is relatively slow. Because air bubbles are likely to be generated at positions where the rotation speed is high, it is considered desirable to arrange the holes 71 at a position where the rotation speed is relatively slow in order to prevent air bubbles from being drawn into the lubricating oil through the holes 71. Therefore, the position of (b) is desirable as a planar position candidate for the holes 71.

[0034] <Third Embodiment> Fig. 6 is a side cross-sectional view of a swing device 11 provided in a hydraulic excavator 1 according to a third embodiment of the present invention. In the third embodiment, as shown in Fig. 6, the area of ​​the flat plate 51 on the rotary shaft side of the hydraulic motor 16 is inclined so as to be recessed toward the gear (inclination 51A), and a communication hole 71 is provided in a portion close to the oil surface on the hydraulic motor 16 side. The other configurations are the same as those of the first embodiment.

[0035] The presence of the slope 51A simultaneously causes the bubbles to move horizontally toward the communicating hole 71 as they rise along the slope 51A. In other words, the bubbles can be guided toward the hole 71. On the other hand, if the slope 51A is inclined so as to protrude toward the hydraulic motor 16, the bubbles will escape from around the rotation axis, so the communicating hole 71 is not necessarily required.

[0036] [Actions and Effects] In the slewing device 11 configured as described above, it is possible to suppress the generation of air bubbles caused by the entrainment of air as the gears rotate. Furthermore, air bubbles generated due to internal pressure changes or the like are guided to the communication hole 71 by the inclination 51A of the flat plate 51, and can be discharged out of the lubricating oil. As a result, the sensor 62 is less susceptible to the effects of air bubbles, and the amount of wear debris in the lubricating oil can be accurately determined.

[0037] <Fourth Embodiment> Fig. 7 is a side cross-sectional view of a swing device 11 provided in a hydraulic excavator 1 according to a fourth embodiment of the present invention. In the fourth embodiment, as shown in Fig. 7, a swash plate 75 having a gap in the rotating shaft portion is installed in the housing between the reducer 44 and the sensor 62, inclined so as to be lower toward the sensor 62. The other configurations are the same as those of the third embodiment.

[0038] The swash plate 75 is a disk-shaped member and is centered on the rotation axis of the reducer 44. As will be described below, the swash plate 75 is inclined so that wear debris is guided toward the sensor 62. In FIG. 7, the sensor 62 is located on the right side of the drawing, so the swash plate 75 is attached to the housing 12 so as to be inclined downward to the right (the attachment position between the housing 12 and the swash plate 75 on the left side of FIG. 7 is located higher than the attachment position between the housing 12 and the swash plate 75 on the right side of FIG. 7). In other words, it should be noted that the inclination of the swash plate 75 is adjusted depending on the position of the sensor 62.

[0039] [Actions and Effects] The slewing device 11 configured as described above can suppress the generation of air bubbles due to air entrainment as the gears rotate. Furthermore, air bubbles generated due to internal pressure changes, etc., are guided to the communication hole 71 by the inclination 51A of the flat plate 51 and can be discharged out of the lubricating oil. Generated gear wear debris falls onto the swash plate 75 and accumulates. Accumulated wear debris due to the flow of lubricating oil caused by the inclination of the swash plate 75 and the rotation of the gears moves toward the sensor 62, passes through the communication hole 75A provided in the swash plate 75, and reaches the sensor 62 for measurement. This method can capture most of the generated wear debris without it reaching the lower bearings, etc. Therefore, the sensor 62 is less affected by air bubbles, allowing the amount of wear debris in the lubricating oil to be accurately determined.

[0040] <Fifth Embodiment> Fig. 8 is a network diagram showing the connection between the controller 30 provided in a construction machine according to a fifth embodiment of the present invention and its communication destination. As shown in this diagram, in addition to the controller 30, this embodiment uses a server computer 101, an administrator computer 112, and a service computer 111. The arrows in the diagram indicate the flow of data. Like the controller 30, each computer (101, 112, 111) is equipped with a processor (e.g., a CPU) and a storage device (e.g., a memory), and is configured so that the processor can execute various processes based on programs stored in the storage device.

[0041] In this embodiment, the controller 30 of the hydraulic excavator 1 transmits detection data acquired by the sensor 62 to a server computer (hereinafter referred to as the server) 101. Based on the data, the server 101 diagnoses the lubricating oil of the hydraulic excavator 1 and transmits the diagnosis results to the administrator computer 112 and the service computer 111.

[0042] The following describes the lubricant diagnosis performed by the server 101. This process can also be performed by the controller 30, or it can be performed by a computer installed in the sensor 62. The following description will be given assuming that the server 101 performs the lubricant diagnosis.

[0043] FIG. 9 is an example showing the change over time in the number of foreign objects counted by the sensor 62. In the example shown in FIG. 9, the number of foreign objects counted tends to increase as the operating time of the swing device 11 increases. Furthermore, it can be seen that the slope of the count increases significantly after a certain operating time. When the slope of the count increases significantly in this way, it is determined that an abnormality has occurred in the lubricating oil (i.e., the reducer 44).

[0044] FIG. 10 is a flowchart illustrating the procedure for the server 101 to diagnose the lubricant. The server 101 diagnoses the lubricant based on the count of foreign matter in the lubricant, and diagnoses an abnormality in the reducer 44 based on the result. The processing in FIG. 10 is a repetitive process, and this flowchart starts after the hydraulic excavator 1 starts operating. At predetermined time intervals (for example, one hour) set by a timer or the like, the sensor 62 transmits the collected detection data to the server 101. The server 101 performs a diagnosis based on the detection data.

[0045] In S106, the server 101 acquires detection data from the sensor 62. The server 101 counts the number of foreign particles in the lubricating oil based on the detection data. The server 101 calculates a change index value that indicates the degree of change between the number of foreign particles counted previously and the number of foreign particles counted currently. Possible change index values ​​include, for example, the difference between the previous count value and the current count value; the number of count value changes per hour obtained by dividing that difference by the operating time; and the moving average of the most recent predetermined number of count values.

[0046] In S107, the server 101 determines whether the change index value exceeds a threshold value. If the change index value is less than the threshold value, it is determined that the count value has not changed significantly (i.e., the reducer 44 is normal), and the count value is saved (S108). If the change index value is equal to or greater than the threshold value, it is determined that the count value has changed significantly (i.e., an abnormality has occurred in the reducer 44), and the process proceeds to S110 and subsequent steps. A possible threshold value is, for example, that if the difference between the previous count value and the current count value is 10% or more, it is deemed to be an abnormality.

[0047] In S110, the server 101 notifies the administrator computer 112 and the service computer 111 that an abnormality has occurred in the reducer 44 of the hydraulic excavator 1. A similar notification is also given to the user (S111). This triggers the operation of the hydraulic excavator 1 to be stopped, and the user, for example, disassembles the swing device 11 to check the condition of the gears. In S112, the server 101 saves the foreign object count value and waits until the next processing start timing.

[0048] As described above, by having the server 101 perform an abnormality diagnosis based on the count value from the sensor 62, an abnormality in the reducer 44 can be detected early, and an increase in downtime of the hydraulic excavator 1 can be suppressed.

[0049] <Modifications of the present invention> The above-described embodiments are merely examples for explaining the present invention, and appropriate omissions and simplifications have been made for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural. The position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc., in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings. When there are multiple components having the same or similar functions, they may be described using the same reference numeral with different subscripts. Furthermore, when it is not necessary to distinguish between these multiple components, the subscripts may be omitted.

[0050] In the above embodiments, the components of the controller 30 and the server 101 and the functions and processes of the components may be partially or entirely implemented by hardware (for example, by designing logic for executing the functions as an integrated circuit). These components may also be implemented as programs (software) that are read and executed by an arithmetic processing device (for example, a CPU) to implement the functions. Information related to the programs may be stored in, for example, semiconductor memory (flash memory, SSD, etc.), magnetic storage devices (hard disk drives, etc.), and recording media (magnetic disks, optical disks, etc.).

[0051] An arithmetic device executes a program using a processor (e.g., a CPU or a GPU) and performs processing defined by the program using storage resources (e.g., a memory) and interface devices (e.g., a communication port). Therefore, the entity that executes the program and performs the processing may be the processor. Similarly, the entity that executes the program and performs the processing may be a controller, device, system, computer, or node that has a processor. The entity that executes the program and performs the processing may be any arithmetic device, and may include a dedicated circuit that performs specific processing. Here, the dedicated circuit is, for example, an FPGA (Field Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), or a CPLD (Complex Programmable Logic Device).

[0052] A program may be installed on a computer from a program source. The program source may be, for example, a program distribution server or a computer-readable storage medium. When the program source is a program distribution server, the program distribution server may include a processor and storage resources for storing the program to be distributed, and the processor of the program distribution server may distribute the program to be distributed to other computers. In addition, in an embodiment, two or more programs may be realized as one program, or one program may be realized as two or more programs.

[0053] In addition, in the above description of each embodiment, the control lines and information lines are those that are considered necessary for the description of the embodiment, but they do not necessarily represent all the control lines and information lines related to the product. In reality, it can be considered that almost all components are interconnected.

[0054] In the above embodiment, the flat plate 51 and the swash plate 75 may be provided with ribs or other portions.

[0055] In the above embodiment, it has been explained that the hydraulic motor 16 rotates the swivel device 11, but the above embodiment can be applied to any rotary drive device that can rotate the swivel device 11, even if it is not necessarily a hydraulic motor.

[0056] In the above embodiment, the flat plate 51 is described as being a disk, but this is because the housing 12 is cylindrical. In other words, from the perspective of preventing air from being drawn into the lubricating oil, the shape of the flat plate 51 only needs to be similar to the planar shape of the internal space of the housing 12 that houses the gear reducer. [Explanation of symbols]

[0057] 1...hydraulic excavator, 3...upper rotating body, 3A...swivel frame, 5...swivel ring, 5A...inner ring, 5B...outer ring, 5C...steel ball, 5D...internal teeth, 11...swivel device, 12...housing, 16...hydraulic motor (swivel hydraulic motor), 30...controller, 33...wireless communication device, 40...output shaft, 44...reduction gear, 45...first planetary gear mechanism, 45A...first sun gear, 45B...first planetary gear, 45C...first internal gear, 45D...first carrier, 46...second planetary gear mechanism, 46A...second sun gear, 46B...second planetary gear, 46C...second internal gear, 46D...second carrier, 50...oil level, 51...flat plate, 62...sensor, 63...funnel-shaped member, 64...foreign matter collection section, 65...mounting part, 66...holding part, 68...sealing member, 71...communication hole, 75...swash plate, 75A...communication hole, 101...server computer (server)

Claims

1. A gear reducer having a rotating shaft, A planetary gear mechanism; a housing that accommodates the planetary gear mechanism; a flat plate disposed between the oil surface of the lubricating oil filled in the housing and the planetary gear mechanism; a sensor provided in the housing for detecting foreign matter in the lubricating oil; A gear reducer comprising:

2. the sensor is disposed below the planetary gear mechanism, A funnel-shaped member that tapers in a direction from the planetary gear mechanism toward the sensor and is connected to the sensor is disposed between the sensor and the gear reducer.

2. The gear reducer according to claim 1.

3. the gear reducer further includes a foreign matter collection unit that collects the foreign matter that has passed through the sensor, a flow path for transporting the foreign matter is disposed between the sensor and the foreign matter collection unit, The sensor and the foreign matter collection unit are connected via the flow path.

2. The gear reducer according to claim 1.

4. The sensor is configured to be detachable from the housing, The sensor is sealed by a seal member to prevent the lubricating oil from leaking out of the housing, and is attached to the housing by an attachment part.

2. The gear reducer according to claim 1.

5. the flow channel has a lower opening; The lower opening is disposed so as to return the lubricating oil into the housing after the foreign matter has been collected by the foreign matter collecting section.

4. The gear reducer according to claim 3.

6. The planar shape of the internal space of the housing that accommodates the planetary gear mechanism and the planar shape of the flat plate are similar in shape.

2. The gear reducer according to claim 1.

7. The flat plate has a communication hole penetrating the flat plate.

2. The gear reducer according to claim 1.

8. The communication hole is disposed above the rotation shaft of the planetary gear mechanism.

8. The gear reducer according to claim 7.

9. The communication hole is disposed on the outer circumferential side of the flat plate relative to the rotation shaft of the planetary gear mechanism.

8. The gear reducer according to claim 7.

10. The flat plate has an inclined portion inclined in a direction from the oil surface toward the planetary gear mechanism.

8. The gear reducer according to claim 7.

11. the sensor is disposed below the planetary gear mechanism, the gear reducer further includes a swash plate disposed between the planetary gear mechanism and the sensor; The swash plate is inclined so as to guide foreign matter to the sensor.

2. The gear reducer according to claim 1.

12. A rotating body; a rotation drive device that rotates the rotating body; The gear reducer according to claim 1; Equipped with The gear reducer is configured to reduce the speed of rotation input from the rotary drive device and output the reduced speed to the rotary shaft. Construction machinery characterized by:

13. The construction machine further includes a controller that acquires detection data describing the results of the sensor detecting a foreign object, The controller counts the amount of foreign matter in the lubricating oil based on the detection data, and if the amount of the counted foreign matter exceeds a threshold, outputs a warning to that effect.

13. The construction machine according to claim 12.

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