Work equipment

Abstract

To inhibit deterioration of elements forming a transmission device in a work machine including the transmission device which transmits power.SOLUTION: A work machine according to one embodiment has: a work part which conducts predetermined work; a transmission device which has a power transmission member wound around multiple rotation parts and a space between the rotation parts and transmits power to the work part; a fan attached to at least one of the rotation parts; and a cover member which protects the transmission device. The rotation parts have a driving side rotation part and a driven side rotation part. The fan may be attached to the driving side rotation part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a work machine including a transmission device for transmitting power. [Background technology]

[0002] Conventionally, mowers are known as working machines used to remove weeds from farm roads and wastelands. Generally, a mower is attached to the rear of a traveling machine body such as a tractor, and performs mowing by operating a working unit while moving together with the traveling machine body. The working unit has a tine shaft extending perpendicular to the traveling direction of the traveling machine body, and performs mowing by rotating multiple cutting blades attached to the tine shaft. Rotational power for the tine shaft is obtained by transmitting power input from the traveling machine body to the tine shaft. A winding transmission device such as a chain transmission or a belt transmission is typically used as a power transmission mechanism. For example, Patent Document 1 discloses a mower equipped with a belt transmission device that transmits rotational power using a belt wound between two rotating pulleys. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-103844 Summary of the Invention [Problem to be solved by the invention]

[0004] In the belt transmission device of the conventional brush cutter described above, the transmission device is covered with a belt cover, so heat generated by the operation of the transmission device tends to accumulate inside the belt cover. As a result, if the temperature inside the belt cover becomes too high, it can cause a problem of accelerating the deterioration of the grease applied to the belt and the rotating shaft of the pulley that make up the transmission device. Conventionally, this problem has been addressed by providing ventilation holes in the belt cover, but ventilation holes alone are not effective in reducing the temperature inside the belt cover unless outside air is introduced by wind or other means.

[0005] One of the objects of the present invention is to suppress deterioration of elements constituting a power transmission device in a work machine including the power transmission device. [Means for solving the problem]

[0006] In one embodiment of the present invention, the work machine comprises a working unit that performs a specified task, a transmission device having a plurality of rotating parts and a power transmission member wound between the plurality of rotating parts, which transmits power to the working unit, a fan attached to at least one of the plurality of rotating parts, and a cover member that protects the transmission device.

[0007] In the above work machine, the fan may be attached to a drive-side rotating portion of the plurality of rotating portions.

[0008] In the work machine, each of the rotating parts may include a rotor and a shaft that rotates the rotor. In this case, the fan may be attached to the rotor or the shaft. The outer diameter of the fan may be smaller or larger than the inner diameter of the rotor.

[0009] In the above-described work machine, the power transmission member may be a belt, and the rotating body may be a pulley.

[0010] In the above-described work machine, the power transmission member may be a roller chain, and the rotating body may be a sprocket.

[0011] In the above-described work machine, the cover member may have an air vent at a position overlapping with the fan. [Effects of the Invention]

[0012] According to one embodiment of the present invention, in a work machine including a transmission device that transmits power, deterioration of elements that make up the transmission device can be suppressed. [Brief explanation of the drawings]

[0013] [Figure 1] 1A and 1B are diagrams showing the configuration of a mower according to a first embodiment, in which (A) is a perspective view of the mower as seen diagonally from the upper left rear, and (B) is a rear view of the mower as seen from the rear. [Figure 2] 1 is a diagram showing the configuration of a transmission device in a mower according to a first embodiment. FIG. [Figure 3] 1A and 1B are perspective views showing the configuration of the transmission device of the first embodiment, in which (A) shows the state in which the fan is separated from the drive side pulley, and (B) shows the state in which the fan is attached to the drive side pulley. [Figure 4] 10A and 10B are diagrams showing other configurations of the cover member that protects the transmission device, where (A) is an example in which the cover member has a vent hole arranged around the fan, and (B) is an example in which the vent hole is arranged above the fan. [Figure 5] FIG. 6 is a diagram showing the configuration of a transmission device in a mower according to a second embodiment. [Figure 6] 10A and 10B are perspective views showing the configuration of a transmission device of a second embodiment, in which (A) shows a state in which the fan is separated from the drive side pulley, and (B) shows a state in which the fan is attached to the drive side pulley. [Figure 7] FIG. 10 is a perspective view showing the configuration of a fan in a mower according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] A grass mower according to one embodiment of the present invention will be described below with reference to the drawings. However, the grass mower according to one embodiment of the present invention can be implemented in many different ways, and should not be construed as being limited to the description of the example shown below. In the drawings referred to in this embodiment, the same parts or parts having similar functions are given the same reference numerals, and repeated explanations thereof will be omitted.

[0015] In the following explanation, for the sake of convenience, terms indicating directions such as "up," "down," "front," "rear," "right," and "left" are used. The direction in which gravity acts on the mower is "down," and the opposite is "up." Furthermore, the direction in which the mower moves is "front," and the opposite is "rear." Furthermore, facing the "front," the right side is "right" and the left side is "left." Furthermore, using the center line along the direction of movement of the mower as a reference, the direction away from the center line is considered to be the outside, and the direction toward the center line is considered to be the inside.

[0016] First Embodiment [Grass cutter configuration] FIG. 1 is a diagram showing the configuration of a mower 100 according to a first embodiment. Specifically, FIG. 1(A) is a perspective view of the mower 100 as seen diagonally from the upper left rear, and FIG. 1(B) is a rear view of the mower 100 as seen from the rear. In this embodiment, an example of the mower 100 is a mower that is towed by a traveling body such as a tractor and performs mowing work behind the traveling body. However, the mower is not limited to this example, and may be an offset-type mower that has the function of offsetting the mowing working unit laterally, or a self-propelled mower that does not require a traveling body.

[0017] As shown in Figure 1, the basic components of the mower 100 of this embodiment include a mounting unit 110, a power transmission unit 120, a working unit 130, and a mowing height adjustment unit 140. The mower 100 is towed by a traveling machine body (not shown) connected via the mounting unit 110, and moves forward as the traveling machine body travels. While the mower 100 moves, the working unit 130 mows using power input from the traveling machine body and transmitted via the power transmission unit 120.

[0018] The mounting part 110 is a part for connecting the traveling machine body and the mower 100, and has the function of connecting the mower 100 to the rear part of the traveling machine body. The mounting part 110 includes a top link connecting part 111, a lower link connecting part 112, and an input shaft (not shown).

[0019] The top link coupling part 111 is provided in the front center part of the mower 100, and the lower link coupling parts 112 are provided in two places on the front left and right of the mower 100. The top link coupling part 111 and the lower link coupling part 112 are each connected to a three-point link mechanism provided at the rear of the traveling machine body, so that the mower 100 is connected to the rear of the traveling machine body so that it can be raised and lowered. The top link coupling part 111 and the lower link coupling part 112 may be connected to the three-point link mechanism of the traveling machine body via an auto hitch arm (not shown).

[0020] Although not shown in the drawings, the input shaft is connected to the PTO shaft of the traveling machine body via a universal joint or the like, and inputs the power transmitted from the traveling machine body to the mower 100.

[0021] The power transmission unit 120 has a function of transmitting power input via the input shaft of the mounting unit 110 to the working unit 130. The power transmission unit 120 includes a gear box 121, a main frame 122, and a transmission device (not shown). In Figures 1(A) and 1(B), the transmission device is disposed inside a cover member 280 that protects the transmission device.

[0022] The gearbox 121 is connected to the input shaft and performs operations such as changing the speed of the input power. The main frame 122 is a frame that forms the skeleton of the brush mower 100, and extends toward both the left and right sides of the gearbox 121 in a direction that is approximately perpendicular to the direction of travel (the left-right direction). A transmission shaft (not shown) is installed inside the main frame 122, which is arranged between the gearbox 121 and the transmission device. Power is transmitted from the gearbox 121 to the transmission device via this transmission shaft.

[0023] The transmission device arranged inside the cover member 280 transmits power transmitted by the transmission shaft inside the main frame 122 to the claw shaft 131a of the working unit 130. Details of the transmission device will be described later using FIG. 2. In the mower 100 of this embodiment, the transmission device is a belt-driven wrap-around transmission device. Note that in FIG. 1, the cover member 280 has two vents 281a and 281b. In this case, for example, if outside air can be drawn in through vent 281b and exhausted through vent 281a, the air-cooling effect can be further enhanced. However, the number and positions of the vents arranged in the cover member 280 are not limited to this example.

[0024] The working unit 130 has the function of performing grass cutting work by rotating the work rotor using power transmitted via the power transmission unit 120. The working unit 130 includes a work rotor 131, a shield cover 132, and a side plate 133. The work rotor 131 includes a blade shaft 131a and multiple cutting blades 131b attached to the blade shaft 131a. In this embodiment, flail blades are used as the cutting blades 131b, but the present invention is not limited to this example.

[0025] The claw shaft 131a extends in the left-right direction, approximately perpendicular to the direction of travel. The multiple cutting blades 131b are attached at predetermined intervals to the outer circumferential surface of the claw shaft 131a. In this case, the multiple cutting blades 131b may be attached radially when the work rotor 131 is viewed along the axial direction of the claw shaft 131a. The work rotor 131 performs grass cutting work by rotating the multiple cutting blades 131b as the claw shaft 131a rotates. In this embodiment, the work rotor 131 rotates in an uppercut direction. In other words, when the brush cutter 100 is viewed from the left side, the work rotor 131 rotates clockwise.

[0026] The shield cover 132 is disposed above the work rotor 131 and prevents grass and soil from flying upward during mowing work. The side plates 133 are disposed on the left and right sides of the work rotor 131 and rotatably support both ends of the claw shaft 131a. In this embodiment, the shield cover 132 and the side plates 133 are integral with each other, but they may also be provided as separate members. Also, in FIG. 1(A), the side plates 133 are composed of two plate-like members, an upper plate and a lower plate, but this is not limited to this and the side plates 133 may also be composed of a single plate-like member.

[0027] The mowing height adjustment unit 140 is disposed behind the work rotor 131 and has the function of adjusting the mowing height during mowing work. In this embodiment, the mowing height adjustment unit 140 includes a roller support member 141, a gauge roller 142, a scraper 143, and a cover member 144. However, the configuration of the mowing height adjustment unit 140 is not limited to this example, and other elements may be added, or the scraper 143 may be omitted.

[0028] The roller support member 141 is a plate-shaped member that pivotally supports the gauge roller 142, and is connected to the rear lower portion of each of the left and right side plates 133 so as to be rotatable in the vertical direction. That is, in this embodiment, the height of the gauge roller 142 can be adjusted by rotating the roller support member 141 in the vertical direction and fixing it at a desired position. Although not shown in the figure, the roller support member 141 includes a bearing portion and a bearing portion for rotatably supporting the gauge roller 142.

[0029] The gauge roller 142 is a rotating body whose both ends are axially supported by the roller support member 141, and during mowing work, it is in contact with the work area (ground) to be mowed. Therefore, during mowing work, the gauge roller 142 rotates on its axis in accordance with the progress of the mower 100. Furthermore, by the gauge roller 142 coming into contact with the work area, the relative positional relationship between the outer periphery of the rotational trajectory of the cutting blade 131b and the grass to be mowed is determined. In other words, in this embodiment, the height of the gauge roller 142 is adjusted to adjust the height of the grass mowed by the cutting blade 131b.

[0030] The scraper 143 is a long member arranged along the gauge roller 142, and is made of an elastic member such as rubber. The scraper 143 comes into contact with the surface of the gauge roller 142 to remove grass and soil adhering to the surface of the gauge roller 142.

[0031] The cover member 144 is a member that covers the gap between the roller support member 141 and the gauge roller 142, and has the function of preventing cut grass and scattered soil from becoming entangled or accumulating in the gap between the roller support member 141 and the gauge roller 142.

[0032] [Configuration of transmission device] FIG. 2 is a diagram showing the configuration of the transmission device 200 in the brush mower 100 of the first embodiment. In other words, FIG. 2 corresponds to the configuration of the transmission device 200 when the brush mower 100 is viewed from the left side. The transmission device 200 is a mechanical element arranged inside the cover member 280 shown in FIG. 1, and is a belt-driven wrapping transmission device. As shown in FIG. 2, the transmission device 200 of this embodiment includes a drive-side rotating portion 210, a driven-side rotating portion 220, a belt 230, and a tensioner 240. The drive-side rotating portion 210 is a rotating portion located on the power input side, and the driven-side rotating portion 220 is a rotating portion located on the power output side. Also, as shown in FIG. 2, in the brush mower 100 of this embodiment, a fan 250 is attached to the drive-side rotating portion 210 of the transmission device 200.

[0033] The drive-side rotating unit 210 is a mechanical element that rotates by rotational power transmitted by a transmission shaft inside the main frame 122, and includes a drive-side shaft 211, a drive-side pulley 212, and a clutch 213. In this embodiment, a one-way clutch is used as the clutch 213. The drive-side shaft 211 rotates by the power transmitted by the transmission shaft. The drive-side pulley 212 is connected to the drive-side shaft 211 via the clutch 213, and rotates around the drive-side shaft 211 as a rotation axis.

[0034] The driven-side rotating unit 220 is a mechanical element that transmits rotational power to the claw shaft 131a of the working unit 130, and includes a driven-side shaft (not shown) and a driven-side pulley 222. The driven-side pulley 222 rotates by power transmitted from the driving-side pulley 212 via the belt 230. The driven-side pulley 222 is rotatable around the driven-side shaft as a central axis, and the driven-side shaft also rotates as the driven-side pulley 222 rotates. Although not shown in the present embodiment, the driven-side shaft has a threaded hole at its tip, into which a bolt 223 can be threaded. The bolt 223 is used as a fixing member that attaches the driven-side pulley 222 to the driven-side shaft via a collar member 224. The collar member 224 functions to prevent the driven-side pulley 222 from coming off the driven-side shaft.

[0035] The belt 230 is a power transmission member wound between the drive-side rotating part 210 and the driven-side rotating part 220, and is a mechanical element that uses frictional force to transmit power. Specifically, the belt 230 is an annular member that forms an endless loop, and is wound between the drive-side pulley 212 and the driven-side pulley 222 to transmit the rotation of the drive-side pulley 212 to the driven-side pulley 222. In this embodiment, a V-belt is used as the belt 230.

[0036] The tensioner 240 is a mechanical element that applies tension (tensile force) to the belt 230 from the inside to the outside. The tension applied to the belt 230 can be adjusted by the tensioner 240. Note that, although the present embodiment shows an example in which the tensioner 240 is included in the transmission device 200, the present invention is not limited to this example, and the tensioner 240 may be omitted.

[0037] The fan 250 is a member having a plurality of blades, and is a mechanical element that generates an air flow by rotating. In this embodiment, an example will be described in which a propeller fan is used as the fan 250. As will be described later with reference to FIG. 3 , the fan 250 of this embodiment is fixed to the drive-side pulley 212 using a fixing member that is composed of a screw portion 261 and a nut 262. Therefore, as the drive-side pulley 212 rotates, the fan 250 also rotates. With this structure, the transmission device 200 can spontaneously agitate the air inside the cover member 280.

[0038] When the air inside the cover member 280 is agitated, heat generated inside the cover member 280 by the operation of the transmission 200 is discharged to the outside together with the agitated air through the vents 281a and 281b (see FIG. 1). In this way, the mower 100 of this embodiment has the function of spontaneously forcibly cooling the inside of the cover member 280 as the transmission 200 operates, and can discharge heat generated inside the cover member 280.

[0039] As described above, the mower 100 of this embodiment is equipped with a transmission device 200 equipped with a forced air-cooling function (specifically, the fan 250), and is able to suppress an increase in the internal temperature of the cover member 280 even during operation (i.e., when the transmission device 200 is operating). This allows the mower 100 to suppress deterioration of elements that make up the transmission device 200, such as the belt 230, the grease applied to the drive-side shaft 211 and the driven-side shaft, and oil seals.

[0040] In the transmission device 200 described above, the fan 250 is detachably attached to the drive-side rotating portion 210. Therefore, even if the fan 250 is damaged for some reason, it can be easily replaced with a new one.

[0041] Fig. 3 is a perspective view showing the configuration of the transmission device 200 of the first embodiment. Specifically, Fig. 3(A) is a view showing a state in which the fan 250 is separated from the drive-side pulley 212, and Fig. 3(B) is a view showing a state in which the fan 250 is attached to the drive-side pulley 212.

[0042] 3(A), the drive-side pulley 212 of this embodiment has four spokes 212a that extend outward from the center of rotation and are equally spaced in the rotational direction, each of which has a threaded portion 261. The fan 250 has mounting holes 251 formed at four locations corresponding to the threaded portions 261, and the fan 250 can be mounted to the drive-side pulley 212 by inserting the threaded portions 261 into the mounting holes 251 of the fan 250. After the fan 250 is mounted, the fan 250 is fixed to the drive-side pulley 212 by screwing nuts 262 onto the threaded portions 261.

[0043] 3(B), in this embodiment, the outer diameter (maximum diameter of the rotational path) of the fan 250 is smaller than the inner diameter of the drive-side pulley 212, and so the fan 250 is attached to the inside of the drive-side pulley 212. Therefore, the fan 250 can be attached to the transmission device 200 without increasing the width of the transmission device 200 in the left-right direction. In this way, according to this embodiment, it is possible to provide the brush mower 100 with a forced air-cooling function without increasing the width of the transmission device 200 in the left-right direction.

[0044] (Variation 1) In the present embodiment, an example in which the fan 250 is attached to the drive-side pulley 212 has been described, but the present invention is not limited to this example, and the fan 250 may also be attached to the driven-side pulley 222. In this case, similar to the first embodiment, the fan 250 may be attached to the spokes 222a of the driven-side pulley 222. It is also possible to attach the fan 250 to both the drive-side pulley 212 and the driven-side pulley 222. However, when attaching the fan 250 to only one of the pulleys, it is desirable to attach it to the pulley with the larger inner diameter (in this embodiment, the drive-side pulley 212), as in the present embodiment. This is because the larger the outer diameter of the fan 250, the more effective the air cooling.

[0045] (Variation 2) In this embodiment, a belt-driven winding transmission device has been described as an example of the transmission device 200, but the present invention is not limited to this example and can also be applied to a chain-driven winding transmission device. Although not shown, in the case of a chain-driven transmission device, a roller chain is wound between a driving sprocket and a driven sprocket. In this case, the fan 250 may be attached to either the driving sprocket or the driven sprocket, or both. In this case, the sprocket may be provided with a thread portion 261 as shown in FIG. 3(A).

[0046] Even in the case of this modified example, it is possible to suppress deterioration of elements that make up the transmission device, such as the roller chain, the grease applied to the drive-side shaft and the driven-side shaft, and the oil seal.

[0047] (Variation 3) In this modification, an example will be described in which the configuration of the vent hole of the cover member that protects the transmission device 200 is different from the configuration shown in FIG. 1(A).

[0048] Figure 4 shows another configuration of the cover member that protects the transmission device 200. Specifically, Figure 4(A) shows an example in which the vent 381a is arranged so as to surround the fan 250, and Figure 4(B) shows an example in which the vent 391a is arranged above the fan 250. Note that both Figures 4(A) and 4(B) show the configuration of the cover member when the mower 100 is viewed from the left side.

[0049] In the example shown in FIG. 4(A), the vent 381a is provided at a position where the airflow generated by the rotation of the fan 250 hits the inner wall on the front side of the cover member 380. That is, in the example shown in FIG. 4(A), the airflow generated by the fan 250 efficiently discharges heated air to the outside. Note that in this modified example, the vent 381a is arranged so as to form a discontinuous circle concentric with the fan 250, but this example is not limiting. Also, the vent 381a is not limited to being double, and may be single, triple, or more. Furthermore, in FIG. 4(A), the vent 381a and the fan 250 are positioned so as not to overlap, but this example is not limiting, and the vent 381a may be positioned so as to overlap the fan 250.

[0050] 4(B), vent 391a is provided at the upper end of cover member 390. Air warmed by heat generated inside cover member 390 has a light specific gravity and moves upward inside cover member 390. Therefore, by arranging vent 391a at the upper end of cover member 390, it is possible to efficiently exhaust heated air to the outside.

[0051] As described above, the cover members 380 and 390 of this modified example are provided with vents that take into consideration the movement of air inside the cover members. This allows the heat inside the cover to be efficiently released to the outside when the fan 250 is rotated inside the cover members 380 and 390.

[0052] 4(A) or 4(B), another vent (intake port) for drawing in outside air may be provided in addition to the vent 381a or 391a, although this is not shown in the present modified example. If outside air can be drawn in through the other vent and discharged through the vents 381a and 391a, the air-cooling effect inside the cover can be further improved.

[0053] When an intake port and an exhaust port are provided, it is preferable that the other vents be located away from the vents 381a and 391a so that the entire inside of the cover is cooled. For example, if the exhaust vent is located near the pulley on which the fan 250 is mounted and the intake vent is located near the pulley farthest from the pulley on which the fan 250 is mounted, the air inside the entire cover can be efficiently exchanged. Note that the intake vent may be located on a surface other than the surface on which the vents 381a and 391a are mounted, as in the case of the vent 281b in FIGS. 1(A) and 1(B).

[0054] Second Embodiment In this embodiment, an example will be described in which the method of mounting the fan on the drive-side rotating part is different from that of the first embodiment. Specifically, the brush cutter of this embodiment is structured so that the fan is mounted on the rotating shaft of the pulley (i.e., the transmission shaft). This embodiment will be described focusing on the differences from the first embodiment, and the same parts as in the first embodiment will be indicated by the same reference numerals in the drawings, and duplicated explanations will be omitted.

[0055] Fig. 5 is a diagram showing the configuration of a transmission device 300 in a grass mower according to a second embodiment. Fig. 6 is a perspective view showing the configuration of the transmission device 300 according to the second embodiment. Specifically, Fig. 6(A) is a diagram showing a state in which the fan 350 is separated from the drive-side pulley 312, and Fig. 6(B) is a diagram showing a state in which the fan 350 is attached to the drive-side pulley 312.

[0056] As shown in FIGS. 5 and 6, the transmission device 300 of this embodiment includes a drive-side rotating portion 310, a driven-side rotating portion 220, a belt 230, and a tensioner 240. The drive-side rotating portion 310 of this embodiment is a rotating portion located on the power input side, and the driven-side rotating portion 220 is a rotating portion located on the power output side. Also, as shown in FIGS. 5 and 6, the brush mower of this embodiment has a fan 350 attached to the drive-side rotating portion 310. The drive-side rotating portion 310 includes a drive-side shaft 311, a drive-side pulley 312, and a clutch 313. This embodiment differs from the first embodiment in that the fan 350 is attached to the drive-side shaft 311, not to the spokes 312a of the drive-side pulley 312. In this embodiment, the clutch 313 is also a one-way clutch.

[0057] As shown in FIG. 6A, in this embodiment, a screw hole 311a is formed in the center of the tip of the drive-side shaft 311, and a bolt 314 inserted into a mounting hole 351 of the fan 350 is threaded into the screw hole 311a, thereby mounting the fan 350 to the drive-side shaft 311. However, the method of mounting the fan 350 is not limited to this example. For example, a mounting hole having a diameter matching the diameter of the drive-side shaft 311 may be formed in the fan 350, and threads may be formed on the inner wall of the mounting hole to be threaded onto threads cut on the outer periphery of the tip of the drive-side shaft 311. Furthermore, the fan 350 may be mounted to the drive-side shaft 311 using a mechanical element other than a screw.

[0058] In this embodiment, the fan 350 can be attached simply by fixing it to the tip of the drive-side shaft 311 using the bolt 314, so there is no need to process the drive-side pulley 312 as in the first embodiment. Therefore, the fan 350 can be attached in a simpler manner than in the first embodiment.

[0059] Furthermore, in this embodiment, as in the first embodiment, the outer diameter (maximum diameter of the rotation locus) of the fan 350 is smaller than the inner diameter of the drive-side pulley 312, so the fan 350 is attached to the inside of the drive-side pulley 312. Therefore, the fan 350 can be added without increasing the width of the transmission device 300 in the left-right direction.

[0060] However, the present embodiment is not limited to this example, and the outer diameter of the fan 350 may be larger than the inner diameter of the drive-side pulley 312. In other words, by preventing interference between the rotation of the fan 350 and the rotation of the drive-side pulley 312, the size (i.e., outer diameter) of the fan 350 can be set independently of the inner diameter of the drive-side pulley 312. To achieve such a structure, for example, the drive-side shaft 311 may be extended so that the fan 350 can be mounted at a position where it does not come into contact with the drive-side pulley 312. In this case, the degree of freedom in designing the size of the fan 350 increases, thereby maximizing the air-cooling effect.

[0061] <3rd embodiment> In this embodiment, an example will be described in which the structure of the fan attached to the transmission device is different from that of the first embodiment. In this embodiment, the differences from the first embodiment will be focused on, and the same parts as those in the first embodiment will be indicated by the same reference numerals in the drawings, and duplicated explanations will be omitted.

[0062] Figure 7 is a perspective view showing the configuration of a fan 450 in a mower according to the third embodiment. Similar to the second embodiment, the fan 450 of this embodiment is configured to be attached to the drive-side shaft 311 of the drive-side rotating part 310. That is, the fan 450 has an attachment hole 451 at the center of rotation, and is attached to the drive-side shaft 311 using a bolt 314 (see Figure 6(A)) inserted into the attachment hole 451.

[0063] The fan 450 of this embodiment has a dual-structure blade structure with inner blades 452 on the side closer to the rotation axis and outer blades 453 on the side farther from the rotation axis, and the inclination directions of the inner blades 452 and outer blades 453 are different. This enables the fan 450 to simultaneously generate winds of different speeds. The fan 450 is a known technique, and the technique described in Japanese Patent Application Laid-Open No. 2011-256876, for example, can be used.

[0064] In this embodiment, an example of using a fan with double-structured blades has been described, but applicable fans are not limited to this example. For example, in addition to propeller fans, sirocco fans, turbo fans, mixed-flow fans, etc. can also be used.

[0065] Fourth Embodiment In the first to third embodiments, examples have been described in which a fan is attached to a transmission device of a mower to provide a forced air-cooling function, but the present invention is not limited to these examples and can be applied to any work machine equipped with a transmission device. For example, the present invention may be applied to agricultural work machines such as rotary work machines, plows, and ridgers, or to work machines that perform work other than agricultural work.

[0066] Although the present invention has been described above with reference to the drawings, the present invention is not limited to the above-described embodiments (including variations) and can be modified as appropriate without departing from the spirit of the present invention. For example, even if a person skilled in the art appropriately adds, deletes, or modifies components based on the embodiments, such modifications are included within the scope of the present invention as long as they incorporate the gist of the present invention. Furthermore, the above-described embodiments can be appropriately combined as long as there are no mutual contradictions, and technical matters common to the embodiments are included in each embodiment even if not explicitly stated.

[0067] Even if there are other effects and advantages different from those brought about by the aspects of each of the above-mentioned embodiments, those that are clear from the description in this specification or that can be easily predicted by a person skilled in the art are naturally understood to be brought about by the present invention. [Explanation of symbols]

[0068] 100...grass mower, 110...mounting portion, 111...top link connecting portion, 112...lower link connecting portion, 120...power transmission portion, 121...gear box, 122...main frame, 130...working portion, 131...working rotor, 131a...claw shaft, 131b...cutting blade, 132...shield cover, 133...side plate, 140...cutting height adjusting portion, 141...roller support member, 142...gauge roller, 143...scraper, 144...cover member, 200...transmission device, 210...driving side rotating portion, 211...driving side shaft, 212...driving side pulley, 212a...spoke, 213...clutch, 220...driven side rotating portion, 222...driven Drive-side pulley, 223...bolt, 224...collar member, 230...belt, 240...tensioner, 250...fan, 251...mounting hole, 261...threaded portion, 262...nut, 280...cover member, 281a, 281b...ventilation hole, 300...transmission device, 310...drive-side rotating portion, 311...drive-side shaft, 311a...screw hole, 312...drive-side pulley, 312a...spokes, 313...clutch, 314...bolt, 350...fan, 351...mounting hole, 380...cover member, 381a...ventilation hole, 390...cover member, 391a...ventilation hole, 450...fan, 451...mounting hole, 452...inner blade, 453...outer blade

Claims

1. a working unit that performs a predetermined work; a transmission device having a plurality of rotating parts and a belt wound between the plurality of rotating parts, and transmitting power to the working part; a fan attached to at least one of the plurality of rotating parts; a cover member for protecting the transmission device; Equipped with the plurality of rotating portions include a driving-side rotating portion and a driven-side rotating portion, the drive-side rotating portion includes a drive-side pulley and a drive-side shaft that rotates the drive-side pulley, the driven-side rotating portion includes a driven-side pulley and a driven-side shaft that rotates in conjunction with rotation of the driven-side pulley, the drive pulley includes a plurality of spokes extending outward from a rotation center of the drive pulley and arranged at equal intervals; The fan is attached to the plurality of spokes of the drive-side pulley.

2. an outer diameter of the fan is smaller than an inner diameter of the drive-side pulley; The work machine according to claim 1 , wherein the fan is disposed inside the drive-side pulley.

3. The work machine according to claim 1 or 2, wherein the cover member has a vent hole at a position overlapping the fan.

4. The work machine according to claim 1 or 2, wherein the cover member has a vent hole on a rear surface thereof.

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