JP7035663B2 - Cooling device for work machines - Google Patents

Description

The present invention relates to a cooling device for a work machine that cools the contents by blowing gas toward the contents arranged inside the machine room of the work machine.

Conventionally, there is a work machine provided with a lower traveling body having a crawler or the like and an upper turning body (body frame) mounted on the lower traveling body. This type of work machine includes a vehicle body frame, a driver's cab, various work machines (for example, a work machine composed of a boom, an arm, a bucket, etc.), and various machines (for example, an engine, a hydraulic pump, etc.). It is known that these are provided with a machine room for accommodating (referred to as “contained items”) (see, for example, Patent Document 1).

In the work machine described in Patent Document 1, a cooling device for the work machine (hereinafter, also simply referred to as “cooling device”) for cooling the contents is installed inside the machine room. This cooling device cools the contents by blowing air toward the contents by a fan.

Japanese Unexamined Patent Publication No. 2013-104310

By the way, in the conventional cooling device for working machines as described in Patent Document 1, the rotation speed and the like are controlled with reference to the temperature of the contained object such as an engine and a hydraulic pump to be cooled. However, when such a control method is used, sufficient responsiveness may not be obtained, and the temperature control of the contained material may be delayed. As a result, there is a risk of overheating or supercooling of the contained material.

Here, as a method for improving the responsiveness, an electromagnetic rotation sensor, a non-contact distance sensor, an optical sensor, or the like is used to directly detect the rotation speed of the fan, and control is performed based on the rotation speed. There are ways to do it. When such a method is adopted, it is preferable that the sensor is arranged so as to face the fan from the direction along the rotation axis.

However, when the sensor is arranged in this way, the sensor is located in the air passage formed by the fan, so that the air flow is obstructed by the sensor, and problems such as deterioration of cooling performance and generation of noise occur. There was a risk. Further, if foreign matter such as sand is contained in the blown air, the foreign matter may collide with the sensor.

The present invention has been made in view of the above points, and an object of the present invention is to provide a cooling device for a work machine, which has good responsiveness and can smoothly blow air while protecting a sensor.

The cooling device for a work machine of the present invention is
A work having a boss portion connected to a rotating shaft and a blade portion extending radially outward from the boss portion, and equipped with a fan that blows air in a direction along the rotating axis by the blade portion during rotation. It ’s a mechanical cooling device.
A bearing that supports the rotating shaft, a bearing case that houses the bearing, and a sensor that detects the rotation of the fan are provided.
The sensor has a sensor main body portion and a wiring portion connected to the sensor main body portion.
The bearing case is located in a region facing the boss portion when viewed from the direction along the rotation axis, at a position deviated in the circumferential direction from the first accommodating portion accommodating the sensor main body portion and the first accommodating portion. A second accommodating portion provided in the above and accommodating the wiring portion, a first annular portion provided on the outer peripheral surface of the bearing case and formed with the first accommodating portion, and the first annular portion provided on the outer peripheral surface of the bearing case. It has a second annular portion that is provided at a distance from the first annular portion to the side opposite to the boss portion and in which the second accommodating portion is formed .
The first accommodating portion is characterized by being a notch penetrating the first annular portion in a direction along the rotation axis .

As described above, the cooling device for work machines of the present invention (hereinafter, also simply referred to as “cooling device”) can detect the rotation speed of the fan by the sensor. By utilizing this detection result, the cooling device of the present invention can directly control the rotation speed of the fan and the like, so that high responsiveness can be realized.

By the way, in the cooling device of the present invention, air is blown in the direction along the rotation axis by the blade portion extending radially outward from the boss portion during rotation. Therefore, in the direction along the rotation axis, it is difficult for the wind to hit the region where the blade portion does not exist (that is, the region facing the boss portion).

Here, in this cooling device, the accommodating portion of the sensor is formed in a region facing the boss portion in the direction along the rotation axis of the bearing case. That is, in this cooling device, since the sensor is arranged in the region facing the boss portion, it is difficult for the sensor to be exposed to the wind.

In addition to this, in this cooling device, the first accommodating portion accommodating the sensor main body portion and the second accommodating portion accommodating the wiring portion are provided at positions displaced in the circumferential direction.

That is, in this cooling device, even if it is a part of the same sensor, the sensor main body portion that needs to be removed at the time of maintenance can be arranged at a position where it is difficult for the wind to hit to some extent and it is easy to remove. .. On the other hand, the wiring part, which does not need to be removed much during maintenance and has a higher possibility of damage due to foreign matter, is located at a position where the wind (and thus foreign matter) is less likely to hit than the sensor body. Can be placed in.

Therefore, according to the cooling device of the present invention, since the gas flow is not easily obstructed by the sensor, the air can be blown smoothly, and the deterioration of the cooling performance and the generation of noise due to the arrangement of the mechanism can be suppressed. can. Further, even if the air blown by the fan contains foreign matter such as sand, the sensor is sufficiently protected.

Further , when the annular portion is provided on the outer peripheral surface of the bearing case in this way, a recess is formed in the central portion of the bearing case, so that a part of the wiring portion of the sensor or the like can be accommodated in the recess. This makes it possible to make the entire device compact.

Further, the accommodating portion may be a hole through which the sensor can be inserted, but if the notch is used as the accommodating portion in this way, the accommodating portion is opened at least on one side in the radial direction. On the other hand, the sensor can be removed and installed from the radial direction. This makes it possible to improve maintainability.

Further, in the cooling device for a work machine of the present invention, when the accommodating portion is notched,
It is preferable that the notch forming the first accommodating portion is open to the side or the lower side of the bearing case.

Possible collisions with the sensor include foreign matter such as sand contained in the air and falling objects such as parts that have fallen during maintenance. Therefore, if the accommodating portion is notched and the open direction is set to the side or the lower side, the upper side of the sensor will be covered by the wall surface of the bearing case, so that a falling object with respect to the sensor will be covered. It becomes easier to prevent collisions.
Further, the cooling device for a work machine of the present invention is
A work having a boss portion connected to a rotating shaft and a blade portion extending radially outward from the boss portion, and equipped with a fan that blows air in a direction along the rotating axis by the blade portion during rotation. It ’s a mechanical cooling device.
A bearing that supports the rotating shaft, a bearing case that houses the bearing, and a sensor that detects the rotation of the fan are provided.
The sensor has a sensor main body portion and a wiring portion connected to the sensor main body portion.
The bearing case is located in a region facing the boss portion when viewed from the direction along the rotation axis, at a position deviated in the circumferential direction from the first accommodating portion accommodating the sensor main body portion and the first accommodating portion. A second accommodating portion provided in the above and accommodating the wiring portion, a first annular portion provided on the outer peripheral surface of the bearing case and formed with the first accommodating portion, and the first annular portion provided on the outer peripheral surface of the bearing case. It is characterized by having a second annular portion formed by the second accommodating portion, which is provided at a distance from the first annular portion on the side opposite to the boss portion.

The side view which shows the structure of the hydraulic excavator which concerns on embodiment. The plan view which shows the inside of the machine room of the hydraulic excavator of FIG. 1 schematically. FIG. 2 is a perspective view of a cooling device arranged in the machine room of FIG. FIG. 3 is a plan view showing a structure of a main part of the cooling device of FIG. 3 as a partial cross section. FIG. 3 is a perspective view showing the shape of the bearing case of the cooling device of FIG. The perspective view which shows the shape of the detected member of the cooling device of FIG.

Hereinafter, the hydraulic excavator S, which is a work machine according to the embodiment, will be described with reference to the drawings. In the following description, the front and front sides of the hydraulic excavator S in the traveling direction are simply referred to as "front" and "front side", and the rear and rear sides in the traveling direction are simply referred to as "rear" and "rear side".

In the present embodiment, the hydraulic excavator S is used as an example of the work machine, but the work machine of the present invention may be provided with a cooling device for the work machine (hereinafter, also simply referred to as “cooling device”). It is not limited to hydraulic excavators. For example, it may be a crane car or the like.

First, the configuration of the hydraulic excavator S will be described with reference to FIGS. 1 and 2.

As shown in FIG. 1, the hydraulic excavator S includes a lower traveling body 1 and an upper rotating body 2 rotatably mounted on the lower traveling body 1.

The lower traveling body 1 includes a lower frame 1a and a pair of crawlers 1b provided on both sides of the lower frame 1a. The crawler 1b is driven by a traveling hydraulic motor which is a hydraulic actuator.

The lower traveling body in the work machine of the present invention is not limited to the one composed of the lower frame and the crawler. For example, the lower traveling body may be one that moves by wheels or one that moves by legs. Further, when the work machine is used on the water, the lower traveling body may be a pontoon or the like.

The upper swivel body 2 is provided on the side of the upper frame 2a that is swivelably supported with respect to the lower frame 1a, the cab 2b provided on the front side of the upper frame 2a, and the cab 2b. It has a working machine 2c, a counterweight 2d mounted behind the cab 2b and the working machine 2c, and a machine room 2e defined by an upper frame 2a and a counterweight 2d.

In the driver's cab 2b, the driver operates the hydraulic excavator S such as various levers (not shown) for operating the movement of the working machine 2c, the turning of the upper turning body 2, and the movement of the lower traveling body 1. Various equipment is provided.

The working machine 2c is rotatably connected to a boom 2c1 rotatably connected to the upper frame 2a of the upper swing body 2, an arm 2c2 rotatably connected to the boom 2c1, and an arm 2c2. It has a bucket 2c3 and a bucket 2c3.

Further, the working machine 2c includes a boom cylinder 2c4 having both ends attached to the upper frame 2a and the boom 2c1 of the upper swing body 2, an arm cylinder 2c5 having both ends attached to the boom 2c1 and the arm 2c2, and an arm 2c2. It has a bucket cylinder 2c6 with both ends attached to the bucket 2c3.

The boom 2c1 is rotatably supported by the upper frame 2a of the upper swing body 2, and is rotated by the expansion / contraction operation of the boom cylinder 2c4 with the shaft as a fulcrum. The arm 2c2 is rotatably supported by the boom 2c1, and is rotated by the expansion / contraction operation of the arm cylinder 2c5 with the shaft as a fulcrum. The bucket 2c3 is rotatably supported by the arm 2c2, and is rotated by the expansion / contraction operation of the bucket cylinder 2c6 with the shaft as a fulcrum.

The counterweight 2d maintains the balance of the hydraulic excavator S as a whole with the working machine 2c due to its weight. A space serving as a machine room 2e is formed between the counterweight 2d, the cab 2b, and the working machine 2c.

As shown in FIG. 2, the inside and the outside of the machine room 2e are communicated with each other through an opening 2e1 provided on a side surface portion of the upper swivel body 2. Maintenance and the like of various machines housed inside the machine room 2e (hereinafter referred to as "contained items") are performed through the opening 2e1. The upper swivel body 2 is provided with a panel 2f that can be opened and closed so as to cover the opening 2e1.

In the machine room 2e, a hydraulic pump 4 or the like for supplying oil to the engine 3 or the like as a drive source is installed as an accommodation. Further, in the machine room 2e, a cooling device 5 for cooling the contents and a heat exchanger 6 are arranged on the side of the contents.

In the machine room 2e, in addition to the engine 3 and the hydraulic pump 4, the generator motor as the drive source, the aftertreatment device connected to the exhaust system of the engine 3, and the gantry on which they are placed are placed. A support structure such as may be installed.

The cooling device 5 sucks outside air from an intake hole 2g (see FIG. 1) formed on the side wall of the machine room 2e of the hydraulic excavator S, guides it to the inside of the machine room 2e as cooling air, and is housed in the machine room 2e. Cool the contents of the engine 3 and the like.

Specifically, the air sucked by the cooling device 5 first cools the cooling water, hydraulic oil, etc. flowing inside the heat exchanger 6 when passing through the heat exchanger 6. In the hydraulic excavator S, the engine 3, the hydraulic pump 4, and the like are cooled by using the cooling water or the hydraulic oil. Next, the air that has passed through the heat exchanger 6 passes through the cooling device 5 and is blown toward the contents. As a result, the contents are air-cooled. The air after cooling the contained object is exhausted to the outside of the hydraulic excavator S through an exhaust hole (not shown) formed in the panel 2f.

Next, the configuration of the cooling device 5 will be described in detail with reference to FIGS. 3 to 6.

As shown in FIG. 3, the cooling device 5 includes a first frame 5a configured as a rectangular frame fixed inside the machine room 2e, and a downstream side (engine 3 and the like) of the first frame 5a. The second frame 5b fixed to the first frame 5a, the bearing case 5c fixed to the center of the second frame 5b, and the downstream of the bearing case 5c so as to cross the central portion of the second frame 5a. The drive source 5d fixed to the side (only the vicinity of the rotation shaft 5d1 is shown in FIG. 3), and the drive source 5d fixed to the inside of the first frame 5a and rotatably fixed to the upstream side of the bearing case 5c. It is equipped with a bearing 5e.

Further, as shown in FIG. 4, the cooling device 5 is fixed to the downstream side of the boss portion 5e1 of the fan 5e, and the detected member 5f into which the rotating shaft 5d1 of the drive source 5d is inserted and the inside of the bearing case 5c. It is provided with a bearing 5g that rotatably supports the fan 5e via a member to be detected 5f, and a sensor 5h that is an electromagnetic rotation sensor.

As shown in FIG. 5, the bearing case 5c is provided on the outer peripheral surface thereof with a distance between the first annular portion 5c1 and the first annular portion 5c1 to the boss portion 5e1 of the fan 5e. It has two annular portions 5c2.

On the side of the first annular portion 5c1, the first notch portion 5c2 (first accommodating portion) faces the boss portion 5e1 when viewed from the direction along the rotation axis a of the bearing case 5c, and the bearing case 5c Is formed so as to penetrate in the direction along the rotation axis a. The first notch portion 5c2 accommodates a sensor main body portion 5h1 that detects the rotation speed among the portions constituting the sensor 5h.

That is, by being housed in the first notch portion 5c2 opened toward the side of the bearing case 5c, the upper side, the lower side, and one side side of the sensor main body portion 5h1 are the bearing case 5c. It is in a state of being covered with the wall surface of.

As a result, in the cooling device 5, the sensor main body portion 5h1 can be removed and installed from the radial direction with respect to the bearing case 5c, and maintainability is improved. Further, even if a part or the like falls during maintenance or the like, the part is blocked by the bearing case 5c, so that the part does not collide with the sensor main body 5h1.

Below the second annular portion 5c2, the second notch portion 5c4 (second accommodating portion) is the first notch in the region facing the boss portion 5e1 when viewed from the direction along the rotation axis a of the bearing case 5c. The bearing case 5c is formed so as to penetrate the bearing case 5c in the direction along the rotation axis a at a position displaced in the circumferential direction with respect to the portion 5c2. The second notch portion 5c4 accommodates the wiring portion 5h2 connected to the sensor main body portion 5h1 among the portions constituting the sensor 5h.

That is, by being housed in the second notch portion 5c4 opened downward of the bearing case 5c, the upper side and the side side of the wiring portion 5h2 are covered with the wall surface of the bearing case 5c. It has become.

As a result, in the cooling device 5, even if a part or the like falls during maintenance or the like, the part is blocked by the bearing case 5c and does not collide with the wiring portion 5h2.

Further, in the bearing case 5c, since the first annular portion 5c1 and the second annular portion 5c2 are provided on the outer peripheral surface thereof, a concave portion is formed in the central portion of the bearing case 5c. In the bearing case 5c, a part of the wiring portion 5h2 of the sensor 5h is housed in the recess, so that the cooling device 5 as a whole is made compact.

The first accommodating portion and the second accommodating portion of the present invention are not limited to the shapes such as the first notch portion 5c2 and the second notch portion 5c4, but are in the direction along the rotation axis of the bearing case. Anything may be provided in the area facing the boss portion.

For example, the sensor main body portion or the wiring portion may be formed as an insertable hole portion. Further, the accommodating portion may be provided directly in the bearing case without providing the first annular portion and the second annular portion. Further, depending on the installation position of the cooling device in the machine room, falling objects may not be generated. In such a case, the opening direction of the first notch may be other than the lateral direction, and the open direction of the second notch may be other than the downward direction.

Returning to FIG. 4, in the cooling device 5, the detected member 5f (and by extension, the drive source 5d inserted in the detected member 5f) is inserted through the first frame 5a, the second frame 5b, the bearing case 5c, and the bearing 5g. A rotary shaft 5d1 (not shown in FIG. 4) is rotatably supported. This prevents an excessive load from being applied to the rotating shaft 5d1 and prevents its deflection and the like.

The fan 5e includes a disk-shaped boss portion 5e1 fixed to the tip of the rotation shaft 5d1 of the drive source 5d, and a plurality of blade portions 5e2 extending radially outward from the peripheral edge of the boss portion 5e1 (FIG. 3) and. On the downstream side of the boss portion 5e1, the detected member 5f is fixed so as to rotate integrally with the boss portion 5e1 (and thus the fan 5e).

As shown in FIG. 6, the detected member 5f extends from the central portion of the annular portion 5f1 to the downstream side with the annular portion 5f1 covering the downstream side surface (that is, the surface on the sensor 5h side) of the boss portion 5e1. It has an insertion tube portion 5f2 provided.

The surface on the downstream side of the annular portion 5f1 is a surface to be detected 5f3 that extends so as to intersect the rotation axis a (see FIG. 4). On the detected surface 5f3, a plurality of convex portions 5f4 (detected portions) protruding toward the sensor 5h in the direction along the rotation axis a in the region facing the sensor 5h (see FIGS. 3 and 4). ) Is formed. The sensor 5h detects the rotation speed of the fan 5e by detecting whether or not the convex portions 5f4 are located at opposite positions.

The insertion cylinder portion 5f2 is configured to be movable in a state where the rotation shaft 5d1 of the drive source 5d is inserted. Further, the insertion cylinder portion 5f2 is rotatably supported by the bearing case 5c via the bearing 5g. Further, a fixing hole 5f5 is formed in the peripheral portion of the insertion cylinder portion 5f2 of the annular portion 5f1, and the detected member 5f can be fixed to the boss portion 5e1 by the bolt 5i via the fixing hole 5f5. There is.

By providing the insertion tube portion 5f2, the detected member 5f can be used as a member for connecting the rotating shaft 5d1 of the drive source 5d and the boss portion 5e1 of the fan 5e. As a result, the manufacturing process and the manufacturing cost are reduced, and the weight increase due to the provision of the detected member 5f is suppressed.

Further, since the rotating shaft 5d1 is supported by the first frame 5a and the second frame 5b via the insertion cylinder portion 5f2 (and by extension, the bearing 5g that supports it), an excessive load is applied to the rotating shaft 5d1. It is prevented from joining. As a result, the rotation shaft 5d1 is prevented from bending or the like.

As described above, the cooling device 5 can detect the rotation speed of the fan 5e by the sensor 5h via the detected member 5f that rotates integrally with the boss portion 5e1 (and by extension, the fan 5e). By using this detection result, the cooling device 5 can directly control the rotation speed of the fan 5e and the like, so that high responsiveness can be realized.

By the way, in the cooling device 5, air is blown in the direction along the rotation axis a by the blade portion 5e2 extending radially outward from the boss portion 5e1 during rotation. Therefore, in the direction along the rotation axis a, it is difficult for the wind to hit the region where the blade portion 5e2 does not exist (that is, the region facing the boss portion 5e1).

Then, in this cooling device 5, the first notch portion 5c2 and the second notch portion 5c4, which are the accommodating portions of the sensor 5h, are formed in a region facing the boss portion 5e1 in the direction along the rotation axis a of the bearing case 5c. is doing. That is, in this cooling device 5, since the sensor 5h is arranged in the region facing the boss portion 5e1, it is difficult for the sensor 5h to be exposed to the wind.

In addition to this, in the cooling device 5, the first notch portion 5c3 accommodating the sensor main body portion 5h1 and the second notch portion 5c4 accommodating the wiring portion 5h2 are provided at positions displaced in the circumferential direction. ..

That is, in this cooling device 5, even if it is a part of the same sensor 5h, the sensor main body portion 5h1 that needs to be removed at the time of maintenance is arranged at a position where it is difficult for wind to hit to some extent and it is easy to remove. ing. On the other hand, the wiring portion 5h2, which does not need to be removed much during maintenance and has a higher possibility of damage due to foreign matter than the sensor main body portion 5h1, is more windy (and thus foreign matter) than the sensor main body portion 5h1. It is placed in a position that is difficult to hit.

As a result, in the cooling device 5, the flow of gas is less likely to be obstructed by the sensor 5h, so that air can be blown smoothly, and deterioration of cooling performance and generation of noise due to the arrangement of the mechanism can be suppressed.

Further, even if the air blown by the fan 5e contains foreign matter such as sand, the sensor main body portion 5h1 of the sensor 5h is covered with a bearing case 5c within a range that does not impair maintainability. Therefore, it is also prevented that the foreign matter collides with the sensor 5h.

Although the illustrated embodiment has been described above, the present invention is not limited to such an embodiment.

For example, in the above embodiment, a plurality of convex portions 5f4 provided on the detected member 5f so as to project downstream are used as the detection target of the sensor 5h. However, since the cooling device of the present invention may directly detect the boss portion, the member to be detected may be omitted.

Further, in the above embodiment, an electromagnetic rotation sensor is used as the sensor 5h. However, the sensor of the present invention is not limited to the electromagnetic rotation sensor, and may be any one that can detect the rotation speed of the boss portion (and thus the fan). For example, in addition to a non-contact distance sensor and an optical sensor, various sensors such as a pressure sensor and a temperature sensor may be used.

1 ... Lower traveling body, 1a ... Lower frame, 1b ... Crawler, 2 ... Upper swivel body, 2a ... Upper frame, 2b ... Driver's cab, 2c ... Working machine, 2c1 ... Boom, 2c2 ... Arm, 2c3 ... Bucket, 2c4 ... Boom cylinder, 2c5 ... Arm cylinder, 2c6 ... Bucket cylinder, 2d ... Counter weight, 2e ... Machine room, 2e1 ... Opening, 2f ... Panel, 2g ... Intake hole, 3 ... Engine, 4 ... Hydraulic pump, 5 ... Cooling device 5, 5a ... 1st frame, 5b ... 2nd frame, 5c ... Bearing case, 5c1 ... 1st annular portion, 5c2 ... 2nd annular portion, 5c3 ... 1st notch portion (1st accommodating portion), 5c4 ... 2nd Notch (2nd accommodation), 5d ... Drive source,
5d1 ... Rotating shaft, 5e ... Fan, 5e1 ... Boss part, 5e2 ... Blade part, 5f ... Detected member, 5f1 ... Circular part, 5f2 ... Insert cylinder part, 5f3 ... Detected surface, 5f4 ... Convex part, 5f5 ... Fixed Hole, 5g ... Bearing, 5h ... Sensor, 5h1 ... Sensor body, 5h2 ... Wiring, 5i ... Bolt, 6 ... Heat exchanger, a ... Rotating axis, S ... Hydraulic excavator.

Claims (3)

A work having a boss portion connected to a rotating shaft and a blade portion extending radially outward from the boss portion, and equipped with a fan that blows air in a direction along the rotating axis by the blade portion during rotation. It ’s a mechanical cooling device.
A bearing that supports the rotating shaft, a bearing case that houses the bearing, and a sensor that detects the rotation of the fan are provided.
The sensor has a sensor main body portion and a wiring portion connected to the sensor main body portion.
The bearing case is located in a region facing the boss portion when viewed from the direction along the rotation axis, at a position deviated in the circumferential direction from the first accommodating portion accommodating the sensor main body portion and the first accommodating portion. A second accommodating portion provided in the above and accommodating the wiring portion, a first annular portion provided on the outer peripheral surface of the bearing case and formed with the first accommodating portion, and the first annular portion provided on the outer peripheral surface of the bearing case. It has a second annular portion that is provided at a distance from the first annular portion to the side opposite to the boss portion and in which the second accommodating portion is formed .
The first accommodating portion is a cooling device for a work machine, characterized in that the first accommodating portion is a notch penetrating the first annular portion in a direction along the rotation axis . In the cooling device for a work machine according to claim 1 ,
A cooling device for a work machine, wherein the notch forming the first accommodating portion is opened to the side or the lower side of the bearing case. A work having a boss portion connected to a rotating shaft and a blade portion extending radially outward from the boss portion, and equipped with a fan that blows air in a direction along the rotating axis by the blade portion during rotation. It ’s a mechanical cooling device.
A bearing that supports the rotating shaft, a bearing case that houses the bearing, and a sensor that detects the rotation of the fan are provided.
The sensor has a sensor main body portion and a wiring portion connected to the sensor main body portion.
The bearing case is located in a region facing the boss portion when viewed from the direction along the rotation axis, at a position deviated in the circumferential direction from the first accommodating portion accommodating the sensor main body portion and the first accommodating portion. A second accommodating portion provided in the above and accommodating the wiring portion, a first annular portion provided on the outer peripheral surface of the bearing case and formed with the first accommodating portion, and the first annular portion provided on the outer peripheral surface of the bearing case. A cooling device for a work machine, characterized in that it has a second annular portion formed by the second accommodating portion, which is provided at a distance from the first annular portion on the side opposite to the boss portion.

Images