Patent Publication Number: US-2022233990-A1

Title: Dust collector

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority to Japanese Patent Application No. 2021-008535, filed on Jan. 22, 2021, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a dust collector. 
     2. Description of the Background 
     In the field of dust collectors, an electric vacuum cleaner including a control board (controller) is known as described in Japanese Unexamined Patent Application Publication No. 2000-093368. 
     BRIEF SUMMARY 
     Such a controller generates heat. The controller is thus to be cooled. 
     One or more aspects of the present disclosure are directed to a technique for cooling a controller. 
     A first aspect of the present disclosure provides a dust collector, including: 
     a body housing; 
     a motor located inside the body housing; 
     a fan rotatable by the motor; 
     a controller configured to control the motor; and 
     a thermal insulator between the motor and the controller, the thermal insulator defining a flow channel through which an airflow generated by the fan passes. 
     The structure according to the above aspect of the present disclosure cools the controller. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a dust collector according to an embodiment as viewed from the left front. 
         FIG. 2  is a perspective view of the dust collector according to the embodiment as viewed from the right rear. 
         FIG. 3  is a cross-sectional view of the dust collector according to the embodiment. 
         FIG. 4  is a cross-sectional view of the dust collector according to the embodiment. 
         FIG. 5  is a cross-sectional view of the dust collector according to the embodiment. 
         FIG. 6  is a perspective view of the dust collector according to the embodiment with body openings uncovered as viewed from the left front. 
         FIG. 7  is a front view of the dust collector according to the embodiment without a battery cover. 
         FIG. 8  is a perspective view of battery packs in the embodiment being attached to battery mounts as viewed from the left front. 
         FIG. 9  is a perspective view of the dust collector without a cowling in the embodiment as viewed from the upper left. 
         FIG. 10  is an exploded perspective view of the dust collector without the cowling in the embodiment as viewed from the upper left. 
     
    
    
     DETAILED DESCRIPTION 
     Although one or more embodiments of the present disclosure will now be described with reference to the drawings, the present disclosure is not limited to the present embodiments. The components in the embodiments described below may be combined as appropriate. One or more components may be eliminated. 
     In the embodiments, the positional relationships between the components will be described using the directional terms such as front and rear (or forward and backward), right and left (or lateral), and up and down (or vertical). The terms indicate relative positions or directions with respect to the center of a dust collector  1 . 
     Dust Collector 
       FIG. 1  is a perspective view of the dust collector  1  according to an embodiment as viewed from the left front.  FIG. 2  is a perspective view of the dust collector  1  according to the embodiment as viewed from the right rear.  FIGS. 3 to 5  are cross-sectional views of the dust collector  1  according to the embodiment.  FIG. 3  is a cross-sectional view taken along line A-A in  FIG. 1  as viewed in the direction indicated by arrows.  FIG. 4  is a cross-sectional view taken along line B-B in  FIG. 1  as viewed in the direction indicated by arrows.  FIG. 5  is a cross-sectional view taken along line C-C in  FIG. 4  as viewed in the direction indicated by arrows. 
     The dust collector  1  according to the embodiment is a wet and dry dust collector that can suck liquid as well as gas. The gas is, for example, air. The liquid is, for example, water. 
     As shown in  FIGS. 1 to 5 , the dust collector  1  includes a tank unit  2 , a body  3 , and latches  4 . The body  3  is located above the tank unit  2 . The tank unit  2  supports the body  3 . The latches  4  fasten the tank unit  2  and the body  3  together. The latches  4  are on the right and left sides of the tank unit  2 . 
     The tank unit  2  includes a suction tube  5 , a tank  6 , a tank housing  7 , a tank cover  8 , a lower tank cover  9 , a support  10 , and a float  11 . 
     The suction tube  5  sucks in at least one of gas or liquid. The suction tube  5  is at the front of the tank unit  2 . The suction tube  5  includes a suction port  12 , an exhaust port  13 , and a flow channel  14 . The flow channel  14  connects the suction port  12  and the exhaust port  13 . 
     The suction tube  5  has the suction port  12  at its front end. The suction tube  5  has the exhaust port  13  at its rear end. The suction port  12  is in the front of the tank unit  2 . The suction port  12  faces frontward. The exhaust port  13  is located in an internal space of the tank  6 . Dust is sucked in through the suction port  12  together with gas or liquid, or both, and then flows into the internal space of the tank  6 . 
     The suction port  12  is connected to a dust collection hose (not shown). The tank unit  2  includes a joint  15 . The joint  15  surrounds the front end of the suction tube  5 . The joint  15  is fastened to the front of the suction tube  5  and to the front of the tank housing  7  with a screw  16 . The dust collection hose is at least partially received in the suction tube  5  through the suction port  12 . The dust collection hose is at least partially fastened to the joint  15 . 
     The tank  6  has the internal space to store dust sucked in through the suction port  12 . When liquid is sucked in through the suction port  12 , the tank  6  stores the liquid. The liquid is stored in the internal space of the tank  6 . 
     The tank housing  7  surrounds the tank  6 . The tank housing  7  receives casters  17  in its lower portion. The casters  17  support the tank unit  2  in a movable manner. The tank unit  2  supporting the body  3  moves with the casters  17  on a target cleaning surface. The user of the dust collector  1  can move the dust collector  1  forward on the target cleaning surface by pulling the dust collector  1  forward using the dust collection hose. 
     The tank cover  8  covers an opening in an upper portion of the tank  6 . The tank cover  8  has a vent  18 . 
     The lower tank cover  9  is fastened to the lower surface of the tank cover  8  with a screw (not shown). The lower tank cover  9  has an inflow port  19  facing the internal space of the tank  6 . The tank cover  8  and the lower tank cover  9  define a flow channel  20  between them. The flow channel  20  connects the inflow port  19  and the vent  18 . 
     The support  10  is located in the internal space of the tank  6 . The support  10  supports the float  11  in a manner movable in the vertical direction. The support  10  is fastened to the lower surface of the lower tank cover  9  with a screw  21 . The support  10  includes a cylinder  22  and multiple plates  23 . The plates  23  surround the cylinder  22 . The cylinder  22  is surrounded by a filter (not shown). The cylinder  22  has openings  24 . The gas or liquid around the cylinder  22  flows into an inner space of the cylinder  22  through the filter and the openings  24 . The filter collects dust from the gas or the liquid flowing into the cylinder  22 . 
     The float  11  is located in the internal space of the tank  6 , or more specifically, in the inner space of the cylinder  22 . The float  11  floats on liquid. When no liquid is in the inner space of the cylinder  22 , the float  11  is at the bottom of the cylinder  22 . When liquid is sucked into the internal space of the tank  6  through the suction port  12 , the liquid flows into the inner space of the cylinder  22  through the openings  24 . The float  11  then moves upward following the liquid level (water level) in the inner space of the cylinder  22 . The liquid level in the inner space of the cylinder  22  refers to the height of the surface of the liquid (water surface) in the inner space of the cylinder  22 . The float  11  moves upward as it is guided by the cylinder  22 . The float  11  moves upward with the liquid in the inner space of the cylinder  22  to close the inflow port  19  in the lower tank cover  9 . 
     The body  3  includes a body housing  25 , a motor  26 , a fan  27 , a motor housing  28 , a fan base  29 , a fan cover  30 , a support ring  31 , a controller  32 , a thermal insulator  33 , a switch base  34 , a switch button  35 , a handle  36 , a battery cover  37 , and battery mounts  38 . 
     The body housing  25  is supported on the tank unit  2 . The body housing  25  includes a lower housing  40 , an upper housing  41 , a separator housing  42 , and a cowling  43 . 
     The lower housing  40  and the upper housing  41  are located in a front portion of the body  3 . The separator housing  42  is located in a rear portion of the body  3 . 
     The lower housing  40  is connected to the tank cover  8 . The upper housing  41  is located above the lower housing  40 . The upper housing  41  is fastened to the tank cover  8  with a screw  44 . The lower housing  40  is held between the upper housing  41  and the tank cover  8 . 
     The lower housing  40 , the upper housing  41 , and the tank cover  8  define battery compartments  45 . 
     The separator housing  42  is connected to the tank cover  8 . The separator housing  42  is fastened to the tank cover  8  with a screw (not shown). 
     The separator housing  42  contains a drive unit compartment  46 . The separator housing  42  at least partially separates the battery compartments  45  and the drive unit compartment  46 . 
     The cowling  43  covers the lower housing  40 , the upper housing  41 , and the separator housing  42 . 
     The motor  26  is accommodated in the body housing  25 . The motor  26  in the embodiment is accommodated in the drive unit compartment  46  in the separator housing  42 . The motor  26  is a brushless inner-rotor motor. The motor  26  generates power for rotating the fan  27 . The motor  26  includes a stator  47 , a rotor  48 , and a rotor shaft  49 . The rotor  48  is located inside the stator  47 . The rotor shaft  49  is fixed to the rotor  48 . The rotor shaft  49  extends vertically. The rotor shaft  49  is rotatably supported by bearings  50  and  51 . The bearings  50  and  51  are ball bearings. The bearing  50  rotatably supports an upper portion of the rotor shaft  49 . The bearing  51  rotatably supports a lower portion of the rotor shaft  49 . The rotor shaft  49  has its rotation axis extending vertically. 
     The fan  27  is fixed to the rotor shaft  49 . The fan  27  rotates in response to the motor  26 . The fan  27  rotates as the rotor shaft  49  rotates. The fan  27  includes a blowing fan  271  and a cooling fan  272 . The blowing fan  271  generates a suction force at the suction port  12 . The cooling fan  272  generates an airflow to cool the motor  26 . The blowing fan  271  is fixed to the lower end of the rotor shaft  49 . The cooling fan  272  is fixed to a portion of the rotor shaft  49  between the lower end of the stator  47  and the blowing fan  271 . The blowing fan  271  and the cooling fan  272  are centrifugal fans. The blowing fan  271  has a larger outer diameter than the cooling fan  272 . The blowing fan  271  and the cooling fan  272  rotate as the rotor shaft  49  rotates. 
     The motor housing  28  accommodates the motor  26  and the cooling fan  272  in the body housing  25 . The motor housing  28  supports the motor  26 . The motor housing  28  supports the bearings  50  and  51 . The motor housing  28  is cylindrical and dividable into halves. As shown in  FIG. 5 , the motor housing  28  includes a left motor housing  28 L and a right motor housing  28 R. The right motor housing  28 R is joined to the left motor housing  28 L. The motor housing  28  has its upper end receiving an annular seal  28 S. The seal  28 S is formed from synthetic rubber, such as nitrile rubber (NBR) or silicone rubber. The upper end of the motor housing  28  is joined to the separator housing  42  with the seal  28 S in between. The seal  28 S seals the boundary between the upper end of the motor housing  28  and the inner surface of the separator housing  42 . 
     The motor housing  28  is located inside the separator housing  42 . More specifically, the motor housing  28  is located in the drive unit compartment  46 . The motor housing  28  accommodates the motor  26  and the cooling fan  272  in the separator housing  42 . The motor  26  and the cooling fan  272  are located in an internal space of the motor housing  28 . The motor housing  28  has a motor inlet  52  in its upper end and a motor outlet  53  in a lower portion of its side surface. The gas around the motor housing  28  flows into the internal space of the motor housing  28  through the motor inlet  52 . The gas inside the internal space of the motor housing  28  flows out of the motor housing  28  through the motor outlet  53 . 
     The fan base  29  surrounds and supports the motor housing  28 . The fan base  29  is formed from a synthetic resin, such as a polycarbonate resin. The fan base  29  has its upper end receiving an annular seal  54 . The seal  54  is formed from synthetic rubber, such as NBR or silicone rubber. The upper end of the fan base  29  is joined to the separator housing  42  with the seal  54  in between. The seal  54  seals the boundary between the upper end of the fan base  29  and the inner surface of the separator housing  42 . 
     The fan cover  30  covers at least a part of the blowing fan  271 . The fan cover  30  is supported on the fan base  29 . The fan cover  30  at least partially surrounds the blowing fan  271 . The fan cover  30  is at least partially located below the blowing fan  271 . The fan cover  30  has a fan inlet  55  in its lower portion. The fan inlet  55  is located above the vent  18  in the tank cover  8 . The fan inlet  55  faces the vent  18 . The fan cover  30  has a vent in a portion adjacent to the blowing fan  271 . 
     The support ring  31  supports the lower surface of the fan cover  30 . The support ring  31  is annular and is formed from synthetic rubber, such as NBR or silicone rubber. The support ring  31  is supported on the tank cover  8 . The support ring  31  is in tight contact with the lower surface of the fan cover  30  and with the upper surface of the tank cover  8 . The support ring  31  seals the boundary between the fan cover  30  and the tank cover  8 . 
     The blowing fan  271  rotates to generate a suction force at the suction port  12 . As shown by arrow Fa in  FIG. 3 , the gas sucked into the internal space of the tank  6  through the suction port  12  flows into the inner space of the cylinder  22  in the support  10  through the openings  24  and then into the inflow port  19  in the lower tank cover  9 . The gas then flows through the flow channel  20  between the lower tank cover  9  and the tank cover  8  and through the vent  18  and the support ring  31 . The gas then flows into the blowing fan  271  through the fan inlet  55  and flows out of the fan cover  30  through the vent in the fan cover  30 . 
     As the cooling fan  272  rotates, the gas around the motor housing  28  flows into the internal space of the motor housing  28  through the motor inlet  52  to cool the motor  26 . The gas then flows out of the motor housing  28  through the motor outlet  53 . 
     The body housing  25  in the embodiment has cooling inlets  56 , an intake channel  57 , cooling outlets  58 , and an exhaust channel  59 . The cooling inlets  56  are located in a right rear portion of the body housing  25 . The cooling inlets  56  connect the outside and the inside of the body housing  25 . The cooling outlets  58  are located in a left rear portion of the body housing  25 . The cooling outlets  58  connect the inside and the outside of the body housing  25 . The intake channel  57  is defined in an internal space of the body housing  25 . The intake channel  57  connects the cooling inlets  56  to the motor inlet  52 . The exhaust channel  59  is defined in the internal space of the body housing  25 . The exhaust channel  59  connects the motor outlet  53  to the cooling outlets  58 . 
     As shown by arrow Fb in  FIG. 5 , in response to rotation of the cooling fan  272 , the gas for cooling the motor  26  flows into the intake channel  57  through the cooling inlets  56 . The gas flowing through the intake channel  57  then flows into the internal space of the motor housing  28  through the motor inlet  52  to cool the motor  26 . The gas then flows into the exhaust channel  59  through the motor outlet  53 . The gas flowing through the exhaust channel  59  then flows out of the body housing  25  through the cooling outlets  58 . 
     When liquid is sucked in through the suction port  12 , the liquid is stored in the internal space of the tank  6 . When the water level in the inner space of the cylinder  22  in the support  10  rises, the float  11  moves upward. The float  11 , which has moved upward, closes the inflow port  19  in the lower tank cover  9 . This closes the flow channel  20  communicating with the fan inlet  55  in the fan cover  30 . In other words, the float  11  moves upward with the liquid in the inner space of the cylinder  22  to close the flow channel  20  that communicates with the fan inlet  55 . The inflow port  19  in the lower tank cover  9  is closed by the float  11  and the flow channel  20  is thus closed, reducing entry of the liquid into the drive unit compartment  46 . 
     Although the fan inlet  55  is closed, the rotating cooling fan  272  can cool the motor  26 . 
     The controller  32  includes a computer system. The controller  32  outputs control signals for controlling an electronic device incorporated in the dust collector  1 . The electronic device includes the motor  26 . The controller  32  outputs control signals for controlling the motor  26 . The controller  32  includes a control board on which multiple electronic components are mounted. Examples of the electronic components mounted on the control board include a processor such as a central processing unit (CPU), a nonvolatile memory such as a read-only memory (ROM) or a storage device, a volatile memory such as a random-access memory (RAM), a transistor, a capacitor, and a resistor. 
     The thermal insulator  33  is located between the motor  26  and the controller  32 . The thermal insulator  33  in the embodiment supports the controller  32 . The thermal insulator  33  is located at the top of the separator housing  42 . 
     The switch base  34  is located at the front of the body housing  25 . The switch base  34  is a plate elongated in the vertical direction. The switch base  34  includes a main power switch  60  and a suction force adjustment switch  61 . The main power switch  60  and the suction force adjustment switch  61  are located on the switch base  34 . The main power switch  60  and the suction force adjustment switch  61  are arranged in the vertical direction. The suction force adjustment switch  61  in the embodiment is located below the main power switch  60 . The suction force adjustment switch  61  may be located above the main power switch  60 . 
     The switch button  35  is located at the front of the body housing  25  and above the switch base  34 . The switch button  35  is supported by the body housing  25  in a pivotable manner. 
     The handle  36  is supported in an upper portion of the body housing  25  in a pivotable manner. The handle  36  is located behind the switch button  35 . The user of the dust collector  1  carries the dust collector  1  by holding the handle  36 . 
     The body housing  25  has body openings  62  communicating with the battery compartments  45 . The body openings  62  are located in the body housing  25 . The body openings  62  in the embodiment are located in the front of the body housing  25 . 
     The battery cover  37  is operable to cover and uncover the body openings  62 . The battery cover  37  has its upper end pivotably supported on an upper front portion of the body housing  25 . 
       FIG. 6  is a perspective view of the dust collector  1  according to the embodiment with the body openings  62  uncovered as viewed from the left front.  FIG. 7  is a front view of the dust collector  1  according to the embodiment without the battery cover  37 . 
     Each body opening  62  communicates with the corresponding battery compartment  45 . The body openings  62  are located in the front of the body housing  25 . The battery cover  37  is operable to cover and uncover the body openings  62 . In the embodiment, the battery cover  37  has its upper end pivotably supported on the upper front portion of the body housing  25 . The upper end of the battery cover  37  is hinged to the upper front portion of the body housing  25 . The battery cover  37  has a hinge axis extending laterally. The battery cover  37  is supported on the body housing  25  to have its lower end rotatable in the vertical direction. 
     A lock lever  63  is located at the lower end of the battery cover  37 . A hook  64  is located on the front surface of the body housing  25 . The hook  64  is located below the switch base  34  and the body openings  62 . The lock lever  63  is engaged with the hook  64  to fasten the battery cover  37  to the body housing  25 . 
     The battery mounts  38  are located frontward from the motor  26  in the body housing  25 . Each battery mount  38  is located in the corresponding battery compartment  45 . Each body opening  62  communicates with the corresponding battery mount  38 . A battery pack  65  is attachable to and detachable from the battery mount  38 . 
     The battery pack  65  serves as a power supply for the dust collector  1 . When mounted on the battery mount  38 , the battery pack  65  powers the electronic device incorporated in the dust collector  1 . The motor  26  runs on power supplied from the battery pack  65 . The controller  32  operates on power supplied from the battery pack  65 . The battery pack  65  is a general-purpose battery usable as a power supply for various electrical instruments. The battery pack  65  is usable for powering power tools. The battery pack  65  is usable for powering electrical instruments other than power tools. The battery pack  65  is usable for powering dust collectors other than the dust collector  1  according to the embodiment. The battery pack  65  includes a lithium-ion battery. The battery pack  65  includes a rechargeable battery. The battery mount  38  has the same structure as a battery mount included in a power tool. 
     The switch base  34  is adjacent to the body openings  62 . The battery mounts  38  in the embodiment include a first battery mount  381  and a second battery mount  382 . The first battery mount  381  is located leftward from the switch base  34 . The second battery mount  382  is located rightward from the switch base  34 . The battery compartments  45  include a first battery compartment  451  and a second battery compartment  452 . The first battery compartment  451  receives the first battery mount  381 . The second battery compartment  452  receives the second battery mount  382 . The body openings  62  include a first body opening  621  and a second body opening  622 . The first body opening  621  communicates with the first battery mount  381 . The second body opening  622  communicates with the second battery mount  382 . 
     The battery cover  37  includes a cover  69  and a cover opening  70 . The cover  69  covers the body openings  62 . The cover opening  70  receives the switch base  34 . The cover  69  includes a first cover portion  691  and a second cover portion  692 . The first cover portion  691  covers the first body opening  621 . The second cover portion  692  covers the second body opening  622 . When the cover  69  covers the body openings  62 , the switch base  34  has its surface received in the cover opening  70 . The switch base  34  is exposed through the cover opening  70 . 
     Battery Mount 
       FIG. 8  is a perspective view of the battery packs  65  in the embodiment being attached to the battery mounts  38  as viewed from the left front. 
     The user of the dust collector  1  attaches and detaches the battery packs  65  to and from the battery mounts  38 . Each battery mount  38  includes guides  66  and body terminals  67 . Each battery pack  65  includes battery terminals. The guides  66  on the battery mount  38  guide the battery pack  65  placed through the body opening  62  in a horizontal direction. 
     In the embodiment, the horizontal direction refers to a direction parallel to a plane including a front-rear axis parallel to the front-rear direction and a lateral axis parallel to the lateral direction. 
     In an embodiment, the guides  66  guide the battery pack  65  in the front-rear direction. 
     The body terminals  67  on the battery mount  38  are connectable to the battery terminals on the battery pack  65 . The user places the battery pack  65  onto the battery mount  38  from the front of the battery mount  38  and moves the battery pack  65  backward. The battery pack  65  is thus attached to the battery mount  38 . The battery pack  65  moves backward as it is guided by the guides  66  on the battery mount  38 . This allows the battery pack  65  to be attached to the battery mount  38 . The battery terminals on the battery pack  65  are thus electrically connected to the body terminals  67  on the battery mount  38 . The battery pack  65  includes a release button  68 . The user of the dust collector  1  operates the release button  68  and moves the battery pack  65  forward to remove the battery pack  65  from the battery mount  38 . 
     The first battery mount  381  and the second battery mount  382  are electrically connected in parallel. When a battery pack  65  is attached to the first battery mount  381  without another battery pack  65  attached to the second battery mount  382 , the electronic device incorporated in the dust collector  1  is operable on power supplied from the battery pack  65  attached to the first battery mount  381 . When a battery pack  65  is attached to the second battery mount  382  without another battery pack  65  attached to the first battery mount  381 , the electronic device incorporated in the dust collector  1  is operable on power from the battery pack  65  attached to the second battery mount  382 . 
     The main power switch  60  switches between supplying power and stopping supplying power from the battery pack  65  to the dust collector  1 . The suction force adjustment switch  61  adjusts the rotational speed per unit time of the motor  26 . This adjusts the suction force at the suction port  12 . 
     The switch button  35  is operable to switch the motor  26  between a driving state and a stopping state while the battery pack  65  is supplying power to the dust collector  1 . 
     Thermal Insulator 
       FIG. 9  is a perspective view of the dust collector  1  without the cowling  43  in the embodiment as viewed from the upper left.  FIG. 10  is an exploded perspective view of the dust collector  1  without the cowling  43  in the embodiment as viewed from the upper left. 
     As shown in  FIGS. 5, 9, and 10 , the thermal insulator  33  is located between the motor  26  and the controller  32 . The thermal insulator  33  reduces transfer of heat from the motor  26  to the controller  32 . 
     The thermal insulator  33  is at least partially located between the motor outlet  53  and the controller  32 . The thermal insulator  33  reduces transfer of heat from gas discharged through the motor outlet  53  to the controller  32 . The thermal insulator  33  reduces flow of the gas discharged through the motor outlet  53  hitting the controller  32 . More specifically, the thermal insulator  33  reduces transfer of heat from the gas that has cooled the motor  26  to the controller  32 . The thermal insulator  33  reduces flow of the gas that has cooled the motor  26  hitting the controller  32 . 
     The thermal insulator  33  has lower thermal conductivity than the separator housing  42 . The thermal insulator  33  in the embodiment is formed from synthetic rubber, such as NBR or silicone rubber. 
     The controller  32  is located above the motor  26 . The controller  32  is located above the thermal insulator  33 . The motor  26  is located below the thermal insulator  33 . 
     The thermal insulator  33  is located above the motor housing  28 . The thermal insulator  33  is located at the top of the separator housing  42 . 
     The thermal insulator  33  supports the controller  32 . The thermal insulator  33  includes a plate  331 , a rib  332 , and a partition  333 . 
     The plate  331  faces the lower surface of the controller  32 . The plate  331  has its upper surface in contact with the lower surface of the controller  32 . 
     The rib  332  protrudes upward from the upper surface of the plate  331 . The rib  332  at least partially surrounds the controller  32 . The rib  332  is in contact with at least a part of the controller  32 . The rib  332  positions the controller  32 . 
     As shown in  FIG. 5 , the partition  333  protrudes downward from the lower surface of the plate  331 . 
     The controller  32  includes a control board  321  and a controller case  322 . The control board  321  receives multiple electronic components. The controller case  322  accommodates the control board  321 . The controller  32  in the embodiment has its lower surface including the lower surface of the controller case  322 . The controller  32  has its side surfaces including the side surfaces of the controller case  322 . 
     The controller case  322  is rectangular. The rib  332  is in contact with the left front corner of the controller case  322 . The separator housing  42  includes a rib  421 , a rib  422 , and a rib  423 . The rib  421  is in contact with the left rear corner of the controller case  322 . The rib  422  is in contact with the right rear corner of the controller case  322 . The rib  423  is in contact with the right front corner of the controller case  322 . The controller  32  is positioned by the ribs  332 ,  421 ,  422 , and  423 . 
     The thermal insulator  33  defines a flow channel through which the airflow generated by the cooling fan  272  passes. The flow channel through which the airflow generated by the cooling fan  272  passes includes the exhaust channel  59  that connects to the motor outlet  53 . The flow channel through which the airflow generated by the cooling fan  272  passes includes the intake channel  57  that connects to the motor inlet  52 . 
     The intake channel  57  is located rightward from the exhaust channel  59 . The intake channel  57  and the exhaust channel  59  each extend laterally. 
     The intake channel  57  is at least partially defined by the separator housing  42  and the cowling  43 . As shown in  FIGS. 9 and 10 , the separator housing  42  includes a pair of intake ribs  424 . The intake ribs  424  protrude upward from the upper surface of the separator housing  42 . 
     The intake ribs  424  each extend laterally. The intake ribs  424  are arranged in the front-rear direction. The cowling  43  covers the intake ribs  424 . The upper surface of the separator housing  42 , the pair of intake ribs  424 , and the cowling  43  define a space that is at least a part of the intake channel  57 . 
     The exhaust channel  59  is at least partially defined by the separator housing  42  and the cowling  43 . As shown in  FIGS. 9 and 10 , the separator housing  42  includes a pair of exhaust ribs  425 . The exhaust ribs  425  protrude upward from the upper surface of the separator housing  42 . The exhaust ribs  425  each extend laterally. The exhaust ribs  425  are arranged in the front-rear direction. The cowling  43  covers the exhaust ribs  425 . The upper surface of the separator housing  42 , the pair of exhaust ribs  425 , and the cowling  43  define a space that is at least a part of the exhaust channel  59 . 
     The separator housing  42  has an inlet  426  and an outlet  427 . The inlet  426  communicates with the motor inlet  52 . The outlet  427  communicates with the motor outlet  53 . The inlet  426  is located above the motor inlet  52 . The outlet  427  is located leftward from the inlet  426 . As shown in  FIG. 5 , a flow channel  77  is defined between a left portion of the motor housing  28  and the fan base  29 . Gas discharged through the motor outlet  53  flows through the flow channel  77 . The outlet  427  is located above the flow channel  77 . 
     The intake channel  57  and the exhaust channel  59  each accommodate a sound absorber  78 . The sound absorbers  78  are, for example, porous members formed from a synthetic resin. 
     The thermal insulator  33  at least partially separates the intake channel  57  and the exhaust channel  59 . As shown in  FIG. 5 , the partition  333  in the thermal insulator  33  separates the intake channel  57  and the exhaust channel  59 . The partition  333  is located between the intake channel  57  and the exhaust channel  59  in the lateral direction. The thermal insulator  33  is in contact with the separator housing  42 . The thermal insulator  33  seals the boundary between the intake channel  57  and the exhaust channel  59 . 
     The thermal insulator  33  partially surrounds the inlet  426 . The thermal insulator  33  does not cover the inlet  426 . The thermal insulator  33  is at least partially located above the outlet  427 . The thermal insulator  33  at least partially faces the outlet  427  with a clearance between them. The thermal insulator  33  supported by the separator housing  42  does not cover the outlet  427 . 
     The intake channel  57  is at least partially defined by the separator housing  42  and the controller  32 . The plate  331  supports a part of the controller  32 . The controller  32  is at least partially located above the inlet  426 . The controller  32  supported by the thermal insulator  33  does not cover the inlet  426 . The controller  32  is at least partially located above the upper surface of the separator housing  42 . The controller  32  has its lower surface portion located rightward from the inlet  426  and uncovered by the plate  331  in the thermal insulator  33 . The lower surface portion of the controller  32  located rightward from the inlet  426  faces the intake channel  57 . More specifically, the controller  32  has its lower surface portion partially uncovered by the thermal insulator  33  in the intake channel  57 . The controller  32  is thus partially exposed to the intake channel  57 . The upper surface of the separator housing  42 , the pair of intake ribs  424 , and the lower surface portion of the controller  32  define a space that is at least a part of the intake channel  57 . 
     The intake channel  57  is at least partially defined by the separator housing  42  and the thermal insulator  33 . The rib  332  on the thermal insulator  33  is at least partially located frontward from the inlet  426 . The rib  332  connects to the intake rib  424 . The rib  332  defines at least a part of the intake channel  57 . 
     The exhaust channel  59  is at least partially defined by the separator housing  42  and the thermal insulator  33 . The plate  331  in the thermal insulator  33  is at least partially located above the outlet  427 . The plate  331  does not cover the outlet  427 . The plate  331  is at least partially located above the upper surface of the separator housing  42 . The plate  331  connects to the exhaust ribs  425 . The controller  32  has its lower surface portion located leftward from the inlet  426  and covered by the plate  331  in the thermal insulator  33 . The lower surface portion of the controller  32  located leftward from the inlet  426  is unexposed to the exhaust channel  59 . More specifically, the controller  32  has its lower surface portion covered by the thermal insulator  33  in the exhaust channel  59 . The controller  32  is thus unexposed to the exhaust channel  59 . The upper surface of the separator housing  42 , the pair of exhaust ribs  425 , and the lower surface of the plate  331  defines a space that is at least a part of the exhaust channel  59 . 
     As described above, the thermal insulator  33  is located between the motor  26  and the controller  32  in the embodiment. The thermal insulator  33  reduces transfer of heat from the motor  26  or heat from the gas that has cooled the motor  26  to the controller  32 . The thermal insulator  33  defines a flow channel through which the airflow generated by the cooling fan  272  passes. The airflow passing through the flow channels defined by the thermal insulator  33  effectively cools the controller  32 . 
     The motor  26  is accommodated in the motor housing  28 . The motor housing  28  has the motor inlet  52  and the motor outlet  53 . The thermal insulator  33  defines at least a part of the exhaust channel  59  that connects to the motor outlet  53 . The thermal insulator  33  defines at least a part of the intake channel  57  that connects to the motor inlet  52 . 
     The controller  32  is unexposed to the exhaust channel  59 . The controller  32  is covered by the thermal insulator  33  in the exhaust channel  59 . The gas then flows through the exhaust channel  59  after cooling the motor  26 . The thermal insulator  33  reduces flow of the gas that has cooled the motor  26  hitting the controller  32 . This reduces transfer of heat from the gas that has cooled the motor  26  to the controller  32 . 
     The controller  32  is at least partially exposed to the intake channel  57 . The controller  32  is uncovered by the thermal insulator  33  in the intake channel  57 . Before cooling the motor  26 , the gas flows through the intake channel  57 . The gas hits the controller  32  before cooling the motor  26 , thus effectively cooling the controller  32 . 
     The partition  333  in the thermal insulator  33  separates the intake channel  57  and the exhaust channel  59 . This reduces mixing of the gas flowing through the intake channel  57  with the gas flowing through the exhaust channel  59 . 
     The thermal insulator  33  is at least partially located between the motor outlet  53  and the controller  32 . This reduces flow of the gas that has cooled the motor  26  hitting the controller  32 . 
     The controller  32  is located above the motor  26 . The controller  32  is located above the thermal insulator  33 . The motor  26  is located below the thermal insulator  33 . This reduces transfer of heat from the motor  26  to the controller  32 . The thermal insulator  33  properly defines at least one of the intake channel  57  or the exhaust channel  59 . 
     The thermal insulator  33  supports the controller  32 . This effectively reduces transfer of heat from the motor  26  to the controller  32 . 
     The thermal insulator  33  includes the plate  331  facing the lower surface of the controller  32  and the rib  332  at least partially surrounding the controller  32 . The thermal insulator  33  positioning the controller  32  thus stably supports the controller  32 . 
     The dust collector  1  according to the embodiment is a wet and dry dust collector that can suck liquid as well as gas. The fan  27  includes the blowing fan  271  that generates a suction force at the suction port  12  and the cooling fan  272  that generates an airflow to cool the motor  26 . Although the fan inlet  55  is closed by the float  11 , the rotating cooling fan  272  can cool the motor  26 . 
     OTHER EMBODIMENTS 
     In the above embodiment, the cooling fan  272  may be eliminated. The rotating blowing fan  271  may generate an airflow for fooling the motor  26 . 
     In the above embodiment, the dust collector  1  is a wet and dry dust collector. The dust collector  1  may be a dry dust collector. 
     REFERENCE SIGNS LIST 
     
         
           1  dust collector 
           2  tank unit 
           3  body 
           4  latch 
           5  suction tube 
           6  tank 
           7  tank housing 
           8  tank cover 
           9  lower tank cover 
           10  support 
           11  float 
           12  suction port 
           13  exhaust port 
           14  flow channel 
           15  joint 
           16  screw 
           17  caster 
           18  vent 
           19  inflow port 
           20  flow channel 
           21  screw 
           22  cylinder 
           23  plate 
           24  opening 
           25  body housing 
           26  motor 
           27  fan 
           28  motor housing 
           28 L left motor housing 
           28 R right motor housing 
           28 S seal 
           29  fan base 
           30  fan cover 
           31  support ring 
           32  controller 
           33  thermal insulator 
           34  switch base 
           35  switch button 
           36  handle 
           37  battery cover 
           38  battery mount 
           40  lower housing 
           41  upper housing 
           42  separator housing 
           43  cowling 
           44  screw 
           45  battery compartment 
           46  drive unit compartment 
           47  stator 
           48  rotor 
           49  rotor shaft 
           50  bearing 
           51  bearing 
           52  motor inlet 
           53  motor outlet 
           54  seal 
           55  fan inlet 
           56  cooling inlet 
           57  intake channel 
           58  cooling outlet 
           59  exhaust channel 
           60  main power switch 
           61  suction force adjustment switch 
           62  body opening 
           63  lock lever 
           64  hook 
           65  battery pack 
           66  guide 
           67  body terminal 
           68  release button 
           69  cover 
           70  cover opening 
           77  flow channel 
           78  sound absorber 
           271  blowing fan 
           272  cooling fan 
           321  control board 
           322  controller case 
           331  plate 
           332  rib 
           333  partition 
           381  first battery mount 
           382  second battery mount 
           421  rib 
           422  rib 
           423  rib 
           424  intake rib 
           425  exhaust rib 
           426  inlet 
           427  outlet 
           451  first battery compartment 
           452  second battery compartment 
           621  first body opening 
           622  second body opening 
           691  first cover portion 
           692  second cover portion