Patent Description:
A conventional canned motor device disclosed in <CIT> includes a base, a fixed seat, a motor unit, a motor cover and a heat-dissipating cover. The base is made of plastic materials, and includes a covering member and a main body member that has an inner annular surface surrounding an axis to define a mounting space. The fixed seat is made of metal materials, is formed in a shape of a hollow cylinder that surrounds the axis, is fixedly mounted within the mounting space, and has an outer annular surface that abuts against the inner annular surface of the base. The motor unit includes a case body, a stator, a rotor and an impeller. The case body is disposed on the base. The stator is sleeved on the case body and is disposed within the mounting space. The rotor is disposed within the case body. The impeller is connected to the rotor. The motor cover is disposed on the base and covers the impeller. The heat-dissipating cover is disposed on the covering member of the base. The fixed seat and the motor unit are positioned relative to the base along the axis by the heat-dissipating cover.

Because the fixed seat is made of metal materials, the fixed seat has relatively high structural strength and is capable of withstanding heat generated by the stator during operation. However, the heat may not be effectively dissipated because the outer annular surface of the fixed seat and the inner annular surface of the base closely abut against each other.

A canned motor device including a fixed seat, a motor unit, and a heat-dissipation cover is known from <CIT>.

Therefore, an object of the disclosure is to provide a canned motor device that can alleviate the drawback of the prior art.

According to the disclosure, the canned motor device includes a base, a fixed seat, a motor unit and a motor cover. The base is made of a plastic material, is formed in a shape of a hollow cylinder that surrounds an axis, and has a first end surface, a second end surface and an inner base surface. The second end surface is opposite to the first end surface along the axis. The inner base surface surrounds the axis, interconnects the first end surface and the second end surface, and defines an accommodating space. The fixed seat is made of an aluminum alloy, is formed in a shape of a hollow cylinder that surrounds the axis (L), is disposed in the accommodating space, and has an inner seat surface, an outer seat surface, a plurality of recesses and a plurality of first heat-dissipating fins. The inner seat surface surrounds the axis and defines an inner space. The outer seat surface surrounds and corresponds in position to the inner seat surface, and cooperates with the inner base surface of the base to define at least one gap therebetween. The recesses are indented from the outer seat surface and extend toward the inner seat surface. Each of the first heat-dissipating fins is located between two adjacent ones of the recesses. The motor unit includes a case body, a stator, a rotor and an impeller. The case body is disposed on the base. The stator is sleeved on the case body and is disposed in the accommodating space. The rotor is disposed in the case body. The impeller is connected to the rotor. The motor cover is disposed on the first end surface of the base and covers the impeller.

Other features and advantages of the disclosure will become apparent in the following detailed description of the embodiment with reference to the accompanying drawings, of which:.

Referring to <FIG>, <FIG> and <FIG>, an embodiment of a canned motor device according to the disclosure includes a base <NUM>, a fixed seat <NUM>, a motor unit <NUM>, a motor cover <NUM> and a heat-dissipating cover <NUM>.

The base <NUM> is made of a plastic material and is formed in a shape of a hollow cylinder that surrounds an axis (L). In this embodiment, the plastic material may be an engineering plastic with acid and alkali resistance, such as polypropylene (PP), glass fiber reinforced polypropylene (GFRPP), polyvinylidene difluoride (PVDF) and carbon fiber filled ethylene tetrafluoroethylene (CFRETFE). The base <NUM> includes a main body member <NUM> and a covering member <NUM> that are arranged in a direction (X) of the axis (L). The covering member <NUM> is connected to the main body member <NUM>. The base <NUM> has a first end surface <NUM>, a second end surface <NUM> and an inner base surface <NUM>. The first end surface <NUM> is located on one side of the main body member <NUM> opposite to the covering member <NUM>. The second end surface <NUM> is located on one side of the covering member <NUM> opposite to the first end surface <NUM> along the axis (L). The inner base surface <NUM> surrounds the axis (L), interconnects the first end surface <NUM> and the second end surface <NUM>, and defines an accommodating space <NUM>.

The inner base surface <NUM> of the base <NUM> has a stepped profile, and has a first axial segment <NUM>, a second axial segment <NUM>, a third axial segment <NUM>, a fourth axial segment <NUM>", a first abutting part <NUM>, a second abutting part <NUM> and a third abutting part <NUM>'. The first axial segment <NUM> is connected to the first end surface <NUM>. Each of the first axial segment <NUM>, the second axial segment <NUM>, the third axial segment <NUM> and the fourth axial segment <NUM>" extends substantially in the direction (X) of the axis (L). Each of the first abutting part <NUM>, the second abutting part <NUM> and the third abutting part <NUM>' extends substantially perpendicularly to the axis (L). The first abutting part <NUM>, the second abutting part <NUM> and the third abutting part <NUM>' respectively interconnect the first axial segment <NUM> and the second axial segment <NUM>, the second axial segment <NUM> and the third axial segment <NUM>, and the third axial segment <NUM> and the fourth axial segment <NUM>". The fourth axial segment <NUM>'' is connected to the second end surface <NUM>. In this embodiment, the first abutting part <NUM>, the second abutting part <NUM> and the third abutting part <NUM>' face away from the first end surface <NUM>. Referring to <FIG>, a cross section of a space defined by the third axial segment <NUM> that is perpendicular to the axis (L) is non-circular. The third axial segment <NUM> has a base dovetail region <NUM>, and a base multi-corner region <NUM> connected to the base dovetail region <NUM>. The base multi-corner region <NUM> has a plurality of inner edge parts <NUM>. In this embodiment, the base multi-corner region <NUM> has seven inner edge parts <NUM>. Any two adjacent ones of the inner edge parts <NUM> define an inner corner part <NUM> therebetween.

Referring further to <FIG>, the fixed seat <NUM> is made of an aluminum alloy, is formed in a shape of a hollow cylinder that surrounds the axis (L), is non-rotatably disposed in the accommodating space <NUM> of the base <NUM>, and has an inner seat surface <NUM>, an outer seat surface <NUM>, a plurality of recesses <NUM> and a plurality of first heat-dissipating fins <NUM>. The fixed seat <NUM> further has a first seat surface <NUM> that abuts against the second abutting segment <NUM> of the inner base surface <NUM>, and a second seat surface <NUM> that is opposite to the first seat surface <NUM> along the axis (L). The inner seat surface <NUM> interconnects the first seat surface <NUM> and the second seat surface <NUM>, surrounds the axis (L) and defines an inner space <NUM>. The outer seat surface <NUM> surrounds and corresponds in position to the inner seat surface <NUM>, and cooperates with the inner base surface <NUM> of the base <NUM> to define at least one gap <NUM> therebetween. In this embodiment, the outer seat surface <NUM> cooperates with the inner base surface <NUM> to define a plurality of gaps <NUM> therebetween. The recesses <NUM> are indented from the outer seat surface <NUM> and extend toward the inner seat surface <NUM>. The first heat-dissipating fins <NUM> are each located between two adjacent ones of the recesses <NUM>. A cross section of the fixed seat <NUM> perpendicular to the axis (L) is non-circular and has a shape corresponding to the shape of the cross section of the space defined by the third axial segment <NUM>. The outer seat surface <NUM> has a seat dovetail region <NUM>, and a seat multi-corner region <NUM> connected to the seat dovetail region <NUM>. The seat multi-corner region <NUM> has a plurality of outer edge parts <NUM> at which the recesses <NUM> are formed. In this embodiment, the seat multi-corner region <NUM> has seven outer edge parts <NUM>. The outer edge parts <NUM> respectively face the inner edge parts <NUM> of the inner base surface <NUM>. Any two adjacent ones of the outer edge parts <NUM> define an outer corner part <NUM> therebetween. Each of the outer edge parts <NUM> cooperates with the respective one of the inner edge parts <NUM> of the third axial segment <NUM> to define one of the gaps <NUM> therebetween. Each of the gaps <NUM> extends in the direction (X) of the axis (L). At least one of the first heat-dissipating fins <NUM> is located between two adjacent ones of the recesses <NUM> respectively formed at two adjacent ones of the outer edge parts <NUM>. In this embodiment, each of the outer edge parts <NUM> is recessed with a shallow groove <NUM> extending in the direction (X) of the axis (L) to serve as the respective one of the gaps <NUM>. That is to say, each of the gaps <NUM> is formed in the respective one of the outer edge parts <NUM>. The depth of each of the shallow grooves <NUM> in a radial direction transverse to the axis (L) is substantially <NUM> millimeter. In this embodiment, each of the shallow grooves <NUM> extends through two opposite end surfaces of the fixed seat <NUM> along the axis (L).

The motor unit <NUM> includes a case body <NUM>, a stator <NUM>, a rotor <NUM> and an impeller <NUM>. The case body <NUM> is disposed on the base <NUM>. The stator <NUM> is sleeved on the case body <NUM>, is disposed in the accommodating space <NUM>, and has two stator end surfaces each perpendicular to the axis (L), and an outer stator surface interconnecting the stator end surfaces. Specifically, the stator <NUM> is partly disposed in the inner space <NUM> of the fixed seat <NUM>, abuts against the first abutting part <NUM> of the inner base surface <NUM> with one of the stator end surfaces thereof, and abuts against the second axial segment <NUM> and the inner seat surface <NUM> of the fixed seat <NUM> with the outer stator surface thereof. The rotor <NUM> is disposed in the case body <NUM>. The impeller <NUM> is connected to the rotor <NUM>. Since the relevant features of this disclosure do not concern the specific configuration of the motor unit <NUM>, further details of the same are omitted herein for the sake of brevity.

The motor cover <NUM> is disposed on the first end surface <NUM> of the base <NUM> and covers the impeller <NUM>. Specifically, the motor cover <NUM> is fixedly mounted to the first end surface <NUM> by a plurality of screws, and has an intake opening <NUM> at an end thereof along the axis (L), and an exit opening <NUM> located at one side of the intake opening <NUM> that is the same as the impeller <NUM> and extending along a tangent line (not shown) to the outer periphery of the impeller.

The heat-dissipating cover <NUM> is made of an aluminum alloy, is disposed on the base <NUM>, has a first cover surface <NUM> and a second cover surface <NUM>, and includes a plurality of outer heat-dissipating fins <NUM>. The first cover surface <NUM> and the second cover surface <NUM> are respectively located at two opposite sides of the heat-dissipating cover <NUM> in the direction (X) of the axis (L). The outer heat-dissipating fins <NUM> protrude from the second cover surface <NUM> and away from the first cover surface <NUM>. The first cover surface <NUM> abuts against the third abutting part <NUM>' of the inner base surface <NUM>, the second seat surface <NUM> of the fixed seat <NUM> and the other one of the stator end surfaces of the stator <NUM>. The heat-dissipating cover <NUM> corresponds in position to the fourth axial segment <NUM>'' of the inner base surface <NUM> and is surrounded by the covering member <NUM> (i.e., the heat-dissipating cover <NUM> is located in the base <NUM>).

In the following description, the advantages provided by the structures of the embodiment of the canned motor device of the disclosure are described.

When the stator <NUM> of the motor unit <NUM> is energized, the rotor <NUM> of the motor unit <NUM> is driven by the stator <NUM> to rotate and to further drive the impeller <NUM> of the motor unit <NUM> to co-rotate so that the embodiment may pump liquid in a manner that the liquid is moved into the canned motor device through the intake opening <NUM> and are moved toward the exit opening <NUM> by the impeller <NUM> to exit the canned motor device through the exit opening <NUM>.

When the motor unit is in operation, heat is generated by the stator <NUM> and then conducted to the fixed seat <NUM>. By virtue of each of the first heat-dissipating fins <NUM> located between two adjacent ones of the recesses <NUM> that are indented from the outer seat surface <NUM> of the fixed seat <NUM>, the fixed seat <NUM> has a relatively large surface area to dissipate the heat to the gaps <NUM>. By virtue of the gaps <NUM> between the outer seat surface <NUM> and the inner base surface <NUM>, the heat dissipated by the recesses <NUM> and the first heat-dissipating fins <NUM> will be transferred to the heat-dissipating cover <NUM> through the gaps <NUM>, and then be dissipated to the external environment through the outer heat-dissipating fins <NUM> of the heat-dissipating cover <NUM>. Moreover, because the first cover surface <NUM> of the heat-dissipating cover <NUM> abuts the other one of the stator end surfaces of the stator <NUM>, the heat generated by the stator <NUM> may be dissipated directly by the heat-dissipating cover <NUM>. Therefore, heat-dissipation efficiency of the embodiment is relatively high.

In addition, the recesses <NUM> that are indented from the outer seat surface <NUM> of the fixed seat <NUM> reduces the weight of the fixed seat <NUM> so that the embodiment may be lightweight.

Overall, the canned motor device of the disclosure offers a design that is easy to assemble while providing enhanced heat-dissipation efficiency.

Claim 1:
A canned motor device comprising:
a base (<NUM>) made of a plastic material, formed in a shape of a hollow cylinder that surrounds an axis (L), and having
a first end surface (<NUM>),
a second end surface (<NUM>) that is opposite to said first end surface (<NUM>) along the axis (L), and
an inner base surface (<NUM>) that surrounds the axis (L), that interconnects said first end surface (<NUM>) and said second end surface (<NUM>), and that defines an accommodating space (<NUM>);
said canned motor device further comprising
a fixed seat (<NUM>) made of an aluminum alloy, formed in a shape of a hollow cylinder that surrounds the axis (L), disposed in said accommodating space (<NUM>), and having
an inner seat surface (<NUM>) that surrounds the axis (L) and that defines an inner space (<NUM>), and
an outer seat surface (<NUM>) that surrounds and corresponds in position to said inner seat surface (<NUM>);
said canned motor device further comprising
a motor unit (<NUM>) including
a case body (<NUM>) that is disposed on said base (<NUM>),
a stator (<NUM>) that is sleeved on said case body (<NUM>) and that is disposed in said accommodating space (<NUM>),
a rotor (<NUM>) that is disposed in said case body (<NUM>), and
an impeller (<NUM>) that is connected to said rotor (<NUM>),
said case body (<NUM>) being located between said stator (<NUM>) and said rotor (<NUM>), and opening toward said impeller (<NUM>) to accommodate said rotor (<NUM>); and
a motor cover (<NUM>) disposed on said first end surface (<NUM>) of said base (<NUM>) and covering said impeller (<NUM>);
said canned motor device being characterized in that:
said outer seat surface (<NUM>) of said fixed seat (<NUM>) cooperates with said inner base surface (<NUM>) of said base (<NUM>) to define at least one gap (<NUM>) therebetween; and
said fixed seat (<NUM>) further has
a plurality of recesses (<NUM>) indented from said outer seat surface (<NUM>) and extending toward said inner seat surface (<NUM>), and
a plurality of first heat-dissipating fins (<NUM>) each being located between two adjacent ones of said recesses (<NUM>),
said at least one gap (<NUM>) spatially communicating with at least one of said recesses (<NUM>).