Patent Publication Number: US-2019190342-A1

Title: Motor frame with bumps

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a motor frame, and more particularly to the motor frame having bumps for heat conduction. 
     2. Description of the Prior Art 
     A motor is a device that can transform electric energy into mechanical kinetic energy by electromagnetic induction. While in transforming the electric energy into the corresponding kinetic energy, electric current would flow through stator coils, so that corresponding electromagnetic effect can be induced. However, while the electric current flows, excess thermal energy would be generated due to current loss (for example, copper loss or iron loss) from electric resistance of the stator coils. This thermal energy would somehow damage internal elements of the motor, and further affect the operation of motor. 
     In details, refer to  FIG. 1  through  FIG. 2 ; where  FIG. 1  is a schematic front view of a conventional motor frame, and  FIG. 2  is a schematic cross-sectional view of  FIG. 1  along line A-A. As shown, the conventional motor frame PA 1  includes a frame body PA 11  and a plurality of heat-dissipation fins PA 12  (only one labeled in the figure). Out of the frame body PA 11 , four fin-mounting portions PA 111 , PA 111   a , PA 111   b  and PA 111   c  are provided. As shown, among three fin-mounting portions PA 111 , PA 111   a  and PA 111   b , two wiring passages PAT 1  (only one labeled in the figure) are provided, each of the wiring passages PAT 1  is to define walls of the frame body PA 11  into an inner passage wall PA 112  and an external passage wall PA 113 . 
     Referring now to  FIG. 3 , an operation state of the conventional motor frame associated with a major motor assembly is schematically shown. The major motor assembly PA 2  includes a first fan PA 21 , a second fan PA 22 , a stator PA 23 , a rotor PA 24 , a front-end cover PA 25 , a back-end cover PA 26 , an external fan PA 27  and a fancover PA 28 . The rotor PA 24  is furnished with a rotor heat-dissipation passage PAT 2 . The first fan PA 21  and the second fan PA 22  are disposed, respectively, at two opposing ends of a center axis (not labeled in the figure) of the rotor PA 24 . The front-end cover PA 25  and the back-end cover PA 26  are to cover two opposing ends of the frame body PA 11 , such that a sealed room can be formed inside the frame body  11 . The external fan PA 27  is disposed at one end of the center axis of the rotor PA 24  and out of the frame body PA 11 . The fancover PA 28  is to cover the external fan PA 27 . 
     The motor PA 100  includes the motor frame PA 1  and the major motor assembly PA 2 . As the motor PA 100  runs, excess thermal energy would be generated while in transforming the electric energy into kinetic energy. Hence, temperatures of individual internal elements of the motor would rise. With the rotation of the rotor PA 24 , the first fan PA 21  and the second fan PA 22  would induce internal air flow of the frame body PA 11 , so as further to form an internal heat-dissipation flow PAF 1 . The internal heat-dissipation flow PAF 1  would carry away the thermal energy in the rotor heat-dissipation passage PAT 2 , and the thermal energy gone with the internal heat-dissipation flow PAF 1  would be transferred into the wiring passage PAT 1 . Via heat conduction from the inner passage wall PA 112  to the external passage wall PA 113 , the thermal energy in the wiring passage PAT 1  would be shipped out of the wiring passage PAT 1 . Finally, via an external heat-dissipation flow PAF 2  generated by the external fan PA 27 , the thermal energy would be further dissipated into the atmosphere. 
     However, the existence of the wiring passage PAT 1 , served also as a heat-dissipation channel of internal air circulation, would occupy space for constructing the heat-dissipation fins PA 12 . The reduction in the heat-dissipation fins PA 12  would contribute the wiring passage PAT 1  with larger thermal resistance. Further, the construction of the wiring passage PAT 1  would detour the external heat-dissipation flow PAF 2  generated by the external fan PA 27 . Thereby, after the external heat-dissipation flow PAF 2  passes the heat-dissipation fins PA 12 , a windward side and a lee side would be there to make difference. Apparently, the windward side can provide better heat-dissipation efficiency than the lee side can do. Thus, hot spots would be easily formed at the wiring passage PAT 1  respective to the lee side. Such an ill distribution of temperature on the motor frame PA 1  would definitely hurt the entire performance of heat dissipation. 
     SUMMARY OF THE INVENTION 
     In view of the prior art, since the existence of the wiring passages may sacrifice the amount of the heat-dissipation fins. In addition, as the external heat-dissipational flow passes the heat-dissipation fins, the windward side and the lee side with respect to the flow are generated, from which different heat-dissipation efficiency are formed. Thereupon, hot spots would be easily formed at the wiring passage respective to the lee side. Thereby, the major motor assembly would be kept in a high-temperature environment as long as the motor is running. It can be foreseen that, under such an operation situation, the motor would be eventually burned down or damaged at least. In addition, hot spots would cause a non-uniform temperature distribution inside the motor frame, and thus would be harmful to the entire heat dissipation of the motor. 
     Accordingly, it is an object of the present invention to provide a motor frame with bumps for sleeving a major motor assembly includes a frame body, a plurality of bumps and a plurality of heat-dissipation fins. The frame body has an internal surface and an external surface, extends in an extension direction parallel to a center axis, and is defined orderly in the extension direction to have a first fan-accommodating section, a major accommodating section and a second fan-accommodating section. The first fan-accommodating section is to accommodate a first fan, the major accommodating section is to accommodate the major motor assembly, and the second fan-accommodating section is to accommodate a second fan. The plurality of bumps protrude individually toward the center axis from the internal surface, extend from a conjunction of the first fan-accommodating section and the major accommodating section to another conjunction of the second fan-accommodating section and the major accommodating section, and contact the major motor assembly so as to conduct a thermal energy generated by running the major motor assembly. A plurality of internal heat-dissipation passages are individually formed between every two neighboring bumps. The plurality of heat-dissipation fins protrude individually from the external surface by back-warding the center axis, and extend in the extension direction. A plurality of external heat-dissipation passages are individually formed between every two neighboring heat-dissipation fins, and extend in the extension direction. Each of the plurality of bumps is radially outwards respective to at least two of the plurality of heat-dissipation fins, and each of the plurality of internal heat-dissipation passages is to flow a internal heat-dissipation flow. 
     In one embodiment of the present invention, the motor frame with bumps further includes a mounting structure on the frame body for supporting and positioning the frame body. 
     In one embodiment of the present invention, the major motor assembly is furnished with a rotor passage and a stator passage, and a heat-dissipation flow circulation space for circulating the internal heat-dissipation flow is formed by integrating the first fan-accommodating section, the internal flow passage, the second fan-accommodating section, the rotor passage and the stator passage. 
     In one embodiment of the present invention, the plurality of heat-dissipation fins have individual correspondence sections, and each of the plurality of bumps is radially outwards respective to at least two of the correspondence sections of the plurality of heat-dissipation fins. 
     In one embodiment of the present invention, the plurality of bumps extends in the extension direction from the conjunction of the first fan-accommodating section and the major accommodating section to the another conjunction of the second fan-accommodating section and the major accommodating section, and the internal heat-dissipation passage is formed by having every two neighboring said bumps to define therebetween one of the plurality of internal heat-dissipation passages extending in the extension direction. 
     In one embodiment of the present invention, the frame body has a frame-extension length in the extension direction, each of the plurality of bumps has a bump-extension length in the extension direction, and the bump-extension length is smaller than the frame-extension length. 
     As described above, by providing the motor frame of the present invention to include a plurality of bumps, every two neighboring bumps are used to form in between an internal flow passage extending in the extension direction, and thereby a heat-dissipation flow circulation space can be formed. 
     Thereupon, even more heat-dissipation efficiency can be achieved by the motor frame with bumps of the present invention. 
     In comparison with the prior art, the motor frame with bumps can implement the bumps respective radially outwards to a plurality of heat-dissipation fins for conducting the thermal energy generated by the major motor assembly, and provides more available contact surfaces for heat transfer. Thereupon, more thermal energy can be transferred per unit time. Also, the inclusion of the internal flow passages defined by every two neighboring bumps can allow the internal heat-dissipation flow to flow through, and thus the thermal energy absorbed and carried away by the internal heat-dissipation flow can be dissipated to the frame body. Finally, the heat-dissipation fins take charge in dissipating the thermal energy into the atmosphere. In addition, the number of the heat-dissipation fins at a place radially outwards respective to the internal heat-dissipation passage can be reduced, and thus the usage efficiency of the heat-dissipation fins and the space occupied by the frame body can be substantially increased. Thereupon, the goal of lightweight in the frame body can be achieved without trading off the heat-dissipation performance. 
     All these objects are achieved by the motor frame with bumps described below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will now be specified with reference to its preferred embodiment illustrated in the drawings, in which: 
         FIG. 1  is a schematic front view of a conventional motor frame; 
         FIG. 2  is a schematic cross-sectional view of  FIG. 1  along line A-A; 
         FIG. 3  demonstrates schematically an operation state of the conventional motor frame associated with a major motor assembly; 
         FIG. 4  is a schematic perspective view of a preferred embodiment of the motor frame with bumps in accordance with the present invention; 
         FIG. 5  is a schematic front view of  FIG. 4 ; 
         FIG. 6  is a schematic cross-sectional view of  FIG. 5  along line B-B; 
         FIG. 7  demonstrates schematically an operation state of the motor frame of  FIG. 4  associated with the major motor assembly; 
         FIG. 8  is a schematic cross-sectional view of  FIG. 5  along line C-C; and 
         FIG. 9  demonstrates schematically another operation state of the motor frame of  FIG. 4  associated with the major motor assembly, particularly showing the heat dissipation flow. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The invention disclosed herein is directed to a motor frame with bumps. In the following description, numerous details are set forth in order to provide a thorough understanding of the present invention. It will be appreciated by one skilled in the art that variations of these specific details are possible while still achieving the results of the present invention. In other instance, well-known components are not described in detail in order not to unnecessarily obscure the present invention. 
     Refer now to  FIG. 4  and  FIG. 5 ; where  FIG. 4  is a schematic perspective view of a preferred embodiment of the motor frame with bumps in accordance with the present invention, and  FIG. 5  is a schematic front view of  FIG. 4 . As shown, the motor frame with bumps (“motor frame” thereafter)  1  includes a frame body  11 , a plurality of bumps  12  (only one labeled in the figure) and a plurality of heat-dissipation fins  13  (only one labeled in the figure). In this preferred embodiment, the motor frame  1  further includes a mounting structure  14  for mounting and positioning the motor frame  1 . 
     The frame body  11  has an internal surface  111  and an external surface  112 , both of which extend in an extension direction D parallel to a center axis X. The frame body  11  are largely divided into a first fan-accommodating section S 1  (see  FIG. 6 ), a major accommodating section S 2  (see  FIG. 6 ) and a second fan-accommodating section S 3  (see  FIG. 6 ). The plurality of bumps  12  (only one labeled in the figure) protruding toward the center axis X directly from the internal surface  111  are spaced to each other, and each the bump  12  extends in the extension direction D from a conjunction of the first fan-accommodating section S 1  and the major accommodating section S 2  to another conjunction of the second fan-accommodating section S 3  and the major accommodating section S 2 . A plurality of heat-dissipation fins  13  (only one labeled in the figure) protrude individually from the external surface  112  in a direction away from the center axis X. In addition, each of the bumps  12  is radially respective to at least two of the heat-dissipation fins  13 . 
     In details, the frame body  11  of the motor frame  1  is to form thereinside an accommodation space S for sleeving a major motor assembly  2  (see  FIG. 7 ). As shown, every two neighboring bumps ( 12   a  and  12   b  for example) among the plurality of bumps  12  are there to define one of internal heat-dissipation passages TI (only one labeled in the figure) extending in the extension direction D and parallel to each other. Similarly, every two heat-dissipation fins  13  ( 13   a  and  13   b  for example) among the plurality of heat-dissipation fins  13  are there to define one of external heat-dissipation passages TO (only one labeled in the figure) extending in the extension direction D and parallel to each other. 
     As described above, each of the bumps  12  is radially outwards respective to at least two of the heat-dissipation fins  13  on the other side with respect to the wall of the frame body  11 . It shall be elucidated further that, to understand the meaning of “one bump is radially outwards respective to at least two of the heat-dissipation fins”,  FIG. 5  can be referred. As shown, two radial reference lines R 1  and R 2 , both originated at the same center located on the center axis X, are extended outwards in corresponding radial directions and penetrate the respective internal heat-dissipation passages TI located neighborly to the concerned bump  12 . In the present invention, the sector range limited by these two radial reference lines R 1  and R 2  is defined as a radial correspondence range Z 1 . Within the radial correspondence range Z 1  of  FIG. 5 , a bump  12   c  and four heat-dissipation fins  13   c  (only one labeled in the figure) are included. Namely, one bump  12   c  is radially outwards respective to four heat-dissipation fins  13   c . Following the same criterion, each of the bumps  12  is found to be respective to at least two of the plurality of heat-dissipation fins  13 . In addition, due to different viewing angles, the radial correspondence range Z 1  is actually a three-dimensional region elongated from a sector base. 
     Similarly, the internal heat-dissipation passage TI is also radially outwards respective to at least one of the plurality of heat-dissipation fins  13 , and thus a corresponding radial correspondence passage range (not labeled in the figure) can be defined. Within the radial correspondence passage range, fewer heat-dissipation fins  13 , than those within the radial correspondence range Z 1 , can be arranged do as to achieve the goal of lightweight for the motor. 
     In the preferred embodiment of the present invention, each bump  12  extends in the extension direction D, but not limited to, from the conjunction of the first fan-accommodating section S 1  and the major accommodating section S 2  to the conjunction of the second fan-accommodating section S 3  and the major accommodating section S 2 . In other embodiments of the present invention, the bump  12  can extend in a first extension direction from the conjunction of the first fan-accommodating section S 1  and the major accommodating section S 2  to the conjunction of the second fan-accommodating section S 3  and the major accommodating section S 2 , in which the first direction is neither parallel nor perpendicular to the extension direction D. Namely, the bump  12  extends in an oblique manner from the conjunction of the first fan-accommodating section S 1  and the major accommodating section S 2  to the conjunction of the second fan-accommodating section S 3  and the major accommodating section S 2 . 
     Refer also to  FIG. 5  through  FIG. 9 ; where  FIG. 6  is a schematic cross-sectional view of  FIG. 5  along line B-B,  FIG. 7  demonstrates schematically an operation state of the motor frame of  FIG. 4  associated with the major motor assembly,  FIG. 8  is a schematic cross-sectional view of  FIG. 5  along line C-C, and  FIG. 9  demonstrates schematically another operation state of the motor frame of  FIG. 4  associated with the major motor assembly, particularly showing the heat dissipation flow. As shown, the motor frame  1  is to sleeve the major motor assembly  2 . 
     In the preferred embodiment of the present invention, the frame body  11  of the motor frame  1  has a frame-extension length L in the extension direction D, while the bump  12  has a bump-extension length L 2  in the extension direction. The bump-extension length L 2  is smaller than the frame-extension length L 1 . The area of the frame body  11  between the frame-extension length L 1  and the bump-extension length L 2  is the first fan-accommodating section S 1  and the second fan-accommodating section S 3 . In addition, the internal heat-dissipation passage TI has a passage-extension length (not labeled in the figure) in the extension direction D equal to the bump-extension length L 2 . 
     In addition, in the preferred embodiment, the major motor assembly  2  sleeved by the motor frame  1  includes a first fan  21 , a second fan  22 , an external fan  23 , a rotor structure  24 , a stator structure  25 , a front-end cover  26 , a back-end cover  27  and a fancover  28 . The first fan  21  and the second fan  22  is accommodated inside the first fan-accommodating section S 1  and the second fan-accommodating section S 3 , respectively. The front-end cover  26  and the back-end cover  27  are to seal the accommodation space S (including S 1 ˜S 3 ) of the frame body  11  at both ends thereof, respectively, so that a unique sealed space can be formed. In the preferred embodiment, the major motor assembly  2  is furnished with a rotor passage T 1  and a stator passage T 2 . While the major motor assembly  2  is running, a thermal energy would be generated inside the accommodation space S. 
     Inside the accommodation space S, the first fan-accommodating section S 1 , the internal flow passage TI, the second fan-accommodating section S 3 , the rotor passage T 1  and the stator passage T 2  would be integrated to form an air-circulation space for circulating an internal heat-dissipation flow FI, such that the thermal energy inside the accommodation space S can be dissipated through the internal heat-dissipation flow FI. 
     As shown in  FIG. 7 , the bumps  12  are structurally connected with the stator structure  25 , so that part of the thermal energy of the stator structure  15  can be thermally transferred to the bumps  12  by heat conduction, and then further to the corresponding heat-dissipation fins  13 . Since the bumps  12  are radially outwards respective to the plurality of heat-dissipation fins  13  as shown in  FIG. 5 , and thus the area available for heat contact and heat conduction would be substantially increased than the prior art can do. Namely, the plurality of heat-dissipation fins  13  of this present invention can dissipate the thermal energy more efficiently. In the preferred embodiment of the present invention, each of the heat-dissipation fins  13  further has a correspondence section  131 . The correspondence section  131  has a correspondence section length (not labeled in the figure) equal to the bump-extension length L 2  in the extension direction D, so as to have the bump  12  to match radially the correspondence sections  131  of the corresponding heat-dissipation fins  13 . 
     In addition, as shown in  FIG. 9 , as the first fan  21  and the second fan  22  run, the aforesaid internal heat-dissipation flow FI would be generated so as to discharge the thermal energy in the rotor passage T 1  and the stator passage T 2  to the internal heat-dissipation flow FI. Then, the internal heat-dissipation flow FI would flow from the rotor passage T 1  and the stator passage T 2  to the first fan-accommodating section S 1 , driven continuously by the first fan  21  and the second fan  22 , and further to the internal heat-dissipation passage TI. When the internal heat-dissipation flow FI is driven to reach the internal heat-dissipation passage TI, the thermal energy carried by the internal heat-dissipation flow FI (mainly at the rotor passage T 1  and the stator passage T 2 ) would be dissipated to the frame body at the internal heat-dissipation passage TI. Via the protrusive heat-dissipation fins  13  integrated as a unit to the frame body  11 , the thermal energy would be dissipated into the atmosphere. Then, the first fan  21  and the second fan  22  keep driving the internal heat-dissipation flow FI to orderly flow through the second fan-accommodating section S 3 , the rotor passage T 1  and the stator passage T 2 . After the internal heat-dissipation flow FI flows through the rotor passage T 1  and the stator passage T 2  again, the aforesaid heat-dissipation process is performed again. Namely, repeating heat-dissipation processes can be performed by continuously circulating the internal heat-dissipation flow FI in the air-circulation space. 
     In the preferred embodiment of the present invention, the first fan  21  and the second fan  22  are furnished together. However, in practice, the aforesaid internal air circulation can be also achieved by simply implementing one of the first fan  21  and the second fan  22 . 
     Thereupon, the thermal energy in the accommodation space S can be transferred to the frame body  11  by the bumps  12  and also by the cooperation of the internal heat-dissipation passage TI and the internal heat-dissipation flow FI. After the thermal energy is transferred to the frame body  11 , the heat-dissipation fins  13  on the frame body  11  would take the charge to dissipate the thermal energy into the atmosphere. 
     Preferably, in the preferred embodiment of the present invention, the external fan  23  would guide an external heat-dissipation flow FO to pass through the heat-dissipation fins  13  and the external heat-dissipation passage TO, so that an enforced heat convection can take place among the heat-dissipation fins  13 , the external heat-dissipation passage TO and the atmosphere. Thereupon, better heat-dissipation efficiency can be achieved. 
     In some other embodiments of the present invention, each of the bumps  12  can extend obliquely from the conjunction of the first fan-accommodating section S 1  and the major accommodating section S 2  to that of the second fan-accommodating section S 3  and the major accommodating section S 2 . In this circumstance, by viewing from the first fan  21  to the second fan  22 , as the first fan  21  rotates counter clockwisely, and if the bumps  12  extend leftwards from the conjunction of the first fan-accommodating section S 1  and the major accommodating section S 2  to that of the second fan-accommodating section S 3  and the major accommodating section S 2 , the internal heat-dissipation passages TI would be formed as leftward passages that match the rotation of the first fan  21 , such that an internal pressure drop of the motor frame  1  can be smaller so as to obtain a larger internal heat-dissipation flow FI and thus to provide better heat-dissipation efficiency. Similarly, as the first fan  21  rotates clockwisely, and if the bumps  12  extend rightwards from the conjunction of the first fan-accommodating section S 1  and the major accommodating section S 2  to that of the second fan-accommodating section S 3  and the major accommodating section S 2 , the internal heat-dissipation passage TI can also be provided to right match the rotation of the first fan  21 . 
     In summary, by providing the motor frame of the present invention to include a plurality of bumps, and by having any two neighboring bumps to form an internal flow passage in between, then a plurality of internal flow passages can be structured, and each of the bumps can be radially outwards respective to at least two of plural heat-dissipation fins. 
     In comparison with the prior art, the preferred motor frame with bumps provided by the present invention can implement the bumps to better pair the plurality of heat-dissipation fins, such that more thermal energy can be transferred per unit time. Further, the inclusion of the internal flow passages defined by every two neighboring bumps can allow the internal heat-dissipation flow to flow through, and thus the thermal energy absorbed and carried away by the internal heat-dissipation flow can be dissipated to the frame body. Thereupon, even more heat-dissipation efficiency can be achieved by the motor frame with bumps of the present invention. 
     While the present invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in forth and detail may be without departing from the spirit and scope of the present invention.