JP4750478B2 - Cand motor cooling structure - Google Patents

Description

  The present invention relates to a cooling structure for a canned motor, and more particularly, to cool a rotor attached to a motor output shaft of a canned motor by a lubricating oil sealed in a rotor chamber and to lubricate a bearing of the motor output shaft. This invention relates to a cooling structure for a canned motor constructed as described above.

  In a canned motor, if the heat of the rotor is not dissipated, the canned motor is heated to lower the motor efficiency. Therefore, the canned motor needs to be enlarged in order to obtain the required power, and the manufacturing cost is increased. In addition, if a heat-resistant insulating material is used in preparation for a high temperature, the manufacturing cost of the canned motor is increased. Therefore, the canned motor cools its rotor and lubricates the motor output shaft.

  In an example of the cooling structure for cooling the canned motor, referring to FIG. 5, the cooling of the motor rotor 105 of the canned motor unit 112 and the lubrication of the bearings 109 a and 109 b of the rotor shaft 130 are performed from the pump unit 110. The separated pump handling liquid (for example, water) is guided from the space A through the flow paths c and d to the rotor chambers D and E of the canned motor unit 112 and is further guided from the flow paths f and g to the space F to form the rotor 105. And the bearing 109a and the bearing 109b are made to flow, and then returned to the pump unit 110 via the axial hole 114a provided in the axial center portion of the rotor shaft 130 (for example, Patent Document 1). See).

  In addition, in the canned motor pump of another example shown in FIG. 6, a part of the pump handling liquid is introduced from the circulating fluid supply system 238 on the side opposite to the pump unit 210 to the rear rotor chamber 218 of the motor unit 212, The motor rotor 228 is cooled by being fed into the pump unit 210 through the rotor chamber 216, and the bearing 226 and the bearing 224 are lubricated (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 2003-184783 No. 7-36150

  In addition, when the rotating device driven by the canned motor is a vacuum pump, the atmosphere in the rotor chamber of the canned motor is equivalent to the exhaust, so that if the exhaust is corrosive gas, the rotor chamber is corroded. Become. In addition, when the exhaust gas is a reactive gas, minute particulate reaction products adhere to and accumulate on members such as the rotor and motor output shaft bearings, and in any case, the canned motor must be stopped and repaired. However, there is a problem that the operating time is greatly reduced. Further, since the rotor chamber has the same degree of vacuum as the exhaust gas of the vacuum pump, it is difficult to dissipate heat, and the bearing grease is liable to deteriorate.

  Each of the canned motor pumps disclosed in Patent Document 1 and Patent Document 2 described above is a liquid seal type in which the rotor chamber is completely filled with pump handling liquid for cooling the rotor of the motor unit and lubricating the bearing. . Since the rotor chamber is completely filled with pump handling liquid, the motor output shaft provided with the rotor has a large rotational resistance, and if the rotary device connected to the motor unit is a vacuum pump, for example. During operation near the ultimate pressure, the power consumption of the motor increases. Further, if bubbles are contained in the pump handling liquid, cavitation is generated and the can and the rotor are damaged.

  The present invention has been made in view of the above-described problems, can cool the rotor and lubricate the bearing of the motor output shaft, can suppress power consumption, and can also avoid corrosion and adhesion of reaction products. It is an object of the present invention to provide a canned motor cooling structure.

  The above problem can be solved by the configuration of claim 1, and the solution means will be described as follows.

  The cooling structure of the can motor according to claim 1 includes a stator disposed in a space closed by a motor housing and an outer peripheral side of a cylindrical can, and a motor that rotates in a rotor chamber that is an inner peripheral side of the can. A canned motor cooling structure in which the rotor is cooled and the bearing of the motor output shaft is lubricated. It is equal to or less than that, and at least a part of the rotated rotor is enclosed as a level to be immersed.

  In such a canned motor cooling structure, even when the rotor chamber is not completely filled with the lubricating oil, the rotor is rotated and immersed in the lubricating oil during operation, and the lubricating oil is cooled. The motor output shaft bearing is lubricated by being splashed and scattered along with the rotating rotor. Further, since the lubricating oil has a level equal to or lower than that of the motor output shaft, the rotational resistance of the motor output shaft is not significantly increased.

According to a second aspect of the present invention, there is provided a canned motor cooling structure in which oil scattering means is provided on a side surface of the rotor.
Such a cand motor cooling structure increases the degree of splashing and scattering of the lubricating oil by the rotor.

  The cooling structure of the canned motor according to claim 3, wherein a connecting chamber for connecting the motor output shaft of the canned motor and the rotating shaft of the rotating device is provided between the canned motor and the rotating device to which the canned motor is attached. The rotor chamber is provided with an oil overflow port to the connection chamber, and the connection chamber has an oil receiver having an oil supply path to the rotor chamber in the upper portion and the rotor chamber in the lower portion. An oil return path for receiving the lubricating oil that has overflowed and returning it to the connection chamber, a connection chamber oil sump is provided at the bottom, and a rotating member for oil scattering is attached to the rotating shaft. An amount of the lubricating oil is circulated between the connection chamber and the rotor chamber.

  In such a canned motor cooling structure, the rotor is rotated and cooled because it is immersed in the lubricating oil in the rotor chamber oil sump, and the motor output shaft bearing is driven by the rotor or the rotor provided with oil scattering means. The oil film of the lubricating oil is formed on the inner wall surface and the member surface of the rotor chamber and the bearing of the rotary shaft of the vacuum pump is also connected to the rotary shaft. Are lubricated by the lubricating oil splashed up and scattered by the oil scattering rotary member attached to the inner wall of the connecting chamber, and an oil film is formed on the inner wall surface of the connection chamber and the member surface in the connection chamber. Further, a part of the lubricating oil in the connecting chamber oil reservoir that has been bounced up is received by the upper oil receiver and supplied from the oil supply path into the rotor chamber by the position potential, and the lubricating oil in the rotor chamber is supplied to the oil overflow port. Since the oil overflows and returns to the connection chamber oil sump via the oil return path, the lubricating oil is circulated between the connection chamber and the rotor chamber. Since the lubricating oil in the rotor chamber oil sump is held at a constant level by the oil overflow port, the oil level of the connecting chamber oil sump is also kept constant, and the lubricating oil is not unevenly distributed to either one. .

  The cooling structure of the canned motor according to claim 4, wherein the connecting chamber that connects the motor output shaft of the canned motor and the rotating shaft of the rotating device between the canned motor and the rotating device to which the canned motor is attached. The rotor chamber is provided with an oil overflow port to the connecting chamber, and the connecting chamber receives the lubricating oil overflowing from the rotor chamber at the lower portion and receives the lubricating oil. An oil return path to return to the oil, a connecting chamber oil sump is provided at the bottom, an oil scattering rotating member is attached to the rotating shaft, and the lubricating oil is transferred from the connecting chamber oil sump to the rotor chamber A feed pipe is provided together with the oil feed pump, and a certain amount of the enclosed lubricating oil is circulated between the connection chamber and the rotor chamber.

  In such a canned motor cooling structure, the rotor is cooled by being rotated and immersed in the lubricating oil in the rotor chamber oil sump, and the bearing of the motor output shaft is supported by the rotor or the rotor provided with oil scattering means. The oil film of the lubricating oil is formed on the inner wall surface and the member surface of the rotor chamber and the bearing of the rotary shaft of the vacuum pump is also connected to the rotary shaft. Are lubricated by the lubricating oil splashed up and scattered by the oil scattering rotary member attached to the inner wall of the connecting chamber, and an oil film is formed on the inner wall surface of the connection chamber and the member surface in the connection chamber. Furthermore, the lubricating oil in the connecting chamber oil sump is forcibly fed into the rotor chamber via the oil feed pipe by the oil feed pump, and the lubricating oil in the rotor chamber sump overflows from the oil overflow port and passes through the oil return path. Then, the lubricating oil is circulated between the connection chamber and the rotor chamber by being returned to the connection chamber oil reservoir. Since the lubricating oil in the rotor chamber oil sump is held at a constant level by the oil overflow port, the oil level of the connecting chamber oil sump is also kept constant, and the lubricating oil is not unevenly distributed to either one. .

  The canned motor cooling structure according to the present invention includes a can-structured stator disposed in a space surrounded by the motor housing and the outer peripheral surface of the cylindrical can, and both ends of the rotor chamber on the inner peripheral side of the can. It consists of a rotor attached to a motor output shaft that is supported by a bearing and rotates. The bottom of the rotor chamber is a rotor chamber oil reservoir, and a predetermined amount of lubricating oil is enclosed. That is, the oil level of the lubricating oil is equal to or lower than that of the motor output shaft, and at least a part of the rotating rotor is immersed. Even with such an amount of lubricating oil, the rotor is rotated and the whole is immersed in the lubricating oil, so that it is sufficiently cooled. Among the levels that are equal to or less than the motor output shaft, the oil level is set high when the cooling of the rotor is considered as the main component, and the oil level is set low when reducing the rotation resistance of the motor output shaft. Is done. Further, since the lubricating oil has an inherent viscosity, the bearing of the motor output shaft is lubricated by the lubricating oil splashed up and attached to the rotating rotor, and scattered in the space of the rotor chamber. .

  Desirably, oil splashing means is provided on the side surface of the rotor, so that the splashing and splashing of the lubricating oil by the rotor can be promoted. A suitable thing as an oil scattering means is a fin. However, if a large number of fins are provided, the rotational resistance of the motor output shaft increases accordingly, so the number of fins is appropriately selected. Other oil scattering means, for example, a curved groove or protrusion like a pump impeller may be provided on the side surface of the rotor. That is, the lubricating oil in the rotor chamber oil reservoir associated with the rotating rotor is guided by the groove or the ridge and splashed upward to be scattered.

  When a canned motor having a cooling structure as described above is attached to a rotating device, a connecting chamber is provided between the canned motor and the rotating device in order to connect the motor output shaft of the canned motor and the rotating shaft of the rotating device. Intervened. When the connection chamber is a sealed type, it is preferable to enclose lubricating oil in the connection chamber and circulate the lubricant between the rotor chamber and the connection chamber. In other words, there is a bearing for the rotating shaft of a rotating device that requires lubrication in the connection chamber, and the connection chamber is sealed when the rotating device is a vacuum pump and the vacuum pump exhausts corrosive gas or reactive gas. If it is a type, the atmosphere in the connection chamber and the rotor chamber will be equivalent to exhaust due to seal leakage, so an oil film as a protective film is formed on the inner wall of the connection chamber and the rotor chamber to prevent corrosion and adhesion of reaction products It is necessary.

  In order to circulate the lubricating oil, the rotor chamber is provided with an oil overflow port for keeping the oil level of the rotor chamber oil sump constant. An oil return path for returning the lubricating oil overflowing from the rotor chamber to the connection chamber is provided at the lower portion of the connection chamber, and the bottom of the connection chamber serves as a connection chamber oil reservoir. Further, an oil scattering rotary member is attached to the rotary shaft of the rotary device. Of course, the oil scattering rotary member may be attached to the motor output shaft in the connection chamber. As the oil scattering rotating member, a disk-shaped member is used simply, but it is necessary that the lower end of the rotating member is always immersed in the lubricating oil in the connection chamber oil reservoir. That is, the oil adhering to the disk is splashed up by centrifugal force and scattered into the upper space of the connection chamber, and an oil film is formed on the inner wall surface of the connection chamber and the member surface in the connection chamber. The oil scattering rotating member may be other than the above-described disk, for example, an impeller-like member or a rod-like member, and its shape is not limited. An oil receiver having an oil supply path for receiving a part of the splashed and scattered lubricating oil and holding a certain amount of oil and supplying the oil to the rotor chamber is attached to the upper part of the connection chamber. It is done.

  Therefore, the lubricating oil in the connection chamber oil pool splashed and scattered by the oil scattering rotary member forms an oil film on the inner wall surface of the connection chamber, etc., and a part of the lubricating oil splashed and scattered is an oil receiver. It is received and supplied from the oil receiver to the rotor chamber by its own weight through the oil supply path. The lubricating oil in the rotor chamber oil pool overflows when the oil level becomes higher than the oil overflow port, and returns to the connecting chamber through the oil return path, whereby the lubricating oil is circulated between the rotor chamber and the connecting chamber. The In this circulation, the amount of lubricating oil equivalent to the supply amount is returned to the connection chamber due to overflow from the rotor chamber oil sump, so even if the amount of supply to the rotor chamber becomes large, the oil level of the rotor chamber oil sump, And the oil level of the connecting chamber oil sump is always kept constant.

  In the above canned motor cooling structure, a part of the lubricating oil in the connecting chamber oil reservoir splashed up and scattered by the oil scattering rotary member is stored in the upper oil receiver, and the oil is supplied to the rotor chamber by utilizing the position potential. However, the lubricating oil in the connecting chamber oil reservoir may be fed into the rotor chamber by an oil feed pump. In this case, an oil feed pipe for feeding the lubricating oil in the connection chamber oil sump into the rotor chamber is installed together with the oil feed pump. The oil feed pipe is preferably installed so that the lubricating oil extracted from the bottom of the connection chamber oil sump is fed into the opening in the center of the end plate on the opposite side of the connection chamber of the rotor chamber. This is because all the lubricating oil in the rotor chamber oil sump can be evenly circulated and stirred over the length direction. An oil receiver for supplying lubricating oil to the rotor chamber is not provided in the upper portion of the connection chamber, but an oil scattering rotating member is attached to the rotating shaft of the rotating device. This is because an oil film of lubricating oil is formed on the inner wall surface of the connection chamber and the bearing of the rotating shaft is lubricated. An oil overflow port is provided in the rotor chamber to keep the oil level of the rotor chamber oil sump constant, and an oil return path is provided in the lower portion of the connection chamber to return the lubricating oil overflowing to the connection chamber. It is the same that a connecting chamber oil sump for storing lubricating oil is provided at the bottom of the oil tank.

  In the above description, the case where the lubricating oil is circulated between the rotor chamber and the connecting chamber has been described. However, the lubricating oil is sealed independently in each of the rotor chamber and the connecting chamber, and the lubricating oil in the oil reservoir is stored inside each. You may make it fly up and scatter.

  Further, when the canned motor having the cooling structure as described above is attached to the rotating device, generally, the canned motor having the cooling structure of the present invention and the connecting chamber are manufactured independently, and the rotating device and A combined process is employed, but it may be attached by other processes. That is, a rotor is attached to an extended portion of a rotating shaft of a rotating device, and an element corresponding to a connecting chamber is attached to the rotor, and a connecting member that also serves as an end plate inside the rotor chamber is attached to the rotating device side, An assembly member composed of a motor housing, an outer end plate of the motor housing, a can, and an encased stator is covered so as to cover the rotor from the front end side of the extended portion of the rotating shaft to form a main part of the canned motor, and The canned motor of the present invention can also be attached to the rotating device by assembling so that the connecting member becomes an end plate inside the motor housing. That is, the cand motor cooling structure of the present invention is formed during the process of attaching the cand motor to the rotating device.

  As long as the lubricating oil sealed in the rotor chamber or the connecting chamber can cool the rotor and has an electrical insulation property, the type of lubricating oil is not limited, but the temperature rose by cooling the rotor. When considering the cooling of the lubricating oil as a main component, it is desirable that it has a relatively low viscosity without containing volatile components.

  Rotating equipment to which the canned motor is attached includes various rotating equipment including water supply / drainage pumps and blowers. Among these, vacuum pumps that exhaust corrosive gas, reactive gas, etc., exhaust enters the connection chamber and rotor chamber. The inside is corroded by and the reaction product by the reactive gas is adhered inside. On the other hand, in the canned motor having the above cooling structure, the oil film formed on the inner wall surface of the rotor chamber and the connection chamber serves as a protective film, so that corrosion in the rotor chamber and adhesion of reaction products to the rotor chamber are prevented. This is particularly suitable as a driving source for a vacuum pump.

  FIG. 1 is a cross-sectional view of the cooling structure of the canned motor 10A according to the first embodiment. The canned motor 10A is shown as being attached to the vacuum pump 30 via the connection chamber 20A. Note that only the end of the vacuum pump 30 is shown.

  The connecting chamber 20 </ b> A is a space for connecting the motor output shaft 15 of the canned motor 10 </ b> A and the rotating shaft 35 of the vacuum pump 30. The vacuum pump 30 shows only the end on the canned motor 10A side. In FIG. 1, a can motor 10A has a stator 13 comprising a stator core 13a and a coil end 13b disposed in a space surrounded by a motor housing 11, end plates 11a and 11b on both sides, and an outer peripheral surface of a cylindrical can 12. The end of the stator core 13 a closer to the motor output shaft 15 is in contact with the can 12, and the end far from the motor output shaft 15 is in contact with the inner surface of the motor housing 11. Four water-cooled pipes 19 are embedded in the peripheral wall 11w of the motor housing 11 with which the far end of the stator core 13a is in contact.

  A motor output shaft 15 of the can motor 10 </ b> A is supported and rotated by bearings 17 a and 17 b at both ends in the rotor chamber 14 on the inner peripheral side of the can 12, and the motor output shaft 15 has a position corresponding to the stator 13. A rotor 16 is attached to the rotor. On both side surfaces of the rotor 16, four fins 16F as oil scattering means are attached at positions that divide the side surfaces at equal angular intervals of 90 degrees. Further, the bottom of the rotor chamber 14 is a rotor chamber oil sump 18 filled with lubricating oil L, and the oil level thereof is about the same as the portion below the bearings 17a and 17b of the motor output shaft 15. The rotor 16 and the fins 16F that are rotated and rotated immediately below the motor output shaft 15 are immersed in the lubricating oil L.

  In the connection chamber 20 </ b> A, the motor output shaft 15 protrudes through the end plate 11 b of the motor housing 11 and the end plate 21 a of the connection chamber 20, and the rotary shaft 35 of the vacuum pump 30 is projected to the end plate 31 of the vacuum pump 30. It is supported by the attached bearing 37 and protrudes into the connecting chamber 20. The motor output shaft 15 and the rotary shaft 35 are connected to the flexible coupling 25 (the rubber-like substance G is engaged with the claw-like portion of the member 25a on the motor output shaft 15 side and the claw-like portion of the member 25b on the rotary shaft 35 side). Are inserted through). In this case, since there is no lubricating oil in the connecting chamber 20, the bearing 37 of the rotating shaft 35 is lubricated with grease.

  The cooling structure of the canned motor 10A according to the first embodiment is configured as described above, and the operation thereof will be described next. When the canned motor 10A is driven, the rotor 16 attached to the rotating motor output shaft 15 causes the lubricating oil in the rotor chamber oil sump 18 to be sequentially rotated even if the oil level of the rotor chamber 14 is lowered. Heat is removed by soaking in L and cooled. Further, the rotor 16 and the fins 16F on both side surfaces are sequentially immersed in the lubricating oil L of the rotor chamber oil sump 18 and cooled, and at the same time, the lubricating oil L is stirred and sprinkled up and scattered into the upper space of the rotor chamber 14. The bearings 17 a and 17 b that support the motor output shaft 15 at both ends of the rotor chamber 14 are lubricated by the scattered lubricating oil L. The scattered lubricating oil L adheres to the inner wall surface of the rotor chamber 14 including the inner peripheral surface of the can 12 and the surfaces of the bearings 17a and 17b to flow down by forming an oil film.

  The heat of the lubricating oil L that has risen in temperature due to cooling of the rotor 15 is mainly fixed to the peripheral wall 11w of the motor housing 11 that is in contact with the lubricating oil L in the rotor chamber oil sump 18 and is cooled by the water cooling pipe 19. The motor housing cooled by the water cooling pipe 19 through the stator core 13a from the can 12 in which the lubricating oil L of the rotor chamber oil sump 18 is in contact is cooled. 11 is dissipated to the peripheral wall 11w. Since the entire rotor 16 and fins 16F are not completely immersed in the lubricating oil L, the motor output shaft 15 to which the rotor 16 and the fins 16F are attached does not receive a large rotational resistance during rotation, and the power consumption is It will be reduced.

  FIG. 2 is a cross-sectional view of the cooling structure of the canned motor 10B according to the second embodiment. The canned motor 10B is shown as being attached to the vacuum pump 30 through the connection chamber 20B.

  The canned motor 10B according to the second embodiment is basically configured in the same manner as the canned motor 10A according to the first embodiment, except that the sealed lubricating oil L is different from the canned motor 10A according to the first embodiment. The lubrication is performed between the rotor chamber 14 of 10B and the connecting chamber 20B. Therefore, the rotor chamber 14 of the canned motor 10B of the second embodiment is slightly different from the rotor chamber 14 of the canned motor 10A of the first embodiment. That is, in the rotor chamber 14 of the canned motor 10B, an oil supply path 23 that continues to an oil receiver 22 of the connection chamber 20B described later is provided through the upper end plate 11b of the motor housing 11 at the upper portion thereof. Lubricating oil L is supplied from the chamber 20B. The end plate 11b is provided with an oil overflow port 18a at a height equivalent to the lower portion of the bearing 17b of the motor output shaft 15, and the oil level of the rotor chamber oil sump 18 is the oil level. When it is higher than the overflow port 18a, the lubricating oil L overflows into the connection chamber 20B. Accordingly, the oil level is maintained at a level equivalent to that of the oil overflow port 18a, and the portion directly below the motor output shaft 15 of the rotor 16 and the fins 16F attached to the portion are immersed in the lubricating oil L. It is supposed to be in a state.

  In the connection chamber 20 </ b> B, the motor output shaft 15 of the canned motor 10 </ b> B is connected to the rotary shaft 35 of the vacuum pump 30 through the flexible coupling 25 as in the case of the first embodiment. And the oil receiver 22 of the lubricating oil L is provided in the upper part by the side of the rotor chamber 14 of the connection chamber 20B, and the end plate 21a of the connection chamber 20B and the end of the motor housing 11 are provided from the oil receiver 22 as described above. An oil supply path 23 that passes through the plate 11 b and communicates with the rotor chamber 14 is formed. The bottom of the connection chamber 20B is a connection chamber oil sump 28, and a water cooling pipe 29 is embedded in the lower peripheral wall 21w of the connection chamber oil sump 28. An oil return path 24 that receives the lubricating oil L overflowing from the oil overflow port 18 a of the rotor chamber 14 and flows into the connecting chamber 20 is provided immediately below the flexible coupling 25.

  Further, the rotating shaft 35 of the vacuum pump 30 is used as an oil scattering rotating member that splashes and scatters the lubricating oil L in the connecting chamber oil reservoir 28 on the flexible coupling 25 side of the bearing 37. An oil scattering disk 26 is attached. That is, the oil level of the lubricating oil L in the connecting chamber oil reservoir 28 is set to a level where at least the lower end of the rotating oil scattering disk 26 is immersed in the lubricating oil L.

  The canned motor 10B is attached to the vacuum pump 30 through the connecting chamber 20B as described above. Next, the operation thereof will be described. When the canned motor 10B is driven, the rotor 16 and the fins 16F attached to the motor output shaft 15 are in the rotor chamber 14 even when the oil level of the lubricating oil L is lower than the motor output shaft 15. By being immersed in the lubricating oil L of the rotor chamber oil reservoir 18 while being rotated, the heat of the rotor 16 is removed and cooled by the lubricating oil L. Further, the lubricating oil L is agitated and splashed up by the fins 16F on both side surfaces of the rotor 16 and scattered into the upper space of the rotor chamber 14, whereby the bearings 17a and 17b of the rotor chamber 14 are lubricated. Further, the scattered lubricating oil L forms an oil film on the inner wall surface and each member surface of the rotor chamber 14 including the inner peripheral surface of the can 12 and flows down as in the case of the first embodiment.

  In the connection chamber 20B, the oil scattering disk 26 attached to the rotary shaft 35 of the vacuum pump 30 rotates with the lubricating oil L of the connection chamber oil reservoir 28 attached thereto, but the attached lubricating oil L moves upward by centrifugal force. The bearing 37 that supports the rotating shaft 35 is lubricated by the scattered lubricating oil L by being splashed up and scattered in the upper space in the connection chamber 20. Further, the scattered lubricating oil L forms an oil film on the inner wall surface of the connection chamber 20B and each member surface in the connection chamber 20 and flows down to the connection chamber oil reservoir 28. Then, the lubricating oil L whose temperature is rising is radiated and cooled to the peripheral surface 21w of the bottom of the connection chamber 20B cooled by the water cooling pipe 29.

  Further, a part of the lubricating oil scattered in the upper space in the connection chamber 20B is received by the oil receiver 22, supplied to the rotor chamber 14 via the oil supply path 23, and flows down to the rotor chamber oil reservoir 18. Flows in. When the oil level of the lubricating oil L in the rotor chamber oil reservoir 18 becomes higher than the oil overflow port 18 a, the lubricating oil L overflows from the oil overflow port 18 a and passes through the oil return path 24 to the connection chamber 20. The oil level of the rotor chamber oil sump 18 is always maintained at a constant level. Thus, during operation of the canned motor 10B, the lubricating oil L is circulated between the rotor chamber 14 and the connecting chamber 20B. However, as described above, the rotor chamber oil sump 18 causes the lubricating oil L to overflow. In other words, by causing the amount of lubricating oil L equivalent to the supply amount to flow out from the rotor chamber 14, the level of the oil level in the rotor chamber oil sump 18, and hence the level of the oil level in the connection chamber oil sump 28, is also constant. The lubricating oil L is not unevenly distributed anywhere.

  When the vacuum pump 30 evacuates the corrosive gas, if the connecting chamber 20A is a sealed type, the connecting chamber 20B and the rotor chamber 14 have the same corrosive gas atmosphere as the exhaust due to seal leakage, and the connecting chamber 20B. The rotor chamber 14 is corroded, but the oil film of the lubricating oil L in the connecting chamber 20B and the rotor chamber 14 acts as a corrosion-resistant film. When the vacuum pump 30 evacuates the reactive gas, it prevents the minute reaction product contained in the reactive gas from adhering to and growing in the connection chamber 20B and the rotor chamber 14. In any case, the maintenance interval of the canned motor 10B becomes longer, and the operating rate of the canned motor 10B is improved.

  FIG. 3 is a cross-sectional view of the cooling structure of the canned motor 10C according to the third embodiment, and the canned motor 10C is shown as being attached to the vacuum pump 30 via the connection chamber 20C.

  The cooling structure of the canned motor 10C of the third embodiment is basically similar to the cooling structure of the canned motor 10B of the second embodiment, but the means for supplying the lubricating oil L from the connecting chamber 20C to the rotor chamber 14 is different. It has become. Therefore, in the cooling structure of the canned motor 10C shown in FIG. 3 and the cooling structure of the canned motor 10B shown in FIG. 2, the same components are denoted by the same reference numerals, description thereof is omitted, and only different portions will be described.

  The oil receiver 22 and the oil supply path 23 provided in the cooling structure of the canned motor 10B of the second embodiment are not provided in the upper part of the connection chamber 20C in FIG. An oil feed pipe 27 that connects the bottom of the reservoir 28 and the opening at the center of the end plate 11a located far from the connection chamber 20C of the motor housing 11 of the canned motor 10C is disposed together with the oil feed pump 27P. The lubricating oil L in the chamber oil reservoir 28 is forcibly fed into the shaft center portion at the end of the rotor chamber 14. Similar to the canned motor 10B of the second embodiment, an oil return path 24 that receives the lubricating oil L overflowing from the oil overflow port 18a of the rotor chamber 14 and returns to the connecting chamber 20C is provided. Therefore, when the canned motor 10C is driven, the lubricating oil L in the connecting chamber oil reservoir 28 is passed through the oil feed pipe 27 by the oil feed pump 27P and the opening of the rotor chamber 14 from the center opening of the end plate 11a of the rotor chamber 14. When the oil level of the rotor chamber 14 is sent to the end and the oil level of the rotor chamber 14 becomes higher than the oil overflow port 18a, the lubricating oil L is circulated from the oil overflow port 18a via the oil return path 24 to the connection chamber oil sump 28.

  During this time, in the rotor chamber 14, the lubricating oil L is splashed by the rotor 16 and the fins 16F and dispersed in the upper space in the rotor chamber 14, and in the connecting chamber 21C, the lubricating oil L is splashed by the oil scattering disk 26 and connected. Dispersing in the upper space in the chamber 21C is the same as in the second embodiment. When the vacuum pump 30 evacuates corrosive gas or reactive gas, the oil film of the lubricating oil L formed on the inner wall of the connecting chamber 21C, such as the inner wall of the rotor chamber 14, is the rotor chamber 14, the connecting chamber 21C. As in the case of the second embodiment, the corrosion product is suppressed and the reaction product is prevented from adhering to the inner wall of the rotor chamber 14 and the inner wall of the connecting chamber 21C.

  FIG. 4 is a cross-sectional view of the cooling structure of the canned motor 10D according to the fourth embodiment. The canned motor 10D serves as an inner end plate of the housing 11 and includes a connecting member 10D ′ having an element corresponding to a connecting chamber. It is shown as the state attached to the vacuum pump 30 via. As shown in FIG. 4, the configuration of the canned motor 10D of the fourth embodiment is basically similar to that of the canned motor 10B according to the second embodiment of FIG. 2, but is manufactured by a different process. . Therefore, in the components of the canned motor 10D of FIG. 4, the same reference numerals are given to the same components as those of the canned motor 10B according to the second embodiment of FIG. Will be described.

  The canned motors 10A, 10B, and 10C of the first to third embodiments are the same. For example, when the canned motor 10B of the second embodiment is attached to the vacuum pump 30, the canned motor 10B and the connecting chamber 20B are independently provided. Manufactured and attached to the vacuum pump 30. In contrast, the canned motor 10D according to the fourth embodiment, in short, has the rotor 16 attached to the extended portion 35e of the rotary shaft 35 of the vacuum pump 30, and the rotor 16 is surrounded by the motor housing 11 and the can 12. The main part of the motor is formed by covering the broken stator 13.

  When the canned motor 10D shown in FIG. 4 is manufactured, for example, the end plate 31 of the vacuum pump 30 includes a connecting member 10D ′, that is, an element corresponding to the connecting chamber 20B in the second embodiment shown in FIG. 11, a connecting member 10D ′ configured to replace the inner end plate 11b is attached, and an extended portion 35E of the rotary shaft 35 of the vacuum pump 30 is integrally connected to the rotary shaft 35, and the extended portion 35E is connected to the extended portion 35E. The rotor 16 and the fin 16F are attached. The rotor 16 was manufactured by covering the motor housing 11, the end plate 11a outside the motor housing 11, the can 12, and the included stator 13 from the distal end side of the extension portion 35E. Is. Since the canned motor 10D shown in FIG. 4 does not have the flexible coupling 25 in the canned motor 10B of the second embodiment, mechanical loss or breakage of the insert due to the rubber-like insert of the flexible coupling 25 occurs. And high-load operation is possible. Also, the number of parts is reduced.

  In the fourth embodiment, the connecting member 10D ′ having elements corresponding to the connecting chamber 20B of the second embodiment based on the canned motor 10B of the second embodiment is used as the end of the motor housing 11 of the canned motor 10D on the vacuum pump 30 side. Although the case where the canned motor 10D is manufactured also as a plate has been described, the same process as in the fourth embodiment can be applied to the canned motor 10A according to the first embodiment and the canned motor 10C according to the third embodiment. .

  The cooling structure of the canned motor according to the present invention has been described above with reference to the embodiments. Of course, the present invention is not limited thereto, and various modifications can be made based on the technical idea of the present invention.

  For example, in the first embodiment, the case where the lubricating oil L is sealed only in the rotor chamber 14 of the canned motor 10A and the lubricating oil L is not sealed in the connecting chamber 20A has been described, but the rotor chamber 14 and the connecting chamber 20A The lubricating oil L may be enclosed in each of these.

  In Examples 2, 3, and 4, the oil overflow port 18a of the rotor chamber 14 is provided at the same height as the lower portion of the bearing 17b. However, depending on the use conditions, the mounting height of the oil overflow port 18a It is possible to change the position to lower the oil level of the rotor chamber 14 and vice versa.

  In the third embodiment, the lubricating oil L in the connection chamber oil reservoir 28 is removed from the connection chamber oil reservoir 28 through the central opening of the end plate 11a of the motor housing 11 from the connection chamber oil reservoir 28 and the oil feed pump 27P. However, as long as the lubricating oil L can be fed into the rotor chamber 14 without any problem, the feeding location is not limited. For example, the lubricating oil L may be fed into the rotor chamber oil sump 18.

  In each of the embodiments, the lubricating oil L is used as the oil that fills the rotor chamber 14 and the connecting chamber 20 with a certain amount. However, the oil other than the lubricating oil L, for example, an insulating material having the same viscosity as the lubricating oil L. Oil may be enclosed, and the type of oil to be enclosed is limited as long as cooling of the rotor 16 and lubrication of the bearings 17a and 17b of the motor output shaft 15 and the bearing 37 of the rotary shaft 35 of the vacuum pump 30 are possible. Not.

  In each example, the vacuum pump is exemplified as the rotating device to which the canned motor having the cooling structure of the present invention is attached. However, the rotating device other than the canned motor, for example, a pumping pump or a slurry pump, The type of rotating device to be attached is not limited.

  In each embodiment, the case where there is one motor output shaft 15 of the canned motor is illustrated, but two motor output shafts are provided, and they are configured to rotate in the opposite direction synchronously. The canned motor cooling structure of the present invention is also applied to the canned motor. These canned motors are attached to a pump or a blower having a roots type rotor.

It is sectional drawing which shows the cooling structure of the canned motor by Example 1. FIG. It is sectional drawing which shows the cooling structure of the canned motor by Example 2. FIG. 6 is a cross-sectional view illustrating a cand motor cooling structure according to a third embodiment. FIG. 6 is a cross-sectional view illustrating a cand motor cooling structure according to a fourth embodiment. It is sectional drawing of the canned motor pump by a prior art. It is sectional drawing of the canned motor pump by another prior art.

Explanation of symbols

10A, 10B, 10C, 10D ... canned motor,
11 ... Motor housing, 11a, 11b ... Housing end plate,
12 ... can, 13 ... stator, 14 ... rotor chamber,
15 ... motor output shaft, 16 ... rotor,
16F .. Fins, 17a, 17b ... Bearings of motor output shaft,
18 ... Rotor chamber oil sump, 18a ... Oil overflow port,
19 ... Water-cooled pipe, 20A, 20B, 20C, ... Connection room,
22 ... Oil receiver, 23 ... Oil supply path, 24 ... Oil return path,
25 ... flexible coupling, 26 ... oil scattering disc,
27 ... Oil feed pipe, 27P ... Oil feed pump, 28 ... Connection chamber oil sump,
29 ... Water-cooled pipe, 30 ... Vacuum pump,
35 ... Rotating shaft of vacuum pump, 35E ... Extension part of rotating shaft,
37 ... bearings, L ... lubricating oil,

Claims (3)

The stator is arranged in a space closed by the motor housing and the outer peripheral surface of the cylindrical can, and the rotor is attached to the motor output shaft that rotates in the rotor chamber on the inner peripheral side of the can. In the canned motor cooling structure in which the rotor is cooled and the bearing of the motor output shaft is lubricated,
Oil scattering means is provided on a side surface of the rotor, and the oil level in the rotor chamber is equal to or less than that of the motor output shaft, and at least a part of the oil scattering means of the rotated rotor is immersed in the rotor chamber. A canned motor cooling structure characterized by being enclosed as a level. A connecting chamber for connecting the motor output shaft of the canned motor and the rotating shaft of the rotating device is interposed between the canned motor and the rotating device to which the canned motor is attached. An oil overflow port to the chamber is provided, and the connection chamber receives an oil receiver having an oil supply path to the rotor chamber at an upper portion, and receives the lubricating oil overflowed from the rotor chamber at a lower portion. An oil return path for returning to the connection chamber, a connection chamber oil sump is provided at the bottom, a rotating member for oil scattering is attached to the rotating shaft, and a fixed amount of the enclosed lubricating oil is supplied to the connection chamber and the rotor. The canned motor cooling structure according to claim 1 , wherein the canned motor is circulated between the chamber and the chamber. A connecting chamber that connects a motor output shaft of the canned motor and a rotating shaft of the rotating device is interposed between the canned motor and the rotating device to which the canned motor is attached. An oil overflow port to the connection chamber is provided, and an oil return path for receiving the lubricating oil overflowing from the rotor chamber at the lower part and returning it to the connection chamber is provided in the connection chamber, and a connection chamber oil reservoir is provided at the bottom. An oil scattering rotary member is attached to the rotary shaft, and an oil feed pipe for transferring the lubricating oil from the connection chamber oil reservoir to the rotor chamber is disposed together with an oil feed pump. The canned motor cooling structure according to claim 1 , wherein a certain amount of the enclosed lubricating oil is circulated between the connection chamber and the rotor chamber.

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