JP6157302B2 - Motor cooling device for vertical electric pump - Google Patents

Description

  The present invention relates to a motor cooling device for a saddle type electric pump.

  In order to prevent the motor from generating heat, it is well known that the motor frame has an oil seal structure.

  And if the electric pump using this oil-sealed motor is used with the motor part immersed in clean water, there will be no problem in cooling the motor. Cooling function is hindered due to adhesion of scale, sludge, etc. Even when used in fresh water, the motor frame is exposed to the atmosphere when draining residual water at low water level, or the cooling function is lost or relayed on land Even when used as an industrial pump, it does not have a cooling function at all, and the oil enclosed by the motor heat generation is significantly deteriorated, so that it is difficult to ensure a stable cooling function. (See, for example, the specification of Patent Document 1, page 2, line 6 to page 3, line 2.)

  Conventionally, as a measure to suppress motor heat generation in an electric pump using an oil-sealed motor, in addition to using a large-capacity motor with a margin compared to the pump load, compared to water As the heat conductivity of oil is low, the cooling capacity is low, so a large heat exchanger is required, which is well known to be a factor in increasing product size and cost.

  Furthermore, as an improvement technique of the electric pump using the conventional oil-sealed motor, an annular cooling jacket for heat exchange is provided in a motor frame in which oil is enclosed, and a discharge pipe on the discharge side of the pump section is provided by a supply pipe. The liquid is allowed to flow into the cooling jacket, and the discharged liquid is sucked and discharged from the cooling jacket to the low pressure portion on the pump suction side by the discharge pipe, and is sucked from the upper part of the motor shaft by a through hole formed in the motor shaft. The cooling medium in the motor frame is cooled by forcibly jetting the oil in the cooling medium inside the annular cooling jacket and exchanging heat with the blades stretched and fixed to the motor shaft. The cooling function is improved by circulating and convection of oil from the bottom to the top. (For example, see the figure and claims of Patent Document 1)

  However, compared to the most commonly used non-oil-sealed dry motors, both the conventional and improved techniques are wet oil-sealed motors in which the cooling medium oil is sealed inside the motor. When the motor is driven to rotate, the enclosed viscous oil acts as a rotational resistance of the rotor that houses the main shaft to reduce the motor efficiency. The air gap, which is the gap between the inner circumferences of the stator, is configured to be as close as possible. However, in the above-mentioned conventional products, the air gap is configured to be wide so that the cooling medium oil can be secured in order to ensure the cooling function. As the circulation convection of the motor has to be improved, the motor efficiency is further reduced, and in particular, the conventional improved technique has a complicated structure and increases the cost. In the pump specification for pumping up sewage containing foreign substances such as objects, the sewage that is the cooling source causes clogging of foreign substances in the supply pipe, discharge pipe, or cooling jacket connected to the cooling jacket of the heat exchanger to ensure the cooling function. It has a serious problem that it cannot be done.

Japanese Utility Model Publication No. 56-136473

  The object of the present invention is that it does not require frequent replacement of the sealing oil due to deterioration of the sealing oil, and can be produced at a low cost without employing an oil sealing structure that enlarges the motor, and the surface of the motor frame. It is an object of the present invention to provide a motor cooling device for a vertical electric pump that is highly reliable and functions effectively even when scales, sludge, etc. are attached to it or when the motor frame is exposed to the air.

  In order to achieve the above object, the present invention is configured as follows.

In the motor cooling device for a vertical electric pump according to the first aspect of the present invention, a motor frame including a rotor having a stator and a motor shaft fitted therein, and a motor frame fixed on the upper surface of the motor frame and mounted on the upper end of the motor shaft A dry motor comprising a head cover for supporting the upper part of the motor shaft by an upper bearing to be fitted, and a bearing bracket for supporting the lower part of the motor shaft by a lower bearing fixed to the lower surface of the motor frame and fitted to the lower part of the motor shaft. in mounting the cooling jacket which forms an annular space enclosing the cooling medium surrounding the Motafure over arm, interposed between the head cover and the bearing bracket, the seal member into the through portion of the motor shaft of the bearing bracket lower end Then, the cooling circulation blade is fitted and fixed to the motor shaft on the lower end side of the seal member to surround the cooling circulation blade. The ring casing is fixed to the lower surface of the bearing bracket, the cooling medium sucked from the suction port of the circulation casing is accelerated by the centrifugal action of the cooling circulation blade, and the discharge port of the circulation casing is decelerated and increased by the circulation casing. A cooling medium bracket that forms a cooling medium chamber that encloses the cooling medium at a distance from the lower surface of the circulation casing through a conduction path that is open to the bearing bracket. Is fixed to the lower surface of the bearing bracket, and a mechanical seal is provided in an oil casing fixed to the lower surface of the cooling medium bracket to form an oil chamber in which oil is sealed. The impeller is attached to the tip of the motor shaft extended from the lower end surface of the oil casing, and the pump casing surrounding the impeller The pump casing is fixed to the lower surface of the oil casing, and the pumped water sucked from the suction inlet of the pump casing is surrounded by a cooling pipe on the outer periphery of the discharge pipe connected to the discharge outlet of the pump casing and led upward. An upper communication pipe that conducts the cooling medium from the cooling jacket into the cooling pipe is provided on the upper outer circumference of the cooling pipe, and a lower communication pipe that conducts the cooled cooling medium to the cooling medium bracket is provided on the lower outer circumference of the cooling pipe. The cooling medium sucked from the inlet of the circulation casing in the cooling medium chamber is again sent from the outlet of the circulation casing to the bearing bracket by the centrifugal action of the cooling circulation blade and the decelerating pressure increase action of the circulation casing. Through the opened conduction path, it is guided to the annular space in the cooling jacket, and the cooling medium is forced to circulate and convection to efficiently reduce the heat generated by the motor. The most important feature is that the heat exchanging part is configured so that

  In the motor cooling device for a saddle type electric pump according to claim 1 according to the present invention, in the invention according to claim 2 of the present invention, a cooling guide vane for rotating and guiding a cooling medium is provided in the annular space in the cooling jacket. The heat exchanging section is configured to efficiently reduce the heat generated by the motor from the outer peripheral surface of the motor frame by the action of the swirling upward flow by the cooling guide vanes.

  Further, in the motor cooling device for a saddle type electric pump according to claim 1 or 2 according to the present invention, in the invention according to claim 3 of the present invention, from the inside of the cooling jacket by the communication of the upper communication pipe to the inside of the cooling pipe. The upper communication pipe is attached so that the inflowing cooling medium smoothly flows down from the tangential direction of the inner circumference of the cooling jacket to the tangential direction of the inner circumference of the cooling pipe, and the cooling medium is introduced from the tangential direction of the inner circumference of the cooling pipe. From the outer peripheral surface of the discharge pipe surrounded by the cooling pipe by the cooling action of the pumped water in the discharge pipe by attaching the lower communication pipe so as to smoothly flow out in the tangential direction of the bracket inner circumference. The heat exchange unit is configured to efficiently reduce the heat absorption of the cooling medium that has absorbed the generated heat.

  According to the motor cooling device of the vertical electric pump of the present invention, a coolant such as water having a low thermal conductivity and lower viscosity than oil is provided between the lower surface of the bearing bracket at the lower end of the motor unit and the upper surface of the oil casing at the upper end of the pump unit. Is forcedly circulated as a cooling medium, so that the flow of the cooling medium spirals around the outer peripheral surface of the motor frame by the action of the swirling upward flow by the cooling guide vanes attached to the annular space in the cooling jacket surrounding the motor frame. Since it is circulated ascending while turning, the contact area and time of the endothermic convection are expanded, so that the heat generation of the motor is efficiently absorbed and removed, thereby suppressing the heat generation of the motor.

  Then, the cooling medium smoothly swirls from the tangential direction of the inner circumference of the cooling jacket to the tangential direction of the inner circumference of the cooling pipe surrounding the outer wall of the discharge pipe for draining the pump discharge pumping water through the upper communication pipe. The cooling medium is efficiently cooled by exchanging heat to the pump discharge pumping water flowing through the discharge pipe of the heat exchange section, and the cooled cooling medium passes through the lower communication pipe from the tangential direction of the inner periphery below the cooling pipe. Thus, the recirculation cooling function is efficiently maintained by smoothly returning and circulating in the tangential direction of the inner periphery of the cooling medium bracket.

  Further, in order to reuse the cooled cooling medium for motor cooling, a cooling medium bracket in which a circulation casing and circulation blades are installed is interposed between the motor unit and the pump unit, thereby cooling the circulation cooling function. A functional part can be provided compactly.

  Furthermore, the cooling function section provided in the compact is formed in a forced circulation path of a sealed cooling medium that is isolated from the motor section and the pump section, so that it is affected by external conditions outside the machine. Therefore, it is possible to obtain a cooling effect by efficient heat exchange in a stable cooling environment free from foreign matters.

  Therefore, the above-mentioned effect ensures a reliable and stable cooling function without clogging of foreign matter, so that the motor can be produced at a low cost without increasing the size of the motor and without the need for troublesome seal oil replacement work. Even when the motor part is exposed in the air capable of pumping water, a reliable and stable cooling function can be secured, and the heat generated by the upper and lower sliding parts of the mechanical seal is sufficiently absorbed and cooled. In addition to ensuring a highly reliable and stable shaft sealing function, it is possible to prevent accidents such as a decrease in motor insulation due to oil rising in the oil chamber into the motor section due to the presence of the cooling medium chamber. It is possible to provide a motor cooling device for a vertical electric pump that functions effectively.

It is the vertical side view which showed the structure of the motor cooling device of the vertical type electric pump of Example 1 thru | or 3 of this invention. It is the fragmentary sectional view which showed the part of the circulation casing and conduction path which governs circulation supply of a cooling medium along the AA line in FIG. It is the fragmentary sectional view which showed the part of the discharge pipe and cooling pipe which manage cooling of the cooling medium accompanying the communication state from the motor part along the BB line in FIG.

  An embodiment of a motor cooling device for a vertical electric pump according to the present invention will be described in detail with reference to FIGS. 1 to 3 of the accompanying drawings. However, the present invention is limited by the embodiments. It is not something.

  In FIG. 1 to FIG. 3, reference numeral 1 denotes a dry motor of a saddle type electric pump that is driven by power supply of a power cable, 2 is a motor frame constituting an outline of the dry motor, and 3 is fitted in the motor frame 2. A rotor 4 that is rotationally driven across an inner periphery of the stator 3 and a gap (air gap); a motor shaft 5 is fitted on the inner periphery of the rotor 4, and an upper surface of the motor frame 2 Is fixed to the upper end of the motor shaft 5 and fixed to the lower surface of the motor frame 2 and is fixed to the lower portion of the motor shaft 5 by an upper bearing 6u which is fixed to the upper end of the motor shaft 5. In the dry motor 1 including the bearing bracket 8 that supports the lower part of the motor shaft 5 by the bearing 6d, the cooling medium 9 used for cooling may be an insulating oil effective for lowering the insulation, but is less viscous than the oil. It is desirable to use a coolant having high conductivity, such as water, and a cooling jacket 10 that surrounds the motor frame 2 and forms an annular space that encloses the cooling medium 9 is interposed between the head cover 7 and the bearing bracket 8. A seal member 11 such as a mechanical seal or a lip type is attached to a through portion of the motor shaft 5 on the lower end side of the bearing bracket 8, and a cooling circulation blade 12 is inserted into the motor shaft 5 on the lower end side of the seal member 11. The circulating casing 13 that fixes and surrounds the cooling circulation blade 12 is fixed to the lower surface of the bearing bracket 8, and the cooling medium 9 sucked from the suction port 13 s of the circulation casing 13 is caused by the centrifugal action of the cooling circulation blade 12. The bearing is accelerated and depressurized and increased by the circulation casing 13 from the discharge port 13d of the circulation casing 13. A cooling medium that forms a cooling medium chamber 16 that encloses the cooling medium 9 at a distance from the lower surface of the circulation casing 13 through the conduction path 14 opened in the racket 8 and leading to the annular space in the cooling jacket. The bracket 17 is fixed to the lower surface of the bearing bracket 8, and a mechanical seal 19 is provided in an oil casing 18 fixed to the lower surface of the cooling medium bracket 17 to form an oil chamber 20 in which oil is sealed, It is desirable to provide an auxiliary seal that penetrates through the oil chamber 20 and prevents foreign matter from entering the lower end surface of the oil casing 18, and an impeller 21 is attached to the tip of the motor shaft 5 that is penetrated and extended. The pump casing 22 surrounding the oil pump 21 is fixed to the lower surface of the oil casing 18, and the pumped water absorbed from the suction port 22 s of the pump casing is The outer periphery of the discharge pipe 23 connected to the discharge port 22d of the pump casing and led upward is surrounded by the cooling pipe 24, and the cooling medium 9 is put into the cooling pipe 24 from the inside of the cooling jacket 10 to the upper outer circumference of the cooling pipe 24. The upper communication pipe 25 that conducts and the lower communication pipe that conducts the cooling medium 9 cooled on the outer periphery of the lower part of the cooling pipe 24 into the cooling medium bracket 17 are connected by a connector as a flexible pipe having flexibility. In addition, the cooling medium 9 sucked from the inlet 13s of the circulation casing in the cooling medium chamber 16 is again provided with the centrifugal action of the cooling circulation blade 12 and the deceleration pressure increasing action of the circulation casing 13. Then, the cooling medium is again led to the annular space in the cooling jacket 10 through the conduction path 14 opened to the bearing bracket 8 from the discharge port 13d of the circulation casing, and the cooling medium By forcibly circulating convection stably constitute a heat exchange unit to reduce heat absorption efficiently motor heating.

  Based on the first embodiment, for example, referring to FIGS. 1 to 3, a cooling guide vane 15 for turning the cooling medium 9 in the annular space in the cooling jacket 10 is attached, and preferably the guide is provided. Attached directly above the passage 14 or, instead of the cooling guide vane 15, a bent pipe material such as a 30 ° or 45 ° elbow is attached to the outlet side of the conduction passage 14 (not shown) and the cooling medium is inclined upward. The flow of the cooling medium 9 is lifted and circulated while spirally turning around the outer peripheral surface of the motor frame 2 by the action of the swirling upward flow in the cooling jacket 10. Since the contact area and time of the endothermic convection are increased, the heat exchanging section is configured to efficiently reduce the heat generated by the motor.

  Based on the first or second embodiment, for example, referring to FIG. 1 to FIG. 3, the cooling that absorbs the heat generated by the motor flowing into the cooling pipe 24 from the cooling jacket 10 due to the communication of the upper communication pipe 25. Since the upper communication pipe 25 is attached so that the medium 9 smoothly swirls down from the tangential direction of the inner periphery of the cooling jacket 10 to the tangential direction of the inner periphery of the cooling pipe 24, the flow of the cooling medium 9 Circulates down the outer periphery of the discharge pipe 23 while spirally swirling, so that the contact area and time of heat dissipation convection are expanded, so heat exchange to the pump discharge pumping water that circulates in the discharge pipe of the heat exchange section As a result, the lower communication pipe 26 is attached so that the cooling medium 9 is efficiently cooled and smoothly flows out from the tangential direction of the inner periphery of the cooling pipe 24 to the tangential direction of the inner periphery of the cooling medium bracket 17. By disposing, in order to reuse the cooled cooling medium 9 for motor cooling, the flow of the cooling medium 9 into the cooling medium bracket 17 in which the circulation casing 13 and the circulation blade 12 are housed is disturbed. By being smoothly returned and circulated without any problems, the recirculation cooling function is efficiently maintained.

  The present invention, for example, treatment water containing foreign matter such as pumping operation such as line relay or low water level where the motor part is exposed to the air, wastewater generated from buildings and other facilities, and facility wastewater that treats wastewater. The vertical electric pump equipped with a dry submersible motor can be used for drainage and the like that require the reliability of equipment even under severe conditions to a predetermined destination.

DESCRIPTION OF SYMBOLS 1 Dry motor 2 Motor frame 3 Stator 4 Rotor 5 Motor shaft 6d Lower bearing 6u Upper and lower bearing 7 Head cover 8 Bearing bracket 9 Cooling medium 10 Cooling jacket 11 Sealing member 12 Cooling circulation blade 13 Circulating casing 13s Circulating casing inlet 13d Circulation casing discharge port 14 Conducting path 15 Cooling guide vane 16 Cooling medium chamber 17 Cooling medium bracket 18 Oil casing 19 Mechanical seal 20 Oil chamber 21 Impeller 22 Pump casing 22d Pump casing discharge port 22s Pump casing suction port 23 Discharge pipe 24 Cooling pipe 25 Upper communication pipe 26 Lower communication pipe

Claims (3)

A motor frame including a stator and a rotor fitted with a motor shaft; a head cover for supporting the upper portion of the motor shaft by an upper bearing fixed to the upper surface of the motor frame and fitted to the upper end of the motor shaft; by the fixing to the lower surface lower bearing which is fitted to the lower the motor shaft, in a dry motor consisting bearing bracket for supporting a lower motor shaft to form an annular space enclosing the cooling medium surrounding the Motafure over arm A cooling jacket is interposed between the head cover and the bearing bracket, a seal member is attached to the through-hole of the motor shaft on the lower end side of the bearing bracket, and a cooling circulation blade is inserted and fixed to the motor shaft on the lower end side of the seal member A circulation casing surrounding the cooling circulation blade is fixed to the lower surface of the bearing bracket, and the circulation casing is The cooling medium sucked from the suction port of the sing is accelerated by the centrifugal action of the cooling circulation blade, and from the discharge opening of the circulation casing by the decelerating pressure increasing action of the circulation casing, through the conduction path opened to the bearing bracket, The cooling medium bracket is fixed to the lower surface of the bearing bracket, and the cooling medium bracket is formed on the lower surface of the bearing bracket. The cooling medium bracket forms a cooling medium chamber that encloses the cooling medium at a distance from the lower surface of the circulation casing. A mechanical seal is provided in an oil casing fixed to the lower surface of the oil chamber to form an oil chamber in which oil is sealed, and a blade is passed through the oil chamber and guided from the lower end surface of the oil casing to the tip of the motor shaft. A car is mounted, and a pump casing surrounding the impeller is fixed to the lower surface of the oil casing. The pumped water sucked in from the inlet is connected to the discharge port of the pump casing, and the outer periphery of the discharge pipe extended upward is surrounded by a cooling pipe, and the cooling medium is cooled from the inside of the cooling jacket to the upper outer periphery of the cooling pipe. An upper communication pipe that conducts in the pipe is provided, and a lower communication pipe that conducts the cooled cooling medium to the cooling medium bracket is provided on the lower outer periphery of the cooling pipe, and is sucked from the inlet of the circulation casing in the cooling medium chamber. The cooling medium is again sent to the annular space in the cooling jacket through the conduction path opened from the discharge port of the circulation casing to the bearing bracket by the centrifugal action of the cooling circulation blade and the deceleration pressure increasing action of the circulation casing. A saddle-type electric pump characterized in that a heat exchanging unit is configured to efficiently reduce the heat generation of the motor by forcibly circulating and convection the cooling medium. Motor cooling device.   The motor cooling device for a vertical electric pump according to claim 1, wherein a cooling guide vane for causing the cooling medium to swirl and pass through the annular space in the cooling jacket is provided, and the action of the swirl upward flow by the cooling guide vane A motor cooling device for a saddle type electric pump, characterized in that the heat exchanging portion is configured to efficiently reduce the heat generated by the motor from the outer peripheral surface of the motor frame.   3. The motor cooling device for a vertical electric pump according to claim 1, wherein a cooling medium flowing into the cooling pipe from the cooling jacket by communication of the upper communication pipe is tangential to the inner circumference of the cooling jacket. The upper communication pipe is attached so as to smoothly flow down to the tangential direction of the inner periphery of the cooling pipe, and smoothly flows out from the tangential direction of the inner periphery of the cooling pipe to the tangential direction of the inner periphery of the cooling medium bracket. By attaching the lower communication pipe, the cooling medium that has absorbed the heat generated by the motor from the outer peripheral surface of the discharge pipe surrounded by the cooling pipe is efficiently absorbed by the cooling action of the pumped water in the discharge pipe. A motor cooling device for a saddle type electric pump, characterized in that a heat exchanging portion is configured.

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