JP3317602B2 - Bearing lubrication fluid flow measurement method for canned motor pumps - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a canned motor pump designed to detect a lubricating state of a bearing that supports a motor rotor shaft and to always provide a proper flow rate of a lubricating liquid to the bearing. The present invention relates to a method for measuring a flow rate of a bearing lubricating fluid required for a vehicle.

[0002]

2. Description of the Related Art Generally, a canned motor pump circulates and supplies a part of a pump handling liquid into a motor rotor chamber of a canned motor to cool the motor and lubricate bearings.

That is, a part of the pump handling liquid taken out of the discharge pipe section of the pump section via an external conduit is introduced into the rear motor rotor chamber of the canned motor section, and this handled liquid is cut into the inner peripheral surface of the rear bearing. The through-hole formed in the provided groove and the bearing support member for supporting the rear bearing is made to flow. Then
The handling liquid introduced into the rear motor rotor chamber is transferred to the front motor rotor chamber via the space between the rotor and the stator of the motor section. In this way, the pumped liquid introduced into the front motor rotor chamber passes through the through-hole formed in the bearing support member for supporting the front bearing and the slot cut out on the inner peripheral surface of the front bearing, and is thus pumped. It is configured to return to the pump section via a liquid passage communicating with the low pressure section of the section.

Accordingly, when a part of the pump handling liquid flows through the slots in the inner peripheral surfaces of the rear bearing and the front bearing in the canned motor, lubrication of the respective bearings is achieved.

[0005]

However, in order to smoothly lubricate the front and rear bearings in the conventional canned motor pump, the pump handling liquid as the lubricating liquid always flows at an appropriate flow rate. It is necessary to. Therefore, when manufacturing this type of pump, it is necessary to take this point into consideration when designing.

However, since the portion of the bearing through which the lubricating liquid flows is an extremely small gap, it is difficult to install a commercially available flow meter or the like to measure the flow rate of the lubricating liquid. Although it is possible to obtain a theoretical value for the flow rate of the lubricating liquid from the design dimensions of the bearing portion and the like, it is not possible to confirm the flow rate of the lubricating liquid generated in the bearing during actual pump operation.

Accordingly, an object of the present invention is to provide a canned motor pump in which a part of a pump handling liquid is circulated and introduced into a rotor chamber of a canned motor to lubricate a rotor shaft bearing and cool a motor unit. In the bearing by using a high-resolution thermistor thermometer for the lubrication part of the bearing, by measuring the flow velocity based on temperature detection between two points of the lubricating fluid flowing through the inner peripheral surface of the bearing, It is an object of the present invention to provide a method for measuring a flow rate of a bearing lubricating liquid in a canned motor pump capable of easily and appropriately calculating a flow rate of a lubricating liquid.

[0008]

In order to achieve the above object, a method for measuring the flow rate of a bearing lubricating liquid in a canned motor pump according to the present invention is described by circulating a part of a pump handling liquid into a rotor chamber of a canned motor. A canned motor pump configured to perform lubrication of a bearing of a rotor shaft and cooling of a motor portion, wherein a high-resolution thermistor thermometer is arranged on a liquid inflow side and a liquid outflow side of the bearing at predetermined intervals. Then, a tracer liquid having a temperature difference from the handling liquid was injected into the pump suction port side, and a temperature change due to the flow of the pump handling liquid in the bearing was detected by the thermistor thermometer, respectively, and detected by each thermistor thermometer. A canned motor pump that measures the flow rate of bearing lubricating fluid by comparing time-series temperature changes and calculates the flow rate of bearing lubricating fluid based on the obtained flow rate Flow measurement scheme odor bearing lubricant
The thermistor thermometer placed on the bearing
Of the liquid inflow and outflow sides of the
Inside the bearing so that each sensor part is exposed.
It is characterized by being arranged in.

In this case, the high-resolution thermistor thermometer has an accuracy of 0.0 in a temperature range of 0 ° C. to 100 ° C.
Use those with 2 ° C and resolution of 0.001 ° C.

[0010]

[0011]

According to the method for measuring the flow rate of the bearing lubricating liquid in the canned motor pump according to the present invention, a high-resolution thermistor thermometer is arranged on the liquid inflow side and the liquid outflow side of the bearing at predetermined intervals, and the pump suction is performed. By injecting a tracer liquid of high-temperature water into the mouth side, and detecting a temperature change due to the flow of the pump handling liquid in the bearing with the thermistor thermometer, a time-series temperature change detected by the thermistor thermometer is obtained. The flow velocity of the bearing lubricating liquid can be measured in comparison, and the flow rate of the bearing lubricating liquid can be appropriately and simply measured and calculated based on the obtained flow velocity.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a system for measuring the flow rate of a bearing lubricating liquid in a canned motor pump according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic sectional view of a canned motor pump which implements a method for measuring a flow rate of a bearing lubricant according to the present invention. In FIG. 1, reference numeral 10 denotes a pump unit, 12 denotes a canned motor unit, and the pump unit 10 and the motor unit 12
Are connected to each other by the adapter 14 so as to be mutually compatible.

The pump section 10 has a suction pipe section 20 and a discharge pipe section 22 communicating with a pump chamber 18 provided with the impeller 16.
The impeller 16 is attached to an extended end of the rotor shaft 24 of the motor unit 12. On the other hand, the motor unit 1
2 includes a stator assembly 26 and a rotor assembly 28, and the rotor shaft 24 is supported by front bearings 30 and rear bearings 32, respectively. At both ends of the rotor assembly 28, a front rotor chamber 34 and a rear rotor chamber 36 are provided, respectively. Are formed.
However, at the rear end of the rear rotor chamber 36, the pump 1
The external conduit 38 led out from the discharge pipe portion 22 of No. 0 is connected in communication.

In this way, a part of the handling liquid is introduced into the rear rotor chamber 36 from the discharge pipe section 22 of the pump section 10, and the handling liquid is cut into the inner peripheral surface of the rear bearing 32. Bearing support member 42 supporting bore 40 and rear bearing 32
To lubricate the rear bearing and cool the motor section 12. The rear rotor chamber 36
The handling liquid introduced into the inside is transferred to the front rotor chamber 34 through the space 46 between the rotor and the stator.

The adapter 14 has a front rotor chamber 3.
There is provided a liquid passage 48 that communicates between the pump 4 and the low pressure side of the pump unit 10. That is, the liquid passage 48 is formed through the through hole 52 formed in the bearing support member 50 that supports the front bearing 30 and the slot 54 formed in the inner peripheral surface of the front bearing 30 through the front rotor chamber. The system is configured so as to lead to the liquid passage 48 the handled liquid that has communicated with the lubrication part 34 and that has lubricated the front bearing 30 and cooled the motor part 12. Then, the handled liquid led out to the liquid passage 48 passes through the balance hole 56 formed in the impeller 16 from the back of the impeller 16 in the pump chamber 18, and then flows through the impeller 16.
Is guided to the suction port side.

However, according to the present invention, in the front bearing 30 and the rear bearing 32, the liquid inflow side and the liquid outflow side are formed in the slots 40, 54 cut in the inner peripheral surface of each bearing 30, 32, respectively. In each of the bearings 30, 3, a pair of high-resolution thermistor thermometers 60a, 60b are respectively exposed so that the respective sensor portions are exposed in the respective slots 40, 54.
2 inside.

As the high-resolution thermistor thermometers 60a and 60b that can be used in the present invention, for example, Model 3312 thermometer and Model 4312 thermometer manufactured by Instrumentlab (USA) are preferable. In the temperature measurement range of 100 ° C. to 100 ° C., one having an accuracy of 0.02 ° C. and a resolution of 0.001 ° C. is obtained.

The lead wires of the thermistor thermometers 60a, 60b disposed inside the bearings 30, 32 are as follows:
The connecting structure portion of the canned motor portion 12 is appropriately arranged so as to be liquid-tightly lead and externally connectable.

Next, the measurement of the flow rate of the lubricating liquid in each of the bearings 30 and 32 in the canned motor pump having the above configuration will be described.

First, a tracer liquid having a temperature difference from the pump handling liquid, for example, a higher temperature water than the handling liquid, is prepared at the pump suction port side. Introduce within. A part of the tracer liquid discharged from the pump unit 10 by the pump operation is introduced into the rear rotor chamber 36 via the external conduit 38 and flows through the slot 40 of the rear bearing 32. At this time, the temperature of the tracer liquid is detected by the thermistor thermometer 60a disposed on the liquid inflow side. Next, the temperature of the tracer liquid is detected by the thermistor thermometer 60b disposed on the liquid outflow side.

If the time points at which the thermistor thermometers 60a and 60b detect the temperature changes caused by the flow of the tracer liquid are denoted by t1 and t2, respectively, the distance l between the measurement points by the thermistor thermometers 60a and 60b will be described. Can be obtained by the following equation.

V = 1 / (t2−t1) (1)

Accordingly, by obtaining the flow velocity v of the tracer liquid as described above, if the cross-sectional area of the slot 40 of the rear bearing 32 through which the tracer liquid flows is A, the tracer liquid flowing through this cross-section (Volume flow rate) q can be obtained by the following equation.

Q = v · A (2)

FIG. 2 schematically shows an arithmetic circuit for measuring the flow rate of the tracer liquid described above. In FIG. 2, reference numeral 62 denotes a flow rate calculator for calculating the flow rate v of the tracer liquid, and 64 denotes a flow rate calculator for calculating the flow rate q of the tracer liquid.

The slot 40 of the front bearing 30 shown in FIG.
When the tracer liquid flows, the flow velocity and the flow rate of the tracer liquid can be measured and calculated in the same manner as described above.

While the preferred embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and many design changes can be made without departing from the spirit of the present invention.

[0029]

As is apparent from the above-described embodiment, according to the system for measuring the flow rate of the bearing lubricating liquid in the canned motor pump according to the present invention, a part of the pump handling liquid is circulated and introduced into the rotor chamber of the canned motor. A canned motor pump configured to perform lubrication of a bearing of a rotor shaft and cooling of a motor portion, wherein a high-resolution thermistor thermometer is disposed on a liquid inflow side and a liquid outflow side of the bearing at predetermined intervals. Then, a tracer liquid having a temperature difference from the handling liquid is injected into the pump suction port side, and a temperature change due to the flow of the pump handling liquid in the bearing is detected by the thermistor thermometer, respectively, and detected by each thermistor thermometer. A canned motor pump that measures the bearing lubricating fluid flow rate by comparing the time-series temperature changes and calculates the bearing lubricating fluid flow rate based on the obtained flow rate. Flow measurement scheme odor bearing lubricant that
The thermistor thermometer placed on the bearing
Of the liquid inflow and outflow sides of the
Inside the bearing so that each sensor part is exposed.
With such a configuration, the actual flow rate of the lubricating liquid in the bearing of the canned motor pump, which has been conventionally difficult, can be appropriately and simply measured.

Therefore, according to the present invention, the effect of contributing to the design of the circulation system of the lubricating liquid, that is, the pump handling liquid for the bearing of the canned motor pump is extremely large.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing a configuration of a canned motor pump that implements a method of measuring a flow rate of a bearing lubricating liquid in the canned motor pump according to the present invention.

FIG. 2 is a block circuit diagram showing one embodiment of an arithmetic circuit for implementing the bearing lubricating fluid flow measurement method according to the present invention.

[Explanation of symbols]

 Reference Signs List 10 pump section 12 canned motor section 14 adapter 16 impeller 18 pump chamber 20 suction pipe section 22 discharge pipe section 24 rotor shaft 26 stator assembly 28 rotor assembly 30 front bearing 32 rear bearing 34 front rotor chamber 36 rear rotor chamber 38 external conduit Reference Signs List 40 slot hole 42 bearing support member 44 through hole 46 between rotor and stator 48 liquid passage 50 bearing support member 52 through hole 54 slot hole 56 balance hole 60a, 60b thermistor thermometer 62 flow rate calculator 64 flow rate calculator

Claims (2)

(57) [Claims] 1. A part of a pump handling liquid is supplied to a canned motor.
Circulation is introduced into the rotor chamber to lubricate and
Canned motor port configured to cool the motor
Pumps on the liquid inflow side and the liquid outflow side of the bearing, respectively.
Place a high-resolution thermistor thermometer at regular intervals and
A tracer liquid having a temperature difference from the
Injection and temperature due to the flow of pump handling liquid in the bearing
Degree change is detected by the thermistor thermometer, respectively.
Time-series temperature change detected by each thermistor thermometer
And measure the flow rate of the bearing lubricating fluid.
Canned motor port that calculates the flow rate of bearing lubricant based on
For measuring the flow rate of bearing lubricant in pumpsAt The thermistor thermometer placed on the bearing is cut on the inner peripheral surface of the bearing.
With respect to the slot provided, on the liquid inflow side and the liquid outflow side.
Place the inside of the bearing so that each sensor part is exposed.
Of bearing lubrication fluid in a canned motor pump
Flow measurement method. 2. The high-resolution thermistor thermometer has a temperature of 0 ° C.
In a temperature measurement range of 100 ° C., at least an accuracy of 0.
2. A method for measuring a flow rate of a bearing lubricating fluid in a canned motor pump according to claim 1, wherein the system has a temperature of 02.degree.