JPH0412193A - Canned type refrigerant pump - Google Patents

Abstract

PURPOSE:To prevent defective lubrication due to gasification of refrigerant by letting flow a part of refrigerant discharged from a displacement type pump mechanism part into an enclosed case through a bearing surface for lubrication, and cooling a stator with discharge flow flowing the inner face of the enclosed case. CONSTITUTION:When a turning scroll 22 is turningly moved setting the eccentric distance between a stationary scroll 21 and the turning scroll 22 as the radius, a transport space 28 is periodically formed between laps 24, 27, and refrigerant is sucked from a suction pipe 33 and discharged to a discharge chamber 29. A part of the discharged refrigerant is supplied to a first and a second groove parts 48, 49 for lubrication, and the bearing surfaces of a thrust bearing part 30a and a bearing part 9a are lubricated. The major part of refrigerant in the discharge chamber 29 is discharged from a discharge pipe 47 through a back pressure chamber 37, a space 43a, and a space 43b, at this time, by the discharge flow of refrigerant flowing between a rotor 12 and the inner face of a case 6a, heat of a stator 11 conducted to an enclosed case 6 is removed, and the stator 11 is cooled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a canned refrigerant pump for transporting refrigerant.

(Prior Art) A system has been considered that transports heat using a refrigerant that is circulated by a pump. In order to achieve this type of heat transfer, the pump handles liquid refrigerant at a temperature close to its boiling point, so it must have performance that no pressure is applied to the refrigerant, and that components contained in the refrigerant do not damage the insulation of the motor stator. A refrigerant pump suitable for refrigerant circulation is required.

Therefore, a refrigerant pump can be considered in which a positive displacement pump mechanism is connected to an end of a canned motor which has a stator provided on the outside of a sealed case and a rotor rotatably supported inside.

By the way, in a refrigerant pump as well as in a normal pump, it is necessary to lubricate the rotor bearing. In this case, it is conceivable to provide a lubricating oil supply mechanism that feeds lubricating oil to the sliding parts in the same way as a normal pump, according to pump technology.
In a structure in which such a lubricating oil supply mechanism is provided, the pump as a whole becomes large due to the use of separate lubricating oil, and also requires a shaft seal.

Therefore, in order to improve these inconveniences, refrigerant pumps
We are considering using the components contained in the refrigerant to lubricate the bearing surface of the rotor, and using the refrigerant to eliminate the shaft seal of the bearing. For example, part of the refrigerant discharged from the discharge side of the positive displacement pump mechanism is guided as a lubricating refrigerant to the bearing surface of the rotor, and then passed through the inside of the sealed case and the rotor shaft to the discharge side of the positive displacement pump mechanism. It is possible to merge it to the side.

(Problem to be solved by the invention) However, in such a refrigerant pump, only a small amount of refrigerant flows through the sealed case depending on the amount of lubrication, so the refrigerant filled in the sealed case is affected by the strong magnetic field of the stator. susceptible to fever. Moreover, the refrigerant has a low boiling point temperature.

For this reason, the refrigerant in the sealed case is likely to exceed its boiling point temperature and vaporize due to the heat generated by the stator, and the vaporization of the refrigerant may lead to poor lubrication. In particular, this point affected the reliability of the pump and prevented the realization of a highly practical refrigerant pump.

This invention was made with attention to these circumstances,
The purpose is to provide a canned refrigerant pump suitable for refrigerant transport that can transport refrigerant without impairing the insulation properties of the stator and while maintaining good lubricity with the refrigerant. .

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the canned refrigerant pump of the present invention includes a sealed case, a stator provided on the outside of the sealed case, and a stator connected to the stator inside. A motor having a corresponding rotor rotatably supported by a bearing, a positive displacement pump mechanism driven by the rotation of the rotor, and a part of the refrigerant in the positive displacement pump mechanism through the bearing surface of the motor. a lubricating refrigerant passageway that guides the refrigerant into the sealed case; and passage means that guides the refrigerant discharged from the discharge part of the positive displacement pump mechanism to one space in the sealed case partitioned by the rotor; A passage formed of a gap between an outer circumferential surface of the rotor and an inner surface of the sealed case opposite thereto and through which the refrigerant flowing into the one space flows into the other space in the sealed case, and a passage provided in the sealed case. and a discharge port for discharging the refrigerant that has flowed into the other space to the outside.

(Function) In the canned refrigerant pump of the present invention, the rotor is rotated by exciting the motor. As the rotor rotates, the positive displacement pump mechanism is driven, and refrigerant is sucked in from the suction section of the pump mechanism. Next, the refrigerant is discharged from the discharge section of the positive displacement pump mechanism into one space of the sealed case with the rotor as a boundary. This refrigerant passes between the rotor of the motor and the inner surface of the sealed case, is discharged into the other space within the sealed case, and is then discharged to the outside from the discharge port. On the other hand, along with this flow, the refrigerant from the volumetric pump mechanism flows into the sealed case via the bearing surface for lubrication, and lubricates the bearing surface.

Thus, the stator is cooled by the discharge flow that flows along the inner surface of the sealed case.

Therefore, it is possible to prevent a rise in the temperature of the stator and the temperature of the refrigerant in the sealed case, and lubrication failure due to vaporization of the lubricating refrigerant does not occur.

Furthermore, by using a canned motor, the insulation properties of the stems are not impaired by the refrigerant.

The present invention will be explained below based on a first embodiment shown in FIGS. FIG. 2 shows a fluid heat exhaust system to which the present invention is applied, in which 1 is a canned refrigerant pump;
2 is a heat absorber, 3 is a heat radiator, and 4 is an accumulator. A refrigerant circulation path 5 is provided in the canned refrigerant pump 1.
through the heat absorber 2. Heat sink 3. Accumulator 4
are connected in sequence to form a closed circuit that transports heat from the heat absorber 2 to the radiator 3 by circulating the refrigerant.

The structure of the canned refrigerant pump 1 is shown in FIG. To explain the refrigerant pump 1, 6
is a closed case. The sealed case 6 has a blind plate part 8 provided at one end of the cylindrical case 6a so as to close the opening.
A frame 9 is provided at the other end so as to close the opening. A motor 10 is installed in the center of this sealed case 6.
is provided.

This motor 10 has a stator 11 attached to the outer circumferential portion of the axial center of a case 6a, and a rotor 12 provided inside the case 6a corresponding to the position of the stator 1. The rotor 12 has an outer diameter slightly smaller than the inner diameter of the case, and has a shaft 1 serving as a rotor axis at its axial center.
3 is attached by press fitting. And frame 9
The end portion of the shaft 13 extending to the side is supported by a bearing portion 9a (bearing) formed in the frame 9. That is, the bearing portion 9a is formed by integrally protruding a cylindrical bearing boss communicating between the inside and outside of the case 6a at the center of the inner surface of a disc-shaped portion 9b that closes the case opening of the frame 9. The end portion of the shaft 13 is slidably fitted into this bearing boss portion to rotatably support the rotor 12.

On the other hand, the frame 9 is provided with a scroll pump 20 (displacement pump mechanism). To explain this pump 20, 2] is a fixed scroll, and 22 is an orbiting scroll. The fixed scroll 21 has a disc-shaped portion 9b.
A substantially flat disk-shaped mirror plate 23 attached to the collar portion 9C of the
As shown in FIG. 3, a pair of spiral wraps 24, 24 are provided point-symmetrically protruding from the central lower surface of the holder.

Further, the orbiting scroll 22 is attached to the fixed scroll 21 on one side of a disc-shaped end plate 26 disposed in a recess 25 for accommodating the orbiting scroll formed circularly on the outer surface of the frame 9.
Similarly, as shown in Figure 3, Volume 3, it is constructed by protruding a pair of spiral wraps 27° 27 symmetrically.

These fixed scroll 21 and orbiting scroll 2
The two wraps are combined in such a way that they are offset from the center and inserted into each other alternately, so that a crescent-shaped conveyance space 28 can be formed between the wraps 24 and 27. Further, a discharge chamber 29 (corresponding to the discharge section in the present application) constituted by a circular recess is provided at the center of the inner surface of the end plate 23 of the fixed scroll 21 . This discharge chamber 29 faces the central discharge pressure region 1a surrounded by the wrap 24°27. As a result, the orbiting scroll 22 is moved from the fixed scroll 2 to the fixed scroll 2.
1, the refrigerant is sucked in from the suction pipe 33 provided in communication with the suction space 32 on the outer periphery of the wrap, moves toward the center, and is discharged into the discharge chamber 29. . That is, laps 24 and 27 are orbiting scrolls 2
The configuration is such that the formation of the transfer space 28 and the opening of the transfer space 28 are repeated in accordance with the rotation of the pump 2, and the fluid can be delivered without changing the volume from the same setting.

In this embodiment, for example, wraps 24.27 are used, each having a total length equal to one round plus about 1/4 round.

Therefore, the fixed scroll 21 and the orbiting scroll 2
2 constitutes a fluid transport section in which the outer peripheral side is the suction side, the center side is the discharge side, and the volume ratio is rl:IJ.

Further, a cylindrical bearing boss 30 projecting into the discharge chamber 29 is integrally formed in the center of the end plate 26 of the orbiting scroll 22 . A shaft-shaped crank boss 3], which is provided eccentrically with respect to the axis of the shaft 13 on the tip surface of the shaft 3, is slidably inserted into the bearing boss 30, and as the motor 10 is energized, , the orbiting scroll 22 can be rotated around the center of the fixed scroll 21.

Further, at the center of the lower surface of the end plate 26 of the orbiting scroll 22, as shown in FIG. 4, an annular seal ring 35 having a square outer shape, for example, is protruded around the opening of the bearing boss 30. Further, a recess 36 (described later) is formed in the center of the recess 25 of the frame 9 to slidably receive the seal ring 35, and a back pressure chamber 37 is formed at the center of the lower surface of the mirror plate 26 defined by the seal ring 35. It consists of The back pressure chamber 37 communicates with the discharge chamber 29 through a plurality of through holes 38 provided in the surface of the mirror plate 26 around the bearing boss 30 . As a result, discharge pressure is applied to the center of the back surface of the orbiting scroll 22, and suction pressure is applied to the outer peripheral side of the back surface of the orbiting scroll 22, thereby balancing the internal pressure between the fixed scroll 2] and the orbiting scroll 22. ing. In other words, to prevent seal failure, the pressure is balanced to maintain a seal between the wrap end and the mirror plate surface.

Further, 40 is an Oldham mechanism that prevents the orbiting scroll 22 from rotating. To explain the Oldham mechanism 40, 4
1 is an Oldham ring constructed in the shape of a rectangular frame.

As shown in FIG. 4, the Oldham ring 40 is formed such that the inner dimensions of a pair of short sides 40a correspond to the lengths of the sides forming the outer periphery of the seal ring 35, and a pair of long sides 40b.

The inner dimension of 40b is at least larger than that of the shaft 13.
The crank boss 31 is formed with a large dimension corresponding to the eccentricity of the crank boss 31. This Oldham ring 41 is slidably inserted into the outer peripheral portion of the seal ring 35.

This combination restricts the Oldham ring 41 to be able to slide relative to the shaft 13 only in one direction passing through the axis of the shaft 13 and perpendicular to the axis, that is, along the longitudinal direction. Furthermore, by combining this Oldham ring 41 with the recess 36, the entire Oldham ring is restricted so that it can slide only in the lateral direction with respect to the frame 9. That is, the inner peripheral shape of the four portions 36 has a square shape with sides having a length corresponding to the outer dimension of the long side 40b of the Oldham ring 41. The Oldham ring 41 is slidably inserted into this recess 36, so that the entire Oldham ring can be slid only in the transverse direction perpendicular to the longitudinal direction. This regulation of the Oldham ring 41 in the longitudinal and lateral directions allows the orbiting scroll 21 to rotate around the center of the fixed scroll 22 without rotating.

A plurality of case communication holes 44 communicating with the space 43a between the rotor 12 and the frame 9 are provided in the bottom wall portion of the concave portion 36 facing the back pressure chamber 37 around the bearing portion 9a. Through these case communication holes 44 and the through hole 38, all of the refrigerant discharged from the discharge chamber 29 can be guided to one case space in the sealed case 6 divided by the rotor 12. I have to.

Further, a passage 45 is provided between the rotor 12 and the sealed case 6, and is formed by a gap between the outer peripheral surface of the rotor 12 and the inner peripheral surface of the case 6a facing thereto. The discharged refrigerant is allowed to flow into the other case space, that is, the space 43b between the opening 12 and the blind plate portion 8. Further, a discharge pipe 47 (corresponding to a discharge port) is provided in the center of the blind plate portion 8, and a space 43b
The refrigerant that has flowed into the refrigerant can be sent to the outside, that is, to the heat absorber 2.

Further, on the outer circumferential surface of the crank boss 31 of the shaft 13, as shown in FIG. A groove portion 48 is provided. and,
By the action of the viscous pump constituted by the first groove portion 48 (pump action generated when the spiral groove rotates together with the shaft 13), refrigerant for lubrication is sucked from the discharge chamber 29, and the refrigerant is transferred to the motor 10. The thrust bearing of
It can be supplied to the thrust receiving part 30a on the root side of the bearing boss 30 which receives the thrust collar part 31a. Further, as shown in FIG. 4, a spiral second groove 49 (a first
A groove 48 (corresponding to a lubricating refrigerant passage) is provided. The refrigerant after lubricating the thrust bearing portion 30a can be similarly supplied to the bearing surface of the bearing boss 30. Further, the end of the second groove portion 49 opens into the space 43a, so that the refrigerant after lubrication flows into the sealed case 6.

Furthermore, a communication groove 50 is provided on the outer peripheral surface of the portion of the shaft 13 that is fitted into the rotor 12, and communicates the space 43a and the space 43b at both ends of the sealed case 6. , the refrigerant discharged into the space 43a can flow into the space 43b on the opposite side.

First, the operation of the refrigerant pump configured as described above will be explained.

When the motor 10 is excited, the rotor 12 rotates and the shaft 13 rotates. This rotation is then transmitted to the orbiting scroll 22.

Here, the orbiting scroll 22 has a sliding structure composed of a seal ring 35 and an Oldham ring 41, and allows movement necessary for orbit in one of two orthogonal directions.
In other words, it is restricted to move only in the "X direction" shown in FIG.
Although it is restricted to move only in the "X" direction,
.

Rotation is prevented in each direction of rYJ.

As a result, the orbiting scroll 22 does not rotate, but rotates around the eccentric distance between the fixed scroll 21 and the orbiting scroll 22 as a radius.

Due to this swirling movement, conveyance spaces 28 , 28 are periodically formed between the wraps 24 , 27 , and the refrigerant is sucked in from the suction pipe 33 , conveyed, and discharged into the discharge chamber 29 . A portion of this discharged refrigerant is used for lubrication in the first groove portion 48.
The liquid flows into the second groove portion 49 and lubricates the bearing surfaces of the thrust receiving portion 30a and the bearing portion 9a. After the lubrication, the refrigerant flows out into the space 43a on one side of the rotor of the sealed case 6.

On the other hand, most of the refrigerant discharged into the discharge chamber 29 passes through the through hole 38, the back pressure chamber 37, and the case communication hole 44, and is discharged into the space 43a on one side of the rotor of the sealed case 6. Then, this refrigerant flows into the other space 43b through both passages, mainly through the passage 45 and secondary through the communication groove 50.

At this time, the heat of the stator 11 ( heat generated by strong magnetic fields). As a result, the stator 1 is
1 to cool down. The discharged refrigerant that has flowed into this space 43b is quickly discharged from the discharge pipe 47 to the heat absorber 2 together with the refrigerant that has flowed into the space 43b through the communication groove 50. Note that the refrigerant is used in the radiator 3. Accumulator 4,
The refrigerant circulates through the refrigerant pump 1 in order, and the heat obtained in the heat absorber 2 is transported to the radiator 3.

However, it is possible to prevent the refrigerant in the sealed case 6 from rising above its vaporization temperature.

Therefore, poor lubrication of each bearing surface due to vaporization of the refrigerant in the sealed case 6 can be prevented, and good lubricity can be maintained. However, by cooling the stator 11, the efficiency of the motor 1o can be improved.

Furthermore, by adopting a canned motor in which the stator 11 does not come into contact with the refrigerant, various motor performances such as the insulation properties of the stator 11 are not impaired.

In addition, by using the communication groove 50 to allow the refrigerant to flow from the space 43a to the space 43b from the shaft 13 side, the pressure loss of the refrigerant flow can be reduced, and the motor 1
0 burden can be reduced.

In addition, in the first embodiment, the space 43 on the pump mechanism side
a, the refrigerant is made to flow in the order of the rotor 12, the passage 45° space 43b of the case 6a, but the refrigerant is not limited to this, and it can be flowed in the order of the space 43b, the rotor 12, and the rotor 12, as in the second embodiment shown in FIG. Passage 45 of case 6a. The refrigerant may be made to flow in the order of the spaces 43a.

That is, in this embodiment, a through passage 51 is provided inside the shaft 13 and the crank boss 21 along the axial direction to communicate the discharge chamber 29 and the space 43b. Then, a discharge pipe 47 communicating with the space 43a is connected to the flange portion 9C of the disc-shaped portion 9a (frame 9), and the refrigerant discharged from the discharge chamber 29 is transferred to the through passage 51, the space 43b2, the passage 45. Space 43a,
It is arranged to flow in the order of discharge pipe 47.

Further, although a scroll pump is used in both the first and second embodiments, a positive displacement pump mechanism having a structure or type other than this may be used.

[Effects of the Invention] As explained above, according to the present invention, the stator can be cooled by the discharge flow that flows along the inner surface of the sealed case.

Therefore, it is possible to prevent the temperature of the refrigerant in the sealed case from rising, and it is possible to prevent lubrication failure caused by vaporization of the lubricating refrigerant. Furthermore, by preventing a rise in the temperature of the stator, motor efficiency can also be improved.

Furthermore, by using a canned motor, the insulation properties of the stems are not impaired by refrigerant.

[Brief explanation of the drawing]

1 to 4 show a first embodiment of this invention,
Figure 1 is a sectional view showing a canned refrigerant pump, Figure 2 is a diagram schematically showing a fluid heat exhaust system to which the canned refrigerant pump is applied, and Figure 3 is taken along line A-A in Figure 1. A plan sectional view, FIG. 4 is an exploded perspective view showing the configuration of the Oldham mechanism,
FIG. 5 is a sectional view showing a canned refrigerant pump according to a second embodiment of the present invention. 6... Sealed case, 9... Frame, 9a... Bearing part, 10... Motor, 20... Scroll pump (displacement pump mechanism part) 30a... Thrust receiving part, 37...・Back pressure chamber, 38... through hole, 43a...
Space, 43b... Space, 44... Case communication hole, 4
5... Passage, 47... Discharge pipe (discharge port), 48.4
9... First groove, second groove (lubricating refrigerant passage). Applicant's agent Patent attorney Takehiko Suzue No. 2 Figure No. 3 Ward

Claims (1)

[Claims] a sealed case, a motor having a stator provided on the outside of the sealed case and a rotor rotatably supported by a bearing inside in correspondence with the stator; a positive displacement pump mechanism driven by the rotation of the rotor; A lubricating refrigerant passage leads a part of the refrigerant of the positive displacement pump mechanism into the sealed case via the bearing surface of the motor, and a refrigerant passage discharged from the discharge part of the positive displacement pump mechanism connects the rotor to the refrigerant passage. A passage means for guiding the refrigerant into one space in the sealed case divided as a boundary, and a gap between the outer circumferential surface of the rotor and the inner surface of the sealed case opposing thereto. A canned refrigerant pump comprising: a passageway through which the refrigerant flows into the other space in the hermetically sealed case; and a discharge port provided in the hermetically sealed case through which the refrigerant flowing into the other space is discharged to the outside.