JP2006161777A - Refrigerant pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerant pump of a thin shape usable in a unit of a stringent height limitation. <P>SOLUTION: The refrigerant pump is provided with a closed container having an upper container 2 and a lower container 4 joined together, a pump mechanism section 6 received in the closed container and an electric motor having a stator 8 and a rotor 10 disposed adjacent to each other in the pump mechanism section 6. An annular concavity 4a is formed in an outside of the lower container 4 for fixing the stator 8 and the rotor 10 is opposed to the stator 8 and is disposed radially outward of the stator 8 in the lower container 4. The pump mechanism section 6 is received in a space 16 formed between a bearing end plate 12 rotating together with the rotor 10 and a cylinder shaft 14 supporting the bearing end plate 12 fixed to the upper container 2. The pump mechanism section 6 is driven in association with rotation of the rotor 10 and the bearing end plate 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a refrigerant pump provided in a cooling device that cools a highly heat-generating semiconductor element using a refrigerant.

  FIG. 4 is a cross-sectional view of a conventional refrigerant pump used in an air conditioner or the like. A pump mechanism 42 is accommodated in the sealed container 40, and an electric motor 44 that drives the pump mechanism 42 is It is arranged adjacent to the pump mechanism 42. Further, the electric motor 44 employs an inner rotor system constituted by a stator 46 fixed to the outside of the sealed container 40 and a rotor 48 rotatably attached to the inside of the sealed container 40 (for example, , See Patent Document 1).

  In this refrigerant pump, the outer diameter of the hermetic container can be reduced by arranging the stator 46 outside the hermetic container 40 as compared with a configuration in which the pump mechanism and the electric motor are housed in one hermetic container.

Japanese Patent Laid-Open No. 2-28387 (FIG. 1)

  However, a thin refrigerant pump is required for units with severe height restrictions, such as notebook computers and 1U servers, and the refrigerant pump described in Patent Document 1 described above still has room for improvement in terms of height. There has been a demand for a thinner refrigerant pump.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a thin refrigerant pump that can be used in a unit having a severe height restriction.

  In order to achieve the above object, the invention described in claim 1 among the present invention is a refrigerant pump comprising a pump mechanism part and an electric motor for driving the pump mechanism part. A sealed container having a lower container; a pump mechanism portion accommodated in the sealed container; and an electric motor disposed adjacent to the pump mechanism section and having a stator and a rotor, and an annular recess is formed outside the lower container. Forming and fixing the stator in the annular recess, and arranging the rotor in the lower container radially outward of the stator so as to face the stator, and integrally with the rotor The pump mechanism is housed in a space formed between a rotating bearing end plate and a shaft cylinder that is fixed to the upper container and supports the bearing end plate, so that the rotor and the bearing end plate can rotate. The pump mechanism is driven in conjunction Characterized in that the.

  According to a second aspect of the present invention, a ring-shaped groove is formed on a sliding contact surface of the shaft cylinder facing the bearing end plate, a sealing material is inserted into the ring-shaped groove, and the shaft cylinder is drilled. The refrigerant discharged from the pump mechanism through the formed refrigerant passage is discharged to the bearing end plate, and the bearing end plate is moved to the shaft cylinder by the differential pressure between the discharge pressure from the pump mechanism and the suction pressure. It is characterized by being pressed.

  Furthermore, in the invention according to claim 3, the shaft cylinder has a center axis, and the bearing end plate has a cylinder insertion boss protruding from the sliding contact surface with the shaft cylinder toward the shaft cylinder, The center axis of the shaft cylinder is loosely inserted into the cylinder insertion boss, and the height of the cylinder insertion boss from the sliding contact surface with the shaft cylinder is set lower than the height of the pump mechanism housing space, The thrust force of the bearing end plate is received by the sliding surface of the shaft cylinder.

  According to a fourth aspect of the present invention, a refrigerant passage is formed in the shaft cylinder and the bearing end plate, and the refrigerant compressed by the pump mechanism is placed in a sliding contact portion between the shaft cylinder and the bearing end plate. It has been introduced.

  The invention according to claim 5 is characterized in that the thickness of the lower container positioned between the stator and the rotor is set to be thinner than the thickness of other portions.

  The invention described in claim 6 is characterized in that a nonmagnetic material is used for the lower container.

  The invention according to claim 7 is characterized in that the side surface of the central axis of the shaft cylinder is nitrided.

Since the present invention is configured as described above, the following effects can be obtained.
ADVANTAGE OF THE INVENTION According to this invention, a thin refrigerant | coolant pump can be provided by employ | adopting the electric motor of the outer rotor system which has arrange | positioned the rotor to the radial direction outer side of the stator.

  Further, a seal material is inserted into a ring-shaped groove formed on the sliding contact surface of the shaft cylinder, and the refrigerant discharged from the pump mechanism portion through the refrigerant passage of the shaft cylinder is discharged to the bearing end plate side, and the pump mechanism portion Since the bearing end plate is pressed against the shaft cylinder by the differential pressure between the discharge pressure from the cylinder and the suction pressure, the leakage of refrigerant from the bearing end plate is reduced, and the bearing end plate serves as a fixed end plate. A fixed end plate is not required, and the pump mechanism can be made thin. Further, if a self-lubricating seal is employed as the sealing material, the reliability is further improved.

  Furthermore, the shaft axis of the shaft cylinder is loosely inserted into the cylinder insertion boss formed on the bearing end plate, and the height of the cylinder insertion boss from the sliding contact surface with the shaft cylinder is set lower than the height of the pump mechanism housing space. Since the thrust force of the bearing end plate is received by the sliding surface of the shaft cylinder, the refrigerant leakage can be reduced as much as possible.

  In addition, a refrigerant passage is formed in the shaft cylinder and the bearing end plate, and the refrigerant compressed by the pump mechanism is introduced into the sliding contact portion between the shaft cylinder and the bearing end plate, so that the sliding contact portion acts as a slide bearing. A highly reliable bearing configuration can be ensured.

  In addition, since the thickness of the lower container located between the stator and the rotor is set to be thinner than the thickness of other portions, the air gap is reduced, and an efficient electric motor can be provided.

  Moreover, since the non-magnetic material is used for the lower container, eddy current loss can be reduced and an efficient electric motor can be provided.

  Further, since the side surface of the central axis of the shaft cylinder is nitrided, it is possible to provide a highly reliable refrigerant pump with less wear.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a cross-sectional view of a refrigerant pump according to the present invention.
As shown in FIG. 1, the refrigerant pump according to the present invention includes a sealed container composed of an upper container 2 and a lower container 4 whose opening side ends are joined to each other, and a pump mechanism that is rotatably attached to the upper container 2. Part 6 and an electric motor attached to the lower container 4 adjacent to the pump mechanism part 6. The electric motor is opposed to the stator 8 disposed outside the lower container 4 and the stator 8. And the rotor 10 disposed inside the lower container 4. The upper container 2 is connected with a suction pipe 11 through which liquid refrigerant is sucked, while the lower container 4 is connected with a discharge pipe 13 through which liquid refrigerant compressed by the pump mechanism unit 6 is discharged. Yes.

  The material of the lower container 4 is a non-magnetic material such as stainless steel, and the thickness is set to about 1.5 mm. However, the thickness of the portion located between the stator 8 and the rotor 10 is the thickness of the other portion. It is thinner than the thickness, for example, set to 0.6 mm. The material of the upper container 2 is preferably the same as that of the lower container 4 when laser welding or the like is performed. For example, a non-magnetic material such as stainless steel is used, and the thickness is set to about 1.5 mm as with the lower container 4. ing.

  The lower container 4 has an annular recess 4a formed on the outside thereof, and a stator 8 is press-fitted and fixed to the annular recess 4a. On the other hand, the rotor 10 is disposed inside the lower container 4 radially outward of the stator 8 so as to face the stator 8. A bearing end plate 12 that rotates integrally with the rotor 10 is mounted inside the lower container 4, and a shaft cylinder 14 that rotatably supports the bearing end plate 12 is press-fitted and fixed inside the upper container 2. ing.

  As the bearing end plate 12 rotates, the bearing end plate 12 comes into sliding contact with the end surface of the shaft cylinder 14, but in a space (pump mechanism housing chamber) 16 formed between the bearing end plate 12 and the shaft cylinder 14. The pump mechanism 6 is disposed and driven in conjunction with the rotation of the bearing end plate 12.

  In addition, a ring-shaped groove 14 a is formed on the end surface of the shaft cylinder 14 that is in sliding contact with the bearing end plate 12, and a self-lubricating seal 18 is inserted into the ring-shaped groove 14 a, so that liquid refrigerant from the pump mechanism unit 6 It is configured to suppress leakage. Furthermore, since the pressure of the liquid refrigerant compressed and discharged by the pump mechanism 6 is acting on the space around the bearing end plate 12, the discharge pressure of the liquid refrigerant that presses the bearing end plate 12 against the shaft cylinder 14 side A differential pressure from the suction pressure is acting.

  FIG. 2 shows a cross-sectional view of the pump mechanism unit 8. As shown in FIG. 2, the inner rotor 20 and the outer rotor 22 constituting the pump mechanism unit 6 rotate in the pump mechanism unit accommodating chamber 16. A pump chamber 24 is formed between the inner rotor 20 and the outer rotor 22.

  The shaft cylinder 14 has a base portion 14b in which a pump mechanism portion accommodating chamber 16 is formed, and a central shaft 14c that protrudes from the center of the base portion 14b toward the bearing end plate 12 and rotatably supports the bearing end plate 12. The bearing end plate 12 is formed with a cylinder insertion boss 12a into which the central axis 14c of the shaft cylinder 14 is loosely inserted, and the inner rotor 20 is fitted and fixed to the cylinder insertion boss 12a. Therefore, while the central shaft 14c of the shaft cylinder 14, the cylinder insertion boss 12a of the bearing end plate 12 and the inner rotor 20 are arranged concentrically, the pump mechanism housing chamber 16 is formed eccentrically, The rotor 22 is disposed concentrically in the pump mechanism housing chamber 16. In addition, the surface facing the lower container 4 of the bearing end plate 12 has a complementary shape with the inner surface of the lower container 4, and the radially outer side is formed in a ring shape.

  Further, the side surface of the central shaft 14c of the shaft cylinder 14 is subjected to nitriding treatment, so that the wear of the central shaft 14c is reduced as much as possible.

  The inner rotor 20 and the outer rotor 22 housed in the pump mechanism housing chamber 16 and meshing with each other have complementary convex portions and concave portions, respectively, and the number of convex portions (tooth portions) of the inner rotor 20 is the number of the outer rotor 22. It is set to be smaller than the recess. Accordingly, when the bearing end plate 12 rotates together with the rotor 10 in the direction of the arrow A, the inner rotor 20 also rotates integrally, and the outer rotor 22 that meshes with the inner rotor 20 also rotates in the direction of the arrow A. The pump chamber 24 rotates in the direction of arrow A while changing its volume, and exhibits a pump action.

FIG. 3 is a view of the shaft cylinder 14 as seen from the pump mechanism unit 6.
As shown in FIG. 3, the shaft cylinder 14 has a crescent-shaped suction hole 14 d that communicates the upper space of the shaft cylinder 14 through which the refrigerant is sucked through the suction pipe 11 and the pump chamber 24. A crescent-shaped discharge groove 14e is formed on the opposite side of the suction hole 14d. The shaft cylinder 14 also has a first discharge hole 14f extending radially outward from the discharge groove 14e, and extending in a direction orthogonal to the first discharge hole 14f and opening in a radially outward space of the bearing end plate 12. A second discharge hole 14g is formed. Furthermore, a first communication groove 14h extending from the discharge groove 14e toward the center of the shaft cylinder 14 is formed, and the first communication groove 14h is formed in the longitudinal direction of the surface of the central axis 14c of the shaft cylinder 14. It communicates with the second communication groove 14i.

  On the other hand, the outer ring portion of the bearing end plate 12 has a plurality of communication holes 12b extending in the radial direction and communicating between the outer side and the inner side of the ring portion.

  In the refrigerant pump according to the present invention having the above-described configuration, when the pump mechanism 6 generates a pump action, the liquid refrigerant is sucked from the suction pipe 11 and introduced into the space between the upper container 2 and the shaft cylinder 14. The liquid refrigerant introduced into the space is sucked into the pump chamber 24 of the pump mechanism section 6 through the suction hole 14d penetrating the base portion 14b of the shaft cylinder 14. The liquid refrigerant sucked into the pump chamber 24 is compressed by the pump mechanism portion 6 and then passes through the discharge groove 14e formed in the base portion 14b of the shaft cylinder 14 and the first and second discharge holes 14f and 14g. It is discharged into the space between the end plate 12 and the lower container 4 and discharged from the discharge pipe 13.

  The liquid refrigerant discharged into the space between the bearing end plate 12 and the lower container 4 is introduced into the sliding contact portion between the ring portion of the bearing end plate 12 and the lower container 4 through the communication hole 12b. The liquid refrigerant discharged into the discharge groove 14e is introduced into the sliding contact portion between the center shaft 14c of the shaft cylinder 14 and the cylinder insertion boss 12a of the bearing end plate 12 through the first and second communication grooves 14h and 14i. Therefore, the sliding contact portion acts as a slide bearing.

  Further, in the above configuration, the height h at which the cylinder insertion boss 12a of the bearing end plate 12 protrudes from the sliding contact surface with the shaft cylinder 14 toward the shaft cylinder 14 is set lower than the height H of the pump mechanism housing chamber 16. In addition, since the thrust force due to the differential pressure is received by the sliding contact surface between the bearing end plate 12 and the shaft cylinder 14, refrigerant leakage can be reduced as much as possible.

  As described above, the refrigerant pump according to the present invention employs an outer rotor type electric motor in which the stator 8 is attached to the annular recess 4a of the lower container 4 and the rotor 10 facing the stator 8 is provided on the radially outer side. Therefore, the present invention can be applied to cooling refrigerant pumps such as notebook PCs, 1U servers, blade servers, and the like that have severe height restrictions.

It is a longitudinal cross-sectional view of the refrigerant pump concerning this invention. It is sectional drawing along line II-II of FIG. It is the figure which looked at the shaft cylinder provided in the refrigerant | coolant pump of FIG. 1 from the pump mechanism part. It is a longitudinal cross-sectional view of the conventional refrigerant pump.

Explanation of symbols

2 Upper container, 4 Lower container, 4a Annular recess, 6 Pump mechanism, 8 Stator,
10 rotor, 11 suction pipe, 12 bearing end plate, 12a cylinder insertion boss,
12b communication hole, 13 discharge pipe, 14 shaft cylinder,
14a ring groove, 14b base, 14c central axis, 14d suction hole,
14e discharge groove, 14f first discharge hole, 14g second discharge hole,
14h 1st communicating groove, 14i 2nd communicating groove, 16 pump mechanism part accommodation chamber,
18 self-lubricating seal, 20 inner rotor, 22 outer rotor,
24 Pump room.

Claims (7)

A refrigerant pump comprising a pump mechanism and an electric motor that drives the pump mechanism,
A sealed container having an upper container and a lower container joined to each other; a pump mechanism portion accommodated in the sealed container; and an electric motor disposed adjacent to the pump mechanism portion and having a stator and a rotor; An annular recess is formed on the outer side of the stator, the stator is fixed to the annular recess, the rotor is opposed to the stator and disposed in the lower container radially outward of the stator, and The pump mechanism is housed in a space formed between a bearing end plate that rotates integrally with the rotor and a shaft cylinder that is fixed to the upper container and supports the bearing end plate, and the rotor and the A refrigerant pump, wherein the pump mechanism is driven in conjunction with rotation of a bearing end plate. A ring-shaped groove is formed on the sliding surface of the shaft cylinder facing the bearing end plate, a sealing material is inserted into the ring-shaped groove, and the pump mechanism section is inserted through a refrigerant passage formed in the shaft cylinder. The refrigerant discharged from the bearing is discharged toward the bearing end plate, and the bearing end plate is pressed against the shaft cylinder by a differential pressure between a discharge pressure from the pump mechanism and a suction pressure. The refrigerant pump according to 1. The shaft cylinder has a central axis, and the bearing end plate has a cylinder insertion boss that protrudes from the sliding contact surface with the shaft cylinder toward the shaft cylinder, and the cylinder insertion boss has a central axis of the shaft cylinder. And the height of the cylinder insertion boss from the sliding contact surface with the shaft cylinder is set to be lower than the height of the space for accommodating the pump mechanism, and the thrust force of the bearing end plate is set to the shaft cylinder. The refrigerant pump according to claim 1 or 2, wherein the refrigerant pump is received by a sliding contact surface. A refrigerant passage is formed in the shaft cylinder and the bearing end plate, and refrigerant compressed by the pump mechanism is introduced into a sliding contact portion between the shaft cylinder and the bearing end plate. 4. The refrigerant pump according to any one of 3 above. The refrigerant according to any one of claims 1 to 4, wherein a thickness of the lower container positioned between the stator and the rotor is set to be thinner than a thickness of other portions. pump. The refrigerant pump according to claim 1, wherein a nonmagnetic material is used for the lower container. The refrigerant pump according to any one of claims 1 to 6, wherein a side surface of a central axis of the shaft cylinder is nitrided.

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