JPH10266972A - Closed type gear pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make leakless and stable rotation as well as high reliability so as to be securable. SOLUTION: This gear pump is provided with a hermetically sealed vessel 7 where working gas is sealed in with the desired pressure, a driving motor 11 supported in this hermetically sealed vessel 7, a casing 41 housed with a driving gear 43 being rotated by two driving shafts 59 and 60 given torque by a motor shaft 17 of this driving motor 11 and two given shafts 55 and 56 rotatably supported with a driven gear 45 in mesh with this gear 43, and an intake 37 and an exhaust port of a conveying operation medium installed in this casing 41, respectively. In this constitution, working gas pressure in the hermetically sealed vessel 7 is made to act on both ends of these driving shafts 59 and 60, preventing any thrust load due to differential pressure from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hermetic gear pump suitable for, for example, an air conditioner.

[0002]

2. Description of the Related Art Conventionally, there has been known an air conditioner including a refrigeration cycle and a Rankine cycle for applying rotational power to a compressor constituting the refrigeration cycle. In the Rankine cycle, a refrigerant is forcibly circulated. A gear pump is used.

[0003] The outline of the gear pump is, for example, as shown in FIG.
A drive gear 105 rotatably supported by the drive gear 104 and provided with rotational power via one drive shaft 103 extended to the outside, and a driven gear 107 meshing with the drive gear 105. The rotation of the driven gear 107 causes the refrigerant taken in from the suction port 109 to be discharged from the discharge port 11.
No. 1 is discharged (from the drawing table to the back).

[0004]

One drive shaft 103 of the gear-type gear pump serves as an input shaft to which rotational power is input, and is interlocked with a motor shaft of a drive motor (not shown) outside the casing 101. It has a matching structure.

[0005] For this reason, in a system constituting a closed cycle such as an air conditioner, leakage of a seal from a shaft seal of a gear pump becomes a serious problem.

[0006] In particular, the shaft sealing is a very important issue because the pressure of the gear pump increases depending on the operating conditions.

The atmospheric pressure P ₀ acts on the drive shaft 103 extended to the outside, while the drive shaft 104 on the opposite side of the drive gear 105 sandwiches the suction port 10 having a pressure higher than the atmospheric pressure P _0.
9 acts on the suction pressure P ₁ , and by their pressure difference,
A thrust force F acts on the drive shaft 103 extended outward.

In this case, the suction pressures P ₁ , P ₁ also act on the left and right driven shafts 115, 116 of the driven gear 107, but both the driven shafts 115, 116 are in the casing 101 and are substantially the same. , The thrust force is canceled and no pressure difference occurs. However, as described above, the thrust force F acts on the drive shaft 103 whose one is extended outward, due to the pressure difference.
The left and right side plates 117, 118
Of these, it is strongly pressed against the left side plate 117 side (there may be no side plate). (Arrow f)
As a result, the drive gear 105 rotates in a state of strong contact, so that stable rotation cannot be obtained, and furthermore, there is a problem that wear, which causes adverse effects such as seal leakage, is accelerated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a hermetic gear pump in which the shaft is reliably sealed and the side surface of the drive gear is prevented from being worn due to a pressure difference.

[0010]

In order to achieve the above object, the present invention firstly provides a sealed container in which a working gas is sealed at a desired pressure, and a drive motor supported in the sealed container. A casing that houses a driving gear that is rotated by a driving shaft to which a rotational force is applied by a motor shaft of the driving motor, and a driven shaft that rotatably supports a driven gear that rotates by meshing with the gear; and a casing provided in the casing. An inlet and an outlet for the transporting working medium are provided, and a working gas pressure in the closed container is applied to at least both end faces of the drive shaft.

Second, a sealed container in which the working gas is filled at a desired pressure, a drive motor arranged in the sealed container and including a stator and a rotor, and a rotational force applied by a motor shaft of the drive motor. A casing that houses a driving gear that is rotated by a driving shaft and a driven shaft that rotatably supports a driven gear that meshes with the gear and that is rotatably supported, and a stator of the driving motor is integrally mounted and supported. A fixed bearing-supported first bearing member, and an inlet and an outlet for a transfer working medium provided in the casing, wherein at least both end surfaces of the drive shaft act on the working gas pressure in the closed container. Let it.

Third, a second bearing member is integrally mounted and supported on the opposite side of the stator mounted and supported on the first bearing member, and the motor shaft is connected to the first bearing member and the second bearing. Both ends are supported rotatably with the member.

According to the hermetically sealed gear pump, rotational power is given to the drive shaft by the motor shaft of the drive motor, and by the rotation of the drive gear and the driven gear, the working medium taken in from the inlet is discharged from the outlet. Will be discharged.

In this operation, since the gear pump is disposed in the closed container, the closed container itself functions as a sealed container, and a reliable sealed state can be obtained without strictly controlling the shaft seal.

Further, since the same pressure acts on both ends of the drive shaft in the closed container, no thrust force is generated by the differential pressure, and the drive gear is not pressed against one side, and a stable rotation state is achieved. Secured for a long time.

In this case, by mounting the drive gear movably in the axial direction with respect to the drive shaft or the power transmission shaft, it is possible to prevent the pressure from being applied to one of the drive gears due to the differential pressure. Becomes

Further, in the closed container, the motor shaft and the drive shaft may be separately formed and integrally linked to each other, or may be a single continuous power transmission shaft.

In an embodiment in which the motor shaft and the drive shaft are separated from each other, it is preferable that the first bearing member or the second bearing member is provided with a thrust receiving portion which receives a thrust force due to its own weight.

In the case of the embodiment in which one continuous power transmission shaft is used, the casing, the first bearing member, and the second bearing member are supported at three points so that a stable supporting state can be secured. It is preferable that a thrust receiving portion that receives a thrust force due to its own weight be provided on the second bearing member.

Further, the casing or the second bearing member may be directly fixed and supported on the inner wall surface of the sealed container.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1, reference numeral 1 denotes a hermetic gear pump, which is used in a Rankine cycle 5 of an air conditioner circuit having a refrigeration cycle 3 and a Rankine cycle 5, as shown in FIG.

The hermetically sealed container 7 of the hermetically sealed gear pump 1 has a structure in which working gas is sealed at a predetermined pressure, and a gear pump 9 is arranged on the upper side of the sealed vessel 7 and a drive motor 11 is arranged on the lower side. It has become. The drive motor 11 includes a stator 13 and a rotor 15. The rotor 15 is mounted on a vertically arranged motor shaft 17. When a current flows through the stator 13, the motor shaft 17 rotates via the rotor 15. It has become.

The upper shaft end of the motor shaft 17 is connected to the first bearing member 21 via the bush 19, and the lower shaft end is connected to the bearing 27 of the second bearing member 25 via the bush 23. Both ends are rotatably supported.

First bearing member 21 and second bearing member 25
Are mounted vertically with the stator 13 interposed therebetween.
5 fixed. Upper first bearing member 21
Supports a lateral vibration via a guide 29 fixed to the closed container 7, and a coil spring 3
The pump 2 is fixedly supported on the inner wall surface of the closed container 7 so as to be able to absorb vibration of the pump.

The second bearing member 25 is integrally fixed and supported by a mounting bolt 33 on the stator 13 bolted to the first bearing member 21. The bearing portion 27 of the second bearing member 25 has a thrust receiving portion 3 for receiving a downward thrust force F due to the weight of the motor shaft 17.
5 are provided.

As shown in FIG. 2, the gear pump 9 has a drive gear 43 and a driven gear 45 meshing with the drive gear 43 incorporated in a casing 41 having an inlet 37 and an outlet 39. The casing 41 includes the side walls 4.
7, 48, one of the side walls 48 is integrally fixed and supported by the first bearing member 21, and the intake port 37 has an intake pipe 49 extended outside the closed container 7 and a discharge port 39. Are respectively connected to a discharge pipe 51 extended to the outside of the closed container 7.

On both sides of the driving gear 43 and the driven gear 45, side plates 52 for securing seals on both sides,
53 are provided respectively.

Left and right driven shafts 55 and 56 of the driven gear 45
Are rotatably supported by the casing 41 via bearing members 57 such as bushes, and one driven shaft 56 is supported via a bush 57 provided on the casing 48.

The left and right drive shafts 59, 60 of the drive gear 43
Are rotatably supported at both ends via bearing members 61, 61 such as bushes, and one drive shaft 60 is integrally and integrally connected to a motor shaft 17 of the drive motor 11 via a key 63.

In FIG. 3, the refrigeration cycle 3
The compressor 65, the condenser 67 through which the refrigerant discharged from the compressor 65 flows, the expansion valve 69, and the evaporator 7 serving as an indoor heat exchanger
And 1.

The Rankine cycle 5 includes an expander 73 for supplying rotational power to a compressor 65, a recovery heat exchanger 75, and a condenser 7.
7, a receiver 79, a sealed gear pump 1, and a heater 83 in which the refrigerant is heated by a heating means 81 such as a burner. The intake pipe 49 of the gear pump 9 has the receiver 79, and the discharge pipe 51 has the recovered heat. Each is in communication with the exchanger 75.

Therefore, in the cooling mode, the circulation of the refrigerant in the refrigeration cycle 3 and the Rankine cycle 5 is repeated as indicated by the solid line.

On the other hand, in the heating mode, the refrigerant discharged from the discharge pipe 51 of the hermetic gear pump 1 is heated by the heater 83 and then evaporated by the four-way valve 85 to become the indoor heat exchanger, as indicated by the dotted line. The circulation returning from the expansion valve 69 and the receiver 79 to the hermetic gear pump 1 through the vessel 71 is repeated.

The hermetic gear pump 1 constructed as described above
According to the above, the rotation power is given to the drive shafts 59 and 60 by the motor shaft 17 of the drive motor 11,
The drive gear 43 and the driven gear 45 rotate, and the working medium serving as the refrigerant taken in from the inlet 37 is discharged from the outlet 39.

At the time of this operation, the inside of the gear pump 9
Since it is arranged in the closed container 7, the closed container 7 itself functions as a sealed container, and a reliable sealed state can be obtained without strictly controlling the shaft seal.

The same pressure acts on both shaft ends of the drive shafts 59 and 60 via the motor shaft 17 and the same pressure acts on both shaft ends of the driven shafts 55 and 56, respectively. Therefore, no thrust force is generated due to the differential pressure, and the driving gear 43 and the driven gear 45 are not strongly pressed to only one of them by the thrust force. As a result, the side surfaces of the side plates 52 and 53 are not worn, and a stable rotation state is ensured for a long period.

The downward thrust force F caused by the weight of the drive shafts 59 and 60 and the motor shaft 17 is received by the thrust receiving portion 35 and does not adversely affect the rotation of the drive shafts 55 and 60 and the motor shaft 17. And smooth rotation is obtained.

FIGS. 4 and 5 show an embodiment in which the drive shafts 59 and 60 and the motor shaft 17 are continuously formed as one.

That is, the motor shaft 1 of the drive motor 11
7 and the drive shafts 59 and 60 of the gear pump 9 are formed as a single continuous power transmission shaft 87. Power transmission shaft 8
7 penetrates through the drive motor 11 and the casing 41,
The upper end side shaft end of the power transmission shaft 87 penetrated is
9, the intermediate portion is rotatably connected to the first bearing member 21 via the bush 91, and the lower end side shaft end is rotatably connected to the bearing portion 27 of the second bearing member 25 via the bush 23. Supported.

The first bearing member 21 has a structure also serving as one side wall (the side wall 48 in FIG. 1) of the casing 41, and one driven shaft 56 is connected to the first bearing member 21 via a bush 57. It is supported rotatably.

Power transmission shaft 8 penetrating through casing 41
In the area 7, as shown in FIG.
The drive gear 43 rotates integrally with the power transmission shaft 87 and is movable in the axial direction. Further, the rotor 15 is integrally mounted in a region of the power transmission shaft 87 penetrating the drive motor 11.

The bearing 27 supporting the lower end of the power transmission shaft 87 is provided with a thrust receiving portion 95 for receiving a thrust force F caused by the weight of the power transmission shaft 87.

The other components are the same as those shown in FIG.

Therefore, according to the hermetically sealed gear pump 1, in addition to the effects of the above-described embodiment, the number of parts can be reduced, and the motor shaft 17 of the drive motor 11 and the drive shaft of the gear pump 9 can be assembled during assembly. Since the alignment work of 59 and 601 becomes unnecessary, the work becomes easy and it is very preferable in terms of assemblability.

In this case, as shown in FIGS. 6 and 8, in the embodiment in which the drive motor 11 is disposed on the upper side of the closed vessel 7 and the gear pump 9 is disposed on the lower side, the inner wall surface of the closed vessel 7 is disposed. It is preferable to assemble the drive motor 11 and the gear pump 9 as a reference.

That is, in the embodiment of FIG. 6, when the stator 13 and the first and second bearing members 21 and 25 are mounted on the basis of the inner wall surface of the closed casing 7, a continuous power transmission shaft 87 is provided. It is possible to easily and accurately assemble by fixing and supporting while adjusting the center.

In the case of this embodiment, the second bearing member 2
5 is formed of a separate member, the power transmission shaft 87
Can be accurately and reasonably achieved.

In the embodiment of FIG. 8, the side walls 48 of the stator 13 and the casing 41 are connected to the closed container 7.
When the mounting is performed with reference to the inner wall surface of the container, the upper end of the continuous power transmission shaft 87 is inserted into a bearing portion 99 provided directly on the inner wall surface of the sealed container 7 to fix and support the shaft. By doing so, it is possible to assemble easily and accurately.

[0050]

As described above, according to the hermetic gear pump of the present invention, the gear pump disposed in the hermetic container, which is a hermetic container, is capable of leaking without strict shaft seal management. And high performance with high volume efficiency can be achieved.

Also, due to the working gas pressure sealed in the sealed container, no thrust force is generated on the drive shaft due to the differential pressure, and stable rotation can be ensured for a long period of time, improving reliability. Can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a hermetic gear pump according to the present invention.

FIG. 2 is an explanatory view cut along the line AA of FIG. 1;

FIG. 3 is a circuit diagram of an air conditioner including a refrigeration cycle and a Rankine cycle.

FIG. 4 is a schematic cross-sectional view similar to FIG. 1 in which a motor shaft of a drive motor and a drive shaft of a gear pump are one power transmission shaft.

FIG. 5 is an exploded perspective view of one continuous power transmission shaft and a drive gear.

FIG. 6 is a schematic cross-sectional view similar to FIG. 1 in which a drive motor is disposed above and a gear pump is disposed below in a sealed case.

7 is an enlarged explanatory view of a main part of the second bearing member of FIG. 6 in which a bearing portion of the second bearing member is a separate member;

FIG. 8 is a schematic cross-sectional view similar to FIG. 1 in which a drive motor is disposed above and a gear pump is disposed below in a sealed case.

FIG. 9 is an explanatory view showing a conventional gear pump.

[Explanation of symbols]

 7 Closed container 11 Drive motor 17 Motor shaft 37 Inlet 39 Outlet 41 Casing 43 Drive gear 45 Follower gear 55, 56 Follower shaft 59, 60 Drive shaft

Claims (16)

[Claims] 1. A closed container in which a working gas is sealed at a desired pressure, a drive motor supported in the closed container, and a drive gear rotated by a drive shaft to which a torque is applied by a motor shaft of the drive motor. And a casing accommodating a driven shaft rotatably supporting a driven gear that rotates while meshing with the gear, and an inlet and an outlet for a transfer working medium provided in the casing, and at least both ends of the drive shaft. A hermetic gear pump characterized in that a working gas pressure in the hermetic container is applied to the surface. 2. A sealed container in which a working gas is sealed at a desired pressure, a drive motor disposed in the sealed container, the drive motor including a stator and a rotor, and a drive provided with a rotational force by a motor shaft of the drive motor. A casing that houses a driven gear that rotates by a shaft and a driven shaft that rotatably supports a driven gear that rotates in mesh with the gear;
A stator of the drive motor is integrally mounted and supported, a first bearing member fixed and supported on an inner wall surface of the closed case, and an inlet and an outlet for a transfer working medium provided in the casing, at least A hermetic gear pump wherein the working gas pressure in the hermetic container is applied to both end faces of the drive shaft. 3. The hermetic gear pump according to claim 1, wherein the motor shaft and the drive shaft of the drive motor are independently formed, and the motor shaft and the drive shaft are integrally and interlocked. 4. A second bearing member is integrally mounted and supported on the opposite side of the stator mounted and supported by the first bearing member, and the motor shaft is fixed by the first bearing member and the second bearing member. 3. The hermetic gear pump according to claim 2, wherein both ends are rotatably supported. 5. The hermetic gear pump according to claim 3, wherein the first bearing member and the second bearing member are bolted to the stator by fixing bolts. 6. A hermetic seal according to claim 2, wherein a thrust receiving portion for receiving a thrust force generated on a motor shaft via a drive shaft by its own weight is provided on the first bearing member side. Type gear pump. 7. A thrust receiving portion for receiving a thrust force generated on a motor shaft via a drive shaft by its own weight is provided on the second bearing member.
6. The hermetic gear pump according to 5. 8. A sealed container filled with a working gas at a desired pressure, a drive motor supported in the sealed container, and one continuous power transmission shaft for transmitting rotational power of the drive motor to a drive gear. A casing accommodating the drive gear to which a rotational force is directly applied by the power transmission shaft, and a driven shaft rotatably supporting a driven gear that meshes with the drive gear and rotates, and a transfer working medium provided in the casing Wherein the working gas pressure in the closed vessel is applied to at least both end faces of the drive shaft. 9. The hermetic gear pump according to claim 8, wherein the drive gear is mounted on the power transmission shaft so as to be rotatable together and movably along the axial direction. 10. A power transmission shaft, wherein one end of the power transmission shaft is supported by a casing, a substantially middle portion is supported by a first bearing member, and the other end is supported by a second bearing member. A closed gear pump according to claim 8. 11. The hermetic gear pump according to claim 10, wherein a thrust force generated by its own weight on the power transmission shaft is received by a thrust receiving portion provided on the second bearing member. 12. The hermetic gear pump according to claim 10, wherein the first bearing member is directly fixed and supported on an inner wall surface of the sealed case. 13. The hermetic gear pump according to claim 10, wherein a thrust receiving portion for receiving a thrust force generated on the power transmission shaft is provided on the casing side. 14. The hermetic gear pump according to claim 10, wherein the second bearing member is directly fixed and supported on an inner wall surface of the hermetic container. 15. The hermetic gear pump according to claim 14, wherein a bearing portion for directly supporting the power transmission shaft is provided on the second bearing member. 16. The hermetic gear pump according to claim 10, wherein the casing side is directly fixed and supported in the closed vessel.