JPH07247964A - Solution pump for suction type heat pump - Google Patents

Abstract

PURPOSE:To secure the sealability against a highly corrosive liquid, and miniaturize a pump with high efficiency by arranging trochoid displacement pump of stages of even number in series. CONSTITUTION:The boosting capacity per stage is reduced to half by arranging a pump part A17 and a pump part of a trochoid displacement pump in series and the direction of eccentricity of an inner gear A11 and an inner gear B23 which are of trochoid type is reversed between the first stage and in the second stage. A constitution to adjust the side clearance of the inner gear A11 and the inner gear B23 corresponding to the pressure difference of the pump in a successively reversing manner is provided to meet the respective pressure difference of the pump on the first stage and the second stage of the inner gear A11 and the inner gear B23 which are of the trochoid type to balance the direction of forces applying to a main shaft 7 of the pump.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump system of a solution pump used to convey a working solution of an absorption heat pump.

[0002]

2. Description of the Related Art As a conventional absorption pump, particularly a solution pump used in a heat pump using an aqueous ammonia solution as a working medium, a hydraulic pump driven diaphragm pump has been generally used. The structure of this type of pump is a piston type hydraulic pump that can ensure high pump efficiency by using high-viscosity hydraulic oil, and a diaphragm type low viscosity fluid pump that is entirely driven by the hydraulic pressure generated by this hydraulic pump. Consists of. This is a method in which the medium such as ammonia and the pump mechanism are separated from each other by the diaphragm because the refrigerant such as ammonia has low viscosity and is highly corrosive, and the pump efficiency and the pump reliability are secured.

There is also a rotary positive displacement pump having a one-stage boosting structure which is driven by a can seal type motor which does not cause the leakage of fluid to the outside without adopting the indirect pump driving method.

[0004]

However, in the above-mentioned conventional structure, when a hydraulic pump drive type diaphragm pump is used, two types of pumps are required, which is a drawback in terms of downsizing of equipment and cost. . In addition, the absorption type system that uses this type of pump is mainly for commercial use, and is premised on regular maintenance.
It was a pump that required a diaphragm and hydraulic oil that required regular maintenance.

Instead of this conventional diaphragm pump,
The following drawbacks have been encountered when using a rotary type positive displacement pump having a single-stage boosting structure as a direct drive type pump. Absorption heat pumps, especially solution pumps that use aqueous ammonia as the medium, require a pump differential pressure of 20 kg / cm ²
It is extremely high pressure for a solution pump that uses a low-viscosity fluid as a working fluid, and it is extremely difficult to secure volumetric efficiency in order to improve pump efficiency and to secure lubricity of bearings, which is important in terms of reliability such as pump life. Met.

The present invention solves the above-mentioned drawbacks, and an object thereof is to provide a highly efficient and compact solution pump for an absorption heat pump.

[0007]

In order to achieve the above object, the first means is to drive an even number of pressure unbalanced rotary positive displacement pump units by the same main shaft, and to provide an even number of pressure unbalanced. Type rotary positive displacement pump units are connected in series, and the direction of the force acting on the main shaft caused by the pump differential pressure of the even-numbered pressure balanced rotary positive displacement pump units is sequentially reversed. It was done.

The second means is an outer gear A which is eccentric to the inner gear A by an eccentric ring A, a pump portion A which is formed between a side plate A and an intermediate spacer, and an outer gear which is eccentric to the inner gear B by an eccentric ring B. B and
It has a pump portion B formed between the side plate B and the intermediate spacer, drives the inner gear A and the inner gear B coaxially, and sets the pump portion A at the first stage and the pump portion B at the second stage. And the eccentric direction of the outer gear A is reversed by approximately 180 degrees from the eccentric direction of the outer gear B.

The third means is to drive an even number of pressure non-equilibrium rotary positive displacement pump units by the same main shaft,
The even-numbered pressure non-equilibrium rotary positive displacement pump units are connected in series, and the direction of the force acting on the main shaft caused by the pump differential pressure of the even pressure non-equilibrium rotary positive displacement pump units is changed. It is assumed that the even numbers of the pressure non-equilibrium rotary positive displacement pump units have the same basic dimensions and the same pumping capacity.

The fourth means is a pump section A and a pump section B.
Of the eccentric ring A and the inner gear A and the outer gear A, which form the pump portion A, have the same basic dimensions, and the clearance ScA
And the clearance ScB caused by the dimensional difference of the eccentric ring B and the inner gear B and the outer gear B forming the pump portion B in the main axis direction are set to be substantially the same, and the discharge port and the side plate provided on the side plate B are set. A flow path A communicating with the side surface A side of A is provided, and the rigidity in the main axis direction is reduced in the order of the side plate A, the intermediate spacer, and the side plate B.

[0011]

According to the present invention, since the trochoid type positive displacement pumps are arranged in series in an even number of stages, the pressure required for each stage of the pumps is reduced and volumetric efficiency is ensured. Since the eccentric direction of the gear is sequentially reversed for the first step, the second step, and each step, the direction of the pump pressure acting on the trochoid gear is also reversed, and the load on the bearing of the pump is significantly reduced. In addition, the volumetric efficiency of the first-stage pump and the second-stage pump is increased step by step, and the side clearance of the trochoid gear is adjusted according to the differential pressure of the pump so that the performance is almost the same. The side clearance, which has a large effect on the volumetric efficiency of the pump, is set to the optimum value because it is provided corresponding to the pressure difference between the first step, the second step, and each step. Is possible. Also,
Since the basic dimensions and capacities of the first and second stages of the trochoid type positive displacement pump and each stage are set to be almost the same, the pump efficiency for the same pump load is maximized, and for the bearing The load is almost negligible.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 9, reference numeral 1 denotes a DC brushless motor, which is hermetically separated from the rotor 4 by a liner 3 inserted inside the stator 2. The positive displacement pump unit 5 is integrally formed in front of the body 6. The positive displacement pump unit 5 is a trochoid type pump driven by a main shaft 7 press-fitted into the rotor 4, and has a structure for boosting pressure in two stages.
The main members of the positive displacement pump unit 5 are press-fitted into a cavity 6a provided in front of the body 6 to form the positive displacement pump unit 5 with a laminated structure. The side plate A8 is located at the bottom of the main members of the stacked pumps, has a bearing 8a in the center, and also functions as a bearing for the main shaft 7 of the DC brushless motor 1. Stacked on the side plate A8 is an eccentric ring A9. The eccentric ring A9 rotatably holds the trochoidal outer gear A10 while maintaining an appropriate eccentricity with the inner gear A11. Also, the eccentric ring A
Reference numeral 9 has a function of maintaining the clearances in the thickness direction of the outer gear A10 and the inner gear A11 at appropriate values. The main shaft 7 and the inner gear A11 are fixed by a D cut 7a. On the side plate A8 side of the intermediate spacer 12, there is a notch 14 that communicates with the suction port 13 of the pump, and also communicates with the suction groove 15 provided in the intermediate spacer 12.
Further, the discharge groove 16 has a discharge hole 16a. The pump unit A17 that constitutes the first-stage pump is configured in this manner.

An eccentric ring B18 is further stacked on the intermediate spacer 12, and the eccentric direction of the eccentric ring B18 is set to be 180 degrees reversed from the eccentric ring A9. A suction groove 19 and a discharge groove 20 similar to those on the eccentric ring A9 side of the intermediate spacer 12 are provided on the surface of the intermediate spacer 12 on the eccentric ring B18 side, but the angles are set at positions shifted by 180 degrees. The discharge hole 16a of the discharge groove 16 provided on the eccentric ring A9 side of the intermediate spacer 12 communicates with the suction groove 19 provided on the surface of the eccentric ring B18 side. The eccentric ring B18 is a trochoidal outer gear B22.
Is rotatably held while maintaining an appropriate eccentric amount with the inner gear B23, and the eccentric ring B18 has a function of holding the clearance in the thickness direction of the outer gear B22 and the inner gear B23 at an appropriate value. The main shaft 7 and the inner gear B23 are fixed by a D cut 7a. Further, side plates B24 are stacked on the eccentric ring B18. The side plate B24 has a discharge groove 20 of the intermediate spacer 12.
The discharge port 24a is provided at a position corresponding to.
The pump part B25 that constitutes the second-stage pump is configured in this manner, and the main members of the first-stage and second-stage pumps are laminated in this manner to form the pump main part.

The basic dimensions of the pump portion A17 and the pump portion B25 are the inner gear A11 and the inner gear B23.
And the outer diameter, and the pump portion A17 and the pump portion B25 have the same dimensional values. A cavity 6 a provided in front of the body 6 is closed by a pump lid 26. A flow passage A27 is provided in the body 6, and the solution discharged from the discharge port 24a of the side plate B24 passes through the flow passage A27 and a gap between the liner 3 and the rotor 4 inserted inside the stator 2. And a bearing sleeve 2 for fixing a bearing 28 that rotatably supports the rotor 4.
After passing through the flow path B30 provided in 9, it reaches the discharge port 31 and flows out to the system system. The DC brushless motor 1 is driven by directly rectifying a single-phase AC100V, which is a commercial power source, with a rectifier 3
2 is rectified and the transistors 33 to 38 perform switching operation.

The operation of the above configuration will be described. When the rotor 4 of the DC brushless motor 1 rotates, the main shaft 7 press-fitted into the rotor 4 rotates. When the main shaft 7 rotates, the inner gear A11 and the inner gear B fixed to the main shaft 7
23 rotate together, and the outer gear A10 and the outer gear B22, which mesh with these gears, rotate as driven gears and perform pumping operation as a trochoid pump.
The pump operation is performed in two stages in series, and the first gear is pumped by the inner gear A11 and the outer gear A10.
The boosting action is divided by the second stage in which the pump action is performed by the inner gear B23 and the outer gear B22. It is difficult to secure volumetric efficiency with a low-viscosity fluid, high differential pressure positive displacement pump, especially a rotary type pump such as a trochoid pump, but the required pump differential pressure is 20 kg / cm ² By controlling the amount of pressure increase to about 10 kg / cm ² , the volumetric efficiency is 5 even if the fluid viscosity is about 0.5 cp.
About 0% can be secured. Also, the inner gear A
The eccentric direction of the trochoid gear is reversed between the first step in which the pump action is performed by 11 and the outer gear A10 and the second step in which the pump action is performed by the inner gear B23 and the outer gear B22. The inner gear A11 and the inner gear B23 are subjected to a force approximately equal to the product of the boosting amount for each stage of the pump on the projected area of the main shaft 7 in the radial direction. The pump acting on the inner gear A11 and the inner gear B23 is Since the direction of pressure is reversed, most of the load on the bearing 8a and the bearing 28 of the pump is canceled out.

The basic pump element that governs the volumetric efficiency is the tip clearance Tc between the tooth tip of the inner gear and the outer gear with the clearance Sc in the side direction of the trochoid gear. Of these, Sc is usually 1
Although it is set to about 0 μm to 50 μm, there is a limit in processing accuracy, and it has been difficult to keep Sc at an appropriate value. Therefore, in this embodiment, a member that causes deflection due to the differential pressure of the pump is set so that the optimum Sc is obtained according to the differential pressure of the pump, and the side plate A8, the intermediate spacer 12, and the side plate B24 are the members. Is. The pressure difference acting on each member is that the discharge pressure of the pump is 20 kg / cm ² , the suction pressure is 0 kg / cm ² , and the pressure rise amount per stage is 10 k.
g / cm ² , the maximum pressure difference in the side plate A8 is 20 kg / cm ² between the discharge pressure and the suction pressure, 20 kg / cm ² in the intermediate spacer 12, and 10 kg / cm ² in the side plate B24. It becomes cm ² . The side plate A8 and the intermediate spacer 12 are deflected by the pressure difference in the direction in which the Sc of the first stage inner gear A11 and the outer gear A10 is narrowed, and the side plate B24 is the second stage inner gear B23.
And the Sc of the outer gear B22 becomes narrower. Considering these things, the rigidity of axial displacement of each member is
The side plate B24, the intermediate spacer 12, and the side plate A8 are set higher in this order.

With the above structure, first, the volumetric efficiency of the pump under the condition of low viscosity fluid and high differential pressure is such that the boosting amount of each pump is halved because the pump boosting is performed in two stages in series. It becomes easy to secure volume efficiency. In addition, the load on the bearing becomes extremely large in a pump that uses a low viscous fluid and a high differential pressure.In addition, in a product with an endurance time of tens of thousands of hours such as an absorption heat pump, the lubrication condition of the bearing is substantially It is desirable to ensure a fluid lubrication condition that causes little wear. In this embodiment, the eccentric direction of the trochoid gear is reversed by the first stage where the inner gear A11 and the outer gear A10 perform pumping action and the second stage where the inner gear B23 and outer gear B22 perform pumping action. Cage, this inner gear A
Since the directions of the pump pressures acting on 11 and the inner gear B23 are reversed, most of the load on the bearing 8a and the bearing 28 of the pump is canceled out, and the lubrication condition of the bearing ensures a fluid lubrication state in which virtually no wear occurs. can do.

Regarding Sc, which is a factor that governs the volumetric efficiency of the pump, a member that causes deflection due to the differential pressure of the pump is set, and S increases as the differential pressure of the pump increases.
Optimum Sc according to the differential pressure of the pump is obtained for each pump unit so that c can be reduced and the volumetric efficiency can be secured. The volumetric efficiency of the pump under pressure can be ensured.

[0019]

As described above, according to the solution pump for absorption heat pump of the present invention, the following effects can be obtained.

(1) Since the trochoid type positive displacement pumps are arranged in an even number of stages in series, the pressure required per stage of the pumps is reduced, which is advantageous in ensuring the volumetric efficiency, and the eccentric direction of the trochoidal gear is Since the pressure is reversed between the odd-numbered stage and the even-numbered stage, the direction of the pump pressure acting on the trochoid gear is also reversed, and the load on the bearing of the pump is significantly reduced.

(2) A configuration in which even-numbered stages are arranged so that the load share of the pump load in each stage becomes equal, and the side clearance of the trochoid gear is adjusted according to the differential pressure of the pump,
Since the trochoid gears are provided so as to correspond to the respective pressure differences for each stage, it is possible to adjust the side clearance, which greatly affects the volumetric efficiency of the pump, so that the pump efficiency becomes maximum.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a solution pump for an absorption heat pump according to a first embodiment of the present invention.

FIG. 2 is a sectional view of an essential part of the first stage of the solution pump.

FIG. 3 is a sectional view of the intermediate spacer.

FIG. 4 is a plan view of a side plate A side end surface of the intermediate spacer.

FIG. 5 is a plan view of an end surface of the intermediate spacer on the side plate B side.

FIG. 6 is a sectional view of a main part of a second stage of the solution pump.

FIG. 7 is a plan view of a partial main part of the solution pump with the pump lid removed.

FIG. 8 is a plan view of a coaxial receiver and a sleeve.

FIG. 9 is a drive circuit diagram of the same DC brushless motor.

[Explanation of symbols]

 7 Spindle 8 Side plate A 9 Eccentric ring A 10 Outer gear A 11 Inner gear A 12 Intermediate spacer 17 Pump part A 18 Eccentric ring B 22 Outer gear B 23 Inner gear B 24 Side plate B 25 Pump part B 27 Flow path A

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaru Ito 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Takahito Ishii, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. 72) Inventor Yasuhiro Kawamoto 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Yasuhiro Kondo 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] 1. An even-numbered pressure-unbalanced rotary positive displacement pump unit is driven by the same main shaft, and the even-numbered pressure-unbalanced rotary positive displacement pump units are connected in series. The solution pump for an absorption heat pump, in which the directions of the forces acting on the main shaft generated by the pump differential pressure of the pressure non-equilibrium rotary positive displacement pump section are sequentially reversed. 2. An outer gear A which is eccentric with an inner gear A by an eccentric ring A, a pump portion A which is formed between a side plate A and an intermediate spacer, an outer gear B which is eccentric with an inner gear B by an eccentric ring B, and It has a pump portion B formed between the side plate B and the intermediate spacer, drives the inner gear A and the inner gear B coaxially, and sets the pump portion A at the first stage and the pump portion B at the second stage. 2. The eccentric direction of the outer gear A is reversed by approximately 180 degrees from the eccentric direction of the outer gear B.
Solution pump for absorption heat pump described. 3. An even number pressure non-equilibrium rotary positive displacement pump unit is driven by the same main shaft, said even pressure non equilibrium rotary positive displacement pump units are connected in series, and said even number. The direction of the force acting on the main shaft caused by the pump differential pressure of the pressure non-equilibrium rotary positive displacement pump section of
2. The solution pump for an absorption heat pump according to claim 1, wherein the even number of the pressure non-equilibrium rotary positive displacement pump units have the same basic dimensions and the same pumping capacity. 4. A clearance ScA which has the same basic dimensions as the pump portion A and the pump portion B, and which is caused by a dimensional difference in the main axis direction between the eccentric ring A and the inner gear A and the outer gear A which constitute the pump portion A. The clearance ScB caused by the dimensional difference of the eccentric ring B and the inner gear B and the outer gear B constituting the pump portion B in the main axis direction is set to be substantially the same, and the side plate B is
The flow passage A is provided so that the discharge port provided in the side plate and the side face A side of the side plate A communicate with each other, and the rigidity in the main axis direction is reduced in the order of the side plate A, the intermediate spacer, and the side plate B. Solution pump for absorption heat pump.