JP2000314386A - Screw fluid machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect a gear chamber from high temperature of discharged fluid, suppress transfer of the temperature in the gear chamber to suctioned fluid, keep high performance and durability. SOLUTION: A screw fluid machine has a pair of screw rotors, timing gear pairs for synchronously rotating them, while preventing their contact with each other, a casing 9 including rotor chambers 17 housing the respective rotors, a suction port 19 and a discharge port 17 for fluid communicated with the chamber 17, and a gear chamber 25 housing the timing gear pairs. The gear chamber 25 is arranged adjacent to the rotor chamber 17 on the side of the suction port 19. A thermal conduction suppressing means 31 is arranged between the gear chamber 25 and the rotor chamber 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a screw-type fluid machine.

[0002]

2. Description of the Related Art A mechanically driven supercharger 201 (screw type fluid machine) as shown in FIG. 2 is described in Japanese Utility Model Laid-Open Publication No. Hei 4-42284.

[0003] This mechanical drive type supercharger 201 has an input pump.
It comprises a coil 203, an electromagnetic clutch 205, a speed increasing gear set 207, a timing gear set 209, a screw type air compressor 211 and the like.

[0004] The screw type air compressor 211 comprises:
The compressor casing 217 includes a pair of screw rotors 213 and 215 and a casing 217.
A rotor chamber 219 accommodating the rotors 213 and 215;
Suction port 221 and discharge port 22 communicating with rotor chamber 219
3 is provided.

The rotor chamber 219 and the rotors 213 and 215
A suitable gap is provided between the rotors 213 and 215 to prevent contact with each other while minimizing air leakage.

[0006] Speed increasing gear set 207 and timing gear set 20
9 is a gear chamber 227 provided in the gear casing 225.
And is cooled and lubricated by oil sealed in the gear chamber 227.

The gear casing 225 (the gear chamber 22)
7) is a compressor casing 217 at the discharge port 223 side.
(Rotor chamber 219).

[0008] The driving power of the engine is
The speed is increased by a speed increasing gear set 207, and further transmitted through a timing gear set 209 to the rotors 213, 2.
15 to drive the air compressor 211.

The driven air compressor 211 compresses the intake air sucked from the suction port 221 while moving it to the left in the axial direction between the rotors 213 and 215 and the rotor chamber 219, and discharges the air from the discharge port 223. Supercharge the engine.

[0010]

The screw type fluid machine is a compression type fluid machine, for example, having a pressure ratio of 3.
5 (MMC) and the fluid temperature on the discharge port side is 250 ° C
(Calculated value: 360%).

However, the conventional mechanically driven supercharger 201
In this case, since the gear casing 225 is disposed on the discharge port 223 side of the compressor casing 217, the oil in the gear chamber 227 and the oil sheath are reduced due to the high temperature of the discharged intake air.
May deteriorate beyond the heat resistance limit.

When the oil and the oil seal deteriorate, lubrication and cooling become insufficient, and the performance and durability deteriorate due to heat generation and vibration.

In order to prevent this, for example, forced cooling means such as circulating cooling water or spraying cooling oil is required, which complicates the system, increases the cost and increases the size. And the complexity reduces the reliability of the system.

A screw-type fluid machine is also used in a fuel cell or the like. In this case, a large amount of air is compressed by being driven at a high speed by an electric motor to supply fuel oxygen to the fuel cell.

In the case of driving at such a high speed, the temperature of the discharge port becomes higher, and the deterioration of oil and oil seal is promoted.

Further, as described above, in order to provide an appropriate gap between the rotor chamber 219 and the rotors 213 and 215, it is necessary to increase the processing accuracy of the related members alone. In addition, it is necessary to sort each member according to the grade of processing accuracy, and to assemble them in such a manner as to have a predetermined gap, resulting in poor assemblability.

Therefore, the processing cost of the member is high and the assembly cost is high.

Accordingly, the present invention provides a screw-type fluid machine that protects the gear chamber from high temperature on the discharge side to maintain high performance and durability, reduces the processing cost of members, and has good assemblability. With the goal.

[0019]

According to a first aspect of the present invention, there is provided a screw-type fluid machine, wherein a pair of rotors meshing with each other by screw-shaped teeth are provided, and each tooth is transmitted while transmitting driving force to each rotor. A timing gear set for synchronously rotating them so that streaks do not come into contact, a compressor casing having a rotor chamber for accommodating each rotor and a fluid inlet and a discharge port communicating therewith, and a timing gear set And a gear casing having a gear chamber for accommodating the gear casing. The gear casing is connected to the compressor casing on the suction port side,
A heat conduction suppressing means is arranged between the gear casing and the compressor casing.

As described above, the screw-type fluid machine of the present invention differs from the conventional example in that the gear casing (gear chamber) is arranged on the suction side of the compressor casing (rotor chamber). The gear chamber is released from the influence of the high temperature on the discharge port side.

Accordingly, the oil and the oil seal in the gear chamber do not deteriorate beyond the heat-resistant limit, and the timing gear set and the like are sufficiently lubricated and cooled, so that temperature rise and vibration are prevented, and performance and durability are improved. The nature is kept high.

Further, since the forced cooling means is not required, the system complexity, cost increase, size increase, and complexity reduction of the system due to this are prevented.

Further, in the screw type fluid machine according to the present invention, the heat conduction suppressing means is disposed between the gear chamber and the rotor chamber to suppress the heat conduction therebetween. The generated heat is prevented from being transmitted to the suction port side to raise the temperature of the fluid, and the efficiency is kept high.

Therefore, even in an application driven at a high speed, for example, when used in a fuel cell, the screw-type fluid machine of the present invention can be used to reduce the deterioration of oil and oil seals and increase the fluid temperature on the suction side. And performance, durability and efficiency are kept high.

According to a second aspect of the present invention, there is provided the screw-type fluid machine according to the first aspect, wherein the heat conduction suppressing means is a spacer arranged at a contact point between the compressor casing and the gear casing. In this case, the same effects as those of the first aspect are obtained.

Further, heat conduction from the gear chamber to the suction port side can be suppressed at extremely low cost by the spacer.

Further, since a spacer having a different thickness or a material having a different material (a function of suppressing heat conduction) can be obtained at a low cost, it is necessary to selectively use them according to the use of the screw type fluid machine. Thereby, a sufficient heat conduction suppressing effect can be obtained.

Further, by disposing the spacer between the compressor casing and the gear casing, the relative positions thereof can be adjusted, so that the machining accuracy of the related members can be reduced accordingly. There is no need to sort and assemble members according to the grade of processing accuracy. Accordingly, the processing cost of the member is greatly reduced, and the assembling is facilitated, so that the assembling cost is reduced.

According to a third aspect of the present invention, there is provided the screw-type fluid machine according to the second aspect, wherein by changing the thickness of the spacer, the rotor end face and the rotor chamber are arranged on the discharge port side. Is adjusted to an appropriate value, and the same effect as the configuration of claim 2 is obtained.

If the interval between the compressor casing and the gear casing is changed, the gap between the rotor end face and the rotor chamber on the discharge port side changes.

Therefore, in this configuration, the compressor casing
By changing the thickness of the spacer arranged between the shing and the gear casing, the rotor end face and the
The clearance between the rotor chamber and the rotor chamber was adjusted to an appropriate value to prevent contact between the rotor and the casing and leakage of the fluid.

Therefore, noise, vibration, heat generation, and the like due to contact are prevented, and high efficiency and durability are maintained.

Further, by using the spacer for suppressing heat conduction as the spacer for adjusting the gap, a spacer dedicated to adjusting the gap is not required, so that the number of parts and the cost of parts are reduced accordingly. You.

Further, since the gap between the rotor end face and the rotor chamber can be adjusted to an appropriate value by the spacer, it becomes possible to lower the processing accuracy of the related member alone and to process the member. There is no need to sort and assemble according to the accuracy grade, and the processing cost of the members is greatly reduced,
The assembling becomes easier and the assembling cost is reduced.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention (screw
The fluid machine 1) will be described.

The screw type fluid machine 1 is used for supplying fuel oxygen to a fuel cell, and has the features of the first, second and third aspects. FIG. 1 shows a screw-type fluid machine 1, and the left and right directions are the left and right directions in FIG. In addition, members and the like without reference numerals are not shown.

The screw type fluid machine 1 comprises an air compressor 3, a timing gear set, an electric motor 5, and the like.

The air compressor 3 comprises a screw rotor 7 (for example, a male screw rotor), a female screw rotor, a compressor casing 9 and the like.

The male screw rotor 7 has a rotor shaft 1
1 is formed by fixing a rotor main body 13, and similarly, a female screw rotor is formed by fixing the rotor main body to a rotor shaft.

The rotor body 13 of the male screw rotor 7
Is provided with a male screw-shaped tooth line 15, and a female screw-shaped tooth line is provided on the rotor body of the female screw rotor. They are intermeshed by their teeth.

The casing 9 includes a rotor chamber 17 and a suction port 19 and a discharge port 21 communicating with the rotor chamber 17. Each rotor is housed in the rotor chamber 17.

An appropriate gap is provided between the rotor chamber 17 and each rotor main body and between each rotor main body to minimize air leakage and prevent mutual contact.

The timing gear set is accommodated in a gear chamber 25 provided in the gear casing 23, and the gear chamber 25 is filled with oil.

The timing gear set includes a timing gear 27 meshing with the other and a timing gear on the other side. The timing gear 27 is connected to one rotor shaft 11, and the other timing gear is connected to the other rotor shaft.

The timing gear set synchronously rotates the rotors in opposite directions, and meshes with each other so that the respective teeth do not contact each other.

The casing 23 is an inlet 1 of the casing 9.
The partition wall 29 is shared by the rotor chamber 17 and the gear chamber 25.

The casing 23 (gear chamber 25) is connected to the suction port 1
9 side and away from the discharge port 21,
The gear chamber 25 is protected from the high temperature on the discharge port 21 side.

A spacer 31 (heat conduction suppressing means) is disposed at a contact point between the compressor casing 9 (rotor chamber 17) and the casing 23 (gear chamber 25).

Each of the rotor shafts penetrates the partition wall 29 and is supported on the casing 9 by a bearing 33 and on the casing 23 by a bearing 35, respectively.

Between the casing 23 and each rotor shaft,
Oil seals 37 and 39 are arranged on both sides of the bearing 35 and the timing gear set, respectively.
5 prevents oil leakage.

The casing 23 has an oil seal 3
An oil flow path 41 is provided on the left side of 7. Oil is injected from the oil flow path 41 to form an oil film between each rotor shaft and the partition wall 29.

Further, the rotor shaft 11 protrudes outside the gear case 25, and a key 43 is attached to a tip end thereof.

The output shaft 45 of the electric motor 5 is arranged coaxially with the rotor shaft 11, and a key 47 is attached to the end thereof.

The rotor shaft 11 and the output shaft 45 are connected to each other by sleeves which engage with their outer circumferences and are prevented from rotating by the respective keys 43 and 47, or
And the keys 43 and 47 engage with the outer circumference of the output shaft 45, respectively.
The flanges that have been prevented from rotating are fixedly connected.

The electric motor 5 rotates each rotor via a timing gear set, and drives the air compressor 3. The driven air compressor 3 compresses the air sucked from the suction port 19 while moving it to the left in the axial direction between the teeth of each rotor body and the rotor chamber 17, and discharges the fuel from the discharge port 21. To supply.

The spacer 31 disposed between the rotor chamber 17 and the gear chamber 25 is configured to transfer heat generated in the gear chamber 25 to the suction port 19.
To prevent the temperature of the intake air from becoming high and keep the efficiency of the air compressor 3 high.

When the distance between the casing 9 and the casing 23 is changed, the gap 49 between the end face of each rotor and the rotor chamber 17 on the discharge port 21 side changes.

Therefore, the thickness of the spacer 31 is adjusted so that the gap 49 has an appropriate value. As described above, the leakage of the fluid and the contact between the rotor and the rotor chamber 17 are reduced. Has been prevented.

Thus, the screw type fluid machine 1 is configured.

As described above, the screw type fluid machine 1
Since the gear casing 23 is disposed on the suction port 19 side of the compressor casing 9, the oil in the gear chamber 25 and the oil seals 37 and 39 do not deteriorate beyond the heat resistance limit.

Accordingly, since the timing gear set is sufficiently lubricated and cooled, temperature rise, vibration, and the like are prevented.

Further, since the forced cooling means is not required, the complexity, cost, size, and complexity of the system due to the forced cooling are prevented from being reduced.

Further, since a spacer 31 for suppressing heat conduction is disposed between the rotor chamber 17 (the casing 9) and the gear chamber 25 (the casing 23), the spacer 31 is generated in the gear chamber 25. Since the generated heat is prevented from being transmitted to the suction port 19 side to raise the temperature of the air, the efficiency is kept high.

Therefore, even when driven at a high speed, such as for a fuel cell, the screw type fluid machine 1 has high performance, high efficiency,
Durability is kept high.

Further, the space 31 between the end face of the rotor main body and the rotor chamber 17 can be appropriately adjusted by the spacer 31, so that it is possible to lower the processing accuracy of the related parts individually. There is no need to sort and assemble members according to the grade of processing accuracy.

Accordingly, the processing cost of the member is greatly reduced, and the assembling is facilitated, so that the assembling cost is reduced.

Since the spacer 31 is inexpensive,
Heat conduction can be suppressed at low cost.

Further, since the spacer 31 can be made of a material having a different thickness or a material having a different material (a function of suppressing heat conduction) at low cost, these materials can be used in accordance with the use of the screw type fluid machine 1. By using them properly, a sufficient heat conduction suppressing effect can be obtained.

Further, since the spacer 31 for suppressing heat conduction is used as a spacer for adjusting the gap, a spacer dedicated to adjusting the gap is not required, so that the number of parts and the component cost are reduced accordingly. Is done.

In the screw type fluid machine of the present invention, the spacer may be a shim for adjusting the thickness.

If the spacer has a temperature characteristic capable of withstanding the heat generated at the discharge port and the gear chamber of the compressor and a function of suppressing heat conduction, plastic, rubber, or metal is used as the spacer. -All materials and structures can be used, such as those that have been coated.

The heat conduction suppressing means is not an independent member such as a spacer, but may be, for example, a casing or a gear case.
It may be formed by applying a coating having low thermal conductivity to the substrate.

Further, the screw type fluid machine of the present invention may be used for a supercharger for supercharging an engine.

[0074]

According to the screw-type fluid machine of the present invention, the gear chamber is arranged on the suction side of the compressor casing so that the oil and the oil seal in the gear chamber are prevented from deteriorating, and the timing gear assembly is sufficiently provided. The lubrication and cooling ensure high performance and durability.

Further, since the forced cooling means is not required, the complexity of the system, increase in cost, increase in size, and reduction in reliability of the system due to the increase in complexity are prevented.

Further, by disposing the heat conduction suppressing means between the gear chamber and the rotor chamber, it is possible to prevent the heat of the gear chamber from being transmitted to the suction port to raise the temperature of the fluid, thereby increasing the efficiency. Will be kept.

According to the second aspect of the invention, the same effect as that of the first aspect is obtained, and the heat conduction between the gear chamber and the suction fluid can be suppressed at low cost by the spacer.

Further, by using spacers having different thicknesses or different materials, heat conduction can be sufficiently suppressed at low cost according to the use of the screw type fluid machine.

Further, the use of the spacer makes it possible to reduce the precision of processing a single component of a related member, thereby greatly reducing the processing cost and assembly cost of the member.

According to the third aspect of the present invention, the same effect as that of the second aspect is obtained, and the gap between the rotor end face and the rotor chamber is properly adjusted on the discharge port side by changing the thickness of the spacer. Since the value can be adjusted, noise, vibration, heat generation, and the like are prevented, and the efficiency is kept high.

Further, since the spacer for suppressing heat conduction is used as the spacer for adjusting the gap, a spacer dedicated to adjusting the gap is not required, and the number of parts and the cost of parts are reduced accordingly. .

Further, the gap between the rotor end face and the rotor chamber is adjusted to an appropriate value by the spacer, so that it is possible to reduce the single machining accuracy of the related member product by that much. The cost is greatly reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view of a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 screw-type fluid machine 7 screw rotor 9 compressor casing 17 rotor chamber 19 suction port 21 discharge port 23 gear casing 25 gear chamber 27 timing gear 31 spacer (heat conduction suppressing means) 37, 39 Oil seal

Claims (3)

[Claims] 1. A pair of rotors meshing with each other with screw-shaped teeth, and a timing gear set for synchronously rotating the teeth while transmitting driving force to the rotors so that the teeth do not contact each other. A compressor case having a rotor chamber for accommodating each rotor and a fluid suction port and a discharge port communicating therewith; and a gear casing having a gear chamber for accommodating a timing gear set. A screw, wherein a gear casing is connected to the compressor casing on the suction port side and heat conduction suppressing means is arranged between the gear casing and the compressor casing.
Fluid machine. 2. The screw type according to claim 1, wherein the heat conduction suppressing means is a spacer arranged at a contact point between the compressor casing and the gear casing. Fluid machinery. 3. The invention according to claim 2, wherein the gap between the end face of the rotor and the rotor chamber is adjusted to an appropriate value on the discharge port side by changing the thickness of the spacer. Screw type fluid machine characterized by the above-mentioned.