RU2511907C1 - Adjustable diffuser of centrifugal compressor - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: adjustable diffuser of a centrifugal compressor includes blades located in the compressor housing between a diaphragm and a diffuser wall and installed with possibility of being turned and equipped with trunnions arranged in the diffuser wall and kinematically connected to a drive shaft by means of levers, a turning disc and a drive lever arranged between the diffuser wall and the end wall of the housing and interacting with a bell crank and a pin, which are installed on the end face of the drive shaft and periphery of the turning disc respectively. The diffuser wall has a flanged projection, in the housing shell on the side facing its end wall, on the inner surface there is an annular projection, in which a spacer ring and a flanged projection of the diffuser wall is fixed. The drive lever is installed so that at least in one of working positions its longitudinal axis is perpendicular to a plane passing through axes of the drive shaft and the bell crank and/or a plane passing through axes of the turning disc and the pin.

EFFECT: improving operating efficiency of a diffuser of a centrifugal compressor; simplifying an installation process.

3 cl, 3 dwg

Description

The invention relates to compressor engineering and relates to the design of diffusers with adjustable position of the blades.

An adjustable centrifugal compressor diffuser is known, comprising blades located in the compressor housing between the diaphragm and the diffuser wall, rotatably mounted and equipped with trunnions placed in the diffuser wall and kinematically connected to the drive drive shaft with levers, a rotary disk and a drive lever (see Patent US No. 4770605, CL F04D 27/00, 1988).

This embodiment of the adjustable diffuser does not provide reliability due to the complexity of the kinematic connection between the blades and the drive.

An adjustable centrifugal compressor diffuser is also known, comprising blades located in the compressor housing between the diaphragm and the diffuser wall, rotatably mounted and equipped with trunnions placed in the diffuser wall and kinematically connected to the rotor trunnion axles with a drive drive shaft using levers, a rotary disk and a drive a lever located between the wall of the diffuser and the end wall of the housing and interacting with the crank and finger installed, respectively Twain, at the end of the drive shaft and the periphery of the rotary disc (see. Patent RU №2112154, Cl. F04D 29/46, published 27.05.1998).

However, this embodiment of an adjustable diffuser has the disadvantage of the difficulty of its installation due to the difficulties of fastening and fixing the diffuser wall in the housing and the blind connection of the drive arm with a crank and a finger. This affects the build quality and reliability of the diffuser.

The technical result of the invention is to increase the reliability of the adjustable diffuser of a centrifugal compressor, simplify the installation process, provide free access to the structural elements of the diffuser of a centrifugal compressor.

The technical result of the invention is achieved by the fact that the adjustable diffuser of the centrifugal compressor contains blades located in the compressor housing between the diaphragm and the diffuser wall, rotatably mounted and equipped with trunnions placed in the diffuser wall and kinematically connected to the drive shaft by means of levers, a rotary disk and a drive lever, placed between the diffuser wall and the end wall of the housing and interacting with a crank and a finger mounted respectively on t The drive shaft and the periphery of the rotary disk, while the diffuser wall has a flange protrusion, in the shell of the body on the side facing its end wall, an annular ledge is made on the inner surface, in which the distance ring and the flange protrusion of the diffuser wall are fixed, the drive lever is mounted so that, in at least one of the operating positions, its longitudinal axis is perpendicular to the plane passing through the axis of the drive shaft and the crank and / or the plane passing through the axis of the rotary disk and the finger.

,In addition, the free ends of the crank and the finger are placed in the holes made in the drive lever on its longitudinal axis at a distance L from each other, determined by the ratio $$L=(0.9÷\mathrm{1,1})\cdot \sqrt{H^2-{(R\pm r)}^2}$$

,

where: N is the distance between the axes of the rotary disk and the drive shaft;

R is the distance from the axis of the rotary disk to the axis of the finger;

r is the distance from the axis of the drive shaft to the axis of the crank.

In addition, the longitudinal axis of the drive arm is perpendicular to the indicated planes with the position of the diffuser blades near their average operating position.

The invention is illustrated by drawings, where figure 1 shows an adjustable diffuser of a centrifugal compressor, a longitudinal section; figure 2 is a section aa in figure 1, an embodiment of a diffuser with the placement of the drive lever between the axes of the drive shaft and the rotary disk; figure 3 is a section aa in figure 1, an embodiment of a diffuser with the placement of the drive lever outside the zone between the axes of the drive shaft and the rotary disk.

The adjustable centrifugal compressor diffuser comprises vanes 4 located in the compressor housing 1 between the diaphragm 2 and the diffuser wall 3, rotatably mounted and provided with pins 5 located in the diffuser wall 3. The trunnions 5 are kinematically connected with the drive shaft 6, while the shaft 6 is mounted in the housing 1 so that its axis is parallel to the axes of the trunnions 5 of the blades 4. The trunnions 5 are kinematically connected to the shaft 6 using levers 7 connected to the rotary disk 8 and the drive the lever 9, also connected with the disk 8 and placed between the diffuser wall 3 and the end wall 1.1 of the housing 1. The drive lever 9 on the one hand interacts with a crank 10 mounted on the end of the drive shaft 6, and on the other hand interacts with a finger 11 mounted on the periphery of the disc 8.

The diffuser wall 3 has a flange protrusion 12, which is located in the annular ledge 13 (bore), made in the shell 1.2 of the housing 1 from the side facing the end wall 1.1 on the inner surface. A distance ring 14 is placed in the step 13 between its annular surface and the flange protrusion 12 of the diffuser wall 3. The distance ring 14 and the flange protrusion 12 are fixed in the shell 1.2 using, for example, tightening bolts (not shown) located in the holes of the flange protrusion 12. Drive the lever 9 is installed so that, at least in one of the operating positions, its longitudinal axis 0-0 is perpendicular to the plane II passing through the axis of the drive shaft 6 and the crank 10, and the plane II-II passing through the axis of the rotary disk 8 and the finger eleven, or one of the planes I-I, II-II. The free ends of the crank 10 and the pin 11 are placed in the holes 15 made in the drive lever 9 on the longitudinal axis 0-0 (at the opposite ends of the lever 9) at a distance L from each other, which is determined from the ratio:

, где $$L=(0.9÷\mathrm{1,1})\cdot \sqrt{H^2-{(R\pm r)}^2}$$

where

H is the distance between the axes of the rotary disk and the drive shaft;

R is the distance from the axis of the rotary disk to the axis of the finger;

r is the distance from the axis of the drive shaft to the axis of the crank.

The longitudinal axis 0-0 of the drive arm 9 is perpendicular to the indicated planes I-I and II-II with the position of the diffuser blades 4 near their average operating position.

. Знак «плюс» или «минус» в круглых скобках соотношения зависит от конструктивного исполнения регулируемого диффузора. При варианте исполнения диффузора с размещением приводного рычага 9 между осями приводного вала 6 и поворотного диска 8 (фиг.2) в соотношении следует принять знак «плюс». Если используется вариант с размещением приводного рычага 9 вне зоны между осями приводного вала 6 и поворотного диска 8 (фиг.3), то в соотношении следует принять знак «минус». Далее обечайку 1.2 с установленным регулируемым диффузором соединяют с торцовой стенкой 1.1 корпуса 1.When assembling the compressor, an adjustable diffuser assembly is assembled in the following order. The blades 4 are installed in the wall 3 of the diffuser, the levers 7 are fixed on the trunnions 5 of the blades 4 and the rotary disk 8 is installed in the diffuser wall 3, with which the levers 7 are connected. Then, the diffuser wall 3 with the blades 4, levers 7 and the rotary disk 8 are installed in the shell 1.2 case 1, placing the flange protrusion 12 of the wall 3 of the diffuser in the bore 13 of the shell 1.2. Before installing the wall 3 of the diffuser in the bore 13 set the distance ring 14, the thickness of which determines the axial position of the wall 3 of the diffuser. The diffuser wall 3 is fixed relative to the shell 1.2, for example, with tightening bolts located in the holes of the flange ledge 12. The drive shaft 6 is mounted in the shell 1.2 and kinematically connected to the rotary disk 8 using the drive lever 9, by placing the free ends of the crank in its holes 15 10 and finger 11. The drive lever 9 is set so that the longitudinal axis 0-0 of the drive lever 9 is perpendicular to the planes II and II-II when the blades 4 of the diffuser are located near their average operating position. The distance L between the holes 15 is made in accordance with the ratio $$L=(0.9÷\mathrm{1,1})\cdot \sqrt{H^2-{(R\pm r)}^2}$$

. The plus or minus sign in parentheses of the ratio depends on the design of the adjustable diffuser. When the embodiment of the diffuser with the placement of the drive lever 9 between the axes of the drive shaft 6 and the rotary disk 8 (figure 2) in the ratio should take the plus sign. If you use the option with the placement of the drive lever 9 outside the area between the axes of the drive shaft 6 and the rotary disk 8 (figure 3), then in the ratio you should take the minus sign. Next, the shell 1.2 with the adjustable diffuser installed is connected to the end wall 1.1 of the housing 1.

During operation of a centrifugal compressor, its parameters are adjusted by turning the diffuser blades 4 after a signal arrives at the drive shaft 6 (not shown). The drive rotates the drive shaft 6 with a crank 10, which acts on the drive lever 9 and moves it in a certain direction. The drive lever 9 acts on the finger 11 and rotates the rotary disk 8, interacting with the levers 7, which rotate the blades 4 at an appropriate angle.

This embodiment of the adjustable diffuser of the centrifugal compressor simplifies its installation and connection with the housing 1 by placing all its elements in the shell 1.2 and providing free access to them from the end wall 1.1 of the housing 1. Access is open to the bore 13 in the shell 1.2 for placement of a flange the protrusion 12 of the wall 3 of the diffuser, to the flange ledge 12 - for mounting and fixing the wall 3 of the diffuser, to the crank 10 and the pin 11 - to install the drive arm 9. No special fixtures for assembly, clearances in movable connections can be made as low as possible.

In addition, the distance between the holes 15 in the drive lever 9, made in accordance with the specified ratio, allows one of the operating positions of the drive lever 9, in which its longitudinal axis 0-0 is perpendicular to the plane II passing through the axis of the drive shaft 6 and crank 10 , and simultaneously the plane II-II, passing through the axis of the rotary disk 8 and the finger 11. This design reduces the drive forces to rotate the blades 4, if moreover, the blades 4 are installed near their average operating position.

Thus, this design of an adjustable diffuser of a centrifugal compressor increases the reliability of its operation, as it ensures the quality of assembly, reliable fastening and fixing of its elements, reduced load on the rotation drive of the blades 4, free access to the structural elements of the diffuser during its installation.

Claims (3)

1. An adjustable centrifugal compressor diffuser comprising blades located in the compressor housing between the diaphragm and the diffuser wall, rotatably mounted and equipped with pins located in the diffuser wall and kinematically connected to the drive shaft by means of levers, a rotary disk and a drive lever located between the diffuser wall and the end wall of the housing and interacting with a crank and a finger mounted respectively on the end of the drive shaft and the periphery of the rotary disk, characterized in that the diffuser wall has a flange protrusion, an annular ledge is made on the inner surface of the casing of the housing from the side facing its end wall, in which the distance ring and the flange protrusion of the diffuser wall are fixed, the drive lever is mounted so that at least , in one of the operating positions, its longitudinal axis is perpendicular to the plane passing through the axis of the drive shaft and the crank and / or the plane passing through the axis of the rotary disk and the finger. 2. The diffuser according to claim 1, characterized in that the free ends of the crank and the finger are placed in the holes made in the drive lever on its longitudinal axis at a distance L from each other, determined by the ratio $$L=(0.9÷\mathrm{1,1})\cdot \sqrt{H^2-{(R\pm r)}^2}$$

,
where: H is the distance between the axes of the rotary disk and the drive shaft;
R is the distance from the axis of the rotary disk to the axis of the finger;
r is the distance from the axis of the drive shaft to the axis of the crank. 3. The diffuser according to claim 1, characterized in that the longitudinal axis of the drive lever is perpendicular to the indicated planes when the diffuser blades are located near their average operating position.

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