JP2010031735A - Centrifugal compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a centrifugal compressor for achieving a greater capacity, higher operating pressure and a smaller size by distributing the transmitting power of a driving gear which drives a guide vane for flow control in a gas intake port, into a plurality of branch gears. <P>SOLUTION: The centrifugal compressor comprises the driving gear, the plurality of branch gears for meshing with the driving gear at two or more positions at the same time, an annular ring gear, and a guide vane gear provided coaxially with a guide vane shaft for meshing with the ring gear. Power input to the driving gear is distributed into the plurality of branch gears once and then transmitted to the ring gear to increase transmitting power without so much increasing the size of a drive mechanism. Thus, the centrifugal compressor achieves a greater capacity, higher operating pressure and a smaller size. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a guide blade drive mechanism provided at a gas suction port for use in controlling the flow rate of a centrifugal compressor, and more particularly, to a guide blade drive mechanism configured using an external gear and an annular ring gear. The present invention relates to the structure of a centrifugal compressor.

  A centrifugal compressor is a mechanical device for obtaining high pressure by rotating a main shaft using a prime mover such as an electric motor, and compressing sucked gas by centrifugal force with an impeller provided on the main shaft. This equipment is widely used in plants such as petroleum refining, petrochemical, and fertilizer production, but it is required to adjust the flow rate of compressed gas according to the operation status of the factory and operate the production line efficiently. Is very strong. In contrast, conventionally, an inverter or the like is used, and the flow rate control is often performed by adjusting the speed of the drive motor.

  However, the compressors used in these plants often have a capacity of several thousand kW, and large capacity inverters are extremely expensive and occupy a large installation area. In order to solve this problem, a method has been proposed in which a plurality of guide vanes are provided along the circumferential direction of the gas inlet and the flow rate is controlled by opening and closing them.

  Since this guide blade needs to be rotated and opened by synchronizing a plurality of the guide blades, for example, as in Patent Document 1, a driven gear provided coaxially with the guide blade shaft and an annular large external gear are engaged with each other. A method has been proposed in which the drive gear is engaged with one of the driven gears and then the drive gear is rotated to obtain synchronization.

  Further, as in Patent Document 2, a pin for driving the guide vane is provided on the side surface of the ring provided around the guide vane, teeth are provided on the outer periphery of the ring, and a worm that meshes with the teeth is provided. There has also been proposed a method for obtaining synchronization by rotating the.

JP 2001-295595 A JP 2006-63895 A

  However, according to the structure described above, the load transmitted by the drive gear or worm is the sum of the driving forces of multiple guide vanes, so the compressor capacity and operating pressure are large, and the number of guide vanes is large. However, there is a problem that the transmission load increases and the strength of the drive gear or worm is insufficient. In order to solve this problem, it is necessary to take measures such as increasing the tooth width of the drive gear and the diameter of the worm, but this causes an increase in the axial dimension of the compressor. A secondary problem such as an increase in cost will occur.

  An object of the present invention is to provide a gear mechanism that transmits a driving force for driving many guide vanes while maintaining the axial dimension of the guide vane driving mechanism.

  In order to achieve the above object, a compressor according to the present invention includes guide vanes in a flow path communicating from a fluid suction port to the inside of the compressor, and rotationally drives a guide vane shaft connected to the guide vanes. In a centrifugal compressor that performs control, a drive gear, a plurality of branch gears that simultaneously mesh with the drive gear at two or more locations, an annular ring gear, and a ring gear that is provided coaxially with the guide vane shaft and meshes with the ring gear And a guide vane gear. In more detail, in the above configuration, the branch gear meshes with the external teeth provided on the outer peripheral portion of the ring gear, and the guide blade gear engages with the internal teeth provided on the inner peripheral portion of the ring gear. A structure in which the guide vane gear is engaged with the inner teeth provided on the inner peripheral portion of the ring gear, or a branch gear is provided coaxially with the guide vane gear, and the guide vane gear is provided on the outer peripheral portion of the ring gear. It has a structure meshed with teeth.

  Further, the branch gear and the guide vane gear are constituted by a single gear. In addition, the branch gear and the guide blade gear are combined. Further, teeth are provided on a part of the drive gear in the circumferential direction. Further, external teeth are provided on a part of the ring gear in the circumferential direction.

  With the structure as described above, the power input to the drive gear is once distributed to a plurality of branch gears and then transmitted to the ring gear, so that the allowable transmission can be achieved without increasing the size of the gear mechanism. Power is increased, thus providing a high capacity, high operating pressure and small centrifugal compressor.

  Examples according to the present invention will be described below.

  FIG. 3 is an overall structural view of a centrifugal compressor according to the present invention, FIG. 1 is a perspective view of the centrifugal compressor of Example 1, and FIG. 2 is a cross-sectional view thereof. .

  As shown in FIG. 3, the electric motor 2 as a prime mover is fixed on the electric motor base 1, and the speed increaser 3 that accelerates and transmits the power from the electric motor 2 is a compressor common to the compressor 4. It is fixed on the base 5. The electric motor 2 and the speed increaser 3 are connected by a speed increaser shaft joint 6, and the speed increaser 3 and the compressor 4 are connected by a compressor shaft joint 7 to form a compressor system 8.

  An impeller 12 for compressing the gas provided in the main shaft 11 is disposed at the tip of a flow path 17 communicating from the gas inlet 14 provided on the side surface of the casing 13 of the compressor 4 to the inside of the compressor 4. In the middle of the flow path 17, a plurality of guide vanes 18 are provided radially along the circumferential direction of the flow path, and are supported by a guide vane shaft 15 and a guide vane bearing 16, respectively. In the middle of the flow path 17, there is a flow path extending in the radial direction from the gas inlet 14 to the main shaft 11 of the impeller 12, and the guide blade 18 is provided in the radial flow path. Yes. When high operating pressure is required, a plurality of impellers 12 are arranged in the axial direction to form a multistage structure, but the illustration is omitted here.

  As shown in FIGS. 1 and 2, a guide blade gear 22 is provided at one end of the guide blade shaft 15 to form a guide blade unit 9. A plurality of the guide vane units 9 are arranged in the circumferential direction, but the details are not shown because they are all the same structure.

  An annular ring gear 21 is provided so as to surround the periphery of the guide vane gear 22, and the internal teeth provided on the inner peripheral portion thereof and the external teeth provided on the outer peripheral portion of the guide vane gear 22 are engaged with each other. . Further, the outer periphery of the ring gear 21 is partially provided with external teeth (the rotation angle is limited), and two branch gears 20a and 20b are provided so as to be engaged with both branch gears. A drive gear 19 is provided.

  The branch gears 20a and 20b are supported by branch gear shafts 25a and 25b and branch gear bearings 26a (not shown) and 26b, and the drive gear 19 is supported by a drive gear shaft 23 and a drive gear bearing 24. The drive gear shaft 23 is connected to an actuator (for example, a servo motor) (not shown) provided outside the compressor casing 13 and rotates as the actuator rotates. The rotation in this case is for changing the angle of the guide vane 18 and the rotation angle is small.

  When the compressor system 8 is configured as described above and the electric motor 2 is rotated, the main shaft 11 of the compressor 4 is rotated at a speed higher than that of the electric motor 2 by the speed increaser 3, and the impeller 12 is rotated simultaneously. Thus, the working gas sucked from the gas suction port 14 flows through the flow path 17, passes through the impeller 12, and is compressed. At this time, when the drive gear 19 is rotated by operating the actuator, the branch gears 20a and 20b, the ring gear 21 and the guide vane gear 22 meshing simultaneously with the drive gear 19 are simultaneously rotated to open and close the guide vane 18. Can do. Since the ring gear 21 and the guide vane gear 22 are synchronized, all the plural guide vanes 18 are opened and closed at the same angle.

  The flow rate of the working gas increases when the guide vane 18 is rotated to the open side and decreases when the guide vane 18 is rotated to the closed side. Therefore, the flow rate can be controlled without changing the rotation speed of the electric motor 2. Since the torque transmitted by the drive gear 19 is once distributed to the branch gears 20a and 20b, the tangential load per gear pair is approximately 1 / compared to the case where the drive gear 19 is directly meshed with the ring gear 21. 2.

  Here, in order to halve the tangential load per pair of gears, when the teeth of the drive gear 19 mesh with the teeth of the branch gears 20a and 20b at the same time, the teeth contact each tooth evenly. The phase is adjusted so that force is transmitted. Since the guide vane 18 receives the resistance of the flowing gas when it is rotated to the closed side, a large torque is required, and the above-described phase adjustment is particularly necessary when the torque is large. Since the guide vane 18 is pushed by the flowing gas when it is rotated to the open side, only a small torque is required. Therefore, there is no need to adjust the phase alignment. Accordingly, the phase alignment can be easily performed because it can be adjusted by rotating in one direction (closing direction).

  The torque transmitted by the drive gear 19 is a sum of the torques required to drive the guide vane unit 9, and therefore when the number of guide vane units 9 is large, the torque required to rotate the ring gear 21 is correspondingly increased. To increase. However, with the structure as described above, the tangential load between the drive gear 19 and the branch gears 20a and 20b is approximately ½ compared to when the drive gear 19 is directly engaged with the ring gear 21, so It is possible to transmit approximately double the torque without changing the tooth width (indicated by 19a in FIG. 1). This provides a large capacity, high operating pressure and small centrifugal compressor.

Next, FIG. 4 shows a perspective view of a centrifugal compressor according to the second embodiment of the present invention, and FIG. 5 shows a cross-sectional view of the centrifugal compressor.

  A fan-shaped drive gear 19 is provided at one end of a drive gear shaft 23 connected to an actuator (not shown), and an annular ring gear 21 is disposed at a position parallel to the drive gear 19. Two gears that mesh simultaneously with the drive gear 19 and the ring gear 21 are provided, and their tooth widths are larger than the sum of the tooth widths of the drive gear 19 and the ring gear 21. The side of the gear that meshes with the drive gear 19 is branch gears 20a and 20b, and the side that meshes with the ring gear 21 is guide vane gears 22a (not shown) and 22b. The branch gears 20a and 20b and the guide blade gears 22a and 22b have the same specifications and are configured as one gear. On the other hand, the other guide blade gears 22 that mesh with the ring gear 21 have substantially the same tooth width as the ring gear 21. Since the configuration excluding the above is the same as that of the first embodiment, the description thereof is omitted.

  In such a configuration, when the drive gear 19 is rotated by operating the actuator, the branch gears 20a and 20b, the guide blade gears 22a and 22b, the ring gear 21, and the guide blade gear 22 that are engaged with the drive gear 19 are simultaneously rotated. 18 can be opened and closed.

  Since the torque transmitted by one guide vane gear 22 is much smaller than the torque transmitted by the drive gear, the tooth widths 22a and 21a of the guide vane gear 22 and the ring gear 21 meshing with the guide vane gear 22 are the drive gear 19 And it may be smaller than the tooth width of the branch gears 20a, 20b. By setting it as the above structures, the gear width of the guide blade gear 22 and the ring gear 21 can be reduced, and a gear mechanism part can be reduced in size.

  In this embodiment, as shown in FIG. 6, the branch gears 20a and 20b and the guide blade gears 22a (not shown) and 22b have different specifications, and the guide blade shaft 15 provided coaxially with the guide blade gear 22b. You may comprise by making the branch gear 20b fit. In this case, since a larger reduction ratio can be obtained, the tooth widths of the drive gear 19 and the branch gears 20a and 20b can be further reduced.

  Next, the perspective view of the centrifugal compressor of Example 3 by this invention is shown in FIG. 7, The structure and operation | movement of a present Example are demonstrated using this.

  A drive gear 19 is provided at one end of a drive gear shaft 23 connected to an actuator (not shown), and branch gears 20 a and 20 b that engage with the drive gear 19 are provided in mesh with external teeth provided on the outer periphery of the ring gear 21. A plurality of guide blade units 9 are arranged along the outer periphery of the ring gear 21, and all the guide blade gears 22 of the guide blade unit 9 are engaged with external teeth provided on the outer peripheral portion of the ring gear 21. Further, the branch gears 20 a and 20 b in this case also serve as the guide vane gear 22. Since the configuration except for the above is the same as that of the first embodiment, the description thereof is omitted.

  In such a configuration, when the drive gear 19 is rotated by operating the actuator, the branch gears 20a and 20b, the ring gear 21 and the guide vane gear 22 meshing with the drive gear 19 are simultaneously rotated, and the guide vane 18 can be opened and closed. .

  Although the radial position of the guide vane is roughly determined by the compressor structure, in this embodiment, it is not necessary to provide the ring gear 21 so as to surround the outer side of the guide vane gear 22, so the radial dimension of the ring gear 21 is small. Thus, the radial dimension of the gear mechanism can be reduced. Further, since it is not necessary to provide the inner teeth only with the outer teeth on the ring gear 21, there is an advantage that the gear can be made compact and the manufacturing cost can be reduced.

The perspective view of the centrifugal compressor of Example 1 of this invention. Sectional drawing of the centrifugal compressor of Example 1 similarly. 1 is an overall structural diagram of a centrifugal compressor according to the present invention. The perspective view of the centrifugal compressor of Example 2 of this invention. Sectional drawing of the centrifugal compressor of Example 2 similarly. Sectional drawing of another structural example of the centrifugal compressor of Example 2 similarly. The perspective view of the centrifugal compressor of Example 3 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electric motor base, 2 ... Electric motor, 3 ... Booster, 4 ... Compressor, 5 ... Compressor base, 6 ... Booster shaft coupling, 7 ... Compressor shaft coupling, 8 ... Compressor system, 9 ... Guide vane unit , 11 ... main shaft, 12 ... impeller, 13 ... casing, 14 ... gas suction port, 15 ... guide blade shaft, 16 ... guide blade bearing, 17 ... flow path, 18 ... guide blade, 19 ... drive gear, 20 ... branch A gear, 21 ... a ring gear, 22 ... a guide vane gear, 23 ... a drive gear shaft, 24 ... a drive gear bearing, 25 ... a branch gear shaft, 26 ... a branch gear bearing.

Claims (9)

A centrifugal compressor that includes a guide vane in a flow path that communicates with the inside of a compressor having an impeller that compresses gas from a fluid suction port, and performs flow rate control by rotationally driving a guide vane shaft connected to the guide vane In
A drive gear, a plurality of branch gears that simultaneously mesh with the drive gear at two or more locations, an annular ring gear, and a guide vane gear that is provided coaxially with the guide vane shaft and meshes with the ring gear A centrifugal compressor characterized by that. The centrifugal compressor according to claim 1,
A centrifugal compressor in which the branch gear meshes with external teeth provided on an outer peripheral portion of the ring gear, and the guide vane gear meshes with internal teeth provided on an inner peripheral portion of the ring gear. The centrifugal compressor according to claim 1,
A centrifugal compressor characterized in that the branch gear is provided coaxially with the guide vane gear, and the guide vane gear is engaged with an internal tooth provided on an inner peripheral portion of the ring gear. The centrifugal compressor according to claim 1,
A centrifugal compressor characterized in that the branch gear is provided coaxially with the guide vane gear, and the guide vane gear meshes with external teeth provided on the outer periphery of the ring gear. The centrifugal compressor according to claim 3 or 4,
A centrifugal compressor characterized in that the branch gear and the guide vane gear are constituted by a single gear. The centrifugal compressor according to claim 3 or 4,
A centrifugal compressor comprising the branch gear and the guide vane gear combined. The centrifugal compressor according to any one of claims 1 to 6,
A centrifugal compressor characterized in that teeth are provided on a part of the drive gear in the circumferential direction. The centrifugal compressor according to claim 1 or 2,
A centrifugal compressor characterized in that external teeth are provided on a part of the ring gear in the circumferential direction. The centrifugal compressor according to claim 1,
The centrifugal compressor is characterized in that the flow path has a flow path in a radial direction with respect to a main shaft of an impeller that compresses fluid, and the guide blade is provided in the radial flow path.

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