JP2012026443A - Variable diffuser for rotating machine and rotating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable diffuser actuation linkage for a cabin air compressor.SOLUTION: A variable diffuser for a rotating machine includes a multiple of diffuser vanes mounted to a drive ring. The multiple of diffuser vanes are movable in unison between a maximum flow position and a minimum flow position in response to rotation of a crank to rotate the drive ring about a centerline through a link arm.

Description

  The present invention relates to a cabin air compressor, and more particularly to a variable diffuser thereof.

  In a conventional aircraft environment control system, pressurized air for an aircraft cabin is extracted from a main engine or an auxiliary power unit. In an environmental control system for a more electric aircraft (MEA), a dedicated compressor for pressurizing outside air is used for air in a cabin. The compressor may have a single-stage centrifugal configuration driven by, for example, a variable speed permanent magnet motor. The variable diffuser includes a drive ring that rotates about a compressor centerline. A series of diffuser vanes are moved simultaneously between a maximum flow position and a minimum flow position by rotation of the drive ring.

  The present invention provides a variable diffuser for a cabin air compressor and its drive linkage.

  A variable diffuser for a rotating machine according to one aspect of the present invention includes a plurality of diffuser vanes engaged with a drive ring. A plurality of diffuser vanes can move simultaneously between a maximum flow position and a minimum flow position in response to rotation of the crank that rotates the drive ring about the center line via the link arm.

  The rotating machine of one embodiment of the present invention includes a compressor that can be driven around a center line by an electric motor. The variable diffuser is downstream of the compressor. A plurality of diffuser vanes engage the drive ring. A plurality of diffuser vanes can move simultaneously between a maximum flow position and a minimum flow position in response to rotation of the crank that rotates the drive ring about the center line via the link arm.

  Various features will be apparent to those skilled in the art from the following detailed description of the non-limiting embodiment disclosed. The drawings that accompany the detailed description can be briefly described as follows.

Schematic of cabin air compressor (CAC). The perspective view of the variable diffuser of a cabin air compressor (CAC). FIG. 3 is an enlarged view of the variable diffuser of FIG. 2 in a maximum flow position. FIG. 3 is an enlarged view of the variable diffuser of FIG. 2 in a minimum flow position. FIG. 5 is a perspective view of a linkage operable to position a variable diffuser between a maximum flow position and a minimum flow position.

  FIG. 1 schematically illustrates a cabin air compressor (CAC) 20 that is used to pressurize outside air to provide fresh air into the cabin of an aircraft. The following description describes the invention as used in an aircraft, but it should be understood that the following description is applicable to other suitable applications such as ground vehicles and stationary equipment. It will also be appreciated that the invention is not limited to use in connection with a particular type of rotating machine. Accordingly, for purposes of explanation, the invention will be described and described as being implemented in a cabin air compressor, although it should be understood that the invention is not limited to gas turbine engines, auxiliary power units, turbochargers, superchargers, air It can be implemented on many other machines, including but not limited to cycle machines, alternators, electric motors, generators, integrated constant speed drive generators, and various gearboxes.

  The CAC 20 generally includes an electric motor 22, a compressor 24, a variable diffuser 26, and a diffuser actuator 28. An electric motor 22, a compressor 24, and a variable diffuser 26 are defined around a center line A of the CAC 20. Inlet 30 allows air to flow to CAC 20 where it is compressed by compressor 24 driven by electric motor 22 and then flows from radial outlet 32 through variable diffuser 26. The variable diffuser 26 includes a plurality of diffuser vanes 34 (FIG. 2) that are responsive to the controller 29 to adjust the air flow of the CAC 20 with a maximum flow position (FIG. 3) and a minimum flow. It is moved all at once with respect to the position (FIG. 4).

  Referring to FIG. 5, the variable diffuser 26 includes a drive ring 36 that is rotatable about a center line A. A series of drive pins 38 extend from the drive ring 36 to engage each diffuser vane 34. Each diffuser vane 34 rotates about a vane pin 40 (FIGS. 3 and 4) that is offset from each of the drive pins 38. Due to the rotation of the drive ring 36, the diffuser vane 34 moves simultaneously between the maximum flow position and the minimum flow position around the vane pins 40.

  A diffuser actuator 28 (not shown in FIG. 5) connects to the drive ring 36 via a linkage 42. The diffuser actuator 28 may include a geared drive motor or other actuator device that operates to generate a rotational input about a rotational axis B for rotating the crank 44. The crank 44 is pivotally connected to the link arm 46 by a pivot 48 that defines an axis C. The link arm 46 is pivotally connected to the drive ring 36 by a drive ring pivot 50 that defines an axis D.

  The crank 44 is rotated by the rotation of the diffuser actuator 28. The crank 44 drives the link arm 46, thereby driving the drive ring 36 about the compressor centerline A. The selective rotation of the drive ring 36 about the compressor centerline A causes the diffuser vane 34 to move simultaneously between the maximum flow position (FIG. 3) and the minimum flow position (FIG. 4). In other words, the rotational motion of the diffuser actuator is converted into the motion of an arcuate path. The linkage 42 facilitates movement of the mechanical advantage at the maximum and minimum flow positions, which are both ends of the operation and in many cases the maximum force is required. Thereby, a relatively low power diffuser actuator 28 is used to control the width of the variable diffuser 26. A small diffuser actuator 28 that maximizes mechanical advantage facilitates an overall lightweight device.

  It should be understood that like reference numerals throughout the several views identify corresponding or similar components. Also, although specific component arrangements are disclosed in the illustrated embodiment, it should be understood that other arrangements may also benefit from the present invention.

  The above description is illustrative rather than limiting. While various non-limiting embodiments have been disclosed, those skilled in the art will recognize that various changes and modifications within the scope of the appended claims in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced other than as specifically described. For that reason, the appended claims should be studied to define the true scope and significance of this invention.

36 ... Drive ring 38 ... Drive pin 42 ... Linkage 44 ... Crank 46 ... Link arm 48 ... Pivot 50 ... Drive ring pivot

Claims (11)

A drive ring that can rotate around a center line;
A crank rotatable around a rotation axis different from the center line;
A link arm pivotably attached to the crank and the drive ring;
A plurality of diffuser vanes engaged with the drive ring;
With
The plurality of diffuser vanes can move simultaneously between a maximum flow position and a minimum flow position according to rotation of the crank that rotates the drive ring around the center line via the link arm. A variable diffuser for a rotating machine, characterized by being.   2. The variable diffuser according to claim 1, wherein the crank is rotatable according to a rotational movement of an actuator around the rotation axis different from the center line.   The variable diffuser according to claim 2, wherein the rotational movement of the actuator is converted into a movement of an arcuate orbit of the drive ring via the crank and the link arm.   The variable diffuser of claim 1, further comprising a series of drive pins extending from the drive ring to engage each of the plurality of diffuser vanes.   The variable diffuser according to claim 1, further comprising a series of vane pins, wherein each of the plurality of diffuser vanes is rotatable about the vane pin. An electric motor,
A compressor capable of being driven around the center line by the electric motor;
A variable diffuser downstream of the compressor;
A rotating machine equipped with
The variable diffuser is
A drive ring rotatable about the center line;
A crank rotatable around a rotation axis different from the center line;
A link arm pivotably attached to the crank and the drive ring;
A plurality of diffuser vanes engaged with the drive ring;
With
The plurality of diffuser vanes can move simultaneously between a maximum flow position and a minimum flow position according to rotation of the crank that rotates the drive ring around the center line via the link arm. A rotating machine characterized by being.   The rotating machine according to claim 6, further comprising an inlet defined along the center line.   The rotating machine according to claim 6, further comprising a radial outlet.   The rotating machine according to claim 6, further comprising an actuator, wherein the actuator is operable to rotate the crank around the rotation axis different from the center line.   10. The rotating machine according to claim 9, wherein the rotational motion of the actuator is converted into the motion of an arcuate track of the drive ring via the crank and the link arm.   The rotating machine according to claim 6, wherein the rotating machine is a cabin air compressor configured to pressurize outside air and supply air into an aircraft cabin.

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