JP2008008470A - Electric actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excellent electric actuator capable of securing an operational function even if a failure occurs in a part thereof. <P>SOLUTION: A torque limiter 7 is interposed between a first rotation member 3 operating a first output member 5, and a second rotation member 4 operating a second output member 6. In a state where either of the output members 5 and 6 has caused jamming, when the other-side rotation member 4 or 3 is intended to be driven, connection of both the rotation members 3 and 4 by the torque limiter 7 is cut off. As a result, either of the rotation members 4 and 3 is allowed to relatively rotate with respect to the other side, and the operational function of the output member 6 or 5 without having caused the jamming is maintained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electric actuator used for a drive system of an aircraft, a general industrial machine or the like.

For example, an aircraft steering surface drive system is configured by arranging control surfaces such as slats and flaps on the front and rear edges of a main wing and attaching actuators that cause the operation of the control surfaces. Many actuators that are hydraulically driven are disclosed in the following patent documents.
JP 2002-323010 A

  The hydraulic drive actuator requires a pump serving as a hydraulic source, a hydraulic supply circuit, and hydraulic oil, which tends to increase the weight of the system. In addition, hydraulic oil leakage cannot be completely avoided, and maintenance is troublesome. Under such circumstances, it has been studied to replace the hydraulic drive actuator with an electric actuator (which does not use hydraulic pressure). On the other hand, especially when mounted on an aircraft, a multiplexing mechanism that can maintain the function even if a failure occurs in a part of the actuator is an essential requirement.

  The present invention made in view of the above is intended to realize a suitable electric actuator in which an operation function is ensured even if a failure occurs in part.

  The electric actuator according to the present invention is transmitted via the first motor, the first rotating member that rotates by receiving the driving force output from the first motor, and the first rotating member. A first output member that operates due to the driving force, a second motor, a second rotating member that rotates in response to the driving force output by the second motor, and the second motor Torque transmitted between the second output member that operates due to the driving force transmitted through the rotating member, the first rotating member and the second rotating member; and And a torque transmission mechanism that allows one rotating member to rotate relative to the other rotating member when an excessive transmission torque of a predetermined level or more is applied.

  The electric actuator normally operates the first output member mainly by the first motor and operates the second output member mainly by the second motor. The required components in the system can be driven using the above operations. In addition, since the first rotating member and the second rotating member are connected via the torque transmission mechanism, the second output member can be operated by the first motor. It is also possible to operate the first output member by this motor. Therefore, even if one of the motors cannot be started due to an electrical system failure or the like, the operation function of the output member is maintained if the other motor can be started.

  Furthermore, if any output member jams and malfunctions, the rotating member on the side corresponding to the output member becomes difficult to rotate, but the rotating member on the opposite side rotates. If it is dynamically driven, an excessive transmission torque exceeding a predetermined value acts on the torque transmission mechanism, and as a result, the connection between both rotating members is substantially released. Thereby, the operation function of the output member which has not caused jamming is still maintained.

  According to the present invention, it is possible to realize a suitable electric actuator that ensures an operation function even if a failure occurs in part.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the electric actuator of this embodiment arrange | positions the 1st output member 5 and the 2nd output member 6 on a substantially concentric axis | shaft, and the operation direction which mutually opposes both the output members 5 and 6 is shown. It is designed to be able to operate. This electric actuator is mounted on a control surface driving system of an aircraft, for example. That is, the front end of one output member 6 is connected to the aircraft body side, and the front end of the other output member 5 is connected to the control surface side, so that the control surface is used to advance or retreat.

  The electric actuator includes a plurality of electric motors 1 and 2, and drives the output members 5 and 6 by the driving force output by the motors 1 and 2. More specifically, the first motor 1 rotates the first rotating member 3 via the first transmission mechanism 8 and operates the first output member 5 through the rotation of the rotating member 3. . The second motor 2 rotates the second rotating member 4 via the second transmission mechanism 9 and operates the second output member 6 through the rotation of the rotating member 4. The first transmission mechanism 8 and the second transmission mechanism 9 are gear transmission mechanisms each having a meshing gear train as an element. The proximal end portions of the transmission mechanisms 8 and 9, the rotating members 3 and 4 and the output members 5 and 6 are housed in the casing, and only the distal end portions of the output members 5 and 6 protrude outside the casing.

  Between the rotating members 3, 4 and the output members 5, 6, an operation conversion mechanism for converting the rotation of the rotating members 3, 4 into the forward / backward movement of the output members 5, 6 is interposed. In the present embodiment, the screw shaft portions 51 and 61 are provided on one of the rotating members 3 and 4 and the output members 5 and 6 (in the illustrated example, the output members 5 and 6), and the other (the rotating members 3 and 4 are provided). ) Are provided with screw nut portions 31 and 41 to constitute a screw feeding mechanism, particularly a ball screw mechanism. When the rotating members 3 and 4 rotate around the axis A, the output members 5 and 6 advance or retract along the axis A direction.

  In addition, a torque limiter 7 serving as a torque transmission mechanism is interposed between the first rotating member 3 and the second rotating member 4. With this torque limiter 7, torque can be transmitted from the first rotating member 3 to the second rotating member 4 and from the second rotating member 4 to the first rotating member 3. However, when the transmission torque acting on the torque limiter 7 exceeds a predetermined value, the transmission of the torque is cut off, and the one rotating member 3, 4 rotates relative to the other rotating member 4, 3. Allow to move.

  In normal times, the first motor 1 rotationally drives the first rotating member 3, and the second motor 2 rotationally drives the second rotating member 4, so that the first output member 5 is driven. And the second output member 6 is actuated. Since both the rotating members 3 and 4 are connected via the torque limiter 7, these rotating members 3 and 4 rotate in the same direction while being force-fighted, and the output members 5 and 6 are opposite to each other. Move in the direction. That is, the distance between the tips of the output members 5 and 6 expands or contracts depending on the driving direction of the motors 1 and 2.

  Even if one of the motors 1 and 2 cannot be started due to a failure of the electric system or the like, both output members 5 and 6 are operated if the other motors 2 and 1 can be started. be able to.

  Further, when a foreign object enters the ball screw, the ball is broken, or the gear teeth in the transmission mechanisms 8 and 9 are damaged, the output members 5 and 6 are jammed. If any one of the output members 5 and 6 is malfunctioning, the rotation members 3 and 4 on the side corresponding to the output members 5 and 6 are also difficult to rotate. At this time, if the rotating members 4 and 3 on the opposite side are rotationally driven, an excessive transmission torque exceeding a predetermined value acts on the torque limiter 7, and the torque transmission is blocked by the function of the torque limiter 7. . As a result, the connection between the rotating members 3 and 4 is substantially released, and the one rotating member 4 and 3 can rotate relative to the other rotating member 3 and 4. In other words, the series that operates the first output member 5 and the series that operates the second output member 6 are mechanically separated. As a result, the output members 6 and 5 that are not jammed can still be operated.

  The electric actuator of the present embodiment includes a first motor 1, a first rotating member 3 that rotates by receiving a driving force output from the first motor 1, and the first rotating member 3. The first output member 5 that operates due to the driving force transmitted through the second motor 2, the second motor 2, and the second rotation that rotates by receiving the driving force output from the second motor 2. A member 4, a second output member 6 that operates due to a driving force transmitted through the second rotating member 4, the first rotating member 3, and the second rotating member. The torque can be transmitted to and from 4 and one of the rotating members 4 and 3 is rotated relative to the other rotating members 3 and 4 when an excessive transmission torque exceeding a predetermined value is applied. A torque transmission mechanism 7 that allows the motors 1 and 2 to output, even if one of the motors 1 and 2 cannot be started, the remaining motors 2 and 1 output. It is possible to operate the timber 6,5. In addition, even if one of the output members 5 and 6 is malfunctioning, the other output member 6 and 5 can still be operated.

  The present invention is not limited to the embodiment described in detail above. For example, the torque transmission mechanism is not limited to a torque limiter that cuts off the connection between both rotating members when an excessive torque is applied. It is also conceivable to employ a friction clutch (slip clutch) or the like as a torque transmission mechanism that transmits torque through friction of a plurality of friction plates and generates a slip when an excessive torque is applied to limit the transmission torque.

  The transmission mechanism is not limited to a gear transmission mechanism, and may be a winding transmission mechanism using a belt, a chain, or the like.

  Further, the output member does not necessarily move forward and backward along the axial direction. The output member may rotate around the axis, and in this case, an operation conversion mechanism that converts the rotation of the rotation member into the advance / retreat movement of the output member is not necessary.

  Other specific configurations of the respective parts are not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

Sectional drawing which shows the electric actuator of one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... 1st motor 2 ... 2nd motor 3 ... 1st rotation member 4 ... 2nd rotation member 5 ... 1st output member 6 ... 2nd output member 7 ... Torque transmission mechanism

Claims (1)

A first motor;
A first rotating member that rotates in response to a driving force output by the first motor;
A first output member that operates due to a driving force transmitted through the first rotating member;
A second motor,
A second rotating member that rotates in response to a driving force output by the second motor;
A second output member that operates due to the driving force transmitted through the second rotating member;
Torque can be transmitted between the first rotating member and the second rotating member, and when an excessive transmission torque exceeding a predetermined level is applied, one rotating member is the other rotating member. An electric actuator comprising: a torque transmission mechanism that allows rotation relative to the actuator.

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