JPS58180869A - Locking device for motor-driven thruster - Google Patents

Abstract

PURPOSE:To enable to retain a threaded shaft in position even when an overload is exerted on the shaft, by a method wherein a gear fitted to a threaded shaft and a gear engaged with said gear are formed to be helical gears having tooth traces in the spiral direction opposite to that of the threads of the shaft. CONSTITUTION:When an external force A is exerted on a rectilinear operating member 6 in a retracting direction under the condition where the rotation of a motor M is stopped by braking, a torque of rotation T1 in the direction of an arrow which is generated in the threaded shaft 5 and a torque of rotation T2 in the direction of an arrow which is generated when the helical gear 4' is moved along the tooth trace in a diagonal direction of the helical gear 3' being immobilized are canceled by each other. As a result, the helical gear 4' can not be easily rotated, and axial movement thereof becomes impossible when the helical gear 4' is not rotated. Consequently, the rectilinear operating member 6 can not be retracted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for locking a linear actuating member in a position where linear movement of the linear actuating member has stopped in a conventionally known electric thruster.

Conventionally, in electric thrusters, the rotational motion of a screw shaft is converted into the linear motion of a member screwed into the screw shaft, and the driven member connected to the member is operated by the forward and backward movement of the member. A transmission gear train is arranged between the motor drive shaft and the screw shaft to drive the motor, but since the gears used in this gear train are all spur gears, even when the motor is stopped, When an overload is applied to the direct actuating member, the screw shaft slides in the direction of the teeth of the spur gear, causing the actuating member to fail to maintain its position.

That is, to explain FIG. 1, the motor MU casing BK is attached, and the motor drive shaft DK is connected to the small spur gear 1.
and the cam plate CIn 02+ C for actuating the direct operating member stroke regulation limit switch via the reduction gear WtR.
I+04 is fixed to the deceleration shaft so that its mounting angle can be adjusted, and a potentiometer P for detecting the position of the linearly actuated member is provided at the end of the deceleration shaft. A small gear 6 is fixed to the large gear 2 that meshes with the small gear 1, a large gear 4 meshes with the small gear 6, the large gear 4 is attached to a screw shaft 5, and the small gear 1 , 3, and the large gears 2 and 4 form a reduced transmission gear. Threaded portion 5' of MiJ screw shaft 5
The linear actuating member 6 screwed into the member 6 moves in a cylindrical portion 7 formed in the casing B in a linearly movable manner in the axial direction, and the tip of the linear actuating member 6 is connected to the tip of the cylindrical portion 7. It protrudes further and is connected to the driven member.

Further, inner races 8 and 9 of a conical thrust bearing are fixed on the screw shaft 5 at a distance in the axial direction, and the outer races 8' and 9' are annular front parts that pinch both ends of the compression spring 100, respectively. Spring receiver member 11 and rear spring receiver member 12
The inner laces 8 and 9 and the outer lace B
', 9' are constructed so that they can be separated and moved from each other, so the inner races 8, 9 move together with the screw shaft 5, and the outer races s/, 9/rs, respectively, are connected to the front spring bearing member 11.
and 12. and front spring receiving member 1
1 and the rear spring bearing member 12 are the front wall of the storage chamber 13 of the annular compression spring 10 formed in the casing B, and the spring bearing 11i 16.1 which is the rear IT stopper surface 14 and 15.
7 and a spring guide direction 18,19, the front spring receiving member 1
1 has a guide surface 21 formed on the rear spring receiving member 12 to guide the guided direction 20, and also has a sliding portion slidably supported on the screw shaft 5, and a bell seal member 22 is attached to the sliding portion. The screw shaft 5 is sealed between the screw shaft 5 and the front spring receiving member 11, and a sealing member 25 is attached to the surface that slides on the inner surface of the compression spring storage chamber 13, so that the front spring The inner chamber of the casing of the ms actuating member 6@ of the receiving member 11 is liquid-tight with the inner chamber of the casing of the rear spring receiving member 121i11. An IJ switch striker member S is attached to the rear end of the screw shaft 5 via a bearing, and a seal member 24 is attached to the rotating sliding surface IIJJ of the striker 1 material 8 and the screw shaft 5. Since a sealing member 25 is attached to each of the front and rear fingers of the partition wall B' and the partition wall B', the large spur gear 4m of the partition wall B' and the striker member SII are liquid-tight.

Therefore, in FIG. 1, a striker S and a limit switch (not shown) actuated by the striker
, a control room y that houses electric control mechanisms such as potentiometers P1 and cam plates 01 to 04, and a drive unit that is housed above the deceleration train. The working chamber G, which houses the threaded part 5' and the linear actuating member 6, is partitioned in a liquid-tight manner, and the driving chamber F is filled with a somewhat fluid grease suitable for lubrication and maintenance of the transmission mechanism. Since grease easily deteriorates, suitable lubricating oil can be filled in the chamber G, and the control chamber mV
It is possible to completely prevent the inflow of grease or other oils that would interfere with cFi electrical control.

Therefore, to explain the operation of the electric thruster, the cam plate C1
The angle M1 of ~C4 is adjusted to give the desired stroke to the linear actuating member 6, and when the motor Mk is started, the screw shaft 5 is rotationally driven through one train of wheels, causing the linear actuating member 6 to protrude and move forward. When the cam plates 01 to 10 move forward by a predetermined distance, the drive shaft of the motor M rotates via the speed reduction device 1ltRa.
04 rotates a predetermined angle and hits a limit switch (not shown), the motor M is stopped and the linear actuating member 6 is completely stopped in its forward movement. Retraction of the linear actuating member 6 is also performed by a reverse operation of the forward movement.

When a shock load or other overload in the backward direction due to an external force is applied to the linear actuating member 6, the screw shaft 5 screwed into the linear actuating member 6 moves backward, and the inner race 8 of the front thrust bearing The front spring receiving member 11 is moved rearward together with the outer race 8', and its spring receiving surface 16 is compressed by the compression spring 10, thereby buffering the impact load and the like to prevent damage to the operating members, etc. The striker member 8 hits a limit switch (not shown) to stop the drive of the motor Mo, and prevents the remoter M from burning out by eliminating excessive load sound rays applied to the motor M. At this time, the inner race 9 of the rear thrust bearing separates from the outer race 9' and retreats together with the screw shaft 5.

When an impact load or other overload due to an external force in the tensile direction, that is, in the forward direction, is applied to the linear movement +111 material 6, the screw shaft 5 moves forward together with the linear movement member 6, and the inner race 9 of the rear thrust bearing is moved forward by the outer race 9''. The forward movement of the front spring receiving member 11 is stopped by the stopper surface 14 of the spring storage storm 16, so the spring receiving surface 17 is compressed into the compression spring 10. It buffers zero loads, etc., moves the striker member BB forward and hits a limit switch (not shown), and stops the drive of the motor M.At this time, the inner race 8 of the front thrust bearing is separated from the outer race 8'. In this way, the sound of a failure caused by an equalizing load or other overload caused by an external force of the electric thruster is prevented. If an overload due to an external force in the axial direction is applied to the motor M, even if the motor M is braked, the line input wheel 4 will hit the teeth of the pinion 6 when the pinion 3 and the big gear 4 are spur gears. Since the linear actuating member 6 can be easily moved in the axial direction,
Because the actuated member connected to the tip of the linear actuating member 6 moves, an unforeseen accident occurs. For example, if the actuated member is a hopper discharge gate, the result is that the discharge gate, which is held in the closed position by the linearly actuated member 6, opens ajar, allowing the hopper contents to leak out.

Therefore, the present invention provides a large wheel 4 attached to the screw shaft 5.
By using helical gears 4' and 3' as the pinion gears 5 meshing with the helical gears 4' and 3', the linear actuating member 6 is locked at its stop position.

That is, to explain the action in FIG. 2, when the outer cam in the backward direction acts on the linear operating member 6 while the motor M is braked and its rotation is prevented, the threaded portion 5' of the threaded shaft moves to the right. In the case of a screw, the tooth trace of the helical gear 4' attached to the screw shaft should be in the left-hand thread direction, and if the threaded portion 5' of the screw shaft is a left-hand thread, the tooth trace of the helical gear 4' should be in the right-hand thread direction. , a helical gear 6' that cannot rotate due to the rotational torque Tl generated in the screw shaft 5 in the direction of the arrow and the brake applied to the motor M.
Since the rotational torque T3 in the direction of the arrow generated when the helical gear 4' moves along the diagonal tooth line of the arrow T3 cancels each other out, it becomes difficult for the helical gear 4' to rotate, and the helical gear 4' When it does not rotate, it becomes impossible to move in the axial direction, and as a result, the linear actuating member 6 cannot retreat.

Further, even when an external force in the forward direction is applied to the linear actuating member 6, the linear actuating member 6 cannot move forward for the same reason as described above.

The degree of locking can also be adjusted by arbitrarily setting the twist angle of the teeth of the helical logic wheel.

Therefore, even if an external force acts on the linearly actuating member 6 in the axial direction, the linearly actuating member 6 will remain locked at its stop position when the motor M is braked.

However, it goes without saying that when the motor M is rotating, the helical gear 4' can easily mesh with the helical gear 3' and move in the direction of its tooth traces.

As described above, the present invention is applicable to Yang Tseng which is subjected to an impact due to an external force in the axial direction or other overload during the operation of a linear operating member.
Not only can the screw shaft move in the axial direction to loosen the motor and turn off the power to the motor to stop the motor, but it can also apply a brake to the motor and lock the stopping position of the linear operating member, so it can be stopped easily. Even if an impact or other overload is applied to the linearly actuating member, the linearly actuating member does not move, and the actuated member connected to the linearly actuating member can maintain its position, resulting in high reliability. It is capable of performing linear motion operations.

[Brief explanation of the drawing]

Figure 11! i indicates an embodiment of the present invention, and FIG. 1 is a sectional view;
FIG. 2 is an explanatory diagram of the locking action. 61, 4/...--Rical gear 5...Screw shaft 6
...Linear operating member. Patent attorney Takeshi Yukawa - 1 other person

Claims (1)

[Claims] In an electric thruster having a linear actuating member that is screwed onto a screw shaft that is rotationally driven by a motor and is completely prevented from co-movement, the screw shaft is a transmission gear train arranged between the screw shaft and the motor drive shaft. A locking device in which a gear attached to the shaft and a gear meshing with the gear are helical gears having tooth traces in a direction opposite to the thread of the screw shaft.