JPH03149449A - Electromotive differential type thrust generator - Google Patents

Abstract

PURPOSE:To realize a super precision motion by freely reducing a motor rotation by means of differential type bevel gears, and rotating a delivery screw nut, and putting a delivery screw shaft through a main body inside, and fixing at a base stand both ends of this shaft, and making the main body finely regulatable. CONSTITUTION:At the inside of a main body A, a stator is fitted, and a rotor 2 is put on a motor hollow shaft 1, and a fixed bevel gear 6 is put on through a propulsion bearing 9. An inclined eccentricity portion 14 is formed at the end of the hollow shaft, and a thrust bearing 15 is put at its outer periphery portion, and an input both side bevel gear 7 meshing with the fixed bevel gear 6 is supported. Next, an output bevel gear 8 meshing with the input gear 7 is provided, and a pressurizing ball delivery screw nut 12 is put inside this output shaft, and at the outer periphery of the output gear 8, fixation at the main body A is done by combining thrust bearings 10. Clearances among the teeth of respective gears 6, 7, 8 are made to be zero by means of a pressurizing pipe 13, and in addition, a delivery screw shaft 11 is put through the inside of the hollow shaft 1, and its both ends are fixed at a base stand 13. As mentioned above, movable parts are few, and there is not rattling between tooth- surfaces, so transmission efficiency becomes high, and a super precision motion becomes possible.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides a linear actuator that is more powerful and more accurate in operation and can be used in all fields in place of the conventional linear actuator that generates thrust mainly by pneumatic or hydraulic cylinders. The present invention relates to a pure electric differential thrust generator.

(Prior Art) Conventionally, pneumatic or hydraulic cylinders have been most used as linear thrust generating devices, and several million cylinders are produced annually in Japan. In particular, most of the steering systems for aircraft are hydraulic, and a large number of hydraulic cylinders are used. The advantage of the hydraulic system is that by increasing the pressure, the thrust increases
Furthermore, since the cylinder body can be made smaller, it is currently used in control systems for jet fighters, jumbo jets, and even space rockets. However, the disadvantage of this method is that the higher the hydraulic pressure, the thicker and heavier the hydraulic pump and hydraulic piping become, and the larger the size, the heavier the weight, and the higher the risk of damage to seals and valves, making it less safe. On the contrary, it decreases. Therefore, recently there has been a trend to lower the oil pressure, which has led to larger piston diameters and larger hydraulic piping diameters, and an increase in the amount of oil.

Of course, the same applies to hydraulic cylinders for general industrial machinery, and in highly reliable machines, the hydraulic pressure is set low to stabilize it.

(Problems to be Solved by the Invention) Recent aircraft accidents have also been caused by hydraulic systems, and as transportation capacity increases, more lives tend to be lost.

In Japan, since the accident involving a jumbo jet, the Ministry of International Trade and Industry and the rest of the country have been working to develop pure electric systems to replace hydraulic systems as a countermeasure.Recently, a control motor and hydraulic pump have been directly connected to a hydraulic cylinder in order to eliminate hydraulic piping. An attached electro-hydraulic cylinder has also been developed. However, due to the characteristics of oil such as viscosity, compressibility, flammability, and deterioration, there are still problems in maintaining accuracy, reliability, and safety for unmanned control.

(Means for Solving the Problems) Therefore, as described above, the present invention aims to arbitrarily reduce the rotational force of an electric motor using a differential bevel gear mechanism in place of the conventional thrust generating cylinder using air pressure or oil pressure, and generate output gears. The feed screw nut formed in the hollow shaft is rotated, the feed screw nut is fitted onto the feed screw nut, the feed screw shaft is passed through the inside of the main body, both ends or one end of which are fixed on the base, and this speed reduction mechanism is used to hold the main body slightly. The purpose is to provide a pure electric thrust generator that is adjustable and enables powerful, ultra-precise movement.

(Embodiment) In order to achieve the above object, the present invention provides an embodiment of the present invention with reference to the drawings. Install the rotor (2
) onto the motor hollow shaft (1), and then fit the fixed bevel gear (
6) through the thrust bearing (9), the hollow shaft end is tilted eccentrically (14), and the thrust bearing (15) is fitted on the outer circumference of the shaft.
) into which the input double-sided bevel gear meshes with the fixed bevel gear (
7) is supported on the shaft. Next, an output bevel gear (8) that meshes with this input bevel gear (7) is provided, and a preload ball screw feed nut (12) is fitted inside this output shaft, and a large number of screws are attached to the outer periphery of the output bevel gear (8). The thrust bearing (lO) is combined to form the main body (A).
and the number of teeth (Nl) of the fixed bevel gear (6), the number of teeth (N2) and (N3) of the input bevel gear (7), and the number of teeth (N4) of the output gear (8), etc. They are preloaded together and the gap between the teeth is maintained at zero using a preload cylinder (13).

Further, a feed screw shaft (11) fitted into the feed screw nut (12) passes through the hollow shaft of the armature, and its both ends are fixed on the base (B).

In addition, an electromagnetic brake (4) is installed to prevent reverse thrust during a power outage.
and an encoder (5) for accurate positioning.
) can be installed.

In the drawing, (16) is a linear guide for sliding the main body.

(Function) The electric differential thrust generator configured as described above has the number of teeth (Nu) of the fixed bevel gear (6) of the double-sided differential bevel gear, the number of teeth on the input side of the input bevel gear (7) ( NZ), by selecting the number of teeth on the output side (N1) of the same gear (7) and the number of teeth (N4) of the output gear (8) to arbitrary numbers of teeth, the number of teeth can be reduced from 10 times to several 1.0.
00 times more torque can be obtained.

The reduction ratio is approximately I Nl XN3
− = 1−□ Nz XN4. For example, N, = 27, Nz, N3.

If N, = 30, then 1 27 x 30 3 - = 1 - = - R30 x 30 30 ■ = 10□, and the output gear (8) will rotate 1/10 in the normal direction, and therefore its torque will be 10 times the motor torque.

Another example is NI=37. Nz =40. N3 = 5
If 4, N, = 50, then 1 37X54 - = 1-□ R40X50 1.998 1 = 1-- = +□ 2.000 1,000, and the output gear (8) is l/l, 000 square. Therefore, the torque is 1.000 times the motor torque.

For accurate positioning, attach the to,
If an ooo pulse encoder (5) is installed and the reduction ratio is 1/R = 1/100 as an example, then 100 x 10,000 pulses = 1,000,000 pulses will rotate the output shaft 71 times, and conventional motor rotation control can be performed using switching control. For example, Daibanshi lO
This is a degree error (360 degrees per rotation), but mechanically this accuracy can be improved 100 times. It can also be said that the use of servo motors has made it possible for the first time to perform positioning with near-ultimate precision even under high loads.

Also, by rearranging the electric motor on the output side of this device and the screw nut on the input side, it is natural that the device can be used as a speed increasing device.

(Effects of the Invention) Since the present invention is configured as described above, when it is combined with a gear reduction mechanism, a worm gear, and a planetary gear mechanism commonly used in the past, which achieve the effects described below, The number of moving parts alone consists of several tens of parts, but in the present invention, only a motor shaft and an input double-sided bevel gear are included.

There are only four moving parts: the output bevel gear and the feed screw shaft, and product variations due to part precision and errors have been reduced to less than one-tenth. In addition, since both sides of the tooth surfaces of each gear in the differential bevel gear mechanism could be preloaded, the gap between the tooth surfaces became zero, and there was no backlash. In a conventional planetary reduction mechanism, at least a three-stage gear would have a play of 6/100 or more. Also, due to the high transmission efficiency, the sliding wear and heat generation that were seen with conventional worm reducers are completely eliminated.

Since the present invention has completed a pure electric high-thrust cylinder, if this is used in the control mechanism of aircraft and space rockets, it will be possible to use the hydraulic pump, hydraulic cylinder, each control valve, and long hydraulic piping using the conventional hydraulic system control mechanism. It eliminates the need for many elements, such as the above, and enables high-precision, highly reliable control with fewer elements as described above. It is also lightweight and low-cost, making a significant contribution to accident prevention and respect for human life. This can be called a groundbreaking invention.

[Brief explanation of the drawing]

The drawing is a partially cutaway front longitudinal sectional view. 1. Motor hollow shaft 2. Rotor 3. Stator 4. Electromagnetic brake 5. Encoder
6. Fixed bevel gear 7. Input double-sided bevel gear
8...Output bevel gear 9...Fixed gear thrust bearing lO.Output gear thrust bearing 11.Feed screw shaft 12.Feed screw nut 13.Preload cylinder 14.Hollow shaft inclined eccentric part 15.Input bevel gear thrust bearing 16.Linear Guide A...
Body B... Base N1... Number of teeth of fixed bevel gear

Claims (1)

[Claims] A main body of an arbitrary rectangular parallelepiped or cylindrical body is provided, and a hollow shaft electric motor and a hollow shaft double-sided differential bevel gear mechanism with a difference in the number of teeth of one or more teeth are disposed in the main body, and a hollow shaft of the hollow shaft of the motor rotor is provided. The input double-sided bevel gear of the differential bevel gear mechanism is supported on the coaxial outer periphery with one end tilted and eccentric, and a feed screw nut is formed inside the hollow shaft of the output bevel gear of the gear mechanism, and the feed screw nut An electric differential thrust generator characterized in that a feed screw shaft inserted into the electric motor passes through the hollow shaft of the electric motor.