JPH01203798A - Reduction gear mechanism for motor-driven universal head - Google Patents

Abstract

PURPOSE:To suppress vibration and noise by executing correct start and stop by installing a ring-shaped pressing member which contacts a trailing roller from the input side in the axial direction and a receiving plate shaped flange member which contacts the trailing roller from the output side in the axial direction. CONSTITUTION:A receiving plate shaped flange member 14 having a collar part projecting to the input side is arranged on the output side of a trailing roller supporting member 12, and a ring-shaped pressing member 13 is arranged on the input side of a trailing roller 9. When an input revolution shaft 7 is applied with revolution by the drive of a motor installed outside, a center roller 8 revolves, and the trailing roller 9 in contact with the center roller 8 revolves, and the trailing roller supporting member 12 which fixes the rotation shaft 10 of the trailing roller 9 revolves concentrically in the same direction to the center roller 8. Further, the flange member 14 in contact with the trailing roller 9 in revolution revolves in the same direction to the trailing roller 9, and an output rotary shaft 15 is revolved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a deceleration mechanism for electric operation of a pan head for directional movement of photographic equipment such as a video camera mounted on a tripod.

(Prior Art) Recently, photographing devices such as video cameras have become popular, and users are becoming more independent when photographing sports days, weddings, wildlife, and other outdoor activities.

Since such a camera is heavy, it is often operated by being mounted on a tripod to save labor. In this case, directional movement operations such as horizontal rotation or vertical movement of the camera attached to the pan head are often performed electrically. In particular, when photographing wild animals such as wary wild birds, the camera is placed close to the subject, and the photographer uses an electric cloud to remotely control the direction of the camera from a distance or from inside an awning. Requires a stand. An electric pan head is also required when connecting a camera to a monitor television to take pictures with a desired composition.

Such an electric pan head has a structure shown in FIG. 5, for example. The electric pan head attached to a tripod A installed on the ground has a horizontal rotation mechanism B and a vertical movement mechanism C that are connected to each other, and a support is fixed to the upper surface of the body of the vertical movement mechanism C. Then, fix camera E to the same support with screws. The horizontal rotation mechanism B and the vertical movement mechanism C each have a ring gear F.

The camera is horizontally rotated and moved up and down by rotating G. The drive mechanism including the motor is housed in a reduction gear case H, and is operated by a person in the background using an operation panel J.

By the way, electric camera heads move the camera at a constant speed, but in order to obtain the required movement speed, the rotational speed of the motor is drastically reduced via a deceleration mechanism. There is. This conventional speed reduction mechanism is usually configured to combine a large number of gears with different diameters to obtain the required deceleration in multiple stages, and is housed in a speed reducer case.

(Problem to be Solved by the Invention) However, in gear transmission, play, or buff crash, is essential between the combined gears in order to ensure smooth transmission. As a result, deceleration loss is large. Therefore, there are performance problems such as the camera not stopping exactly at the desired position when moving, and a time lag occurring when restarting from a stopped state or starting in reverse rotation, resulting in so-called screen blur. Moreover, the drive motor is also relatively large, and there is a limit to the reduction in weight and size of the reduction gear device for the pan head. Furthermore, there is a problem in that continuous vibration noise is generated due to gear transmission during driving, and when a sound collection microphone is used to take a picture, this sound is recorded as noise.

Therefore, it is an object of the present invention to reduce deceleration loss, enable accurate starting and stopping of the photographic camera during directional movement, suppress vibrations and noise, and further provide a high deceleration ratio in the - stage so that the number of components can be reduced. The object of the present invention is to provide a speed reduction mechanism that can be downsized.

(Means for Solving the Problems) In order to achieve this object, the present invention provides a center roller that is coaxial with an input rotating wheel and has a V-shaped groove on its outer peripheral surface, and that contacts the V-shaped groove of the concentric roller on its outer surface. a plurality of spherical driven rollers each having a rotation axis and rotatable; a driven roller support member that supports the end of the rotation axis of the driven roller and is rotatable concentrically with the center roller; and an axial input side of the driven roller. a ring-shaped pressure member having a tapered surface on its inner periphery that contacts the pressure member; a pressure member that presses the pressure member in the axial direction from the input side; and a pressure member that is coaxial with the output rotating shaft and contacts the driven roller from the axial output side. The present invention provides a speed reduction mechanism suitable for an electric pan head, which is comprised of a rotatable saucer-like flange member having a tapered surface on the inner periphery of a flange portion projecting toward the input side.

(Function) When the input rotating shaft is rotated by the drive of an externally attached motor, the center roller rotates, and the driven roller that is in contact with the same center roller moves, fixing the rotating shaft of the driven roller. The driven roller support member rotates concentrically and in the same direction as the center roller.

That is, the driven roller forms a planetary roller mechanism in which the driven roller revolves around the center roller as an axis while rotating on its own axis.

Furthermore, the flange member that is in contact with the rotating driven roller rotates in the same direction as the driven roller, and thus the output rotating shaft rotates. In other words, a differential mechanism operates due to the difference in the contact area between the pressure member and the flange member of the driven roller. In the end, the camera mounting member fixed to the output rotation shaft rotates at a slow speed according to the high reduction ratio obtained by the above-mentioned two mechanisms.
After Rotating the Installed Photographic Camera (Example) Hereinafter, details of an example in which the deceleration mechanism of the present invention is applied to the vertical movement mechanism will be explained with reference to the drawings. Fig. 1 is a cross-sectional view of the main part of an electric pan head equipped with the deceleration mechanism of the present invention, Fig. 2 is a partially cutaway perspective view of the main part of the deceleration mechanism of Fig. FIG. 4 is a cross-sectional view taken along the line mm--m in the figure, and FIG. 4 is a cross-sectional view taken along the line IV--IV in FIG.

In FIG. 1 and FIG. 2, the speed reduction mechanism according to the present invention is
They are housed in the housing 1 as one unit.

A drive motor 2 is attached to the outside of the housing 1, and the shaft end of the motor shaft 3 of the motor 2 is inserted into the housing 1 through a hole in the housing lid 4, and a small gear 5 can be attached to the coaxial end. be. A large gear 6 meshing with the small gear 5 is attached to an input rotation shaft 7, and a center roller 8 having a V-shaped groove 8a on the outer peripheral surface of the same shaft is connected to the input rotation shaft 7. Three spherical driven rollers 9 are arranged on the outer periphery of the concentric roller 8 so as to uniformly contact both sides of the V-shaped groove 8a. The driven rollers 9 each have an input rotation shaft 7.
It has a rotating shaft 10 parallel to the axial direction as a central axis, and six needle rollers 11 are fitted around the rotating shaft 10. Therefore, each of the driven rollers 9 is rotatable about the rotation axis 10. These rotation axes 10
are each fixed at both ends to a driven roller support member 12, and this driven roller support member 12 is rotatable concentrically with the input rotating shaft 7. The outer surface of the driven roller 9 is
The driven roller 9 is held in contact with the tapered surfaces 13a and 14a of the opposing pressure member 13 on the input side and the flange member 14 on the output side, respectively. That is, on the output side of the driven roller support member 12, a saucer-shaped flange member 14 having a flange portion protruding toward the input side is arranged, and the inner peripheral surface of the flange portion is connected to the outer surface of the three driven rollers 9. The flange member 14 has a tapered surface 14a in contact with the flange member 14, and an output rotating shaft 15 extending toward the rear side is fixed to the flange member 14 with a pin 16, and the output rotating shaft 15 is supported by a radial bearing 17. The flange member 14 is in contact with the driven roller 9, and is rotatable with respect to the housing l on the rear side with a thrust bearing 18 interposed therebetween.

Next, a ring-shaped pressure member 1 is placed on the input side of the driven roller 9.
The pressure member 13 has a tapered surface 13a on the inner circumference of the ring, and is fitted into the inner wall of the housing 1 so as to be slidable in the axial direction. They each make point contact with the outer surface of the roller 9. Furthermore, a spring body 19 is disposed in a ring shape on the input side of the pressure member 13, and by covering the spring body 19 and attaching the housing lid 4, the spring body 19 applies pressure to the pressure member 13. It is meant to be used as a means. Further, a rotating member 20 is fixed to the output rotating shaft 15 with a set screw 21, and a camera mounting member 23 to which a camera mounting base 22 is fixed is screwed to the rotating member 20. A restraining plate 24 is mounted on the top. Furthermore, the above speed reduction mechanism is attached to the horizontal rotation mechanism 26 via the attachment member 25.

In the illustrated embodiment described above, the pressure member 13 is urged toward the output side in the axial direction by the spring body 19 within the housing 1, and its tapered surface 13a makes point contact with each of the three driven rollers 9. The driven roller 9 further includes a flange member 14.
The flange member 14 is in point contact with the tapered surface 14a of the flange member 14, and pressurizes the flange member 14 in the axial direction. Therefore, when the motor 2 is switched on, the input rotation shaft 7 is connected via the small gear 5 and the large gear 6.
When the center roller 8 is rotated, the center roller 8 fixed to its tip coaxially with the center roller 8 rotates, and the three driven rollers 9 that are in contact with both sides of the V-shaped groove 8a of the center roller 8 rotate around the rotation axis 10. It rotates around the center roller 8 in the opposite direction, and also revolves concentrically with the center roller 8 in the same direction. As a result, the flange member 14 rotates in the opposite direction and transmits the rotation to the output rotating shaft 15.

Therefore, the camera mount 22 is attached via the rotating member 20 and the like, and moves up and down about the output rotation shaft 15.

As can be seen in the above embodiments, the speed reduction mechanism of the present invention consists of a center roller 8 that rotates around a fixed center and corresponds to a sun roller, and a driven roller that rotates around the center and corresponds to a planetary roller that rotates on its own axis. It has a planetary roller mechanism consisting of rollers 9, and further includes a tapered surface 1 of the pressure member 13.
3a and the tapered surface 14a of the flange member 14, and in this case, the tapered surface 13 of the pressure member 13
If the taper in the axial direction of a is set to be larger, the pressure member 13 and flange member 14 of the driven roller 9
It also has a differential mechanism in which the distances from the axis of the center roller 8 of the point of contact with the roller 8 are different and deceleration is performed.

In the speed reduction mechanism of the present invention, as shown in FIGS. 3 and 4, the radius of the contact orbit circle between the center roller and the driven roller centered around the center roller axis is set to rI+the radius of the driven roller centered around the rotation axis of the driven roller. The radius of the contact orbital circle with the tapered surface of the pressure member is r2 + the radius of the contact orbital circle between the driven roller centered around the driven roller rotation axis and the tapered surface of the flange member is r3r The driven roller centered around the center roller axis and the pressure member If the radius of the contact orbital circle with the tapered surface is R, and the radius of the contact orbital circle between the driven roller and the flange member tapered surface centered on the center roller axis is R2, then the rotation speed of the center roller and the pressure member The ratio of the rotation speed at the point of contact between the tapered surface and the driven roller, i.e., r+ due to the planetary roller mechanism. , is expressed as the ratio of the rotation speed of the output side rotation shaft to the rotation speed of the input side rotation shaft in this reduction mechanism, that is, the reduction/deceleration ratio.

That is, the reduction ratio in the present invention has a large output from the planetary roller mechanism, and in addition, by appropriately selecting the taper of the input side pressure member tapered surface and the taper of the output side flange member taper surface, the driven roller The present invention also includes a differential mechanism via which a high reduction ratio can be obtained in one step.

In the case of the above embodiment, the gearing of the small gear 5 and the large gear 6 is incorporated between the motor shaft 3 and the input rotating shaft 7, the rotation speed of the small gear 5 is set to a, and the rotation speed of the large gear 6 is set to a. When the rotational speed is a2, the reduction/reduction ratio becomes the following formula, which is designed to obtain an even higher reduction/reduction ratio.

As described above, the speed reduction mechanism of the present invention uses rolling friction transmission to transmit rotation from the center roller 8 directly connected to the input rotation shaft 7 to the flange member 14 directly connected to the output rotation shaft 15, which is different from the conventional one. Since we have eliminated what is equivalent to the backlash of a gear mechanism, friction loss is small and deceleration efficiency is extremely high.There is no wasted movement in directional movements such as horizontal rotation and vertical movement of the electric pan head, and there is no need for unnecessary movement during operation. The quality of the product is improved as there is no vibration and the generated noise is extremely low.

Furthermore, in the present invention, since the transmission of power from the driven roller 9 to the output rotating shaft 15 is performed using the frictional resistance of the tapered surface 14a of the flange member 14, the pressure applied to the driven roller 9 can be applied with a weak pressing force. Even with the spring body 19, an extremely large torque is generated on the output rotating shaft 15 due to the wedge effect. In addition to spring bodies, screws,
Hydraulic pressure or pneumatic pressure can be used, but since a small pressurizing force is sufficient, an aluminum alloy material with relatively low strength can also be used as the material for the housing 1.

In addition, the torque limit can be set by adjusting the strength of the pressure spring body 19, and even if the contact portion between the driven roller 9 and the tapered surface 143 of the flange member 14 is worn out after long-term use, the spring body The pressure adjustment function of the spring body 19 allows good tracking and no slippage, and the pressure adjustment of the spring body 19 is easy, so maintenance management is easy. Furthermore, by employing tapered surface contact transmission, it is possible to reduce the level of assembly precision required between conventionally assembled parts, and hence the processing precision of the parts.

Although this reduction mechanism is installed in separate systems for horizontal rotation and vertical movement of the electric pan head, it can be housed in the same reduction gear case and driven by the same motor. Further, the rotation of the output rotating shaft 15 of the present speed reduction mechanism is further controlled via a spur gear and a rack.
The transmission is transmitted to the ring gear of the electric pan head as shown in the figure, but the transmission mechanism can be set arbitrarily and easily within the minimum range without sacrificing the advantages of this reduction mechanism. be.

(Effects of the Invention) As is clear from the above description, according to the present invention, there is little deceleration loss, high deceleration efficiency, and there is no backlash seen in conventional gear mechanisms, so the directional movement of the photographing camera and A deceleration mechanism for an electric pan head that can stop accurately, prevent screen shake, and maintain low vibration and noise can be obtained.

Further, according to the present invention, the mechanism of the present invention has a simple structure and is easy to maintain, has high deceleration efficiency, and can obtain a high reduction ratio in the - stage, so it has fewer components and can be used with motors with low output. This makes it possible to reduce the level of component precision, and together with this, it is possible to achieve smaller size, lighter weight, and lower cost.

[Brief explanation of the drawing]

FIG. 1, which shows an embodiment, is a sectional view of a main part of an electric pan head equipped with a speed reduction mechanism according to the present invention, and FIG. 2 is an enlarged perspective view, partially cut away, of the main part of the speed reduction mechanism of FIG. Figure 3 is a sectional view taken along line m-m in Figure 1, and Figure 4 is a cross-sectional view of Figure 1.
FIG. 5 is a sectional view taken along the TV-TV line in the figure, and FIG. 5 is a perspective view of a conventional electric pan head.

Claims (1)

[Claims] (1) V-shaped groove (8a) on the outer peripheral surface coaxial with the input rotation shaft (7)
) with V of the central roller (8), concentric roller (8)
contact with the groove (8a) on the outer surface, and each has a rotation axis (1).
a plurality of rotatable spherical driven rollers (9) having 0); a driven roller support member that supports the shaft end of the rotation shaft (10) of the driven rollers (9) and is rotatable concentrically with the center roller (8); (12), a ring-shaped pressure member (13) having a tapered surface (13a) on the inner circumference that contacts the driven roller (9) from the input side in the axial direction; A rotatable rotatable member having a tapered surface (14a) coaxial with the output rotating shaft (15) and in contact with the driven roller (9) from the output side in the axial direction on the inner periphery of the collar portion protruding toward the input side. A deceleration mechanism for an electric pan head, characterized in that it is comprised of a saucer-like flange member (14).