JPS6315644Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a harmonic gear system, and more particularly to an oil supply mechanism for a harmonic gear system.

Prior Art A harmonic gear device includes a rigid circular internal gear, a flexible external gear provided inside the internal gear,
A wave gear fits inside this external gear to bend the external gear into an elliptical shape, meshing the external gear with the internal gear on the long axis of the ellipse, and rotating the elliptical shape. The wave generator consists of a bearing in which a large number of balls are arranged between a flexible outer ring and an inner ring, and the outer ring fits inside the external gear, and a It consists of an elliptical cam plate that fits together to deflect the bearing and external gear into an elliptical shape, and a drive shaft rotated by a motor or the like is connected to the cam plate. When the drive shaft is rotated at high speed, the output shaft connected to the external gear or the internal gear can be rotated at a large reduction ratio.

In such a harmonic gear system, if not only the bearing parts but also the meshing parts with the external gears are not lubricated, they will generate heat during operation, which is undesirable. Particularly in a harmonic gear system in which the rotation axis of each member of the harmonic gear system is arranged so as to extend in a vertical direction, lubricating oil leaks from above to below, so it must be constantly refilled.

OBJECT OF THE INVENTION Accordingly, an object of the present invention is to provide a harmonic gear device which is arranged such that its rotating shaft extends in the vertical direction and is equipped with a lubrication mechanism that can constantly supply oil to the parts of the harmonic gear device that require lubrication. It is in.

Composition of the invention In order to achieve this purpose, according to the invention,
A truncated cone-shaped lift cone is fixed to the lower surface of the elliptical cam plate of the wave generator, and the diameter of the truncated cone decreases downward and the opening is immersed in an oil reservoir. A hole is formed to allow oil lifted by the lift cone to communicate with the upper surface of the cam plate, and the upper surface of the cam plate is formed to be inclined upward toward a bearing attached to the outside of the cam plate. A harmonic gear device is provided.

Effects of the invention According to the invention, when the cam plate is rotated at high speed, the lift cone also rotates at high speed, and the oil in the oil reservoir creeps up the sloping inner surface of the cone and passes through the communication hole of the cam plate and onto the cam plate. carried in the direction. The carried oil is spattered outward by the centrifugal force of the cam plate rotating at high speed, but since the upper surface of the cam plate is sloped upward when viewed from the center in the radial direction. The oil droplets fly out slightly upward along the inclined surface, and first a group of oil droplets are caught by the bearing part and lubricate the bearing, and then the oil droplets with momentum move outward and upward onto the internal gear. It is caught in the meshing part between the external gear and the external gear, and lubricates that part. In other words, according to the present invention, lubricating oil can be continuously supplied to the necessary parts simply by operating the harmonic gear system, which not only allows smooth rotation of bearings and meshing of teeth, but also reduces heat generation and wear. can be reduced, and as a result, the life of each component can be extended. Furthermore, forming the upper surface of the cam plate into an inclined surface causes the surface of the cam plate to be concave toward the center, which in turn reduces the inertial mass of the cam plate, which improves the response characteristics of the wave generator. There are also benefits to getting better.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, a typical harmonic gear system 1 to which the present invention is applied is shown. This device 1 is a so-called cup-shaped harmonic gear device,
Another typical example is a so-called flat harmonic gear device which is formed flat as a whole. Of course, the present invention can be applied to any device.

The harmonic gear device 1 includes a circular internal gear 2 made of a rigid body, and a flexible external gear provided inside the internal gear 2 and extending toward one side in a cup shape. 3, the external gear 3 is fitted inside the external gear 3 to bend the external gear into an elliptical shape, and the external gear 3 is meshed with the internal gear 2 at two points on the long axis of the ellipse, and the elliptical shape is The wave generator 4 rotates the wave generator 4. The wave generator 4 is
A large number of balls 7 are arranged between the flexible outer ring 5 and the inner ring 6.
A bearing 8 whose outer ring 5 fits inside the external gear 3 by arranging it, and an inner ring 6 of this bearing 8
It consists of an elliptical cam plate 9 which fits inside the bearing 8 and bends the external gear 3 into an elliptical shape.

For example, an input shaft 10 that is rotated by a motor (not shown) is fixed to the cam plate 9, an output shaft 12 is fixed to the cup bottom portion 11 of the cup-shaped external gear 3, and an output shaft 12 is fixed to the cup-shaped external gear 3. If the outer part is fixed to the machine frame, etc., and the number of teeth of the internal gear 2 is two more (or less) than the number of teeth of the external gear 3, the input shaft 10 (and the cam When the plate 9) is rotated, the elliptical shape rotates, but for each rotation, the external gear 3 does not rotate once, but the meshing point between the external gear 3 and the internal gear 2 shifts by the difference in the number of teeth. As shown, it only rotates by a small angle relative to the internal gear 2, thereby obtaining a large reduction ratio.

The present invention relates to a so-called vertically arranged harmonic gear device in which the rotation axis 14 is arranged so as to extend in the vertical direction as shown in the figure, and the moving part of this vertically arranged harmonic gear device 1, that is, the bearing 8.
The lubricating oil is constantly supplied to the tooth portions of the external gear 3 and the internal gear 2.

Therefore, the cup-shaped portion 15 of the external gear 3 is formed as an oil reservoir, and the lubricating oil is stored here.
6 is accommodated. On the other hand, on the lower side of the cam plate 9,
The diameter decreases downward, and the lower end opens and the opening 17
Lift cone 18 in the shape of a hollow truncated cone immersed in oil
is fixed. Although the angle α of the inclination of the lift cone 18 may be set arbitrarily, good results have been obtained when it is set to approximately 15°. This lift cone 18 is rotated by the rotation of the cam plate 9, and this rotation has the effect of transferring lubricating oil from the oil reservoir toward the cam plate 9 along its inclined inner surface. The lift cone 1 is attached to the cam plate 9.
An appropriate number of communication holes 19 are provided at appropriate locations for sending the oil transferred to the cam plate 9 by the cam plate 8 to the upper side of the cam plate. Therefore, the oil (droplets) to which the lifting force is applied by the lift cone 18 resists gravity and moves through the communication hole 1.
9 and reaches the upper surface of the cam plate 9.

An inclined surface 20 is formed on the upper surface of the cam plate 9 and is inclined upwardly from the position of the communication 19 toward the outside in the radial direction. In other words, the upper surface of the cam plate 9 is recessed toward the center so as to form the inclined surface 20, so that the inertial mass of the cam plate 9 as a whole is reduced.

By forming the inclined surface 20 on the upper surface of the cam plate 9, the oil (droplets) coming out of the communication hole 19 will fly out radially outward in a direction perpendicular to the axis due to the centrifugal force accompanying the rotation of the cam plate 9. Instead, it flies out along the slope 20 slightly upward. In other words, for oil (drops),
A vector force directed radially outward and upward is applied. As a result, the oil to which a weak force has been applied first falls under the influence of gravity at the bearing 8 and lubricates the bearing 8. The oil to which a strong force is applied so as not to fall by the bearing 8 is transferred to the external gear 3.
It falls onto the meshing part between the internal gear 2 and the internal gear 2, and lubricates that part. Since oil is constantly supplied to the upper surface of the cam plate 9 by the rotation of the lift cone 18, the oil supply to the bearing 8 and the oil supply to the meshing parts are performed without interruption during operation. Therefore, there will be no oil shortage in these parts. It is preferable to extend the upper edge 21 of the external gear 3 and the upper edge 22 of the internal gear 2 upward as shown in the drawings to better capture oil in the bearing and the meshing portion. Further, a communication hole 24 may be formed at the bottom of the cup to receive oil that has fallen from the meshing portion and return it to the oil reservoir 15.

Therefore, oil is constantly supplied not only to the bearings but also between the internal and external teeth during operation, allowing the harmonic gear system to rotate smoothly for long periods of time without wear.
Further, the weight of the cam plate can be reduced, and the response characteristics of the entire device can be improved.

[Brief explanation of the drawing]

The drawing is a sectional view of a cup-shaped harmonic gear device to which the present invention is applied. 1... Harmonic gear device, 2... Internal gear, 3...
External gear, 4... Wave generator, 8...
Bearing, 9...Cam plate, 10...Input shaft, 1
2...Output shaft, 14...Rotation axis center, 16...Oil,
18...Lift cone, 19...Communication hole, 20...
...Slope.

Claims (1)

[Scope of utility model registration request] A rigid circular internal gear, a flexible external gear that is provided inside the internal gear and partially meshes with the external gear, and a flexible external gear that fits inside the external gear to form an elliptical external gear. In a harmonic gear device, which is provided with a wave generator that is deflected by the wave generator and rotates its elliptical shape, and is arranged so that the axis of rotation extends in the vertical direction, the lower surface of the elliptical cam plate of the wave generator has a A hollow truncated cone-shaped lift cone is fixed to the cam plate, and the opening is immersed in an oil reservoir, and the oil lifted by the lift cone is communicated to the upper surface of the cam plate. A harmonic gear device characterized in that the upper surface of the cam plate is formed to be inclined upward toward a bearing attached to the outside of the cam plate.