JPH0433485Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a wave gear device, and more particularly to a lubricating oil sealing mechanism for a meshing portion between internal and external teeth of a wave gear device.

BACKGROUND ART A wave gear device includes a rigid circular internal gear, a flexible external gear provided inside the internal gear and partially meshing with the gear, and a flexible external gear provided inside the external gear. It consists of a wave generator that bends the external gear into an elliptical shape so that it meshes with the internal gear on its long axis, and also rotates the ellipse.One gear is fixed and the other gear is fixed. It is known that when an output shaft is attached, an input shaft is provided to a wave generator, and the wave generator is rotated by a motor or the like, the output shaft is rotated at a large reduction ratio.

Problems to be solved by the invention In conventional devices, it is preferable that the meshing part of the teeth of the internal gear and the external gear be lubricated with lubricating oil such as grease, but both sides of the meshing part are open. Therefore, when the wave generator rotates at high speed and the ellipse of the external gear rotates, the lubricating oil scatters, resulting in insufficient lubrication, resulting in heat generation and wear.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a wave gearing device equipped with a sealing mechanism that applies lubricating oil to the meshing portion of the teeth and seals the lubricating oil.

Means for Solving the Problems In order to achieve this purpose, according to the present invention,
Tooth side (inside) of an internal gear molded from a single member
A groove cut radially outward across the circumferential surface is formed approximately in the center of the groove, and lubricating oil is accommodated in the groove, and on both sides of this lubricating oil containing groove,
A strain wave gear device is provided, which is characterized by being provided with an elastic seal ring that seals between the inner circumferential surface of an internal gear and the outer circumferential surface of an external gear over the circumferential surface, and which prevents lubricating oil from scattering. It is prevented.

Embodiment In FIG. 1, an internal gear 1 is fixed to a housing 2, and a flexible external gear 3 is connected to an output shaft 4. Between the outer ring 6 and inner ring 7 of the bearing 5 is a ring-shaped holding member 9 that holds the ball 8.
are provided to hold the balls 8 rotatably and at regular intervals. The elliptical cam plate 10 is connected to the input shaft 11 via a flanged hub 12, and the cam plate 10 and the bearing 5 constitute a wave generator. When the input shaft 11 is driven by a motor (not shown) or the like, the cam plate 10 also rotates, and the output shaft 4 is driven by the input shaft 1.
Rotates in the opposite direction to 1 with a large reduction ratio. Note that an insert 14 is provided between the flange 13 of the hub 12 and the cam plate 10, and together with the flange 13, it absorbs the misalignment of the input shaft 11 when attached to the cam plate 10. Since this is not relevant to the main point, the explanation will be omitted.

In the present invention, a groove 15 for accommodating lubricating oil such as grease is provided on the circumferential surface of the internal gear 1 at approximately the center on the tooth side.
On both sides of this lubricating oil storage groove 15, seal rings 16, 16 made of a material having a damping effect (for example, an elastic material) are formed to seal the gap between the internal gear 1 and the external gear 3. is provided. This situation is shown in detail in FIG.

In FIG. 2, the seal rings 16, 16 on both sides of the lubricating oil storage groove 15 are preferably made of an elastic material such as nylon, and the side (inner circumference) in contact with the external teeth 18 of the external gear 3 is Teeth are formed with the same tooth profile or slightly larger tooth profile and the same number of teeth as the external teeth. Therefore, each ring 16 is fixed to the external gear 3. As shown in FIG. 1, in a so-called cup-shaped wave gear device in which the external gear 3 is formed into a cup shape, the number of teeth of the internal gear 1 is greater than the number of teeth of the external gear 3.
For example, two more (or fewer) than that of the external gear 3 are formed, and when the ellipse of the external gear 3 is rotated, it rotates little by little with respect to the internal gear 1 corresponding to the difference in the number of teeth. Since the ring 16 is fixed to the external gear 3, it rotates with respect to the internal gear like the gear 3. A second circumferential groove 19 is provided at the position where the ring 16 contacts the internal gear 1 to receive the ring so that the ring 16 does not come out of contact due to the rotation.
is formed. This ring housing groove 19, 19
It is preferable that the lubricating oil be provided as close to the edge of the meshing portion of both teeth as possible, thereby maintaining a wide supply of lubricating oil to the meshing portion.

As mentioned above, the external gear 3 is bent into an ellipse by the wave generator consisting of the bearing 5 and the cam plate 10, and the ellipse is rotated, so that the external gear 3 and the internal gear on the long axis are rotated. They engage, and the point of engagement rotates in the circumferential direction. In the position shown in Fig. 2, the external gear 3 meshes with the internal gear 1 on its long axis, and in the position shown in Fig. 3, the external gear 3 on its short axis does not mesh with the internal gear 1. . Correspondingly, the seal ring 16 also moves in the radial direction within the circumferential groove 19 of the internal gear 1. In view of this, as shown in FIG. 4, it is preferable that the height of the seal ring 16 is set to such a level that it enters the groove 19 on the long axis, but is located in the valley of the teeth on the short axis. Friction of the ring 16 within the groove 19 can be minimized while maintaining a high sealing effect. Note that the width of the ring 16 relative to the groove 19 is also selected to minimize friction while increasing the sealing effect for the same reasons as above.

FIG. 5 shows an example in which the present invention is applied to a so-called flat wave gear device in which two internal gears 1 are arranged side by side and have different numbers of teeth. A lubricating oil storage groove 15 is formed in the center, and the meshing part between the internal gear 1 and the external gear 3' is
Seal rings 16, 16 are provided with a groove 15 in between.

Effects of the invention According to the invention, lubricating oil such as grease is prevented from scattering to the outside by the seal ring, thereby preventing heat generation and wear of the meshing parts. In particular, in the present invention, the lubricating oil groove is formed by a simple process of cutting a groove in the center of the tooth side of the internal gear over the circumferential surface, so the internal gear can be integrated into a single member. Therefore, the assembly work of the internal gear becomes easy, and not only the cup type wave gear device which uses one internal gear, but also the flat type wave gear device which uses two internal gears side by side. Even in gear systems, each internal gear can be lubricated individually. Further, since the seal ring is made of an elastic material, it prevents vibrations in the meshing portion, that is, has a damping effect, and furthermore, the seal ring prevents idle movement due to backlash and the like.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a wave gear device according to an embodiment of the present invention, FIG. 2 is a sectional view of the meshing portion on the long axis, and FIG. 3 is a sectional view of the meshing portion on the short axis.
FIG. 4 is a side view of the engaging portion, and FIG. 5 is a sectional view of the engaging portion of another embodiment. 1... Internal gear, 2... Housing, 3... External gear, 4... Output shaft, 5... Bearing, 10
... Cam plate, 11 ... Input shaft, 15 ... Lubricating oil storage groove, 16 ... Seal ring, 19 ... Ring storage groove.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A rigid circular internal gear, a flexible external gear that is provided inside the internal gear and partially meshes with the gear, and A wave gear device formed in a single member and comprising a rotatable wave generator which is provided and which deflects the external gear into an elliptical shape so as to mesh with the internal gear on its long axis. A groove cut radially outward across the circumferential surface is formed at approximately the center of the tooth side of the internal gear, and lubricating oil is accommodated in the groove. ,
A wave gear device characterized in that an elastic seal ring is provided for sealing between the inner circumferential surface of an internal gear and the outer circumferential surface of an external gear over the circumferential surfaces, respectively. (2) Registration of a utility model characterized in that two internal gears are arranged side by side on the outside of an external gear, and each internal gear is provided with a lubricating oil storage groove and an elastic seal ring on both sides of the groove. A wave gear device according to claim 1. (3) The side of the elastic seal ring in contact with the external gear is provided with teeth having the same number of teeth as the external gear and is fixed to the external gear, and the internal gear is provided with teeth at a position corresponding to the seal ring. The wave gear device according to claim 1, which is a registered utility model, characterized in that a circumferential groove is formed so that the ring can move in and out of the groove. (4) Utility model registration claim No. 1, characterized in that the elastic seal ring fits into the circumferential groove of the internal gear along the long axis of the external gear, which is bent in an ellipse. The wave gear device according to item 3.