JP2010014215A - Wave motion gear device - Google Patents

Abstract

An object of the present invention is to increase the load capacity of a wave gear reducer.
A wave generator 4 of a cup-type wave gear reducer 1 includes a wave plug 41 and a wave bearing 42. The wave bearing 42 has two radial ball bearings 43 and 44 arranged in parallel in the direction of the device axis 1a. It is composed of Wide outer teeth 34 including the outer rings 43a and 44a of the radial ball bearings 43 and 44, which are long in the tooth trace direction, are formed on the flexspline 3, and the wide inner teeth 24 corresponding to the wide outer teeth 34 are circular splines. 2 is formed. A plurality of radial ball bearings 43 and 44 can be used to form a meshing state with a wide tooth width between the flexspline 3 and the circular spline 2. Thereby, the load capacity of the wave gear reducer 1 can be increased without increasing the size.
[Selection] Figure 1

Description

  The present invention relates to a wave gear device in which tooth shapes of a circular spline and a flexspline are widened in a tooth trace direction in order to increase a load capacity.

As a wave gear device, a cup-type device whose flexspline has a cup shape and a top-hat type device having a top hat shape are known. In such a wave gear device, in order to increase the load capacity without increasing the size, the tooth profile of the external teeth and the internal teeth is improved, and the thickness shape of the flexspline is optimized. Improvement of the tooth profile is proposed in Patent Document 1 and the like, and improvement of the thickness shape of the flexspline is proposed in Patent Document 2 and the like.
JP 2007-211197 A JP 2006-57684 A

  SUMMARY OF THE INVENTION An object of the present invention is to realize a wave gear device having a high load capacity without increasing the size by adopting a method different from the conventional method for improving tooth profile and wall thickness.

  In order to solve the above problems, the wave gear device of the present invention is characterized by having the following configuration. Reference numerals in parentheses are in the embodiments of the present invention, and are intended to facilitate understanding of the present invention, and are not intended to limit the present invention to the embodiments. .

That is, the present invention includes a circular spline (2), a flexspline (3) disposed inside the circular spline (2), and a wave generator (4) fitted inside the flexspline (3). The flex spline (3) is bent in the radial direction by the wave generator (4) and partially meshed with the circular spline (2), and the flex spline (3) is cup-shaped or silky. An outer tooth (34) is formed on the outer peripheral surface of the flexible cylindrical body (31) on the side of one open end (31a) of the flexible cylindrical body (31), and the cylindrical body (31 ) Is continuous with a radially inward or outwardly extending diaphragm (32). When the wave generator (4) rotates, A wave gear device in which the meshing position of the lines (2, 3) moves in the circumferential direction and relative rotation is generated between the splines (2, 3) according to the difference in the number of teeth of both the splines (2, 3). In 1)
The wave generator (4) has a rigid non-circular contoured wave plug (41), an outer peripheral surface (41a) of the wave plug (41), and the external teeth (34) of the flexspline (3). And a wave bearing (42) fitted between the inner peripheral surface portions (31b) of the at least one portion, and the wave bearing (42) is arranged in parallel in the direction of the device axis (1a). Two rolling bearings (43, 44) or double row rolling bearings are characterized in that they are provided with outer rings (43a, 44a) and inner rings (43b, 44b) that can be bent in the radial direction.

  Here, the outer diameter of the outer peripheral surface (41a) of the wave plug (41) is such that the opening end (31a) extends from the diaphragm (32) of the flexspline (3) along the direction of the device axis (1a). It is desirable to gradually increase toward). The amount of bending of the external teeth (34) of the flexspline (3) is the largest at the opening end side (34a) in the tooth trace direction and the smallest at the diaphragm side end (34b). By setting the shape of the outer peripheral surface of the wave plug (41) in accordance with such a bending state, the meshing state of the flexspline and the circular spline with a wide tooth width can be improved.

  In the wave gear device that is generally used, the flex spline (3) is bent into an ellipse by the wave generator (4), and the circular spline (2 ).

  In the wave gear device according to the present invention, a circular spline is obtained by flexing the flexspline in the radial direction by using a wave generator having two or more rolling bearings arranged in parallel in the device axial direction or a double row rolling bearing. Bite. Accordingly, it is possible to widen the external tooth forming portion of the flex spline supported by the wave bearing of the wave generator. As a result, since the flexspline and the circular spline having a wider tooth width can be used as compared with the prior art, the load capacity of the wave gear device can be increased as compared with the prior art without increasing the size.

  A wave gear device according to an embodiment of the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view including a shaft showing a cup-type wave gear reducer according to the present embodiment. The basic configuration of the cup-type wave gear reducer 1 is the same as that of the conventional one, and a circular spline 2 made of an annular rigid body, a cup-shaped flexspline 3 disposed inside the circular spline 2, and a flexspline 3 and a wave generator 4 having an elliptical profile fitted inside the 3.

  The cup-shaped flexspline 3 includes a cylindrical body 31 that can be bent in the radial direction, and a disk-shaped diaphragm 32 that extends inward in the radial direction continuously to one end of the cylindrical body 31. An annular boss 33 continuing to the inner peripheral edge of the diaphragm 32 and an outer tooth 34 formed on the outer peripheral surface portion of the cylindrical body 31 on the opening end 31a side are provided. The portion of the cylindrical body portion 31 where the external teeth 34 are formed is bent into an elliptical shape by the wave generator 4, and the external teeth 34 positioned at both ends of the elliptical shape in the major axis direction are circular splines 2. Is engaged with the inner teeth 24.

  The wave generator 4 includes a rigid wave plug 41 having an elliptical outline and a wave bearing 42. The wave bearing 42 is fitted between the outer peripheral surface 41a of the wave plug 41 and the inner peripheral surface portion 31b of the portion where the outer teeth 34 of the flexspline 3 are formed.

  The wave bearing 42 is composed of two radial ball bearings 43 and 44 arranged in parallel in the direction of the device axis 1a. Each radial ball bearing 43, 44 is different from a normal radial bearing in that it includes outer rings 43a, 44a and inner rings 43b, 44b that can be bent in the radial direction. Each of the radial ball bearings 43 and 44 is bent in an elliptical shape corresponding to the outer peripheral surface 41a of the wave plug 41 having an elliptical contour.

  The external teeth 34 of the flexspline 3 are set to have a wide tooth width including the outer rings 43a and 44a of the two radial ball bearings 43 and 44. Correspondingly, the internal teeth 24 of the circular spline 31 are also set to have a wide tooth width.

  Further, in the state where the flex spline 3 is bent into an ellipse by the wave generator 4, the amount of bending of the outer teeth 34 in the radial direction is from the end 34b on the diaphragm 32 side to the opening end along the tooth trace direction. It gradually increases toward the end 34a on the 31a side and becomes maximum at the end 34a on the opening end side. Since the outer teeth 34 of the flexspline 3 are wide, the difference in deflection amount between the diaphragm side end 34b and the opening end side end 34a becomes large. The external teeth 34 are reliably supported by the external teeth 43a and 44a of the wave bearing 42 at both the diaphragm end 34b and the open end 34a, so that the meshing state of the external teeth 34 and the internal teeth 24 is improved. As described above, the outer peripheral surface 41a of the wave plug 41 is a tapered surface having an outer diameter gradually increasing from the diaphragm 32 of the flexspline 3 toward the opening end 31a along the direction of the apparatus axis 1a.

  In the wave gear reducer 1 having this configuration, a high-speed rotation shaft (not shown) is connected and fixed to the shaft hole 41b of the wave plug 41 of the wave generator 4, so that the wave generator 4 rotates at high speed. When the wave generator 4 rotates, the meshing position of the two splines 2 and 3 moves in the circumferential direction, and relative rotation occurs between the two splines 2 and 3 according to the difference in the number of teeth of the two splines. In general, the number of teeth of the flex spline 3 is 2n less than the circular spline 2 (n is a positive integer). Further, the circular spline 2 is fixed to a device housing (not shown), and the boss 33 of the flexspline 3 is connected and fixed to the load side. In this case, the decelerated rotation is taken out from the flexspline 3 and transmitted to the load side. In this example, the outer teeth 34 and the inner teeth 24 have a wide tooth profile, and the meshing area of both teeth is wide. Therefore, the wave gear reducer 1 having a high load capacity can be obtained.

  In particular, the wave gear reducer 1 of the present example can be increased in load capacity without increasing its radial dimension, and is therefore incorporated in a drive mechanism such as a robot hand having a limited radial installation space. Suitable for

(Other embodiments)
In the above example, two radial ball bearings are used for the wave bearing 42, but three or more rolling bearings may be arranged in parallel. Two or more rows of double row rolling bearings can also be used.

  Although the above example is for a cup-type wave gear reducer, the present invention is also applicable to a top-hat wave gear reducer in which the diaphragm extends radially outward. .

  Furthermore, although the above example is a case where the wave gear device is used as a speed reducer, it is needless to say that the present invention can be similarly applied to a case where the wave gear device is used as a speed reducer.

It is a schematic sectional drawing which shows the shaft-containing cross section of the cup type wave gear reducer to which this invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wave gear reducer 1a Apparatus axis 2 Circular spline 24 Internal tooth 3 Flex spline 31 Cylindrical trunk | drum 31a Open end 31b Inner peripheral surface part 32 Diaphragm 33 Boss 34 External tooth 34a End of open end side 34b of external tooth End 4 on the diaphragm side Wave generator 41 Wave plug 41a Outer peripheral surface 41b Shaft hole 42 Wave bearings 43, 44 Radial ball bearings 43a, 44a Outer rings 43b, 44b Inner rings

Claims (3)

A circular spline (2), a flexspline (3) disposed inside the circular spline (2), and a wave generator (4) fitted inside the flexspline (3);
The flexspline (3) is bent in the radial direction by the wave generator (4) and partially meshed with the circular spline (2),
The flexspline (3) is cup-shaped or top-hat shaped, and external teeth (34) are formed on the outer peripheral surface portion on the side of one open end (31a) of the flexible cylindrical body (31). A diaphragm (32) extending radially inward or outward is continuous with the other end of the cylindrical body (31),
When the wave generator (4) rotates, the meshing position of both splines (2, 3) moves in the circumferential direction, and according to the difference in the number of teeth of both splines (2, 3), both splines (2, 3) In the wave gear device (1) in which relative rotation occurs,
The wave generator (4) has a rigid non-circular contoured wave plug (41), an outer peripheral surface (41a) of the wave plug (41), and the external teeth (34) of the flexspline (3). A wave bearing (42) fitted between the inner peripheral surface portion (31b) of the portion being
The wave bearing (42) is at least two rolling bearings (43, 44) arranged in parallel in the direction of the device axis (1a), or a double row rolling bearing, and is an outer ring that can be bent in the radial direction ( 43a, 44a) and an inner ring (43b, 44b). In the wave gear device (1) according to claim 1,
The outer diameter of the outer peripheral surface (41a) of the wave plug (41) extends from the diaphragm (32) of the flexspline (3) toward the open end (31a) along the direction of the device axis (1a). The wave gear device (1) is characterized by increasing gradually. In the wave gear device (1) according to claim 1 or 2,
The flex spline (3) is bent elliptically by the wave generator (4), and is engaged with the circular spline (2) at both ends of the major axis of the elliptical shape. Device (1).

Images