JPH06193698A - Friction gearing speed reducer - Google Patents

Abstract

PURPOSE:To secure a friction gearing speed reducer which is excellent in torque transfer efficiency and able to change a speed ratio in an easy manner. CONSTITUTION:Both first and second eccentric shaft parts 31 and 32 different in eccentricity each are formed in an input shaft 3 of a friction gearing type speed reducer 1, and both first and second rotary disks 5 and 7 of the same outer diameter are rotatably supported on each circumference of these eccentric shaft parts. The first rotary disk 5 is made point-contact with a taper inner circumferential surface 11a of a first ring member 11 clamped tight to a casing 2 so as not to be rotated, and the second rotary disk 7 is also made point- contact with another taper ring member 12a of a second ring member 12 connected to an output shaft 21. The first ring member 11 is made into a state of being pressed to the side of the first rotary disk 5 by dint of a presser spring 14. If the input shaft 3 is rotated, these rotary disks 5 and 7 roll on both these taper inner circumferential surfaces 11a, and 12a for contact motion, through which a slow speed output is securable out of the side of the second ring member 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction transmission type speed reducer, and more particularly to a friction transmission type speed reducer having a structure capable of improving torque transmission efficiency and easily changing a speed ratio. Is.

[0002]

2. Description of the Related Art Various structures of friction transmission type speed reducers have been proposed. For example, Japanese Patent Laid-Open No. 3-66959 discloses a planetary roller type speed reducer.

Generally, in such a friction transmission type speed reducer, since torque is transmitted by rolling frictional contact between the respective members, there is a problem that torque transmission efficiency is lower than that of a gear type transmission mechanism. Further, in order to change the speed ratio, it is necessary to replace all or most of the respective constituent members, so that there is a problem that it cannot be easily performed.

An object of the present invention is to propose a friction transmission type speed reducer having a structure capable of solving such problems.

[0005]

In the friction transmission type speed reducer of the present invention, first and second eccentric shaft portions having different eccentric amounts are formed on the input rotary shaft, and the first and second eccentric shaft portions are formed on these portions. Two rotating discs are rotatably supported. For example, the first rotating disk is supported by the input rotating shaft with an eccentric amount e1, and the second rotating disk is supported by the input rotating shaft with an eccentric amount e2 toward the opposite side in the diametrical direction. An outer peripheral surface having an arcuate cross section is formed on each of the first and second rotating disks. Further, these rotating discs are connected together by joint means such as an Oldham joint so that they can rotate integrally and can move relative to each other in the radial direction.

The first and second annular members are arranged so as to sandwich the first and second rotating discs from both sides. The first annular member is fixed so as not to rotate, and the outer peripheral surface of the first rotating disk is in rolling contact with the tapered inner peripheral surface of the annular member. On the other hand, the second annular member is rotatably supported by the speed reducer casing and the like and is connected to the output shaft side. The outer peripheral surface of the rotating disk is in rolling contact. Further, the first annular member is pressed by the pressing means from the back surface side thereof to the first rotating disk side by elastic force.

When the input rotation shaft is rotated at a high speed by a high-speed rotation source such as a motor, the first and second rotating discs eccentrically supported on the outer periphery of the input rotation shaft are eccentrically rotated about the rotation axis. Further, since each rotating disk is in contact with the tapered inner peripheral surface of each of the first and second annular members, it rotates while performing eccentric rotation. As a result, decelerated rotation can be obtained from the second annular member side.

Here, when the eccentricity amounts of the first and second eccentric shaft portions are set to be the same, the taper angles of the tapered inner peripheral surfaces of the first and second annular members are made different from each other. Just set it.

In the friction transmission type speed reducer of the present invention, the first annular member is elastically pressed against the side of the first rotating disk by the pressing means, so that the frictional force between them is sufficient. It can be anything. Therefore, the torque transmission efficiency is good. Further, the speed ratio can be easily changed by replacing the input shaft with an input shaft provided with eccentric shaft portions having different eccentric amounts. When the input shaft having the eccentric shaft portion with the same eccentricity is provided, the first and second annular members can be easily changed by changing the taper angles of the tapered inner peripheral surfaces. The speed ratio can be changed.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, the casing 2 of the friction transmission type speed reducer 1 of the present embodiment is constructed by joining a disk-shaped member 2a and a cup-shaped member 2b to the casing 2. The input shaft 3 is arranged inside along the direction of the axis 1a. This input shaft 3 has an axis 1a
On the other hand, a first eccentric shaft portion 31 that is eccentric by e1 and a second eccentric shaft portion 32 that is eccentric by e2 toward the opposite side in the diametrical direction are integrally formed. First eccentric shaft portion 3
A first rotating disk 5 is rotatably supported on the bearing 1 via a bearing 4. Similarly, a second rotating disk 7 is rotatably supported by the second eccentric shaft portion 32 via a bearing 6. Outer peripheral surfaces 5a, 7a having an arcuate cross section and having the same diameter are formed on these rotating disks 5, 7. The first and second rotating disks 5 and 7 are connected via an Oldham coupling 8 arranged therebetween, and are integrally rotated in a state capable of relative movement in the radial direction.

The first and second annular members 11 and 12 are arranged so as to sandwich the rotating disks 5 and 7 from both sides. The first annular member 11 is attached to the inner peripheral surface of the casing 2 so as to be movable in the axial direction, and
It has a circular inner peripheral surface 11a centered on the axis 1a.
The inner peripheral surface 11a has a tapered cross section that extends radially toward the first rotating disk 5. The first annular member 11 is fixed to the casing 2 side by a rotation stopper 13 so as not to rotate, but is movable in the axial direction. A pressing spring 14 is arranged between the first annular member 11 and the end surface 2c of the casing 2 in a compressed state.
The tapered inner peripheral surface 11a of the annular member 11 is pressed against the outer peripheral surface 5a of the arc-shaped cross section of the first rotating disk 5 in a point contact state.

On the other hand, the second annular member 12 is rotatably supported by the casing 2 via the thrust bearing 15. This second annular member 12 also has the axis 1
It has a circular inner peripheral surface 12a centered on a. The inner peripheral surface 12a has a tapered cross section that is widened in the radial direction toward the second rotating disk 7. The outer peripheral surface 7a having an arc-shaped cross section of the second rotating disk 7 is in point contact with the tapered inner peripheral surface 12a.

Here, the base end side of the input shaft 3 is rotatably supported by the bearing 16 with respect to the inner peripheral surface of the through hole 2d formed in the end wall of the casing 2. Further, the base end of the input shaft 3 is connected via a coupling 17 to an output shaft 18a of a motor 18 mounted outside the end wall of the casing 2. The tip side of the input shaft 3 is
The bearing 19 is rotatably supported on the inner peripheral surface of the through hole 12 a formed in the second annular member 12.

On the other hand, the output shaft 21 penetrates through a through hole 2f formed in the end wall 2e of the cup-shaped member that constitutes the casing 2, and the output shaft 21 has an inner periphery of the through hole 2f via a bearing 22. It is rotatably supported on the surface. A large-diameter flange 21a is integrally formed at the base end of the output shaft 21, and the flange 21a is coupled to the second annular member 12 so as to rotate integrally.

In the speed reducer 1 of this embodiment, the taper angles of the tapered inner peripheral surfaces of the first and second annular members 11 and 12 are the same, and the eccentricity e1 of the first and second rotating disks is equal. , E2 are set to different values. By setting in this way, the high speed rotation input to the input shaft 3 is decelerated and taken out from the second annular member 12 side. Instead of this, the eccentric amounts of the first and second rotating disks are set to the same value, and the taper angles of the tapered inner peripheral surfaces of the first and second annular members are set to mutually different values. You may set it. Further, in this example, the first and second rotating discs are eccentric to the opposite sides in the diametrical direction, but they may be eccentric in the same direction, for example.

In the speed reducer of this embodiment, the pressing spring 14
Since the first annular member 11 is pressed against the first rotating disk 5 side by this, the frictional force between them can be set to a sufficient value, and the torque transmission efficiency can be improved. Further, in this example, by using the input shaft having the eccentric shaft portions having different eccentric amounts, the speed ratio can be changed while the other components remain the same.

[0018]

As described above, the friction transmission type speed reducer of the present invention has the advantages that the torque transmission efficiency is good and the speed ratio can be easily changed.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view showing a speed reducer according to an embodiment of the present invention.

2 is a side view of the speed reducer of FIG. 1. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Reduction gear 2 ... Casing 3 ... Input shaft 31 ... 1st eccentric shaft part 32 ... 2nd eccentric shaft part 5 ... 1st rotating disk 7 ... -Second rotating disk 11 ... First annular member 11a ... Tapered inner peripheral surface 12 ... Second annular member 12a ... Tapered inner peripheral surface 14 ... Pressing spring 18・ ・ ・ Motor 21 ・ ・ ・ Output shaft

Claims (3)

[Claims] 1. An input rotary shaft, first and second eccentric shaft portions formed on the rotary shaft, and an outer peripheral surface of an arcuate section which is rotatably supported on the outer periphery of the first eccentric shaft portion. A first rotating disk having a circular shape, a second rotating disk having an arcuate outer peripheral surface rotatably supported on the outer periphery of the second eccentric shaft portion, and And a taper in which the outer peripheral surface of the first rotating disk is in rolling contact with a joint means for integrally rotating the second rotating disk and connecting them so as to be relatively movable in the radial direction. A first annular member having a circular inner peripheral surface, and the second annular member
A second annular member having a tapered inner peripheral surface with which the outer peripheral surface of the rotating disk comes into rolling contact, and a tapered inner peripheral surface of the first annular disk with respect to the first annular member. And a pressing means for applying elastic force to the side, and the decelerated rotation is taken out from the second annular member. 2. The first and second parts according to claim 1.
The eccentric amounts of the eccentric shaft portions are different from each other, and the taper angles of the tapered inner peripheral surfaces of the first and second annular members are the same. 3. The first and second devices according to claim 1.
The eccentric shaft portions have the same eccentric amount, and the taper angles of the tapered inner peripheral surfaces of the first and second annular members are different from each other.