JPH112300A - Friction roller transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase rigidity against a bending moment even when the bending moment is exerted on an output shaft and to ensure sufficient durability. SOLUTION: A rotary cylinder part 47 of which an outer ring 15 to fix an output shaft 20a thereon constitutes is supported in a fixed cylinder part 48, of which a housing 32 constitutes, by means of a radial needle bearing 49. The bending moment is supported by the radial needle bearing 49. A ball bearing 45 arranged at the periphery of the output shaft 20a sets the location of the axial direction of the output shaft 20 and the outer ring 15a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a friction roller type transmission which transmits rotational motion while reducing or increasing speed by being incorporated in various types of mechanical devices, and relates to an improvement of a bending moment applied to a rotary shaft such as an output shaft. An object of the present invention is to realize a structure that improves rigidity and ensures the life of components such as bearings.

[0002]

2. Description of the Related Art A friction roller type transmission generates less noise even when operated at a high speed than a gear type transmission such as a planetary gear type. For this reason, for example, a friction roller type transmission is mounted on the output portion of the electric motor and used as a speed reducer,
A structure for reducing the rotational movement of the electric motor and increasing the torque is described in, for example, JP-A-8-210455. Further, US Pat. No. 4,709,589 discloses a structure in which the contact pressure between the peripheral surfaces of the rollers is changed in accordance with the magnitude of the torque to be transmitted, thereby ensuring high transmission efficiency. No. 6 to No. 6 are described. In this conventional friction roller type transmission, an inner half portion of a center roller 4 (FIG. 4) is fixed in a fixed housing 3 including a bottomed cylindrical main body 1 and a lid 2 closing a base end opening of the main body 1. Of the cover 2
Is inserted through a through hole 5 formed substantially at the center.
The through hole 5 is provided at a position slightly deviated from the center of the lid 2. In the outer half of the center roller 4 (the left half in FIG. 4), a portion protruding from the lid 2 includes:
The end of the input shaft 6, which is the first rotating shaft, is connected and fixed.

Further, three pivots 7a, 7b, 7c are provided inside the housing 3 and around the center roller 4.
Are arranged in parallel with the center roller 4.
That is, one end (the left end in FIG. 4) of each of the pivots 7a, 7b, 7c is supported by the lid 2, and the other end (FIG. 4).
At the right end of the support plate 8 is supported by the connecting plate 8. Therefore, FIG.
In the conventional structure shown in FIG. 6, the lid 2 also has a function as a support substrate for supporting one ends of the plurality of pivots 7a, 7b, 7c. The three pivots 7
Of the a, 7b, and 7c, one pivot 7a located at the upper center in FIGS. 5 and 6 has both ends press-fitted or rattled into fitting holes formed in the lid 2 and the connecting plate 8. Inserted without. Therefore, the pivot 7a is not displaced in the circumferential direction or the diametrical direction in the housing 3.

On the other hand, the remaining two pivots 7b and 7c located on the lower left and right sides in FIGS. 5 and 6 have both ends with respect to the lid 2 and the connecting plate 8 in the circumferential direction of the housing 3. And, it is supported so as to be slightly displaceable in the diameter direction. For this reason, the pivot 7 is formed by a part of the lid 2 and the connecting plate 8.
As shown in FIG. 6, support holes 9, 9 having an inner diameter larger than the outer diameters of the pivots 7b, 7c are formed in portions matching the both ends of the b, 7c. 9,
Both ends of the pivots 7b and 7c are loosely engaged.
A guide roller 10 and wedge rollers 11a and 11b, which are intermediate rollers, are rotatably supported by radial needle bearings 12, respectively, around intermediate portions of the pivots 7a, 7b and 7c. still,
The connecting plate 8 is a part of the inner surface of the lid 2 (the surface on the space side where the guide roller 10 and the wedge rollers 11a and 11b are installed, and the right surface in FIG. 4).
0 and the projections 13 protruding from the wedge rollers 11a, 11b.
By 14, it is connected and fixed to the lid 2.

An annular outer ring 15 is rotatably provided inside the housing 3 at a portion surrounding the guide roller 10 and the wedge rollers 11a and 11b.
The central portion of the inner peripheral surface of the outer ring 15 is projected inward in the diameter direction to form a bank-shaped convex portion 16, and the inner peripheral surface of the convex portion 16 is a second cylindrical surface 17. The second cylindrical surface 17 and a third cylindrical surface 18, which is the outer peripheral surface of the guide roller 10 and the wedge rollers 11a and 11b,
18 is freely contactable. Also, the outer ring 15 has
The outer diameter end of the coupling bracket 19 is externally fitted and fixed, and the inner end of the output shaft 20, which is the second rotating shaft, is coupled and fixed to the center of the coupling bracket 19. This output shaft 20
Is rotatably inserted through a second through-hole 21 formed at the center of the main body 1 constituting the housing 3 and protrudes outside the housing 3.

Each of the third cylindrical surfaces 1 which is an outer peripheral surface of the guide roller 10 and the wedge rollers 11a and 11b.
Reference numerals 8 and 18 respectively contact a first cylindrical surface 22 provided on the outer peripheral surface of the center roller 4 and a second cylindrical surface 17 provided on the inner peripheral surface of the outer ring 15. The center of the center roller 4 and the centers of the output shaft 20 and the outer ring 15 are eccentric to each other. That is, as described above, the through hole 5 through which the center roller 4 is inserted is provided at a position slightly deviated from the center of the housing 3, whereas the second through hole through which the output shaft 20 is inserted. The hole 21 is provided in the housing 3
Is provided at the center. The output shaft 20 and the outer ring 15 rotatably supported inside the second through hole 21 are concentric with each other. Therefore, the center roller 4 and the outer ring 15
The output shaft 20 and the output shaft 20 are eccentric from each other by an amount of deviation δ (see FIG. 4) of the through hole 5 from the center of the housing 3. The guide roller 10 and the wedge rollers 11a, 11b are present between the first cylindrical surface 22 provided on the outer peripheral surface of the center roller 4 and the second cylindrical surface 17 provided on the outer ring 15. The width dimension of the annular space 23 provided with is uneven in the circumferential direction by an amount corresponding to the eccentric amount of δ.

As described above, the outer diameters of the guide roller 10 and the wedge rollers 11a and 11b are made different from each other because the width of the annular space 23 is made uneven in the circumferential direction. That is, the wedge rollers 11a and 11b located on the side where the center roller 4 is eccentric with respect to the outer ring 15 (the lower side in FIGS. 5 and 6) have the same diameter and have a relatively small diameter. On the other hand, the diameter of the guide roller 10 located on the opposite side (upper side in FIGS. 5 and 6) of the center roller 4 with respect to the outer ring 15 is made larger than those of the wedge rollers 11a and 11b. ing. Then, the third cylindrical surfaces 18, 18 which are the outer peripheral surfaces of the guide roller 10 and the wedge rollers 11 a, 11 b, which are the intermediate rollers, are respectively combined with the first and second cylindrical surfaces 22, 17. Abutting.

The above-mentioned 1 is an intermediate roller.
Guide rollers 10 and two wedge rollers 11
a, 11b, the pivot 7 supporting the guide roller 10
a is fixed in the housing 3 as described above. On the other hand, the pivots 7b and 7c supporting the wedge rollers 11a and 11b freely support a slight displacement in the circumferential direction and the diametric direction in the housing 3 as described above. Therefore, the wedge roller 1
1a and 11b are also slightly displaceable in the circumferential direction and the diametrical direction in the housing 3. Each of the wedge rollers 1 is formed by an elastic material such as compression coil springs 25, 25 mounted in the cylinder holes 24, 24 of the lid 2.
A wedge roller 11 rotatably supporting pivots 7b, 7c supporting the shafts 1a, 11b on the respective pivots 7b, 7c.
In order to move a and 11b toward the narrow portion of the annular space 23, they are elastically lightly pressed.

In the case of the conventional friction roller type transmission constructed as described above, the rotation of the center roller 4 coupled to the input shaft 6 is caused by rotation of the first cylindrical surface 22 which is the outer peripheral surface of the center roller 4. , Guide roller 10 and wedge roller 11a,
The power is transmitted to the guide roller 10 and the wedge rollers 11a, 11b via the respective inner diameter side contact portions 26, 26, which are the contact portions with the third cylindrical surfaces 18, 18, which are the outer peripheral surfaces of 11b. Further, the rotation of the guide roller 10 and the wedge rollers 11a and 11b
The power is transmitted to the outer ring 15 via outer diameter side abutting portions 27, 27 which are abutting portions of the second cylindrical surface 17 provided on the inner peripheral surface of the outer ring 15. Then, the output shaft 20 fixedly connected to the outer ring 15 rotates.

When the center roller 4 rotates clockwise (or counterclockwise) in FIGS. 5 and 6, and the outer race 15 also rotates counterclockwise (or clockwise), the right pivot 7b in FIGS. The wedge roller 11a (or 11b) rotatably supported by the (or left pivot 7c) is provided in the annular space 23 existing between the first and second cylindrical surfaces 22, 17 in the annular space 23. The narrow part of the
6 (lower central part of the image). As a result, the third cylindrical surface 1 which is the outer peripheral surface of the wedge roller 11a (or 11b) rotatably supported on the pivot 7b (or 7c).
8 strongly presses the first cylindrical surface 22 and the second cylindrical surface 17. The inner cylindrical contact portion 26, which is a contact portion between the third cylindrical surface 18 of the wedge roller 11a (or 11b) and the first cylindrical surface 22, and the wedge roller 11a (or 11b). The contact pressure of the outer diameter side contact portion 27, which is the contact portion between the third cylindrical surface 18 and the second cylindrical surface 17, is increased.

The one wedge roller 11a (or one wedge roller 11a)
When the contact pressure of the inner and outer contact portions 26 and 27 with respect to 1b) is increased, at least one of the center roller 4 and the outer ring 15 is subjected to an assembling gap or elastic deformation. A slight displacement along the respective diametrical direction. As a result, the third cylindrical surfaces 18 and 18 which are the outer peripheral surfaces of the guide roller 10 and the wedge roller 11b (or 11a), which are the remaining two intermediate rollers, and the first cylindrical surface which is the outer peripheral surface of the center roller 4 2 which is the contact portion with the surface 22
The third cylindrical surfaces 18, 18 which are the outer peripheral surfaces of the wedge rollers 11 b (or 11 a) and the guide rollers 10 and the second cylinder which is the inner peripheral surface of the outer ring 15. The contact pressure of the two outer-diameter contact portions 27, which are contact portions with the surface 17, increases.

A wedge roller 11a (or 11b) rotatably supported by the one pivot 7b (or 7c) is
The force to move the annular space 23 toward the narrow portion of the annular space 23 changes according to the magnitude of the torque transmitted from the center roller 4 to the outer ring 15. That is, as the driving torque of the center roller 4 increases, the force for moving the wedge roller 11a (or 11b) toward the narrow portion of the annular space 23 increases. The greater the force, the greater the contact pressure between the inner and outer diameter contact portions 26 and 27. Conversely, when the driving torque is small, the contact pressures of the inner and outer contact portions 26 and 27 are small.

In the structure shown in FIGS. 4 to 6, two wedge rollers 11a and 11b are provided because the input shaft 6 may rotate in any direction. If the rotation direction of the shaft is constant, only one wedge roller may be provided, and the other intermediate roller may be used as a guide roller. In this case, the wedge roller and the guide roller are
It is also possible to provide a total of two intermediate rollers, one for each, and to arrange these two intermediate rollers at positions slightly shifted from the diametrically opposite side with respect to the center roller. In addition, if the input shaft and the output shaft are reversed, it can be used as a gearbox. Furthermore, regardless of the torque to be transmitted,
As long as the contact pressure between the outer contact portions 26 and 27 can be kept constant, all the intermediate rollers can be used as guide rollers. However, if the wedge roller is not provided, the optimum contact pressure according to the torque to be transmitted cannot be obtained, so that when the torque fluctuates, not only the transmission efficiency is reduced, but also the outer peripheral surface of the center roller is The work of assembling the plurality of intermediate rollers with the inner peripheral surface of the outer ring while ensuring the necessary contact pressure becomes troublesome.

[0014]

A conventionally known friction roller type transmission constructed and operated as described above is:
When a bending moment is applied to the output shaft 20, the rigidity opposing the bending moment is insufficient. That is, when the friction roller type transmission is installed in various types of mechanical devices and operated, a bending moment that twists the output shaft 20 may be applied to the output shaft 20 in some cases. As shown in FIG. 4, in the case of a structure in which the output shaft 20 is supported inside the second through hole 21, it is difficult to secure rigidity against the bending moment. In the case of the conventional structure shown in FIG.
Since the slide bearing 28 is used to support the output shaft 20 inside the second through hole 21, the rigidity can be secured to some extent, but may not be sufficient. Further, since the sliding bearing has a higher resistance and generates a larger amount of heat during operation than the rolling bearing, it is not suitable for applications in which the output shaft 20 is rotated at a high speed.

On the other hand, US Pat.
The specification discloses a friction roller type transmission in which an output shaft is rotatably supported on a housing by a single row deep groove type ball bearing, which is a kind of radial rolling bearing. According to the structure using such a radial rolling bearing, it is possible to rotate the output shaft at a high speed.However, securing rigidity against a bending moment applied to the output shaft is more difficult than in the case of a sliding bearing. It becomes difficult. A relatively small diameter radial rolling bearing installed around the output shaft is also small in terms of bearing capacity, and its life is likely to be shortened by a load based on the bending moment and the like.

If a plurality of rows of radial rolling bearings are provided between the inner peripheral surface of the (second) through hole formed in the housing and the outer peripheral surface of the output shaft, the rigidity and bearing life can be secured. However, the axial dimension of the rotation supporting portion of the output shaft becomes longer. It is necessary to fix a power transmission member such as a pulley or a gear to the tip of the output shaft, and it may be difficult to increase the axial dimension of the rotation support due to installation space. In view of such circumstances, the present invention has realized a structure capable of securing the rigidity against the bending moment applied to the second rotating shaft such as the output shaft and the life of the bearing without increasing the axial dimension of the rotating support portion. It was invented to do so.

[0017]

SUMMARY OF THE INVENTION The friction roller type transmission of the present invention has the same structure as the above-mentioned conventional friction roller type transmission.
A first rotating shaft, a center roller fixed to the end of the first rotating shaft concentrically with the first rotating shaft, having an outer peripheral surface as a first cylindrical surface, and an inner peripheral surface as a second roller. An outer ring provided around the center roller as a cylindrical surface so as to be freely rotatable relative to the center roller, a second rotating shaft concentric with the outer ring and having one end fixed to the outer ring, and the first cylinder; In the annular space between the surface and the second cylindrical surface, a plurality of pivots arranged in parallel with the first rotation axis, rotatably supported by each of these pivots, each outer peripheral surface A plurality of intermediate rollers serving as a third cylindrical surface, and a support substrate for supporting one ends of the plurality of pivots are provided. The first rotation shaft is rotatably supported in a through hole provided substantially at the center of the support substrate.

In particular, in the friction roller type transmission of the present invention, at least in the state of use of the friction roller type transmission, a fixed cylindrical surface concentric with the outer peripheral surface of the outer ring exists around the outer ring. And the outer ring is
It is rotatably supported by a radial rolling bearing.
As an application example of the present invention, an inner raceway is formed directly on the outer peripheral surface of the outer race, and a plurality of inner raceways are provided between the inner raceway and the outer raceway provided directly or via an outer race member on the fixed cylindrical surface. Rolling elements can be provided. Alternatively, if a roller clutch capable of supporting a radial load and allowing only one-way rotational movement is used as the radial rolling bearing, a function of allowing the outer ring to rotate only in one direction can be added. .

[0019]

With the friction roller type transmission of the present invention configured as described above, the operation of transmitting the rotational force between the first and second rotating shafts while changing the rotational speed is as described above. FIG.
This is the same as the case of a conventionally known friction roller type transmission such as the friction roller type transmission described in Nos. 6 to 6. Especially,
In the case of the friction roller type transmission of the present invention, the outer ring is rotatably supported by a radial rolling bearing provided between the outer peripheral surface of the outer ring and a fixed cylindrical surface provided around the outer ring. In addition, the rigidity against the bending moment applied to the second rotating shaft and the life of the bearing can be ensured.

[0020]

FIG. 1 shows a first embodiment of the present invention. The features of the present invention realize a structure capable of securing the rigidity against the bending moment applied to the output shaft 20a, which is the second rotating shaft, and the life of the rolling bearing for rotatably supporting the output shaft 20a. Therefore, the outer ring 15a that rotates together with the output shaft 20a is rotatably supported by a relatively large-diameter rolling bearing. Center roller 4, outer ring 15a, guide roller 1
The structure and operation of the friction roller type transmission main body composed of a plurality of intermediate rollers including zero are described in FIGS.
Is similar to a conventionally known friction roller type transmission described in U.S. Pat. No. 4,709,589. The structure and operation of the friction roller type transmission main body are not the gist of the present invention. Therefore, the description of the parts equivalent to the conventional structure is omitted or simplified, and the following description will focus on the characteristic parts of the present invention and the parts different from the conventional structure shown in FIGS. Note that FIGS. 1 to 3 show the guide roller 10 in a state located on the lower side of the figure, contrary to FIG.

An electric motor 29, which is a driving means for rotating the center roller 4, has a bottomed cylindrical casing 30, and a central portion of the casing 30 is provided with a rotary drive corresponding to a first rotating shaft. The shaft 31 is rotatably supported. The housing 32 for accommodating the friction roller type transmission main body is also formed in a bottomed cylindrical shape. And
The end opening of the housing 32 and the end opening of the casing 30 are opposed to each other and abut each other via a support substrate 33. The support substrate 33, the casing 30, and the housing 32 are connected and fixed by a plurality of screws 34. For this purpose, an outward flange-shaped flange 35 is formed at the opening end of the casing 30. The screws 34, 34 inserted through the flange 35 and the support board 33 are screwed into screw holes 37, 37 formed in the peripheral wall 36 of the housing 32, and further tightened.

The portion of the support substrate 33 near the outer periphery is
An extension 38 is formed by extending the outer periphery of the flange 35 outward in the diameter direction. And this extension 3
8 functions as a mounting flange. That is, the screws 53, 5
3 (see FIG. 3 showing a third example of the embodiment) is screwed into a screw hole provided in a fixed portion such as a housing of a second-stage reduction gear, which is a driven member, and further tightened. Support substrate 33
Can be freely connected and fixed to the fixing portion.

In the through hole 5 formed in the center of the support substrate 33, the center (the right end in FIG. 1) of the rotary drive shaft 31 is provided integrally with the rotary drive shaft 31. The roller 4 is inserted. The leading end (right end in FIG. 1) of the center roller 4 is inserted into the through hole 5 by a rolling bearing 39, and the base end of the rotary drive shaft 31 is inserted into the bottom inner surface of the casing 30 by another rolling bearing 40. And are rotatably supported. The electric motor 29 is configured by fixing a rotor 41 on an outer peripheral surface of an intermediate portion of the rotary drive shaft 31 and a stator 42 on an inner peripheral surface of the casing 30.

In addition, a second through hole 21a is formed in a substantially central portion of the bottom plate portion 43 constituting the housing 32 so as to allow both surfaces of the bottom plate portion 43 to communicate with each other. A cylindrical portion 44 is formed on the outer surface (the right surface in FIG. 1) of the bottom plate portion 43 so as to surround the second through hole 21a. The central axes of the cylindrical portion 44 and the second through hole 21a are eccentric with respect to the central axes of the rotation drive shaft 31 and the central roller 4 by δ. This is the same as in the case of the conventional structure shown in FIGS. The output shaft 20 serving as a second rotating shaft is provided inside the cylindrical portion 44 and the second through hole 21a.
a is rotatably supported by a single row deep groove ball bearing 45. The output shaft 20a has a cylindrical outer ring 15 with a bottom.
a is fixed to the center of the outer surface of the bottom plate portion 46 which constitutes a at right angles to the outer surface (concentrically with the outer ring 15a).

Further, between the outer peripheral surface of the rotating cylindrical portion 47 constituting the outer ring 15a and the inner peripheral surface of the fixed cylindrical portion 48 constituting the housing 32, it corresponds to the radial rolling bearing described in the claims. The radial needle bearing 49
Has been arranged. That is, the outer peripheral surface of the rotating cylindrical portion 47 is formed into a smooth cylindrical surface to form the inner raceway 50, and the inner raceway 50 and the inner peripheral surface of the cylindrical race 51 fitted inside the fixed cylindrical portion 48. Between the multiple needles 5
2, 52 are provided so as to roll freely. In this case,
The inner peripheral surface of the fixed cylindrical portion 48 corresponds to a fixed cylindrical surface described in claims. Most of the radial load and bending moment applied to the outer ring 15 a are supported by the radial needle bearing 49. On the other hand, the ball bearing 45 is connected to the outer race 15 via the output shaft 20a.
a, the outer ring 15a is positioned in the axial direction.
Rubbing with the support substrate 33 and the housing 43 is prevented.

According to the friction roller type transmission of the present invention constructed as described above, the rigidity against the bending moment applied to the output shaft 20a and the life of the rolling bearing that rotatably supports the output shaft 20a can be ensured. . That is, the outer ring 15a is rotatably supported by the radial needle bearing 49 provided between the outer peripheral surface of the outer ring 15a and the inner peripheral surface of the fixed cylindrical portion 48 provided around the outer ring 15a. For this reason, even when a bending moment is applied to the output shaft 20a, the span of a fulcrum to which a force is applied when the output shaft 20a is to be held at the same position as opposed to the bending moment is long. Therefore, the rigidity can be sufficiently increased. Although the bending moment is applied not only to the radial needle bearing 49 but also to the ball bearing 45, most of the load based on the bending moment is:
The radial needle bearing 49 supports the ball bearing 4.
The load applied to 5 is limited. Therefore, the life of the ball bearing 45 is not short.

Further, the provision of the radial needle bearing 49 does not increase the axial dimension of the rotation supporting portion of the output shaft 20a and the outer ring 15a. In addition, the radial needle bearing 4 having a small thickness in the diameter direction.
The increase in the diameter of the housing 32 due to the provision of 9 is also slight. Therefore, it is not difficult to install the friction roller type transmission in a limited space, and the degree of freedom in designing various types of mechanical devices incorporating the friction roller type transmission is improved.

The radial needle bearing 49 is provided between the outer peripheral surface of the outer ring 15a and the inner peripheral surface of the fixed cylindrical portion 48.
Alternatively, or together with the radial needle bearing 49,
If a roller clutch capable of supporting a radial load and permitting only one-way rotational movement is provided, a function of enabling the outer ring 15a and the output shaft 20a to rotate only in one direction can be added.

Further, in the case of the example shown in the figure, it is possible to realize a structure in which the size and weight of the mechanical device incorporating the friction roller type transmission and the cost can be reduced, and the assembling accuracy can be easily secured. That is, since the support substrate 33 is directly connected to and fixed to a fixed portion of the mechanical device by a screw inserted into an extension 38 provided on a portion near the outer periphery of the support substrate 33, a mounting bracket is omitted. Based on the above, it is possible to reduce the size, weight, and cost. In addition, assembling accuracy can be ensured.

In the example shown in the figure, an electric motor 29 as a driving means is provided adjacent to the friction roller type transmission, and the support substrate 33 closes the opening of the casing 30 constituting the electric motor 29. The function as the cover plate and the function as the cover plate for closing the opening of the housing 32 accommodating the main body of the friction roller type transmission are provided.
Therefore, it is possible to reduce the number of components of the entire machine incorporating the friction roller type transmission. In addition, the size, weight, and cost of the entire machine can be reduced. Further, the rotation drive shaft 31 of the electric motor 29 and the center roller 4 of the friction roller type transmission are rotatably supported on a single support substrate 33 having both functions as the two types of cover plates. Therefore, the support accuracy of the rotation drive shaft 31 and the center roller 4 can be maintained at a high level.

Next, FIG. 2 shows a second embodiment of the present invention.
An example is shown. In the case of this example, the housing 32a for accommodating the main body of the friction roller type transmission is formed in a simple cylindrical shape without the bottom plate 43 (FIG. 1). And corresponds to the fixed cylindrical surface described in the claims,
A single row deep groove ball bearing 45 is provided between the inner peripheral surface of the housing 32a and the outer peripheral surface of the rotating cylindrical portion 47 which also constitutes the outer ring 15a, which also corresponds to the rotating cylindrical surface described in the claims.
a and a radial needle bearing 49a. Of these two bearings 45a, 49a, the ball bearing 45a mainly positions the outer ring 15a in the axial direction, and the radial needle bearing 49a supports a load based on a bending moment applied to the outer ring 15a from the output shaft 20a.

According to the structure of the present embodiment as described above, the cost of the housing 32a and the friction roller type transmission incorporating the housing 32a can be reduced by simplifying the shape of the housing 32a. Further, since the bottom plate 43 is omitted, the axial dimension of the friction roller type transmission can be reduced, and the size and weight can be reduced. Other configurations and operations are
This is the same as the case of the first example described above.

FIG. 3 shows a third embodiment of the present invention.
An example is shown. In the case of this example, a driven device such as a second-stage speed reducer is provided adjacent to the friction roller type transmission,
On the inner peripheral surface of the housing 54 constituting the driven device,
The outer ring 15a constituting the friction roller type transmission is rotatably supported by a single row deep groove type ball bearing 45a and a radial needle bearing 49a. In the case of this example, as described above, the outer ring 15a is directly rotatably supported on the inner peripheral surface of the housing 54, and accordingly, the housing incorporated in the first example and the second example described above. 32, 32a
(FIGS. 1 and 2) can be omitted. Thus, the housing 32,
By omitting 32a, it is possible to reduce the number of components of the entire machine incorporating the friction roller type transmission, and to reduce the size, weight and cost of the entire machine. Other configurations and operations are the same as those in the above-described second example.

[0034]

Since the friction roller type transmission of the present invention is constructed and operates as described above, it is applied to the second rotating shaft such as the output shaft without increasing the axial size of the rotating support. A structure capable of securing rigidity against bending moment and bearing life can be realized.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first example of an embodiment of the present invention.

FIG. 2 is a sectional view showing the second example.

FIG. 3 is a sectional view showing a third example.

FIG. 4 is a sectional view showing an example of a conventional structure.

FIG. 5 is a sectional view taken along line AA of FIG. 4;

FIG. 6 is a sectional view taken along the line BB in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 2 Lid 3 Housing 4 Center roller 5 Through-hole 6 Input shaft 7a, 7b, 7c Axis 8 Connecting plate 9 Support hole 10 Guide roller 11a, 11b Wedge roller 12 Radial needle bearing 13 Projection 14 Connection bolt 15, 15a Outer ring 16 Convex part 17 Second cylindrical surface 18 Third cylindrical surface 19 Coupling bracket 20, 20a Output shaft 21, 21a Second through hole 22 First cylindrical surface 23 Annular space 24 Cylinder hole 25 Compression coil spring 26 Inside diameter side Contact part 27 Outer diameter side contact part 28 Slide bearing 29 Electric motor 30 Casing 31 Rotation drive shaft 32, 32a Housing 33 Support substrate 34 Screw 35 Flange 36 Peripheral wall 37 Screw hole 38 Extension 39 Rolling bearing 40 Rolling bearing 41 Rotor 42 Stator 43 Bottom plate part 44 Cylindrical part 45, 45a Ball bearing 4 Bottom 48 fixed cylinder portion plate portion 47 rotating cylindrical portion 49,49a radial needle bearing 50 the inner ring raceway 51 race 52 needles 53 screw 54 housing

Claims (1)

[Claims] A first rotating shaft, a center roller fixed to an end of the first rotating shaft concentrically with the first rotating shaft and having an outer peripheral surface as a first cylindrical surface; A surface around the center roller as a second cylindrical surface, an outer ring that is freely rotatable relative to the center roller, a second rotating shaft that is concentric with the outer ring and one end of which is fixedly connected to the outer ring, In the annular space between the first cylindrical surface and the second cylindrical surface, a plurality of pivots arranged in parallel with the first rotation axis, rotatably supported by each of these pivots, A plurality of intermediate rollers each of which has a third cylindrical surface as its outer peripheral surface, and a support substrate for supporting one end of the plurality of pivots,
In a friction roller type transmission in which the first rotating shaft is rotatably supported in a through hole provided in a substantially central portion of the support substrate, at least around the outer ring in a use state of the friction roller type transmission. Has a fixed cylindrical surface concentric with the outer peripheral surface of the outer ring, and the outer ring is rotatably supported on the fixed cylindrical surface by a radial rolling bearing. Machine.