JPH11336864A - Friction roller type speed change gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make this speed change gear small in size, and actualize a structure capable of obtaining a high transmission efficiency regardless of abrasion and change in temperature. SOLUTION: An inner wheel 41 the outer circumferential surface of which is formed into a conical projected surface, is fixed to the end part of an input shaft 27. Each conical shaped transmission roller 47 is held in between the outer circumferential surface of the inner wheel 41 and the inner circumferential surface of an outer wheel 49 respectively. A carrier 45 supporting a pivot shaft 46 in which these transmission rollers 47 are pivoted, is combined with an output shaft 28. In addition, a disc spring 52 is provided for a space between the outer wheel 49 and a holder 29.

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. This realizes a structure having the above.

[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, a structure in which a friction roller type transmission is assembled to an output portion of an electric motor and used as a speed reducer, and the rotational movement of the electric motor is reduced and the torque is increased is described in, for example, Japanese Patent Application Laid-Open No. Hei 8-210455. Have been. 8 and 9 are described in this publication.
1 shows an electric motor with a friction roller type reduction gear;

[0003] A motor case 2 constituting the electric motor 1
Consists of a bottomed cylindrical case body 3 and a lid 4 that closes an opening of one end (the lower end in FIG. 8) of the case body 3. The rotation drive shaft 5 is rotatably supported at the center of the inside of the motor case 2. A stator 6 is fixed on the inner peripheral surface of the case body 3, and a rotor 7 is fixed on a portion of the intermediate peripheral surface of the rotary drive shaft 5 facing the inner peripheral surface of the stator 6. The rotation drive shaft 5 is freely rotatable based on the current supply.
A planetary roller type speed reducer 8 is provided on the outer surface of the lid 4 (the lower surface in FIG. 8).

In this planetary roller type speed reducer 8, a portion protruding from the outer surface of the lid 4 at one end (the lower end in FIG. 8) of the rotary drive shaft 5 functions as a center roller 9. The center roller 9 is concentric with the rotation drive shaft 5 and has an outer peripheral surface as a first cylindrical surface 10. An outer ring 11 is disposed around the center roller 9 so as to be rotatable relative to the center roller 9. In the illustrated example, the outer ring 11 is fitted inside a cylindrical wall portion 12 formed near the outer diameter of the outer surface of the lid 4, and the outer ring 11 is fixed to the lid 4 by a plurality of fixing bolts 21, 21. It is fixed to the lower surface of the body 4. That is, in the illustrated example, the fixed outer ring 1 is fixed.
Inside 1, the central roller 9 rotates. The inner peripheral surface of such an outer ring 11 is a second cylindrical surface 13.

In the annular space 14 between the second cylindrical surface 13 and the first cylindrical surface 10, a part of a plurality of (four in the illustrated example) pivots 15, 15 are inserted. ing. These pivots 15 are arranged in parallel with the rotary drive shaft 5, respectively. Further, planetary rollers 16, 16 are rotatably supported by radial needle bearings 17, 17 at portions of the respective pivots 15, 15 which are located inside the annular space 14. ing. The outer peripheral surface of each of the planetary rollers 16 is a third cylindrical surface 18 that comes into contact with the first cylindrical surface 10 and the second cylindrical surface 13, respectively. Further, portions protruding from the annular space 14 at the ends of the pivots 15 and 15 are connected and fixed to a ring-shaped connecting plate 19. The base end of the output shaft 20 is fixedly connected to the center of the connecting plate 19. The output shaft 20 is provided with a pair of ball bearings 25, 25 inside a cylindrical portion 24 provided at the center of a cover 23 fixedly connected to the distal end of the cylindrical wall portion 12 by a plurality of connecting bolts 22, 22. , So that it is rotatably supported.

The operation of the planetary roller type electric motor with a speed reducer constructed as described above is as follows. When the rotation drive shaft 5 rotates based on the energization of the stator 6,
Based on the friction between the first cylindrical surface 10 of the center roller 9 and the third cylindrical surfaces 18 of the planetary rollers 16, these planetary rollers 16, 16 move around the center roller 9. Revolves while rotating. This revolving motion is transmitted to the output shaft 20 via the pivots 15 and 15 and the connecting plate 19, and the output shaft 20 rotates at a lower speed than the rotary drive shaft 5.

In order to secure the transmission efficiency of the planetary roller type speed reducer 8, in order to prevent slippage between the third cylindrical surfaces 18, 18 and the first and second cylindrical surfaces 10, 13, Therefore, it is necessary to secure the contact pressure between these cylindrical surfaces 18, 10, and 13. In order to secure this contact pressure, in the case of the structure shown in FIGS.
16 is pressed into an annular space 14 between the first cylindrical surface 10 and the second cylindrical surface 13. That is, the outer ring 11 provided with the second cylindrical surface 13 is heated to
The respective planetary rollers 16, 16 are inserted into the annular space 14 in a state where the diameter of the second cylindrical surface 13 is expanded by thermally expanding. After the insertion, if the temperature of the outer race 11 is reduced and the diameter of the second cylindrical surface 13 is reduced, the cylindrical surfaces 18, 10, 13 are connected to each other by the components 9, 11, 11 of the planetary roller type speed reducer 8. , 16 based on the elastic deformation
Contact with sufficiently large pressure.

In the above-described conventionally known planetary roller type speed reducer 8, the contact pressure between the cylindrical surfaces 18, 10 and 13 is secured by shrink fitting. For this reason, it is difficult to adjust the contact pressure between these surfaces to an appropriate value. Moreover, even if it can be adjusted to an appropriate value immediately after assembling, the contact pressure between the above-mentioned surfaces changes due to temperature changes after assembling and wear due to long-term use, and power transmission loss may increase. There is.

On the other hand, Japanese Patent Application Laid-Open No. 47-26565 discloses a method in which a first cylindrical surface is provided on the outer peripheral surface of an inner ring whose diameter can be enlarged and reduced, and the outer diameter of the inner ring is determined by the torque to be transmitted. A planetary roller type speed reducer that expands and contracts according to the size is described. According to such a structure, the contact pressure between the third cylindrical surface provided on the outer peripheral surface of the planetary roller and the first and second cylindrical surfaces is changed in accordance with the torque to be transmitted, thereby reducing the planetary roller type deceleration. The internal loss of the machine can be reduced.

[0010]

Problems to be Solved by the Invention
In the case of the planetary roller type speed reducer described in Japanese Patent Publication No. 5 (1993), since a torque cam for expanding and contracting the inner ring is incorporated on the inner diameter side of the inner ring in accordance with the magnitude of the torque to be transmitted, the diameter of the inner ring increases. . When increasing the reduction ratio of the planetary roller type speed reducer, it is necessary to reduce the outer diameter of the first cylindrical surface provided on the outer peripheral surface of the inner ring, so it is not preferable that the diameter of the inner ring is increased. . In other words, it is very difficult to incorporate a torque cam on the inner diameter side of the inner ring when considering that a planetary roller type reduction gear that can obtain a required reduction ratio is installed in a limited space. In view of such circumstances, the present invention can achieve a good transmission efficiency by maintaining a small contact pressure between the cylindrical surfaces regardless of temperature changes and abrasion after assembly. This is intended to realize a friction roller type transmission that can be used.

[0011]

SUMMARY OF THE INVENTION A friction roller type transmission according to the present invention comprises a first shaft and a second shaft which is arranged concentrically with the first shaft and rotates relative to the first shaft. An inner ring having an outer peripheral surface conically convexly fixed to a portion facing the second axis at an end of the first shaft and concentric with the first and second shafts; Between the outer ring, which is disposed concentrically with the inner ring and whose inner peripheral surface is a conical concave surface inclined in the same direction as the outer peripheral surface of the inner ring, and between the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring. And a plurality of pivots inserted into the outer ring and rotatably supported around each of the pivots, each of which has an outer peripheral surface in contact with an inner peripheral surface of the outer ring and an outer peripheral surface of the inner ring. A plurality of transmission rollers, and a first support member for connecting and supporting the base ends of the plurality of pivots, A second support member for supporting the outer ring, and an elastic member that axially presses at least one of the inner ring and the outer ring toward the plurality of transmission rollers; One of the members is connected to the second shaft, and the other of the first and second support members is fixed.

More preferably, one or more of the following are provided. The outer ring, each transmission roller, each pivot, and the first support member are a unit assembled in advance. It has a suppressing member for preventing the constituent members of the unit satisfying the above conditions from being separated from each other. A first support member is coupled to and supported on a second shaft such that the first support member can rotate in synchronization with the second shaft and can be displaced in the axial direction of the second shaft. The extension of the generatrix on the outer peripheral surface of each transmission roller exists at substantially the same point on the center axis of the first and second shafts. An elastic member presses the outer ring, and a thrust bearing for supporting a thrust load applied to the inner ring is provided between the inner ring and a member rotatably supporting the first shaft. A large curvature is applied to at least one of the outer peripheral surface of the inner race and the outer peripheral surface of each transmission roller, which is in contact with each other, and at least one of the outer peripheral surface of each transmission roller and the inner peripheral surface of the outer race. A radiused crowning is applied. The large-diameter end surface of each transmission roller and one surface of an outward flange-shaped flange formed at the large-diameter end portion of the inner ring are in sliding contact with each other, and at least one of the large-diameter end surface and one surface. Is crowned with a large radius of curvature. Each transmission roller is hollow. The first shaft and the inner ring are integrated.

[0013]

In the friction roller type transmission of the present invention constructed as described above, the elastic member presses at least one of the inner ring and the outer ring toward the transmission roller. Therefore, irrespective of the temperature change after the assembly and the wear due to long-term use, the contact portion between the outer peripheral surface of the inner ring and the outer peripheral surface of each transmission roller, and the outer peripheral surface of each transmission roller and the outer ring A good transmission efficiency can be obtained by maintaining the contact pressure of the contact portion with the inner peripheral surface of the contact member at an appropriate value. Moreover, since the elastic member can be disposed at a position shifted in the axial direction with respect to the inner ring or the outer ring, the diameter of the inner ring and the outer ring is not limited by providing the elastic member.

[0014]

FIG. 1 shows a first embodiment of the present invention. In this friction roller type transmission, an end of an input shaft 27 as a first shaft and an end of an output shaft 28 as a second shaft are inserted into a case 26, and both shafts 27 are inserted. , 28 are rotatably supported.
The case 26 is supported and fixed to a fixed portion (not shown) such as a frame of various mechanical devices. The input shaft 27 and the output shaft 28 are rotatably supported inside the case 26 via a holder 29 as a second support member.

The holder 29 includes an intermediate cylinder 30, an end plate 31 fixedly connected to an opening of one end (right end in FIG. 1) of the intermediate cylinder 30, and the other end of the intermediate cylinder 30 (left end in FIG. 1). ) And a support cylinder 32 which is fitted and fixed to the inner peripheral edge. The intermediate cylinder 30 includes a circular ring portion 33, a small-diameter portion 34 concentric with each other and bent at right angles to the circular ring portion 33 in opposite directions from the inner and outer peripheral edges of the circular ring portion 33. And a diameter portion 35. Further, the end plate 31 is provided with the large diameter portion 35.
And a support cylinder 37 bent from the inner peripheral edge of the second annular portion 36 to the opposite side to the annular portion 33. Such an end plate 31 is a state in which the irregularities formed on the outer peripheral edge of the second annular portion 36 and the irregularities formed on the opening edge of the large diameter portion 35 of the intermediate cylinder 30 are engaged with each other. One end of the intermediate cylinder 30 is fixedly connected to the opening. In this state, the support tube 32 and the support tube portion 37 are concentric with each other.

In the illustrated example, the support tube 32 and the support tube portion 37 are rotatably supported inside the case 26 by deep groove type ball bearings 38, 38, respectively. Therefore, in the illustrated example, the input shaft 27 and the output shaft 28 are used as rotation axes, and the support cylinder 32 and the support cylinder section 37 can also function freely as a planetary roller type transmission that also functions as a rotation axis. The input shaft 27 of the input shaft 27 and the output shaft 28 is rotatably supported inside the support cylindrical portion 37 via a first radial bearing 39 such as a slide bearing. Further, the output shaft 28 is provided inside the support cylinder 32,
It is also rotatably supported via a second radial bearing 40 such as a sliding bearing. Thus, the input shaft 27
The output shaft 28 and the output shaft 28 are supported concentrically and rotatably independently of each other, and the ends of both shafts 27 and 28 are opposed to each other inside the holder 29.

Of the input shaft 27 and the output shaft 28, an inner ring 41 is provided at the end of the input shaft 27,
It is fixed integrally and concentrically with. In the illustrated example, the inner race 41 has a main portion 42 that is relatively gently inclined in a direction in which the outer diameter decreases as the outer peripheral surface approaches the distal end portion, and a radially outward portion from the large-diameter end of the main portion 42. And a protruding flange 43. The outer peripheral surfaces of these main portions 42 are crowned with a large radius of curvature. Also, of both side surfaces of the flange portion 43, one side surface on the main portion 42 side is subjected to spherical crowning having a large radius of curvature. Further, the collar 4
3 and a second annular portion 36 forming the end plate 31
And a thrust bearing 44 such as a needle bearing.

On the other hand, a center portion of a carrier 45 as a first support member is spline-engaged with a portion of the output shaft 28 that protrudes inside the holder 29 at the end.
Accordingly, the carrier 45 rotates together with the output shaft 28, but is displaceable in the axial direction of the output shaft 28. The base end of the pivot 46 is supported and fixed at a plurality of positions (for example, 3 to 4 positions) on one side surface (the right side surface in FIG. 1) of the outer peripheral portion of the carrier 45. Each of the pivots 46 is inclined in a direction outward in the diametrical direction of the carrier 45 from the base end connected to the carrier 45 toward the distal end.

A transmission roller 47 is rotatably supported around each pivot 46 by a third radial bearing 48 such as a needle bearing. The outer peripheral surface of each of the transmission rollers 47 is a conical inclined surface that is inclined in a direction in which the diameter increases as the distance from the carrier 45 increases. Such an extension of the generatrix of the outer peripheral surface of each transmission roller 47 exists at substantially the same point O (see FIG. 7) on the central axis of the input shaft 27 and the output shaft 28. The outer peripheral surface of each of the transmission rollers 47 is crowned with a large radius of curvature so that the outer peripheral surface of each of the transmission rollers 47 and the inner ring 41 are formed regardless of manufacturing errors or assembly errors of the constituent members.
The contact state between the main portion 42 and the outer peripheral surface of the main portion 42 is made uniform. For this purpose, the crowning may be applied to at least one of the outer peripheral surface of the main portion 42 and the outer peripheral surface of each of the transmission rollers 47.

The large-diameter end face of each of the transmission rollers 47 is provided with a spherical crowning having a large radius of curvature. During operation of the friction roller type transmission of the present embodiment, the large diameter side end surface and one side surface of the flange portion 43 may come into sliding contact with each other.
Due to the crowning formed on the large-diameter side end face, the frictional force acting on the contact portion can be reduced. For this purpose, the crowning may be formed on at least one of the one side surface and the large-diameter end surface of each transmission roller 47.

An outer ring 49 is provided around each transmission roller 47 so as to be concentric with the inner ring 41. That is, the locking projections 50 protruding at a plurality of locations on the inner side surface (the right side surface in FIG. 1) of the annular portion 33 constituting the intermediate cylinder 30 of the holder 29.
The outer ring 49 is fitted inside the holder 29 by fitting the retaining recess 51 formed on the base end surface (the left end surface in FIG. 1) of the outer ring 49 without looseness.
And the holder 29 is displaceable in the axial direction (the left-right direction in FIG. 1) with respect to the holder 29. The inner peripheral surface of such an outer ring 49 is formed as a conical concave inclined surface that is inclined in a direction in which the diameter increases as the distance from the annular portion 33 increases. Such an inner peripheral surface of the outer ring 49 is subjected to crowning having a large radius of curvature so that the outer peripheral surface of each of the transmission rollers 47 and the inner peripheral surface of the outer ring 49 are formed regardless of a manufacturing error or an assembly error of each component. The contact state with the head is made uniform. For this purpose, the crowning may be formed on at least one of the inner peripheral surface of the outer race 49 and the outer peripheral surface of each of the transmission rollers 47. Therefore, the outer peripheral surface of each of the transmission rollers 47 may be crowned only, and the generatrix of the outer peripheral surface of the inner ring 41 and the inner peripheral surface of the outer ring 49 may be linear.

The inner surface of the ring portion 33 and the outer ring 4
9 between the base plate 9 and the base end surface thereof as an elastic member.
And the like, so that the outer ring 49 is connected to each of the transmission rollers 4.
7 is elastically pressed. The contact pressure between the outer peripheral surface of each of the transmission rollers 47, the inner peripheral surface of the outer ring 49, and the outer peripheral surface of the main portion 42 is regulated to an appropriate size for transmitting the rotational force. I have.

Further, a cover 53, which is the above-described holding member, is fixedly attached to the outer ring 49. The cover 53 is made of a thin metal plate and has a substantially L-shaped cross section and is formed in an annular shape as a whole. The cover 53 has a cylindrical portion 54 and a ring-shaped holding plate bent inward in the diameter direction from an end edge of the cylindrical portion 54. A portion 55. The cylindrical portion 54 is connected to the outer ring 4
9, the holding plate 55 is tightly fitted to the outside.
The inner peripheral edge faces the tip surface of each of the pivots 46. or,
The fact that each of the pivots 46 comes out of the inside of each of the transmission rollers 47 means that each of the pivots 46 is inclined and that an outward flange-shaped flange 56 is formed at the tip of each of the pivots 46. This is prevented. Therefore, when assembling the friction roller type transmission of this embodiment, the outer ring 4
9, the transmission rollers 47, the pivots 46, and the carrier 45 are assembled in advance as a unit, and furthermore, the constituent members 49, 47, 46, 45 of this unit can be prevented from being separated from each other.

When using the friction roller type transmission of the present invention constructed as described above, one of the input shaft 27, the output shaft 28, the support cylinder 32 and the support cylinder 37 is fixed non-rotatably. The rotational force is transmitted between the remaining two members. Therefore, a case where the support cylinder 32 and the support cylinder portion 37 are fixed and the rotational force is transmitted from the input shaft 27 to the output shaft 28 will be described. During operation in such a state, as in the case of the conventional structure shown in FIGS.
The orbital motion of each transmission roller 47 generated based on the rotation of the input shaft 27 and the inner ring 41 is taken out, and the output shaft 2
8 is rotated at a lower speed than the input shaft 27.

That is, when the input shaft 27 is rotationally driven by a drive source such as an electric motor (not shown),
The transmission rollers 47 revolve around the main portion 42 while rotating on the basis of frictional engagement with the outer peripheral surface of the main portion 42 of the inner ring 41 fixed to the tip of the main ring 41. This revolving motion is transmitted to the output shaft 28 via the pivots 46 and the carrier 45, and the output shaft 28 rotates at a lower speed and a larger torque than the input shaft 27. As described above, the extension of the generatrix of the outer peripheral surface of each transmission roller 47 is
And at approximately the same point O on the center axis of the output shaft 28, the spin at the contact portion (traction portion) between the peripheral surfaces during transmission of the power is suppressed, and the transmission loss of the power is slightly reduced. it can.

In order to ensure good transmission efficiency when transmitting the rotational force between the input shaft 27 and the output shaft 28 as described above, the outer peripheral surface of each of the transmission rollers 47 and the main portion 4
It is necessary to make the contact pressure between the outer peripheral surface of the second and the inner peripheral surface of the outer ring 49 an appropriate value. In the case of the friction roller type transmission of the present embodiment, the plate spring 52 elastically presses the outer ring 49 toward the transmission rollers 47. With this pressing, the transmission rollers 47 tend to be displaced in the axial direction of the input shaft 27 and the output shaft 28. In the illustrated example, the carrier 45 supporting each of the transmission rollers 47 via each of the pivots 46 is supported on the output shaft 28 so as to be displaceable in the axial direction by the spline engagement. The contact pressure between the outer peripheral surface of each transmission roller 47 and the outer peripheral surface of the main portion 42 can be sufficiently ensured by allowing the displacement of each transmission roller 47.

In this manner, based on the elasticity of the disc spring 52, the outer peripheral surface of each transmission roller 47 and the main portion 4
In order to set the contact pressure between the outer peripheral surface of the second and the inner peripheral surface of the outer ring 49 to an appropriate value, regardless of the temperature change after assembly and the wear due to long-term use, these peripheral surfaces contact each other. Good transmission efficiency can be obtained by maintaining the contact pressure at an appropriate value. In addition, since the plate spring 52 can be arranged at a position shifted in the axial direction with respect to the outer ring 49, the plate spring 5
By providing 2, the diameters of the inner ring 41 and the outer ring 52 are not limited.

Next, FIG. 2 shows a second embodiment of the present invention.
An example is shown. In the case of this example, an angular ball bearing is used as the thrust bearing 44a provided between the base end of the inner ring 41 and the end plate 31 constituting the holder 29. To this end, an inner ring 57 for forming the thrust bearing 44a is provided around the base end of the inner ring 41 with the end plate 3.
An outer ring 58 for forming the thrust bearing 44a is provided at a portion near the inner peripheral edge of the inner surface of the second circular portion 36 forming
Each of them is fixedly provided, and a plurality of balls 59, 59 are rotatably provided between the inner ring 57 and the outer ring 58. As described above, by using an angular type ball bearing as the thrust bearing 44a, the rolling resistance at the thrust bearing 44a can be reduced, and the internal loss of the friction roller type transmission can be reduced. Other configurations and operations are the same as those of the above-described first example.

FIG. 3 shows a third embodiment of the present invention.
An example is shown. In the case of this example, the end plate 31 and the support tube 32 constituting the holder 29 are provided around the output shaft 28 around the intermediate tube 30 and the support tube portion 3 formed integrally with the intermediate tube 30.
7 are arranged around the input shaft 27, respectively. or,
A step portion 60 is formed at the intermediate portion in the diameter direction of the end plate 31, and the step portion 60 is engaged with the outer peripheral edge of the base end portion of the outer ring 49. The shape of the stepped portion 60 and the outer peripheral edge of the base end portion of the outer ring 49 is an uneven shape extending in the circumferential direction. Accordingly, the outer ring 49 is supported on the inner surface of the end plate 31 in such a manner that it can be freely displaced in the axial direction but cannot rotate with respect to the end plate 31. Other configurations and operations are the same as those of the above-described second example.

FIG. 4 shows a fourth embodiment of the present invention.
An example is shown. In the case of this example, the outer ring 49 is supported on the holder 29 via the holding cylinder 61. A part of a step portion 60 a formed at a radially intermediate portion of the end plate 31 constituting the holder 29 is caulked to the outer peripheral edge of the base end portion of the holding cylinder 61. Therefore, the holding cylinder 61 is disposed on the inner surface of the end plate 31 so as not to rotate and displace in the axial direction.
Bonded and fixed. The outer ring 49 is supported on the inner diameter side of such a holding cylinder 61 by a spline engagement or a key engagement so as to be freely displaced only in the axial direction. A disc spring 52 is provided between the base end surface of the outer ring 49 and an inward flange-shaped receiving plate portion 62 formed on the inner peripheral surface of the holding cylinder 61. A cover 53 for preventing the components of the unit from being separated is fitted and fixed to the holding cylinder 61. Further, the thrust bearing 44b for supporting the thrust load applied to the inner ring 41 is a deep groove type ball bearing. Then, the thrust bearing 44b is connected to the inner ring 41.
And a flange 43a fixed to the base end of the intermediate cylinder 30 and the inner peripheral edge of the intermediate cylinder 30 constituting the holder 29. Other configurations and operations are the same as those of the above-described third example.

FIG. 5 shows a fifth embodiment of the present invention.
An example is shown. In the case of this example, locking recesses 51 formed at a plurality of locations on the base end surface of the holding barrel 61 and locking projections 50 formed at a plurality of locations on the inner surface of the intermediate barrel 30 constituting the holder 29.
The holding cylinder 61 is supported in the holder 29 by the engagement with. The thrust bearing 44 for supporting the thrust load applied to the inner ring 41 is a needle bearing as in the first example described above. Other configurations and operations are the same as those of the above-described fourth example.

Next, FIG. 6 shows a sixth embodiment of the present invention.
An example is shown. In the case of this example, as in the above-described second example, the base plate of the inner race 41 and the end plate 31 forming the holder 29 are used.
Angular ball bearings are used as the thrust bearings 44a provided therebetween. Other configurations and operations are
This is the same as the case of the fifth example described above.

FIG. 7 shows a seventh embodiment of the present invention.
An example is shown. In the case of this example, each transmission roller 47a
Is hollowed out to reduce the weight. Other configurations and operations are the same as in the case of the above-described first example.

[0034]

Since the present invention is constructed and operates as described above, it is possible to realize a small-sized friction roller type transmission having good transmission efficiency and contribute to miniaturization and improvement of performance of various mechanical devices. .

[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 a fourth example.

FIG. 5 is a sectional view showing the fifth example.

FIG. 6 is a sectional view showing a sixth example.

FIG. 7 is a sectional view showing a seventh example.

FIG. 8 is a cross-sectional view of a conventionally known electric motor with a planetary roller type reduction gear.

FIG. 9 is a sectional view taken along line AA of FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric motor 2 Motor case 3 Case main body 4 Lid 5 Rotation drive shaft 6 Stator 7 Rotor 8 Planetary roller type reduction gear 9 Center roller 10 1st cylindrical surface 11 Outer ring 12 Cylindrical wall part 13 2nd cylindrical surface 14 Annular space DESCRIPTION OF SYMBOLS 15 Axis 16 Planetary roller 17 Radial needle bearing 18 Third cylindrical surface 19 Connecting plate 20 Output shaft 21 Fixing bolt 22 Connecting bolt 23 Cover 24 Cylindrical part 25 Ball bearing 26 Case 27 Input shaft 28 Output shaft 29 Holder 30 Intermediate cylinder 31 End Plate 32 Support cylinder 33 Ring section 34 Small diameter section 35 Large diameter section 36 Second circle section 37 Support cylinder section 38 Ball bearing 39 First radial bearing 40 Second radial bearing 41 Inner ring 42 Main section 43, 43a Flange Part 44, 44a, 44b Thrust bearing 45 Carrier 46 Axis 47, 47a Transmission roller 48 The radial bearing 49 outer ring 50 locking projection 51 engaging the recess 52 servings plate spring 53 cover 54 cylindrical portion 55 clamping plates 56 flange portion 57 the inner ring 58 outer ring 59 ball 60,60a step portion 61 holding tube 62 receiving plate portions

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Takashi Imanishi 1-5-50 Kumaguma Shinmei, Fujisawa-shi, Kanagawa Nippon Seiko Co., Ltd. (72) Inventor Hiroyuki Ito 1-50-50 Kugenuma Shinmei, Fujisawa-shi, Kanagawa Nippon Seiko Co., Ltd.

Claims (1)

[Claims] 1. A first shaft, a second shaft concentric with the first shaft and rotating relative to the first shaft, and a second shaft at an end of the first shaft. An inner ring fixed to the portion opposite to the axis concentrically with the first and second shafts and having an outer peripheral surface having a conical convex surface; and an inner peripheral surface disposed concentrically with the inner ring around the inner ring. An outer ring having a conical concave surface inclined in substantially the same direction as the outer peripheral surface of the inner ring; a plurality of pivots inserted between the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring; A plurality of tapered roller-shaped transmission rollers, each of which is rotatably supported around the periphery, and whose outer peripheral surface is in contact with the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring, and the plurality of pivots A first support member for connecting and supporting the base end portion of the inner ring, a second support member for supporting the outer ring, and the inner ring And an elastic member that axially presses at least one of the outer ring toward the plurality of transmission rollers, wherein one of the first and second support members is attached to the second shaft. Together with the first,
A friction roller type transmission in which the other of the second support members is fixed.