JPH0965609A - Motor with reduction mechanism - Google Patents

Abstract

(57) [PROBLEMS] To provide a motor with a reduction mechanism capable of improving rigidity and shortening axial length. SOLUTION: In a motor 12 provided with a speed reduction mechanism that reduces the speed of rotation of a motor output shaft 12a and outputs it, a planetary roller 54 of a planetary roller speed reduction mechanism 25 is arranged so as to be in rolling contact with the outer periphery of the motor output shaft 12a. The planetary roller 5
The shaft 52a of the carrier 52 that supports the motor shaft 4 is formed so as to extend the motor output shaft 12a.
The tip of 2a is pivotally supported via a bearing 73, and an output take-out gear 24d is mounted on the motor 12 side of the bearing 73 of the carrier shaft 52a, and a pawl is provided between the output take-out gear 24d and the carrier shaft 52a. Type one-way clutch 71
Intervene.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor provided with a speed reduction mechanism that reduces the speed of the output shaft of a motor and outputs it.

[0002]

2. Description of the Related Art Conventionally, a human power drive system for traveling by the occupant's tread force and an electric drive system using a motor as a power source are provided, and an auxiliary drive force corresponding to the tread force is supplied from the motor for traveling. Power assisted bicycles have been proposed that are configured to assist.

As a motor serving as a power source for the electric drive system of the power assisted bicycle, there is a motor provided with a speed reducing mechanism for reducing the rotation speed of the motor output shaft. As this type of reduction mechanism, the planetary roller of the planetary roller type reduction mechanism is brought into rolling contact with the motor output shaft, and the output is taken out through the needle roller type one-way clutch in the shaft portion (output shaft) of the carrier supporting the planetary roller. There is a structure in which a shaft is inserted, a tip end portion of the output extraction shaft is axially supported through a bearing, and an output extraction gear is attached further outside the bearing.

[0004]

However, in the above-described conventional reduction gear mechanism, since the output take-out shaft is inserted with the needle roller type one-way clutch interposed in the output shaft to connect both shafts, There is a problem that the rigidity of the shaft coupling portion is low, and the rigidity is low because of the structure in which the output take-out gear is mounted in an overhang shape further outside the bearing portion of the output take-out shaft.

Further, the axial length of the entire motor is increased because the motor output shaft, the output shaft of the reduction mechanism, the output take-out shaft are arranged in a line, and the output take-out gear is arranged outside the bearing. There's a problem.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a motor with a reduction mechanism which can improve rigidity and shorten axial length.

[0007]

According to a first aspect of the present invention, in a motor having a speed reducing mechanism for reducing the rotational speed of a motor output shaft to output the same, the planetary roller of the planetary roller type speed reducing mechanism is connected to the motor output shaft. The shaft of a carrier supporting the planetary roller is formed so as to be in rolling contact with the outer periphery, and the shaft of the carrier is formed to extend the motor output shaft. It is characterized in that an output take-out member is mounted on the motor side of the bearing of the shaft portion, and a one-way clutch is interposed between the output take-out member and the carrier shaft portion.

According to a second aspect of the present invention, there is provided a motor having a speed reducing mechanism for reducing the speed of the motor output shaft and outputting the reduced speed.
The motor output shaft is extended and the tip of the extension is rotatably supported by a bearing, and the planetary roller of the planetary roller reduction mechanism is disposed so as to be rollingly contacted to the motor side of the bearing of the motor output shaft. The shaft portion of the carrier supporting the roller is formed in a tubular shape surrounding the motor output shaft, an output take-out member is attached to the carrier shaft portion, and a one-way clutch is interposed between the output take-out member and the carrier shaft portion. It is characterized by that.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 are views for explaining a motor with a reduction mechanism of a power assisted bicycle according to a first embodiment of the invention of claim 1, and FIG. 1 is a side view schematically showing the power assisted bicycle. 2 is a plan view schematically showing the structure of the drive device, FIG. 3 is a partial cross-sectional plan view of the reduction mechanism portion of the motor, and FIG. 4 is a cross-sectional side view of the pawl type one-way clutch.

In the figure, 1 is a power assisted bicycle,
Reference numeral 2 is a frame of the bicycle 1. This frame 2
A head pipe 2a that steerably supports a front fork 4 having front wheels 3 rotatably supported, a down tube 2b extending rearward and downward from the head pipe 2a, and a seat tube erected at a rear portion of the down tube 2b. 2c, a pair of left and right chain stays 2d connected to the rear end of the down tube 2b, and a pair of left and right seat stays connecting the upper part of the seat tube 2c and the rear end of the chain stay 2d. 2e and.

A steering handle 7a is mounted on the upper end of the front fork 4, and a saddle 7b is mounted on the upper end of the seat tube 2c. Further, the rear wheel 8 is attached to the connecting portion between the chain stay 2d and the seat stay 2e.
Are rotatably supported.

Reference numeral 9 is a drive device for the bicycle 1, and the drive device 9 assists the occupant's treading force by a human power drive system 9a for rotating the rear wheel 8 by the occupant's treading force and an auxiliary driving force from a motor. And an electric drive system 9b.

In the human power drive system 9a, a crankshaft 13 is inserted and disposed with a one-way clutch 28 interposed in a cylindrical resultant shaft 18 supported by a casing 23, and the cranks 16 are provided at both ends of the crank shaft 13. A pedal 17 is mounted through the crankshaft, a crank sprocket 15 is fixed to the right end of the resultant shaft 18, and the crank sprocket 15 and a free wheel sprocket 21 of the rear wheel 8 are connected by a chain 20. is there.

The electric drive system 9b is powered by a battery (not shown) and is provided with a motor 12 having a reduction mechanism controlled by a control unit and an output take-out gear 2 of the motor 12.
The second stage speed reduction mechanism 19 is provided for decelerating the rotation of 4d and transmitting it to the resultant shaft 18.

The reduction mechanism 19 includes a large gear 24c and a small gear 24b fixed to an intermediate shaft 70 arranged in parallel with the motor output shaft and the crankshaft 13, respectively, the output take-out gear 24d and the resultant shaft 18 being provided. Large gear 2 fixed to
It has a structure that is engaged with 4a.

The motor 12 with a reduction mechanism has a structure in which a planetary roller type reduction mechanism 25 is mounted on a motor output shaft 12a, and a flange portion 12c formed on the outer periphery of the front end of a motor case 12b is bolted by a bolt 61 to the casing. It is fixed at 23. Although not shown, both ends of the motor output shaft 12a are axially supported by the motor case 12b via bearings, and the bearing on the front end side is in the vicinity of the flange portion 12c, that is, outside the motor output shaft 12a. It is arranged close to the directional protrusion.

The planetary roller type deceleration mechanism 25 has four planetary rollers 54 arranged at equal angular intervals so as to be in rolling contact with the outer periphery of the output shaft 12a of the motor 12 functioning as a sun roller, and all the planetary planets. It is provided with a cylindrical outer ring 53 whose inner diameter is set so as to circumscribe the roller 54. In addition, the output shaft 12a, the planetary roller 54, and the outer ring 53.
The rolling contact surface is filled with traction grease for increasing the frictional force and improving the transmission of the rotational force.

The outer ring 53 has guide plates 57 and 58 for restricting the axial movement of the planetary roller 54 on both axial end faces, and is fixed to the end face of the flange portion 12c by fixing bolts 59. ing. Reference numeral 74 is a seal member that seals between the outer peripheral surface of the carrier 52 and the guide plate 58, which will be described later, and is for preventing the traction grease from scattering outward.

The planetary rollers 54 are rotatably supported via needle bearings 62 by support pins 55 which are planted by press-fitting in a disk-shaped carrier 52. A ball 65 is interposed between the shaft core portion of the surface of the carrier 52 facing the motor output shaft and the tip end surface of the motor output shaft 12a to allow relative rotation between them and to regulate the axial position of both. ing.

Further, a carrier shaft portion (output shaft) 52a which is coaxial with the motor output shaft 12a and extends outward is integrally formed at the shaft core portion of the carrier 52, and the tip end of the carrier shaft portion 52a. The portion is axially supported by the support portion 23a of the casing 23 via a bearing 73.

The bearing 73 of the carrier shaft 52a
The output take-out gear 24d is provided on a portion closer to the motor, and a pawl type one-way clutch 71 is provided between the gear 24d and the outer surface of the carrier shaft 52a. The one-way clutch 71 includes the carrier shaft portion 5
A plurality of claw pieces 71a are arranged on the outer surface of 2a so that they can be undulated,
A sawtooth step 71b is formed on the inner surface of the gear 24d so that the tip of the claw piece 71a can be locked, and each claw piece 71a is biased in the upright direction by a spring 71c. The carrier shaft 52a is in the direction of arrow a (forward direction)
When the gear 24d is rotated in the direction of arrow b by the rotational force from the rear wheel side, the rotation is transmitted to the output take-out gear 24d via the pawl piece 71a. It is not transmitted to the 52a side.

Next, the function and effect of this embodiment will be described. In the motor 12 with a speed reduction mechanism, when the motor output shaft 12a rotates, the planetary rollers 54 rotate in the opposite direction of the rotation of the output shaft 12a and revolve on the inner peripheral surface of the outer ring 53. As a result, the carrier 52 rotates with a predetermined reduction ratio, the rotation of the carrier shaft 52a is transmitted to the output take-out gear 24d via the one-way clutch 71, and the rotation of the gear 24d is combined with each gear 24c, 24b, 24a. It is transmitted to the crank sprocket 15 via the shaft 18.

In the motor 12 with a reduction mechanism that performs such an operation, the planetary roller 5 is provided on the outer periphery of the motor output shaft 12.
Since the output take-out gear 24d is mounted on the motor side of the bearing 73 of the shaft portion 52a of the carrier 52, the axial direction of the entire motor 12 is larger than that of the conventional structure in which the gear is mounted further outside the bearing, for example. The length can be shortened.

Further, the carrier shaft portion 52a and the gear 24d
Since the pawl type one-way clutch 71 is interposed between and, the axial length can be shortened as compared with the case where a needle roller type one-way clutch is adopted.

Furthermore, since the output take-out gear 24d is mounted on the shaft portion 52a of the carrier 52 which supports the planetary roller 54 rolling on the motor output shaft 12a, the conventional carrier shaft portion and the output take-out shaft are connected via a one-way clutch. Since there is no rigidity lowering element as in the case of coupling, the rigidity of the reduction mechanism mounting portion can be improved, and since the output take-out gear 24d is mounted on the inside of the bearing instead of being mounted on the outside of the bearing in an overhang shape, The rigidity can be improved also from the point of having the both-ends supporting structure. Furthermore, the rigidity can be improved in that the gear 24d is disposed so as to be adjacent to the bearing.

Next, a motor with a reduction mechanism according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a plan view schematically showing the configuration of the driving device, and FIG.
FIG. 3 is a partial cross-sectional plan view of the speed reduction mechanism portion, and the same reference numerals as those in FIGS.

In the motor 12 of this embodiment, the motor output shaft is extended by the shaft 77 functioning as the input shaft of the speed reducing mechanism, and a two-stage planetary roller type speed reducing mechanism 76 is arranged in the extension portion. An output take-out gear 24d is provided between the motor case 12b and the flange portion 12c.

The shaft 77 extends the motor output shaft 12a by spline-fitting the shaft 77 to the joint cylinder 78 which is spline-fitted to the motor output shaft 12a.
The tip of the shaft 77 is rotatably supported by a bearing 73 on a support 23a of the casing 23. The motor output shaft 12
Of course, it does not matter even if a is extended to replace the shaft 77. Further, 75 is a positioning spacer arranged between the end surface of the motor flange 12c and the output take-out gear 24d.

The first-stage planetary roller 54 is rollingly contacted with a portion of the shaft 77 adjacent to the bearing 73, and a cylindrical carrier shaft portion extending toward the motor side of the first-stage carrier 52 supporting the planetary roller 54. The second stage planetary roller 80 is in rolling contact with the outer surface of the roller 52a,
An outer ring 53 common to 0 is circumscribed. In addition, this outer ring 5
3 is fixed to the supporting portion 23b of the casing 23.

The output take-out gear 24d is mounted on the cylindrical carrier shaft portion 81a extending toward the motor side of the second-stage carrier 81 supporting the second-stage planetary roller 80 with the pawl type one-way clutch 71 interposed therebetween. Has been done.

In the motor 12 with a reduction mechanism of the present embodiment, when the output shaft 12a of the motor 12 rotates, the input shaft 77 rotates together with it to rotate the planet roller 54 of the first stage and the inner peripheral surface of the outer ring 53. Revolve the top.
As a result, the carrier 52 rotates to cause the second-stage planetary roller 80 to rotate and revolve around the inner peripheral surface of the outer ring 53, which causes the second-stage carrier 81 to rotate to shift the output take-out gear 24d to the second stage. Rotate with a reduction ratio.

The motor 1 of this embodiment that operates in this way
2, the motor output shaft 12a is extended by the speed reducer input shaft 77, the extended end is pivotally supported, and the two-stage planetary roller speed reducer mechanism 76 is disposed on the motor side of the bearing of the extended part. Since the output take-out gear 24d is arranged between the speed reduction mechanism 76 and the flange portion 12c of the motor case 12b, the motor output shaft 1 having both ends supported by the gear 24d.
Since it is supported by 2a and the gear 24d is located near the bearing of the motor output shaft 12, the support rigidity of the gear 24d is improved.

Since the output take-out gear 24d is arranged on the motor side of the bearing 73 of the speed reducer input shaft 77, the axial length of the entire motor can be shortened as in the first embodiment.

[0034]

As described above, according to the motor with a reduction mechanism according to the present invention, the output take-out member is directly attached to the shaft portion of the carrier that supports the planetary roller rolling on the motor output shaft. The output take-out shaft is connected to the shaft through a one-way clutch, and the rigidity can be improved as compared with the case where the output take-out member is attached to the output take-out shaft. Also, the output take-out member is attached inside the bearing. There is an effect that the rigidity can be improved as compared with the case where the output extracting member is attached to the outside in the form of an overhang.

Further, according to the present invention, the output take-out member is mounted on the motor side of the bearing of the carrier shaft portion, and the one-way clutch is interposed between the output take-out member and the carrier shaft portion. This has the effect of shortening the length.

[Brief description of drawings]

FIG. 1 is a side view schematically showing a power-assisted bicycle equipped with a motor according to a first embodiment of the invention of claim 1. FIG.

FIG. 2 is a plan view schematically showing the configuration of the drive system of the bicycle according to the first embodiment.

FIG. 3 is a partial cross-sectional plan view showing a reduction mechanism portion of the motor of the first embodiment.

FIG. 4 is a sectional side view showing a one-way clutch of the speed reduction mechanism of the first embodiment.

FIG. 5 is a schematic plan view of a drive system including a second embodiment motor according to the invention of claim 2;

FIG. 6 is a partial cross-sectional side view showing a reduction mechanism portion of the motor of the second embodiment.

[Explanation of symbols]

 12 motor 12a motor output shaft 24d output take-out gear (output take-out member) 25 planetary roller type speed reducer 52 carrier 52a carrier shaft 54 planetary roller 71 pawl type one-way clutch 73 bearing

Claims (2)

[Claims] 1. A motor having a speed reducing mechanism for reducing the rotational speed of a motor output shaft and outputting the same, wherein a planetary roller of a planetary roller type speed reducing mechanism is arranged so as to be in rolling contact with the outer circumference of the motor output shaft. The shaft portion of the carrier that supports the roller is formed to extend the motor output shaft, the tip of the carrier shaft portion is axially supported through a bearing, and the output extracting member is located closer to the motor than the bearing of the carrier shaft portion. And a one-way clutch interposed between the output extraction member and the carrier shaft portion. 2. A motor provided with a speed reducing mechanism for reducing the rotational speed of a motor output shaft and outputting the motor output shaft, wherein the motor output shaft is extended and a tip end of the extension is rotatably supported by a bearing. A planetary roller of a planetary roller type speed reducing mechanism is disposed so as to be in rolling contact with the motor side of the shaft bearing, and a shaft portion of a carrier supporting the planetary roller is formed in a cylindrical shape surrounding the motor output shaft. A motor with a speed reduction mechanism, characterized in that an output take-out member is attached to the shaft, and a one-way clutch is interposed between the output take-out member and the carrier shaft.