JP2003023755A - Rotary driving gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of part items and assembling man-hours and improve assembly workability, by eliminating a seal member between a reduction gear and a speed detecting mechanism, in a rotary driving gear for receiving the speed detecting mechanism in the inside. SOLUTION: In this rotary driving gear 1, a housing 31 storing a reduction gear 3, an output shaft 7, a speed-detecting mechanism 8, etc., has a divided structure comprising a first/second member 31a, 31b. The first member 31a has a part, except an opening part 32a in the upper part of an outer wall part 32 covering a periphery of the output shaft 7 and the speed detecting mechanism 8, a first partition part 33 formed integrally in a driven gear side of the outer wall part 32 for inserting the output shaft 7, and a second partition part 34, formed integrally in a side of the reduction gear 3 of the outer wall part 32 for the axially separating the reduction gear 3 and the speed detecting mechanism 8. The second member 31b is a member, fitted to the opening part 32a of the first member 31a for closing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary drive device, and more particularly, to a rotary drive device capable of rotationally driving a driven device and detecting output rotational speed to feedback control the drive rotational speed.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, a printing machine or the like, a rotation driving device for rotating a photosensitive drum or a roller for feeding a film at a relatively low speed and with high accuracy is required. . The rotary drive device disclosed in Japanese Unexamined Patent Publication No. 10-161752 includes a motor, a planetary speed reducer that reduces the rotation of the motor, a transmission unit, a speed detection mechanism, and a feedback control unit.

The planetary type speed reducer includes a gear type speed reducer and a traction or friction transfer type speed reducer. The speed reducer includes a sun roller, a planet roller and a carrier formed on the output shaft of the motor. The transmission means mainly has an output shaft extending from the speed reducer side to the driven device side. The output shaft is rotatably supported by the housing via a bearing such as a ball bearing.

The speed detecting mechanism is composed of, for example, a rotary encoder including a pulse plate and a photodetector for detecting the pulse plate. The feedback control means controls the motor based on the rotation speed detected by the speed detection mechanism. Here, the speed detection mechanism is arranged on the output side of the housing of the reduction gear transmission, which makes the axial dimension of the rotation drive device longer. However, for example, when a rotary driving device is used in a color copying apparatus, there is a strong demand for space saving and a demand for a rotary driving device that is short in the axial direction. Therefore, in the Japanese Patent Application No. 2000-262539, the applicant of the present application arranged the speed detection mechanism in the housing of the reduction gear transmission and moved the biasing member of the reduction gear transmission to the wall surface on the motor side. As a result, a rotation drive device that has been shortened in the axial direction, which has never been achieved, has been realized.

[0005]

The demands on the rotary drive are not limited to axial shortening. There is also a demand for other uses, that is, cost reduction rather than space and stable operation for a long period of time, and a rotary drive device capable of coping with this is also required. Therefore, the applicant of the present application filed Japanese Patent Application No. 2000-26254.
No. 0 invented a structure in which the speed detecting mechanism is arranged in the housing of the speed reducer and the seal member is provided between the carrier and the planetary roller. In this reduction gear,
This prevents the lubricating oil, abrasion powder, etc. in the housing of the reduction gear from entering the speed detection mechanism side and contaminating the pulse plate and the photodetector. As a result, in addition to shortening the rotation drive device in the axial direction, accurate rotation speed can be detected, and stable operation for a long period of time has been realized.

However, since the speed detecting mechanism and the speed reducer are housed in the same housing, the speed detecting mechanism and the seal member are structurally complicated. An object of the present invention is to reduce the number of parts and the number of assembling steps by eliminating the seal member even at the cost of shortening in the axial direction. Another object of the present invention is to realize a rotary drive device that is more easily assembled than before by making the housing a divided structure composed of a plurality of constituent members.

[0007]

According to a first aspect of the present invention, there is provided a rotary drive device, wherein a motor is used as a rotary drive source for rotationally driving a driven device, and an output rotational speed is detected to drive the motor. A rotational drive device for feedback control of a speed reducer driven by a motor,
A transmission unit having an output shaft extending from the reduction gear to the driven device and transmitting the output of the front reduction gear to the driven device; and a speed detection mechanism arranged on the driven device side of the reduction gear for detecting the rotational speed of the output shaft. An outer wall portion surrounding the output shaft and the speed detection mechanism, a first partition wall portion provided on the outer wall portion through which the output shaft penetrates, and a second partition wall portion provided on the reduction gear device side of the outer wall portion and through which the output shaft penetrates. A first bearing disposed between the inner peripheral surface of the first partition wall portion and the output shaft, and a second bearing disposed between the inner peripheral surface of the second partition wall portion and the output shaft. Is equipped with. The second partition wall portion, together with the first partition wall portion and the outer wall portion, forms an accommodation space portion in which the speed detection mechanism is installed, and axially separates the speed reducer and the speed detection mechanism. And
The housing is composed of a plurality of constituent members.

In this rotary drive device, the rotation of the motor is decelerated by the speed reducer and output from the output shaft of the transmission means to drive the driven device. At this time, the output rotation speed of the reduction gear transmission is detected by the speed detection mechanism, and the rotation speed of the motor is feedback-controlled based on the detection result so that the output rotation speed becomes a desired set speed. In this rotary drive device, the second partition wall portion is provided in the housing, whereby the speed detection mechanism portion and the speed reduction mechanism portion are separated in the axial direction, and the second partition wall portion and the second bearing prevent impurities in the speed detection mechanism. A member (sealing member) only for prevention is unnecessary. In addition, since the housing has a divided structure composed of a plurality of constituent members, an opening for inserting the constituent members of the speed detection mechanism can be secured and the opening can be closed. Is improved. Furthermore, it is possible to prevent lubricant such as grease and abrasion powder generated in the speed reduction mechanism from entering the speed detection mechanism, and it is possible to operate stably for a long time by accurate speed detection.

According to a second aspect of the present invention, in the rotary drive apparatus according to the first aspect, the housing has a first member that supports the output shaft via the first bearing and the second bearing, and the speed detecting mechanism is provided in the accommodation space. After being installed, the second member is attached to the first member and can close the accommodation space portion. In this rotary drive device, after the output shaft, the first bearing, the second bearing, and the speed detection mechanism arranged in the speed detection mechanism portion are all installed on the first member, the second member is mounted and the accommodation space is closed. By doing so, the rotary drive device can be assembled. As a result, final adjustment of the mounting accuracy becomes possible with the speed detection mechanism fixed to the predetermined position of the accommodation space of the first member. Further, it becomes easy to manage the dimensional accuracy of the component parts.

According to a third aspect of the present invention, in the rotary drive apparatus according to the second aspect, the first member includes at least a part of the first partition wall portion, at least a part of the second partition wall portion, the first partition wall portion and the first partition wall portion. It has two partition walls and a part of the outer wall portion which is integrated. In this rotary drive device, the first member has the first partition wall portion, the second partition wall portion, and a part of the outer wall portion integrated with these members.
As a result, the dimensional accuracy of the component can be increased while ensuring the opening in the first member, and the assemblability is improved.

According to a fourth aspect of the present invention, in the third aspect, the second member is a member having the same shape as the first member. In this rotary drive device, since the first member and the second member that form the housing are the same, the parts can be made common. In the rotary drive device according to claim 5,
The speed detection mechanism according to any one of claims 1 to 4, wherein the speed detection mechanism includes detection means and a detected member that rotates integrally with the output shaft and is detected by the detection means, and the detection means is disposed in the housing. A window is formed.

In this rotary drive device, the assembling property of the detecting means is improved. In the rotation drive device according to claim 6, in any one of claims 2-5, the 1st member and the 2nd member form an arrangement window part when the 2nd member is attached to the 1st member. Each has a groove and a protrusion. In this rotation drive device, it is not necessary to make a hole in the placement window in the first member or the second member.

According to a seventh aspect of the present invention, in the rotary drive device according to the fifth or sixth aspect, the disposing window portion penetrates the outer wall portion in the radial direction of the output shaft, and the center axis of the disposing window portion is It extends in the penetrating direction and is orthogonal to the output shaft. According to the eighth aspect of the present invention, in the rotary drive apparatus according to the sixth or seventh aspect, the housing is provided with an adjusting window portion for adjusting a mounting position when the detecting means is arranged.

In this rotary drive device, since the adjusting window portion is provided, the detecting means can be accurately attached to a desired position even after the second member is attached to the first member. According to a ninth aspect of the present invention, in the rotary drive device according to the eighth aspect, the adjustment window portion penetrates the first partition wall portion in the axial direction of the output shaft, and the central axis of the adjustment window portion extends in the penetration direction. It is parallel to the output axis.

According to a tenth aspect of the present invention, in the rotary drive device according to any one of the sixth to ninth aspects, the speed detecting mechanism is a magnetic sensor. The detection means is at least one magnetic detection means for detecting a change in magnetic flux, and the detected member is a magnetic detected member having a magnetized portion. In the rotary drive device according to claim 11, in any one of claims 6 to 9, the speed detection mechanism is an optical sensor. The detection means is at least one optical detection means for detecting an optical change,
The detected member is an optically detected member.

According to a twelfth aspect of the present invention, in the rotary drive system according to the first to eleventh aspects, the reduction gear transmission includes a sun wheel into which the rotation of the motor is input, an internal ring arranged concentrically with the sun wheel, and a sun wheel. It has a plurality of planet wheels that come into contact with the vehicle while abutting while receiving a biasing force from the internal ring, and a carrier that supports the plurality of planet wheels and is connected to the output shaft.

In this rotary drive system, the reduction gear transmission presses the planet wheel from the internal ring and transmits torque by friction. According to a thirteenth aspect of the present invention, in the rotary drive apparatus according to the twelfth aspect, the output shaft of the motor constitutes a sun wheel of the reduction gear transmission. According to a twelfth aspect of the present invention, in the rotary drive device according to the twelfth or thirteenth aspect,
A recess for accommodating the biasing member is formed on the surface of the partition wall on the speed reducer side. The bottom surface of the recess is located closer to the driven device than the end surface of the second bearing on the reduction device side.

In this rotary drive device, by providing the concave portion in the second partition wall portion, the axial size of the rotary drive device can be reduced by the axial size in which the biasing member and the second bearing overlap in the radial direction. The rotation drive device according to claim 15 is the rotation drive device according to any one of claims 1 to 1.
4 further includes a motor that rotationally drives the speed reducer. According to a sixteenth aspect of the present invention, the rotary drive device according to any one of the first to fifteenth aspects further includes feedback control means for performing feedback control of the drive speed of the motor based on the detection by the speed detection mechanism.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION 1. First Embodiment (1) Configuration FIG. 1 shows a rotary drive device 1 according to an embodiment of the present invention. The rotary drive device 1 is used, for example, in an image forming apparatus. The rotary drive device 1 includes a motor 2, a planetary speed reducer 3 that decelerates and outputs the rotation from the motor 2, and a transmission unit 4 that outputs the output of the speed reducer 3 to an image forming apparatus as a driven device. It consists of and.
The transmission means 4 has an output shaft 7 and a speed detection mechanism 8 for detecting the output rotation speed thereof. Further, the rotation drive device 1 further includes a controller 5 to which the output from the speed detection mechanism 8 is input, and a drive device 6 that controls the rotation speed of the motor 2 in accordance with a control signal from the controller 5.

OO shown in FIG. 1 is a rotary drive unit 1.
Is the axis of rotation of. Hereinafter, for convenience of description, the direction in which the rotation axis extends is taken as the axial direction, the right side in FIG. 1 is the axial input side, and the left side in FIG. 1 is the axial output side. The direction of rotation with respect to the rotation axis is the rotation direction or the circumferential direction. The direction of the circle radius drawn around the rotation axis is the radial direction. Motor 2
Is driven by a drive signal from the drive device 6 and functions as a rotary drive source of the rotary drive device 1. The motor 2 includes a bracket 10, a stator 11, and a rotor 1.
It is mainly composed of 2 and.

The bracket 10 is composed of a tubular portion 10a and a flange 10b extending from one end thereof to the outer peripheral side. Further, the base substrate 10c is attached to one side surface of the flange 10b, and the support member 10d for supporting the base substrate 10c is attached to the other side surface. The motor 2 is fixed to the side surface of the speed reducer 3, and specifically, the support member 10d is fixed to the housing 31 (described later) of the transmission means 4 by the bolt 9.

The stator 11 is formed by winding a coil around an iron core formed by laminating a plurality of magnetic plates, and is fixed to the outer periphery of the tubular portion 10a of the bracket 10. Rotor 1
The reference numeral 2 includes a rotor yoke 15 and a rotor magnet 16. The rotor yoke 15 has a thin plate shape made of a magnetic material and has a uniform thickness. Specifically, the rotor yoke 15 includes a disk-shaped vertical wall 15a,
A cylindrical annular wall 15 extending from the outer peripheral edge thereof toward the speed reducer 3 side
b and.

The rotor magnet 16 is a cylindrical member having a plurality of poles arranged in the circumferential direction, and has an annular wall 15b.
It is fixed to the inner surface of the. In this way, the rotor magnet 16 is arranged concentrically and opposite to the stator 11 in the radial direction. The rotary drive shaft 14 is the output shaft of the motor 2 and extends inside the tubular portion 10 a of the bracket 10.
The tubular portion 1 is formed by a plurality of bearings 18 and 19 arranged in the axial direction.
It is rotatably supported by 0a. The bearings 18, 1
Reference numeral 9 is a bearing with a sealing function, and the speed reducer 3
This prevents the lubricant from leaking out to the motor 2 side and the lubricant of the bearing from entering the speed reducer 3 side. The tip of the rotary drive shaft 14 (on the speed reducer 3 side) enters the speed reducer 3 and constitutes the sun roller 20 that is the input shaft of the speed reducer 3. The end of the rotary drive shaft 14 (the side opposite to the speed reducer 3) is fixed to the inner peripheral portion of the vertical wall 15 a of the rotor yoke 15.

The speed reducer 3 is a one-stage system and further employs a differential planetary system. More specifically, the speed reducer 3 is a traction type in which a metal roller is driven by pressure contact, and has less angular velocity fluctuation, and is excellent in low noise, low vibration, and low backlash, as compared with a speed reducer using gears. It has a function. The deceleration device 3 decelerates the rotation of the motor 2 to, for example, about 1 rotation / second, and includes the above-described sun roller 20, the internal ring 21, and a plurality of (three in the present embodiment) planet rollers 22. And a carrier 23 that supports the planetary rollers 22. The sun roller 20, the internal ring 21, the plurality of planetary rollers 22, and the carrier 23 are housed in a housing 31 (described later) filled with grease as a lubricant. Depending on the material and specifications of each member constituting the reduction gear 3, the dry type without lubricant may be used.

The internal ring 21 has an annular fixed ring 21a and movable ring 21b, respectively.
Both rings 21a and 21b are provided so as to face each other so as to sandwich the planetary roller 22. The fixed ring 21a is fixed to the support member 10d so as not to be movable in the axial direction and the rotation direction. The movable ring 21b is attached to the housing so as to be movable in the axial direction and non-rotatable. The facing surfaces of the inner peripheral portions of both rings 21a and 21b are formed in a tapered shape.

The planetary roller 22 is rotatably supported by the rod 23a in a cantilevered manner with respect to the carrier 23, and is composed of a large diameter roller portion 22a and a small diameter roller portion 22b. The outer peripheral surface of the large-diameter roller portion 22a is in contact with the outer peripheral surface of the sun roller 20. Small diameter roller section 22b
Is formed so as to be concentric with the large diameter roller portion 22a and protrude in a truncated cone shape from the central portions on both side surfaces of the large diameter roller portion 22a. The tapered surfaces of the small diameter roller portion 22b are in contact with the tapered surfaces formed on the inner peripheral surfaces of the fixed ring 21a and the movable ring 21b. With this configuration,
Each planet roller 22 can rotate around the sun roller 20 while revolving around the sun roller 20. The carrier 23 is a ring-shaped member, and the output shaft 7 is inserted into the hole at the center thereof and fixed so as not to rotate relative to each other. The carrier 23 and the output shaft 7 can also be integrally formed.

Next, the transmission means 4 will be described. The transmission means 4 includes a housing 31, an output shaft 7, and a speed detection mechanism 8.
And so on. The housing 31 mainly includes an outer wall portion 32 having a substantially rectangular tube shape disposed around the output shaft 7, a first partition wall portion 33 having a central hole 33a formed therein, through which the output shaft 7 passes, and a first partition wall portion 33. A second partition having a central hole 34a arranged on the output side in the axial direction of the partition wall 33 and through which the output shaft 7 passes.
It has the partition part 34. And the housing 31
As shown in FIGS. 1 to 3, has a divided structure including a first member 31a and a second member 31b.

First, the first member 31a will be described.
The first member 31a is a member for supporting the output shaft 7 and the magnetic foil 25 via the first bearing 27 and the second bearing 28, and includes a bottom surface portion and a pair of side surface portions of the outer wall portion 32, and a central portion integrated therewith. It has the 1st partition part 33 in which the hole 33a was formed, and the 2nd partition part 34 in which the center hole 34a was formed. The magnetic foil 2 is provided on the first member 31a.
Opening 32a for housing 5 inside the housing 31
Are formed. Further, on the pair of side surface portions of the outer wall portion 32, two detection means insertion window portions 32b for attaching the sensor 26 are formed. The magnetic foil 25
The sensor 26 is a member that constitutes the speed detection mechanism 8, and the details will be described later.

The opening portion 32a has a rectangular shape formed in the upper portion of the outer wall portion 32 so as to be long in the circumferential direction.
The second bearing 28, the output shaft 7, and the magnetic foil 25 are attached to the first member 31a, and then the second member 31b is fitted to the first member 31a to be closed. The detection means insertion window portion 32 b has a rectangular shape formed on the pair of side surface portions of the outer wall portion 32 so as to face each other. Opening 32
The opening width dimension of a is sufficiently larger than the outer dimension of the magnetic foil 25, and the opening width dimension of the detection means insertion window 32b is
The external dimensions of the sensor 26 for mounting the sensor 26 are substantially the same. Each detection means insertion window 32b is circumferentially shorter than the opening 32a. The detection means insertion window 32b is open in the radial direction.

Explaining in more detail, the opening 32a is
A hole that penetrates the upper part of the outer wall portion 32 in the radial direction (referred to as the first radial direction), and the central axis of this hole (the axis extending in the circumferential direction and the axial center in the first radial direction) is It is orthogonal to the output shaft 7. The detection means insertion window portion 32b is a hole that penetrates the side surface portion of the outer wall portion 32 in the second radial direction of the output shaft 7, and the central axis of the hole (the center of the hole in the circumferential direction and the axial direction is The shaft extending in two radial directions is orthogonal to the output shaft 7.

The first partition 33 is substantially rectangular and has a circular center hole 33a through which the output shaft 7 penetrates. At each corner of the first partition 33, a mounting hole for fixing to the driven device is formed. A first bearing 27 that rotatably supports the output shaft 7 is provided on the inner peripheral surface of the central hole 33a of the first partition 33.
Is provided. The first bearing 27 is a ball bearing having a sealing function of preventing the lubricant from flowing from the inside of the bearing to the outside and the foreign matter from entering the inside of the bearing from the outside. The outer race of the first bearing 27 is fitted in the center hole 33a, and the axial input side is supported by the flange 33c formed in the center hole 33a. A snap ring 42 mounted on the output shaft 7 is locked to the inner race of the first bearing 27 on the axial output side thereof, which prohibits the inner race from moving toward the axial output side. Has been done.

Further, in the first partition 33, a pair of sensor adjustment windows 33b are formed on both sides of the central hole 33a. Each sensor adjustment window 33b has an outer wall 32.
The two detection means insertion window portions 32b formed in the above are respectively close to each other. The sensor adjustment window portion 33b is a hole that penetrates the first partition wall portion 33 in the axial direction of the output shaft 7, and the central axis of the hole is parallel to the output shaft 7. This adjustment window 33
In b, the positioning jig is inserted into the magnetic foil 2
It is used to accurately position the sensor 26 with respect to 5.

The second partition wall portion 34 is formed integrally with the bottom surface portion and the pair of side surface portions of the outer wall portion 32, but is separated from the first partition wall portion 33 toward the input side in the axial direction (the reduction gear side). .
Therefore, a rectangular accommodation space 35 covered by the outer wall 32 is provided between the first partition 33 and the second partition 34 in the axial direction.
Is secured. The opening 32a, the detection means insertion window 32b, and the adjustment window 33b are provided in the accommodation space 35.
In that sense, the windows are connected to the accommodation space 3
You may think that it comprises a part of 5.

The second partition wall 34 has a substantially rectangular center hole 34a through which the output shaft 7 passes. A second bearing 28 that rotatably supports the output shaft 7 is provided on the inner peripheral surface of the center hole 34a of the second partition wall portion 34. The second bearing 28 is also a ball bearing having the same sealing function as the first bearing 27. The outer race of the second bearing 28 is supported by the center hole 34a, and the axial output side is supported by the flange 34c formed in the center hole 34a via the wave washer 36. Further, the inner race of the second bearing 28 is in contact with the carrier 23 on the input side in the axial direction, so that the movement of the inner race to the input side in the axial direction is restricted.

Next, the second member 31b will be described.
The second member 31b is attached to the opening 32a of the first member 31a by a method such as bonding or screwing, and is accommodated in the accommodation space 35.
And has a shape corresponding to the rectangular shape of the opening 32a. As described above, the accommodation space 35 and the space on the speed reducer 3 side are axially separated by the second partition wall 34 and the second bearing 28, and the second bearing 2
8 has a sealing function. Therefore, when the speed reducer 3 is filled with a lubricant such as grease,
This lubricant can be prevented from entering the speed detection mechanism 8 side. Further, it is possible to prevent dust (in the case of a dry type) and abrasion powder generated in the speed reducer 3 from entering the speed detection mechanism 8 side. Therefore, speed detection can be performed accurately.

As described above, the first bearing 27 and the second bearing 2
8 are attached to the inner peripheral surfaces of the first partition wall portion 33 and the second partition wall portion 34, respectively, and rotatably support the output shaft 7. Here, the first bearing 27 and the second bearing 28 are separated from each other in the axial direction because they sandwich the magnetic foil 25 and the like (described later) in the axial direction. Therefore, the radial rigidity of the output shaft 7 is higher than that in the structure in which the same two bearings are arranged close to each other in the axial direction.

On the speed reducer 3 side of the second partition wall 34, a plurality of (six in this embodiment) storage recesses 34b are formed which are arranged at equal intervals in the circumferential direction. Storage recess 34b
Extends to the axial output side. The coil spring 29 is arranged in the storage recess 34b. The coil spring 29 has a movable ring 21 via a washer 29a.
b is always biased toward the fixed ring 21a. As a result, a predetermined pressure contact force is applied to each contact surface between the large-diameter roller portion 22a of each planetary roller 22 and the sun roller 20, and each contact surface between each small-diameter roller portion 22b and each of the fixed ring 21a and the movable ring 21b. Can be given. Therefore, torque is transmitted to each contact portion by a traction method, and each planetary roller 22 can revolve around the sun roller 20 while rotating on its axis.

In this way, the coil spring 29 is arranged not on the motor 2 side but on the second partition wall 34 side, and
Since the rotary drive device 1 is arranged inside the partition wall 34, the axial dimension of the rotary drive device 1 is short. More specifically, the bottom surface of the storage recess 34b extends longer than the end surface of the second bearing 28 on the speed reducer 3 side toward the output side in the axial direction.
This means that at least a part of the second bearing 28 and the storage recess 34b are at the same axial position, and both are radially overlapped. That is, the axial dimension of the rotary drive device 1 can be reduced by the axial dimension in which the coil spring 29 and the second bearing 28 overlap in the radial direction.

Since a coil spring is used as the urging member, a stable pressure contact force can always be obtained. A wave spring may be used as the urging member, and in that case, the axial dimension becomes further shorter than that of the coil spring. Alternatively, the biasing member may be omitted, and the internal ring itself may exert a biasing force on the planetary roller 22. For example, a ring having a U-shaped cross section may exert a biasing force on the planetary roller 22. However, a configuration in which they are sandwiched, a configuration in which a ring member that applies a biasing force radially inward to the outer diameter portion of the planetary roller, and the like can be cited.

The first member 31a further has a cylindrical second outer wall portion 39 extending from the outer wall portion 32 toward the input side in the axial direction. The second outer wall portion 39 is formed integrally with the outer wall portion 32,
It covers the periphery of the speed reducer 3. That is, the second outer wall portion 3
Reference numeral 9 constitutes a housing of the speed reducer 3. The outer wall surface of the second outer wall portion 39 has the same rectangular tubular shape as the outer wall portion 32, and the inner wall surface has a large cylindrical shape along the revolution path of the planetary roller 22 of the reduction gear 3 and the outer diameter of the carrier 23. Along with a small diameter cylindrical shape. The tip of the second outer wall portion 39 (on the side of the motor 2) contacts the supporting member 10d of the bracket 10 and is fixed to each other by the bolt 9 described above.

The output shaft 7 is a shaft extending from the reduction gear 3 to the driven device side, and a carrier 23 is fixed to the end of the reduction gear 3 side. The output shaft 7 is arranged concentrically with the rotary drive shaft 14 of the motor 2. As described above, the output shaft 7 penetrates the first partition wall portion 33 and the second partition wall portion 34 inside the housing 31. More specifically, the output shaft 7 includes the first bearing 27 mounted in the center hole 33a of the first partition wall 33.
Is rotatably supported by the second partition wall 34 and is rotatably supported by a second bearing 28 mounted in the center hole 34a of the second partition wall portion 34. That is, the output shaft 7 is supported by the first member 31a.

The speed detecting mechanism 8 is a mechanism arranged in the accommodation space 35 of the housing 31 for detecting the output rotational speed of the speed reducer 3. The speed detection mechanism 8 is a magnetic rotary encoder, and includes a magnetic wheel 25 non-rotatably locked to the outer peripheral surface of the output shaft 7 and a magnetic wheel 25.
And a pair of magnetic sensors 26 arranged with a predetermined gap in the radial direction (second radial direction). The magnetic foil 25 is a substantially disk-shaped plastic magnet, and has a center hole 25 a through which the output shaft 7 penetrates.
The outer peripheral portion of the magnetic foil 25 has, for example, 650 in the circumferential direction.
About N poles and S poles are alternately magnetized at equal intervals.

The locking structure between the magnetic wheel 25 and the output shaft 7 will be described. As shown in FIG. 4, on the side surface of the motor 2 of the magnetic foil 25, a pair of grooves 25b linearly extending in the radial direction are formed at two locations facing each other in the radial direction of the central hole 25a. Further, a hole 7a penetrating in the radial direction is formed near the middle of the output shaft 7 in the axial direction, and the rotation stopping pin 30 is fitted therein. Both ends of the rotation stop pin 30 have an output shaft 7
And is fitted into the pair of grooves 25b. Therefore, in the engaged state, the magnetic wheel 25 rotates integrally with the output shaft 7. Further, the length of the rotation stopping pin 30 is shorter than the length between the radially outer ends of the pair of grooves 25b and shorter than the diameter of the central hole 34a of the second partition wall portion 34.

The detent pin 30 and the pair of grooves 25b can be easily engaged and disengaged in the axial direction, so that the mounting property is improved. A wave washer 41 is arranged between the first bearing 27 and the magnetic wheel 25, and the wave washer 41 biases the magnetic wheel 25 toward the detent pin 30 side. For this reason, the magnetic foil 25 is attached to the detent pin 30.
Is maintained in the engaged state.

As a method of integrally fixing the magnetic foil 25 to the output shaft 7 so as not to rotate, a method of screwing the magnetic wheel to the output shaft using a set bolt may be used. In that case, since it is necessary to secure a thick portion having a constant axial dimension in order to secure the screw hole, the axial dimension is slightly increased. A snap ring may be used instead of the wave washer as a member that engages the detent pin 30 and the groove 25b with each other.

The pair of magnetic sensors 26 are each composed of a magnetoresistive effect element (MR element), and are arranged at positions (180 ° intervals) facing each other. More specifically, each magnetic sensor 26 has a window 3 for insertion of each detection means.
It is arranged at 2b. The MR element of each magnetic sensor 26 is close to the magnetic foil 25, and the close portion corresponds to the sensor adjustment window 33b.

The controller 5 includes a crystal oscillator, a frequency divider,
A control circuit including a phase difference detection means, a drive pulse output means, and the like, which is a circuit that outputs a motor drive pulse based on the detection output from the two magnetic sensors 26 so that the output rotation speed reaches a desired set value. is there. In addition, the drive device 6
Is a device for driving the motor 2 based on the drive pulse from the controller 5. The components and the like that form the controller 5 and the drive device 6 are mounted on the base substrate 10c.

The above-mentioned controller 5 and drive device 6 are feedback control means for realizing the function of controlling the drive state of the motor 2 based on the speed detection result of the speed detection mechanism 8. (2) In the operation motor 2, when the required power is supplied to the stator 11, the rotor magnet 1 of the stator 11 and the rotor 12
The rotor 12 is driven to rotate by an electromagnetic action with the rotor 6. As a result, the rotary drive shaft 14 rotates, and this rotation is input to the speed reducer 3. This rotation is due to the sun roller 20,
The planetary roller 22 and the internal ring 21 are decelerated by a reduction ratio determined by the outer diameter and the inner diameter of the planetary roller 22 and output via the carrier 23 and the output shaft 7.

Magnetic foil 25 and a pair of magnetic sensors 26
The rotation speed of the output shaft 7 is detected by the pulse signal, and this pulse signal is input to the controller 5. The controller 5 compares the detection signals of the two magnetic sensors 26 to synthesize the rotation signal of the output shaft 7 when the magnetic foil 25 is correctly attached. Then, this combined signal and the rotation reference pulse (output shaft 7
Phase difference with the pulse corresponding to the uniform rotation of the drive unit 6), and a control signal for eliminating this phase difference is input to the drive device 6. Regarding this control, JP-A-11-
This is described in detail in Japanese Patent No. 341854. And
The rotation speed of the motor 2 is increased or decreased by a drive signal from the drive device 6.

By such feedback control,
The rotation speed of the motor 2 is controlled so that the output rotation speed of the speed reducer 3 becomes a desired set speed. (3) Assembly Next, the assembly operation of the transmission means 4 will be described with reference to FIG. Note that FIG. 3 is a schematic diagram for explaining the relationship of each member, and the shape and the like are simplified.

The output shaft 7 is previously provided with a carrier 23,
The second bearing 28 and the wave washer 36 are assembled, and the detent pin 30 is further fitted. Next, the magnetic foil 25 is guided from the opening 32a of the first member 31a in the direction of the arrow Y (first radial direction) and temporarily placed in the accommodation space 35. Then, the output shaft 7 is inserted into the housing 31 from the second partition wall portion 34 toward the first partition wall portion 33. The tip of the output shaft 7 penetrates the center hole 34a of the second partition 34,
Then, it penetrates through the center hole 25a of the magnetic foil 25, further penetrates through the center hole 33a of the first partition 33, and
It projects to the outside of the partition 33. At this time, the detent pin 30 passes through the center hole 34a of the second partition 34 and enters the groove 25b of the magnetic foil 25. Next, the wave washer 41 is fitted from the tip of the output shaft 7 and inserted into the center hole 33a of the first partition 33. Further, the first bearing 2
The snap ring 42 is attached to the outer peripheral surface of the output shaft 7 by fitting the snap ring 42 from the tip of the output shaft 7 and pushing it into contact with the flange 34c of the central hole 33a. The wave washer 41 includes an inner race of the first bearing 27,
It is axially compressed between itself and the inner peripheral portion of the magnetic foil 25. Therefore, the magnetic wheel 25 is restricted from moving in the rotation direction by the detent pin 30, and the detent pin 30
It is fixed to the output shaft 7 by being sandwiched between the wave washer 41 and the wave washer 41 so that the movement in the axial direction is restricted.

Here, the first bearing 31 is provided on the first member 31a.
7, the second bearing 28, the output shaft 7, and the magnetic foil 25 are all mounted, and the final confirmation of the mounting accuracy of these members is possible. The quality of their mounting accuracy is
This is done by confirming the rotation trajectory of the magnetic foil 25. If the mounting accuracy is insufficient, the mounting accuracy of the magnetic foil 25 is finally adjusted through the opening 32a while maintaining this mounting state. The final adjustment is, for example, the opening 32.
It is performed by lathing the magnetic foil 25 from a.

After the final adjustment, the second member 31b is connected to the first member 3
1a is mounted from the direction of arrow Z, and the accommodation space 35 is closed. Then, the magnetic sensor 26 is attached to the detection means insertion window 32b. At that time, in order to perform speed detection with high accuracy, the MR element of the magnetic sensor 26 and the magnetic foil 25 are
It is necessary to accurately set the distance to the outer peripheral surface. Therefore, a positioning jig (gap gauge having a wall thickness of the same size as the minute gap width) is inserted from the adjustment window 33b, and the magnetic sensor is arranged so as to sandwich the jig between the magnetic foil 25 and the MR element. 26 is moved in the second radial direction. Magnetic sensor 26
When the magnetic sensor 26 is fixed in a state of being in contact with the jig and the jig is removed, a desired minute gap is secured between the magnetic foil 25 and the MR element. As a result, the first
The magnetic sensor 26 can be easily mounted inside the member 31a with extremely high accuracy. The distance between the magnetic foil 25 and the MR element is, for example, several tens of μm. After that, the detection means insertion window portion 32b and the adjustment window portion 33b.
A sealing tape (not shown) is attached to prevent dust and the like from entering the accommodation space 35. still,
The mounting of the magnetic sensors 26 may be performed before the mounting of the second member 31b, and in this case, the opening 32a can be used instead of the adjustment window 33b.

In the assembly procedure as described above, the opening 3
Since 2a has a sufficiently large opening with respect to the magnetic foil 25, the magnetic foil 25 can be brought close to and cut by a turning tool of a lathe in the same mounting state as in the actual use state, and each component 31a can be cut. After mounting the parts, the mounting accuracy of the speed detecting mechanism 8 including the magnetic foil 25 and the magnetic sensor 26 can be confirmed and final adjustment can be performed. Therefore, the dimensional tolerance of the components before mounting can be relaxed, and the assemblability is improved. Further, it becomes easy to manage the dimensional accuracy of the component parts. Since the mounting accuracy of the magnetic foil 25 directly affects the rotation characteristic of the rotary drive device 1, it greatly contributes to the improvement of the rotation characteristic of the device 1.

(4) Action and effect The feature of the present invention is that "the housing is made up of a plurality of constituent members", and this brings about the following basic effects. Improvement of assemblability By providing the first partition member with the second partition wall portion, the speed detecting mechanism portion and the speed reducing mechanism portion are separated in the axial direction, and the second partition wall portion and the second bearing prevent impurities in the speed detecting mechanism. While deleting the member (seal member) just for
By making the housing a divided structure consisting of a plurality of components, an opening for inserting the components of the speed detection mechanism can be secured and the opening can be closed. it can.

Ease of component mounting Since the housing is divided into a plurality of constituent members in consideration of the mountability of components such as the speed detection mechanism and the bearing, each component can be easily mounted. Since the radial load enhancement speed detection mechanism is provided on the output side, the distance between the pair of bearings supporting the output shaft can be increased. As a result, a higher radial load performance can be realized as compared with the prior art.

Ease of molding parts By constructing the housing from a plurality of constituent members,
Parts processing of those constituent members becomes easy. For example, when these constituent members are molded by a mold, the shape of the mold can be simplified. Further, even when cutting these constituent members, the processing is easy.

Further, in this embodiment, the following special effects are brought about by devising the divisional form of the housing. Assembling accuracy is improved because the constituent members of the housing are divided into a first member having a first partition wall portion and a second partition wall portion that support the output shaft, and a second member that is attached to the first member and closes the accommodation space portion. At the time of assembly, it becomes possible to confirm the mounting accuracy of the speed detection mechanism (especially the magnetic foil) that requires mounting accuracy and make final adjustment.
Further, it becomes easy to manage the dimensional accuracy of the component parts.

2. Second Embodiment In the first embodiment (FIG. 5A), the housing 31 is
It is divided into a first member 31a and a second member 31b.
The first member 31a includes a bottom wall portion of the outer wall portion 32, a first partition wall portion 33 including the center hole 33a, and a second partition wall portion 3 including the center hole 34a.
4 and the second outer wall portion 39, and the second member 31b has only the upper surface portion of the outer wall portion 32. Note that FIG. 5 is a cross-sectional configuration diagram for explaining the components of the housing, and shows a simplified shape of the housing 31.

In this embodiment, as shown in FIG. 5B, the housing 31 is divided into a first member 41a and a second member 41b. The first member 41a has an upper surface portion of the outer wall portion 32, a first partition wall portion 33 including a central hole 33a, and a second partition wall portion 34 including a central hole 34a, and a second member 41b is a bottom surface portion of the outer wall portion 32. It has the 2nd outer wall part 39. That is, the first member 31a is the first partition 33 and the second partition 3
The present embodiment has the same configuration as the first embodiment in that it has four and one surface of the outer wall portion 32 integrated therewith, and therefore, the same effect as the first embodiment can be obtained.

3. Third Embodiment In this embodiment, since the accommodation space of the housing is closed after the speed detection mechanism is mounted, it is not possible to obtain the effect of improving the assembly accuracy among the effects of the first embodiment. It is an embodiment shown in FIGS. 6 (a) to 6 (g) having a basic effect in the case of a divided structure.

The housing 31 of FIG. 6 (a) is divided into a first member 51a and a second member 51b. The first member 51a is a second member including the bottom surface portion of the outer wall portion 32 and the central hole 34a.
The partition member 34 and the second outer wall portion 39 are provided, and the second member 51b is provided.
Has an upper surface portion of the outer wall portion 32 and a first partition wall portion 33 including a central hole 33a. The housing 31 of FIG. 6B is
It is divided into a first member 61a and a second member 61b.
The first member 61a includes the motor side portion of the outer wall portion 32 and the central hole 3
4a including the second partition wall portion 34 and the second outer wall portion 39,
The second member 61b has a portion of the outer wall portion 32 opposite to the motor and the first partition wall portion 33 including the central hole 33a.

The housing 31 shown in FIG. 6 (c) is divided into a first member 71a and a second member 71b. The first member 71a is the second partition wall portion 3 including the outer wall portion 32 and the central hole 34a.
4 and the second outer wall portion 39, and the second member 71b has the first partition wall portion 33 including the central hole 33a. Figure 6 (d)
The housing 31 includes a first member 81a and a second member 81b.
It is divided into and. The first member 81a has a second partition wall portion 34 including a center hole 34a and a second outer wall portion 39, and the second member 31b has an outer wall portion 32 and a first partition wall portion 33 including a center hole 33a. There is.

The housing 31 of FIG. 6 (e) is divided into a first member 91a, a second member 91b and a third member 91c. The first member 91a has the second partition wall portion 34 including the center hole 34a and the second outer wall portion 39, the second member 91b has the first partition wall portion 33 including the center hole 33a, and the third member 9
1 c has an outer wall portion 32. The housing 31 of FIG. 6 (f) is divided into a first member 101a, a second member 101b, and a third member 101c. First member 101a
Has a second partition wall portion 34 including a central hole 34a, the second member 101b has a first partition wall portion 33 including a central hole 33a,
The third member 101c has an outer wall portion 32 and a second outer wall portion 39.

The housing 31 of FIG. 6 (g) includes a first member 111a, a second member 111b, a third member 111c and a fourth member 111a.
It is divided into a member 111d. The first member 111a has the second partition wall portion 34 including the central hole 34a.
11b has the 1st partition part 33 containing the center hole 33a, the 3rd member 111c has the outer wall part 32, and the 4th member 111d.
Has a second outer wall portion 39.

4. Fourth Embodiment In the first embodiment, the detection means insertion window portion 32b is formed in the first member 31a by punching, but as shown in FIGS. 7 and 8A, the second member 121b is formed. When attached to the first member 121a, a groove 122a formed in the first member 121a and a protrusion 122c formed in the second member 121b are combined to form a detection means insertion window 122b. Good. Specifically, the groove portion 1
22a has a rectangular shape provided at the position of the detection means insertion window 122b, and the protrusion 122c is the second member 1.
When the groove 21b is attached to the first member 121a, the groove 122
It is a rectangular portion extending along the side surface of the motor a. The other basic structure is similar to that of the first embodiment.

Further, as a similar embodiment, FIG.
, The first member 131a and the second member 131
b may have the central hole 33a of the first partition 33 separately. In this embodiment,
In addition to the effects of the first embodiment, the first member 121a
In addition, there is an effect that it is not necessary to make a hole in the detection means insertion window 32b.

5. Fifth Embodiment In the first embodiment, the shape of the first member 31a and the second member 3
Although it has a shape different from that of 1b, as shown in FIG. 9, the first member 141a and the second member 141b may have the same shape. In this embodiment, among the effects of the first embodiment, since the housing space of the housing is closed after the speed detection mechanism is mounted, it is not possible to obtain the effect of improving the assembly accuracy, but the common members are used. Can be achieved.

6. Sixth Embodiment Although two magnetic sensors were provided in the first embodiment,
As shown in FIG. 10, one magnetic sensor may be omitted and only one magnetic sensor 26 may be provided. Along with this, the one detection means insertion window 32b and the one adjustment window 33b can be omitted, but the other basic structure is the same as that of the above-described embodiment.

7. Seventh Embodiment An optical detection mechanism may be used instead of the magnetic detection mechanism of the first embodiment. As shown in FIG. 11, the speed detection mechanism 141 is an optical rotary encoder,
It has a pulse disk 142 and a photodetector 143 including a light projector and a light receiver. On the outer peripheral portion of the pulse disk 142, light transmitting portions such as a plurality of slits are arranged side by side at equal intervals in the circumferential direction. The photodetector 143 is U-shaped, and the portion of the pulse disc 142 where the light transmitting portion is formed is intruded into the gap. The pulse disc 142 is a foil 14
It is fixed at 5. The structure of the foil 145 and the relationship with other members are the same as those of the magnetic foil of the above-described embodiment except that the external dimensions are small, and thus the description thereof is omitted here. The photodetector 143 is fixed to the second member 151b and is incorporated so as to enter the inside of the device.

8. Other Embodiments The housing split may be a combination of some of the above embodiments. The outer wall portion of the housing is not limited to the rectangular tube shape and may be a cylindrical shape. The shape of the window is not limited to a rectangle, and may be various shapes such as a circle.

In the above-described embodiment, the member constituting the speed reducer is a friction wheel such as a roller, and the traction system is used between the sun roller and each planetary roller and between each planetary roller and the internal ring. The method may be a part thereof. In addition, a speed reducer called a parent-child type and Japanese Patent Application 2
The speed reducer disclosed in No. 000-307496 may be used.

[0073]

In the rotary drive device according to the present invention, by providing the housing with the second partition wall, the speed detecting mechanism portion and the speed reducing mechanism portion are axially separated from each other, and the second partition wall portion and the second bearing are used. By removing the member (sealing member) only for preventing impurities from entering the speed detecting mechanism, and by making the housing a divided structure composed of a plurality of constituent members, the assemblability is improved as compared with the prior art. in addition,
The rigidity of the housing is improved, and since the speed detection mechanism is not contaminated, stable operation can be achieved for a long time.
Further, by devising the division of the housing, it is possible to realize a structure in which the speed detection mechanism can be attached with high accuracy and easily.

[Brief description of drawings]

FIG. 1 is a sectional configuration diagram of a rotary drive device according to a first embodiment of the present invention.

FIG. 2 is a front view of the rotary drive device taken along the line II of FIG.

FIG. 3 is an exploded perspective view of the transmission unit according to the first embodiment.

FIG. 4 is a view showing an engaged state of a magnetic wheel and an output shaft.

FIG. 5 is a schematic sectional view of the housing according to the second embodiment.

FIG. 6 is a schematic sectional view of a housing according to a third embodiment.

FIG. 7 is an exploded perspective view of a transmission unit according to a fourth embodiment.

FIG. 8 is a schematic sectional view of a housing according to a fourth embodiment.

FIG. 9 is an exploded perspective view of a transmission unit according to a fifth embodiment.

FIG. 10 is a front view of a rotation drive device according to a sixth embodiment.

FIG. 11 is a front view of a rotation drive device according to a seventh embodiment.

[Explanation of symbols]

1 rotary drive 2 motor 3 reducer 4 Transmission means 5 controller 6 Drive device 7 Output shaft 8 Speed detection mechanism 25 Magnetic foil (member to be detected) 26 Magnetic sensor (detection means) 27 First bearing 28 Second bearing 29 Coil spring (biasing member) 30 Non-rotating pin 31 housing 32 outer wall 32a opening 32b Window for detecting means insertion 33 First partition wall 33b Adjustment window 34 Second partition wall 35 accommodation space 39 Second outer wall 41 Wave washer (elastic member)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toshio Wakamatsu             Nidec, No. 1 Kashiterada, Nagaokakyo, Kyoto Prefecture             Within sympo corporation (72) Inventor Masahiro Shibuya             Nidec, No. 1 Kashiterada, Nagaokakyo, Kyoto Prefecture             Within sympo corporation F-term (reference) 2H035 CA07 CB01 CG01 CG03                 2H071 CA02 CA05 DA15 DA27 DA32                 3J051 AA01 BA04 BB06 BC01 BD02                       BE03 EA02 EB04 EC10 FA08                 3J063 AA29 AB35 AC01 BA01 BB46                       CA01 CD45 XA11                 5H611 AA01 BB01 BB08 PP07 QQ01                       RR03 TT01 UA04 UA08

Claims (16)

[Claims] 1. A motor is used as a rotation drive source to drive a driven device to rotate and to detect an output rotation speed,
A rotation drive device for feedback-controlling a drive rotation speed of a motor, comprising: a speed reducer driven by the motor; and an output shaft extending from the speed reducer to the driven device side, wherein an output of the speed reducer is driven by the driven device. A transmission means for transmitting to the device, a speed detection mechanism arranged on the driven device side of the speed reducer for detecting a rotation speed of the output shaft, and an outer wall portion covering the output shaft and the speed detection mechanism. A housing having a first partition wall portion that is provided on the outer wall portion and through which the output shaft penetrates, and a second partition wall portion that is provided on the speed reducer side of the outer wall portion and through which the output shaft penetrates; A first bearing arranged between an inner peripheral surface of the portion and the output shaft, and a second bearing arranged between an inner peripheral surface of the second partition wall portion and the output shaft, The second partition is the first partition. A housing space portion in which the speed detection mechanism is installed together with the portion and the outer wall portion, the speed reducer and the speed detection mechanism are separated in the axial direction, and the housing is composed of a plurality of constituent members. A rotary drive device characterized in that 2. The housing includes a first member supporting an output shaft via the first bearing and the second bearing, and the first member after the speed detection mechanism is installed in the accommodation space.
The rotary drive device according to claim 1, comprising a second member which is attached to a member and is capable of closing the accommodation space. 3. The outer wall portion, wherein the first member is integral with at least a portion of the first partition wall portion, at least a portion of the second partition wall portion, and the first partition wall portion and the second partition wall portion. The rotary drive device according to claim 2, further comprising: 4. The rotary drive device according to claim 3, wherein the second member is a member having the same shape as the first member. 5. The speed detecting mechanism comprises a detecting means and a detected member which rotates integrally with the output shaft and is detected by the detecting means, and the housing is provided with the detecting means. The rotary drive device according to claim 1, wherein an installation window portion is formed. 6. The first member and the second member each have a groove and a protrusion that form the placement window when the second member is mounted on the first member. Two
The rotation drive device according to any one of to 5. 7. The arranging window portion penetrates the outer wall portion in a radial direction of the output shaft, and a central axis of the arranging window portion extends in the penetrating direction to the output shaft. The rotary drive device according to claim 5 or 6, which is orthogonal. 8. The rotary drive device according to claim 6, wherein the housing is provided with an adjusting window portion for adjusting a mounting position when the detecting means is arranged. 9. The adjusting window portion penetrates the first partition wall portion in the axial direction of the output shaft, and the central axis of the adjusting window portion extends in the penetrating direction to the output shaft. 9. The rotary drive device according to claim 8, which is parallel. 10. The speed detecting mechanism is a magnetic sensor, the detecting means is at least one magnetic detecting means for detecting a change in magnetic flux, and the detected member is a magnetized portion having a magnetized portion. The rotation drive device according to any one of claims 6 to 9, which is a static detection member. 11. The speed detecting mechanism is an optical sensor, and the detecting means detects at least one optical change.
7. Optical detection means, wherein the detected member is an optical detected member.
9. The rotary drive device according to any one of 9 above. 12. The speed reducer includes a solar car to which the rotation of the motor is input, a pair of internal rings arranged concentrically with the solar car, and a plurality of abutting solar cars and the internal ring. A planetary car, a carrier that supports the plurality of planetary cars, is connected to the output shaft, and has a biasing member for pressing the pair of internal rings to the planetary car. The rotation drive device according to any one of claims 1 to 11. 13. The rotary drive device according to claim 12, wherein an output shaft of the motor constitutes the sun wheel of the speed reducer. 14. A recess for accommodating the biasing member is formed on a surface of the second partition wall on the speed reducer side, and a bottom surface of the recess is further formed than an end surface of the second bearing on the speed reducer side. 13. Located on the side of the driven device,
Alternatively, the rotary drive device according to item 13. 15. The rotary drive device according to claim 1, further comprising a motor for rotationally driving the speed reducer. 16. A feedback control means for feedback controlling the drive speed of the motor based on the detection from the speed detection mechanism.
16. The rotary drive device according to any one of 15.