JP2012092907A - Planetary gear speed reducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a planetary gear speed reducer, which can prevent the deformation of carriers made of a resin and secure long time operation performance without generating bearing abrasion while securing high rotational accuracy.SOLUTION: There is provided the planetary gear speed reducer 50 in which metal rotation support shafts 52 of rotating and revolving planetary gears 51 are inserted and fixed in the carriers 53 made of the resin, rotation support shaft fixing plates 56 as retaining members formed in a disk shape by punching an inner diameter and an outer diameter of a thin metal plate by punching processing are arranged on the carriers 53, and ends of the rotation support shafts 52 are concentrically fixed to the rotation support shaft fixing plates 56.

Description

  The present invention relates to a planetary gear reduction device, and more particularly to a planetary gear reduction device used in a drive transmission system of an electrophotographic image forming apparatus having a photosensitive drum.

  2. Description of the Related Art Conventionally, as a planetary gear reduction device, a technique is known in which generation of rotational noise of a carrier that supports a planetary gear is suppressed and durability of the planetary gear reduction device is improved (for example, Patent Document 1). reference). In Patent Document 1, the support shaft of the planetary gear provided on the carrier is in a cantilever state.

  Also, as a planetary gear reduction device used for driving an image forming apparatus, a technique in which a support shaft of a planetary gear provided on a carrier is cantilevered is known as in Patent Document 1 (for example, Patent Document 1). 2).

  Further, there are known a perspective view of a planetary carrier assembly and a planetary gear shaft described together with first and second side plates (see, for example, Patent Document 3).

  In these conventional techniques, the carrier to which the rotation support shaft of the planetary gear is fixed is made of metal.

  However, in the conventional planetary gear reduction devices described in Patent Documents 1 to 3, the carrier to which the rotation support shaft of the planetary gear is fixed is made of metal. For example, the rotation support shaft of the planetary gear is used as the rotation support shaft of the planetary gear. It is fixed to a metal carrier by press fitting, and planetary gears are inserted and rotated here. However, in order to improve productivity, if the carrier is made of a resin molded product instead of metal, There is a problem that there is no effective means for fixing to the resin carrier without passing through the rotation support shaft of the gear.

  Specifically, for a carrier made by resin molding, the metal rotation support shaft for planetary gears is accurate and does not come out during operation, and even if it is operated for a long time, play due to wear will occur. There was no good way to support it. In particular, if a carrier having a complicated shape is formed by resin molding and an attempt is made to secure a performance of 10000 hours, the rotation support shaft of the planetary gear may come off from the carrier, and the bearing of the carrier is caused by friction. A technique for preventing the portion from being worn is required.

  The hole position accuracy (coaxiality) of the bearing of the resin carrier must be suppressed to 20 μm or less. If this is to be maintained, there will be no effective means, resulting in high costs, and in some cases, the size will be increased and will not fit within the prescribed device size. In order to obtain high-precision rotation characteristics, the mounting shape and assembly method of the rotation support shaft of the planetary gear so as not to deform the resin carrier, that is, deformation from the rotation support shaft of the planetary gear with respect to the resin carrier It is necessary to consider a method that does not apply stress that causes the problem.

  The present invention has been made to solve such a problem, and can prevent deformation of a resin carrier, and can ensure long-time operation performance that does not cause bearing wear while ensuring high rotational accuracy. A planetary gear reduction device is provided.

  A planetary gear speed reduction device according to the present invention is a planetary gear speed reduction device in which a metal rotation support shaft of a planetary gear that rotates and revolves is inserted and fixed to a resin carrier, and an inner diameter is obtained by punching a metal thin plate. A retaining member formed by punching the outer diameter into a disk shape is provided on the carrier, and the end of the rotation support shaft is concentrically fixed to the retaining member.

  With this configuration, the rotation support shaft fixed to the retaining member increases the sliding resistance of the contact portion with the carrier, so that the contact portion between the rotation support shaft and the carrier is changed with environmental changes such as temperature during operation. Even if the looseness fits within the tolerance, the rotation support shaft can be prevented from falling off the carrier.

  Further, the load received by the rotation support shaft by the meshing rotation of the planetary gear does not directly act on the support portion of the resin carrier, but is received by the metal retaining member, so that the rotation support shaft and the carrier It is possible to prevent the backlash due to wear from occurring at the contact portion, and to maintain the rotation accuracy.

  Therefore, it is possible to prevent deformation of the resin carrier, and to ensure long-time operation performance that does not cause bearing wear while ensuring high rotational accuracy.

  In the planetary gear speed reduction device according to the present invention, the retaining member includes a press-fitting hole into which a peripheral edge is divided by a radial slit and an end of the rotation support shaft is press-fitted, and the rotation support shaft Is fixed to the retaining member by press-fitting.

  With this configuration, the retaining member and the rotation support shaft can be firmly coupled by a simple method. Further, the peripheral edge portion of the press-fitting hole divided by the slit can be engaged with the rotation support shaft during press-fitting, and a strong coupling force between the retaining member and the rotation support shaft can be obtained. Further, the man-hour can be shortened and the production efficiency can be improved as compared with the case where the retaining member and the rotation support shaft are fixed by adhesion.

  In the planetary gear speed reduction device according to the present invention, the carrier has a cylindrical positioning portion that is coaxial with the rotation axis of the carrier, and the retaining member has an inner diameter that fits the positioning portion. In addition, the retaining member is positioned by fitting into the positioning portion, and the end portion of the rotation support shaft is concentrically fixed to the retaining member by welding.

  With this configuration, the retaining member and the rotation support shaft can be firmly coupled by a simple method. Unlike the case where a press-fitting hole is provided in the retaining member and the rotational support shaft is precisely aligned and press-fitted, the fixed position in the revolution direction of the rotational supporting shaft with respect to the retaining member is allowed to some extent. And the rotation support shaft are simplified.

  In the planetary gear speed reduction device according to the present invention, two retaining members are disposed so as to face each other with the carrier interposed therebetween, and the retaining members are fixed to both ends of the rotation support shaft, respectively. Features.

  With this configuration, the effect of preventing the rotation support shaft from coming off can be improved, and the force from the planetary gear acting on the fixed portion of the rotation support shaft of the resin carrier can be further reduced.

  The planetary gear speed reduction device according to the present invention is characterized in that a concave step portion in which the retaining member is embedded is provided on a side surface of the carrier so as not to protrude from the surface of the carrier.

  With this configuration, since the retaining member does not protrude from the side surface of the carrier, the first-stage planetary gear mechanism and the second-stage planetary gear mechanism can be brought close to each other, so that the length in the axial direction can be shortened. The gear transmission can be reduced in size. Further, it is possible to prevent the first stage planetary gear mechanism and the second stage planetary gear mechanism from coming into contact with each other and causing fluctuations in rotational speed.

  The planetary gear speed reduction device according to the present invention is characterized in that the retaining member has a thinning portion at a position concentric with the rotation shaft and at an equal angle.

  With this configuration, the rotational inertia can be reduced along with the reduction of the mass of the retaining member, so that the wear of the meshing planetary gears can be reduced and the durability can be improved when the forward / reverse action is applied.

  ADVANTAGE OF THE INVENTION According to this invention, the planetary gear reduction device which can prevent the deformation | transformation of the resin-made carrier, and can ensure the long-time driving | running performance which does not generate | occur | produce bearing wear while ensuring high rotation accuracy can be provided.

It is a figure which shows schematic structure of the planetary gear speed reducer which concerns on one embodiment of this invention. (A), (b) is a figure which shows the coupling | bonding method of the carrier and rotation support shaft which can be employ | adopted when the carrier is produced by the resin molding in the planetary gear speed reduction device which concerns on one embodiment of this invention. . (A), (b) is a planetary gear speed reduction device according to an embodiment of the present invention, in which a rotation support shaft fixing plate to which a rotation support shaft is fixed by press-fitting is provided on a carrier, and the rotation support shaft of the planetary gear is It is a figure which shows the structure which was made not to come out of a carrier. (A), (b) is the planetary gear speed reduction device according to one embodiment of the present invention, wherein the outer peripheral portion of the cylindrical positioning portion in which the central hole of the rotation support shaft fixing plate is provided in the side wall member of the carrier It is a figure which shows the structure which acquired the concentricity of the rotation support shaft fixing plate by making it fit to, and fixed the rotation support shaft to the rotation support shaft fixing plate by welding. (A), (b), in the planetary gear speed reduction device according to one embodiment of the present invention, two rotation support shaft fixing plates, each having a rotation support shaft fixed by press-fitting, are arranged so as to face each other with a carrier interposed therebetween. It is a figure which shows a structure. (A), (b) is the planetary gear speed reduction device according to one embodiment of the present invention, in which two rotation support shaft fixing plates to which the rotation support shaft is fixed by welding are arranged so as to face each other across the carrier. It is a figure which shows a structure. In the planetary gear speed reduction device according to an embodiment of the present invention, a configuration in which the rotation support shaft fixing plate is embedded by providing step portions on the outer sides of the left and right side wall members so that the rotation support shaft fixing plate does not protrude from the side surface of the carrier. FIG. (A), (b) is a planetary gear speed reduction device according to an embodiment of the present invention, in which the rotation support shaft fixing plate is concentric with the rotation shaft and is equiangularly formed by a blanking process. It is a figure which shows the structure which has a thinning part of a circular diameter. In the planetary gear speed reduction device according to one embodiment of the present invention, it is a diagram showing a press-fitting jig for fixing the rotation support shaft to the rotation support shaft fixing plate by press-fitting. In the planetary gear speed reduction device according to one embodiment of the present invention, it is a diagram showing a welding jig for fixing the rotation support shaft to the rotation support shaft fixing plate by welding.

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

  First, the configuration will be described.

  FIG. 1 is a diagram showing an entire two-stage planetary gear reduction device having fixed internal teeth, which is a subject of the present invention.

  The planetary gear speed reduction device 10 is a high speed accuracy reduction gear used to drive a multi-function printer (MFP), that is, a multifunction machine, or a photosensitive drum of a PP (Production Printing), to which an electrophotographic process is applied. The speed fluctuation rate of the rotational angular velocity is designed with a target of 0.15 to 0.2% PP or less. In the figure, the driven shaft 20 on the left side and the drive shaft (output shaft) 19 are splined to be detachable.

  In the figure, a planetary gear reduction device 10 includes a motor shaft sun gear 12, a first stage planetary gear 13, a first stage carrier 14, a fixed internal gear 15, a second stage planetary gear 16, and a sun gear 17. When the motor shaft sun gear 12 that is the output shaft of the motor 11 rotates, the rotation is decelerated and output from the drive shaft 19. It has become.

  2 (a) and 2 (b) show how the carrier 33 and the rotation support shaft can be combined when the carrier 33 is formed by resin molding.

  FIG. 2A shows four planetary gear speed reduction devices 30 provided at four equal angles with respect to each of the two side wall members 34 and 35 of the carrier 33 molded with a resin such as POM (polyacetal resin). The planetary gear 31 is mounted and fixed in the rotation support shaft mounting holes 34a and 35a, and the planetary gear 31 formed by POM is inserted through the metal rotation support shaft 32 from the lateral direction. The gear 31 is rotated. Both ends of the rotation support shaft 32 are inserted into the two rotation support shaft attachment holes 34a and 35a of the side wall members 34 and 35 of the carrier 33, and are fixed in a press-fit manner (tight fit state). That is, the end portion of the rotation support shaft 32 is inserted and fixed in the rotation support shaft attachment holes 34 a and 35 a of the side wall members 34 and 35 of the carrier 33.

  FIG. 2B is a view for explaining a method of fixing the rotation support shaft of a type different from that in FIG. In the planetary gear speed reduction device 40 of FIG. 2A, the four rotation support shaft mounting holes 44a and 45a provided in the two side wall members 44 and 45 of the carrier 43 are stepped at the tips. Slits 44b and 45b are provided outside the circumference with a width that is equal to or slightly narrower than the diameter of the rotation support shaft 42. After the stepped rotation support shaft 42 is inserted into the planetary gear 41, the two end portions having the step processing are inserted into the slits 44b and 45b, whereby the rotation support is performed. That is, the end portion of the stepped rotation support shaft 42 is inserted and fixed in the rotation support shaft attachment holes 44 a and 45 a of the side wall members 44 and 45 of the carrier 43.

  Both types of FIG. 2A and FIG. 2B obtain desired characteristics in the initial operation, but the following problems occur.

  In the planetary gear speed reduction device 30 of the type shown in FIG. 2A, the shaft hole of the planetary gear 31 and the rotation support shaft 32 have a loose fitting fit tolerance for smooth rotation. When the diameters of the rotation support shaft mounting holes 34a and 35a of the side wall members 34 and 35 made of resin increase due to expansion due to an increase in the environmental temperature or an increase in the ambient temperature in the apparatus, the rotation support shaft 32 moves during rotation. Or contact with the side surface of the carrier of another adjacent planetary gear mechanism (not shown) to cause rotation failure. In particular, when the planetary gear reduction device 30 is used as a second-stage planetary gear mechanism close to a load, a large reduction gear ratio load acts on the bearing portion of the planetary gear shaft of the second-stage carrier. As the wear progresses, a large amount of play occurs.

  In the planetary gear speed reduction device 40 of the type shown in FIG. 2B, there is no problem that the stepped rotation support shaft 42 comes out of the carrier 43 because the stepped rotation support shaft 42 is provided with a step. The rotation support shaft mounting holes 44a and 45a provided in the carrier 43 are provided with open slits 44b and 45b, so that the hole diameter accuracy is difficult to obtain, and the second stage carrier close to the load as described above. However, the planetary gear shaft has a problem that a large amount of play is generated because a load with a large reduction gear ratio acts on the bearing portion and wear progresses.

  Hereinafter, the first feature will be described.

  By adopting the configuration as shown in FIGS. 3A and 3B, the above-described problems are prevented.

  That is, a ring-shaped rotation support shaft fixing member in which an extremely thin metal is processed is prepared for a carrier formed by resin molding, and this is fixed to a metal rotation support shaft for a planetary gear to support the retaining. It was.

  With this configuration, the two parts are fixed so that the carrier is not deformed by resin molding, ensuring high rotation accuracy and no bearing wear, ensuring long-term driving performance. can do.

  FIG. 3A and FIG. 3B are diagrams showing a configuration in which the rotation support shaft of the planetary gear is prevented from being detached from the carrier.

  In the planetary gear reduction device 50 of FIGS. 3A and 3B, the side wall members 54 and 55 of the resin carrier 53 are coaxial with the rotation axis of the carrier 53, and are at 90 degrees, etc. Rotation support shaft attachment holes 54a and 55a for attaching the rotation support shafts 52 of the four distributed planetary gears 51 are provided. In order to maintain the parallelism of the four planetary gears 51, the rotation support shaft mounting holes 54a and 55a provided in the left side wall member 54 and the right side wall member 55 in the drawing are connected to the rotation support shaft 52. Mating accuracy and parallelism are specified.

  Since the carrier 53 rotates at a high speed together with the planetary gear 51, the rotation support shaft fixing plate 56 attached to the carrier 53 balances rotation in order to reduce fluctuations in the rotation speed and to reduce noise. is important.

  For this purpose, the rotation support shaft fixing plate 56 is made of a disk-shaped metal plate (material such as SUS) having an inner diameter and an outer diameter punched by punching, and the inner and outer diameters thereof, and the rotation support shaft provided there The concentricity of the press-fitting hole 56a for 52 is processed with high accuracy.

  The hole 56c, which is the center of rotation of the rotation support shaft fixing plate 56, is fitted to the outer periphery of a cylindrical positioning portion 54b provided in the carrier 53, aligned, and rotated with concentric accuracy. The method of doing so will be described later in the description of the third feature.

  The rotation support shaft 52 to be used is selected in terms of both function and cost, and is a straight pin with no steps, high accuracy in diameter and straightness, high surface roughness accuracy, and sliding performance with POM. In consideration of the goodness, etc., needles for needle bearings that are commercially available for general use are used. This eliminates the need for dedicated component processing (steps such as cutting, heat treatment, and polishing), which is advantageous in terms of cost.

  The rotation support shaft 52 is inserted into the rotation support shaft attachment holes 54 a and 55 a of the side wall members 54 and 55 of the carrier 53 together with the planetary gear 51. Then, one end portion of the rotation support shaft 52 is press-fitted into the four press-fitting holes 56 a formed at positions facing the rotation support shaft fixing plate 56 to complete the fixing. The press-fitting method can be easily performed with a dedicated press-fitting jig as shown in FIG. In FIG. 9, the press-fitting jig includes a die 71 on which the planetary gear reduction device 50 is placed, a punch 72 that presses the rotation support shaft 52, and a pressurizing member 73 that pressurizes the punch 72.

  With such a configuration, one end of the four rotation support shafts 52 is assembled in a state of being coupled to the metal rotation support shaft fixing plate 56, so that the rotation support shaft 52 and the rotation support portion mounting hole 54a are assembled. , 55a, and the rotation support shaft 52 does not move in the thrust direction and fall off the carrier 53.

  Next, the second characteristic part will be described.

  In the above description, the method of press-fitting one end portion of the rotation support shaft 52 into the rotation support shaft fixing plate 56 and fixing the rotation support shaft 52 is described. At this time, the press-fitting hole 56a provided in the rotation support shaft fixing plate 56 is a circular hole, and the tolerance with the rotation support shaft 52 is set as the press-fitting tolerance. Next, the end of the rotation support shaft 52 is set to the rotation support shaft. A description will be given of the shape of the press-fitting hole 56a in which this press-fitting process is reliably and easily performed when press-fitting into the press-fitting hole 56a of the fixed plate 56.

  Similarly, in FIG. 3, some slits 56b are formed around a press-fitting hole 56a formed in a rotation support shaft fixing plate 56 made of a thin metal plate having a thickness of about 0.15 to 0.3 mm. By inserting the slit 56b, the peripheral edge of the divided press-fitting hole 56a is easily deformed, and the peripheral part of the divided press-fitting hole 56a is slightly pushed and deformed by the protrusion of the end of the rotation support shaft 52. Then, an edge portion due to the thickness of the peripheral edge portion of the rotation support shaft fixing plate 56 is engaged with the rotation support shaft 52, and as a result, the rotation support shaft 52 is locked so as not to come off.

  Also regarding this press-fitting, as shown in FIG. 9, it is composed of a die 71 on which the planetary gear reduction device 50 is placed, a punch 72 that presses the rotation support shaft 52, and a pressurizing member 73 that pressurizes the punch 72. It can be done easily with a dedicated jig.

  As described above, even if the metal rotation support shaft fixing plate 56 having a very thin plate pressure is selected, the rotation support shaft 52 can be reliably fixed to the rotation support shaft fixing plate 56.

  Next, the third feature will be described.

  In contrast to the method of fixing the rotation support shaft 52 to the rotation support shaft fixing plate 56 by press-fitting as described in the description of the first feature and the second feature, hereinafter, the rotation support shaft 52 is rotationally supported by welding. A method of fixing to the shaft fixing plate 56 will be described. A method of using an adhesive for fixing the rotation support shaft 52 and the rotation support shaft fixing plate 56 is also conceivable, but considering the strength of the adhesive and the time required for curing, welding is also considered from the viewpoint of simplicity of work. Is a more effective method.

  Here, spot welding (resistance welding) is taken as an example.

  In the rotation support shaft fixing plate 56 described in the explanation of the first and second features, the press-fitting holes 56a are processed concentrically with high precision along with the inner and outer circumferences where the rotation support shaft fixing plate 56 is punched. Therefore, the accuracy of the coaxial position at the time of assembly was obtained automatically by the subsequent press-fitting process. However, in the case of welding, if welding is performed at an arbitrary position, the center position is shaken and rotation fluctuation occurs.

  Therefore, as in the planetary gear reduction device 60 of FIGS. 4A and 4B, the hole diameter accuracy of the center hole 57 c of the rotation support shaft fixing plate 57 is ensured, and the side wall member 54 of the carrier 53 is secured. The concentricity of the rotation support shaft fixing plate 57 is obtained by fitting the hole 57c to the outer peripheral portion of the cylindrical positioning portion 54b provided on the rotating support shaft.

  This spot welding can be easily performed with a dedicated welding jig as shown in FIG. In addition, since the welding position in the rotational direction (revolution direction) is not subject to strict alignment restrictions such as press-fitting with the rotation support shaft 52 aligned with the position of the press-fitting hole 56a, the fixing operation is performed extremely efficiently. In FIG. 10, the welding jig passes a current while crimping the end portion of the rotation support shaft 52 and the rotation support shaft fixing plate 57, and melts and bonds the pressure bonding portions with the resistance heat. An electrode 82 is used.

  Next, the fourth feature will be described.

  Up to this point, the description has been given of the connection between the rotation support shaft 52 and the rotation support shaft fixing plates 56 and 57 performed by press-fitting or welding provided in one side direction, that is, the left side wall member 54 of the carrier 53.

  In order to further reduce the force from the planetary gear 51 acting on the rotation support shaft attachment holes 54a and 55a of the resin carrier 53 as well as the effect of preventing the rotation support shaft 52 from coming off, FIG. Like the planetary gear reduction device 70 shown in FIG. 6B and the planetary gear reduction device 80 shown in FIGS. Applying the same configuration as above, it is effective to fix both ends of the rotation support shaft 52 to the metal rotation support shaft fixing plate 56 by press fitting or to the rotation support shaft fixing plate 57 by welding.

  That is, in the planetary gear speed reduction device 70 shown in FIGS. 5A and 5B, the rotation support shaft fixing plate 56 is also provided on the side wall member 55 of the carrier 53, and the rotation support shaft fixing plate 56 is The hole 56c is fitted to the outer peripheral portion of the positioning portion 55b, so that the side wall member 55 is mounted. In the planetary gear reduction device 80 shown in FIGS. 6A and 6B, the rotation support shaft fixing plate 57 is also provided on the side wall member 55 of the carrier 53, and the rotation support shaft fixing plate 57 is The hole 57c is fitted into the outer peripheral portion of the positioning portion 55b, so that the side wall member 55 is mounted.

  Here, FIGS. 5A and 5B are views showing a state in which both ends of the rotation support shaft 52 are fixed to the rotation support shaft fixing plate 56 by press-fitting, and FIGS. b) is a view showing a state in which both ends of the rotation support shaft 52 are fixed to the rotation support shaft fixing plate 57 by welding.

  Next, the fifth feature will be described.

  As shown in FIG. 1, in the configuration of the fixed internal gear reducer, in order to reduce the size in the longitudinal direction of the rotation axis (left and right direction in the figure) and to increase the transmission rigidity of the drive transmission system, the adjacent 1 It is important to shorten the proximity length L between the stage carrier 14 and the second stage carrier 18 as much as possible.

  Therefore, as shown in FIGS. 3B to 6B, the side wall members 54 and 55 of the carrier 53 are incorporated in a state in which portions corresponding to the rotation support shaft fixing plates 56 and 57 for press-fitting and welding are incorporated. Recessed stepped portions 54c and 55c are provided on the outer sides of the left and right side wall members 54 and 55 so that the rotation supporting shaft fixing plates 56 and 57 do not protrude from the surface, and the rotation supporting shaft fixing plates are provided on the stepped portions 54c and 55c. 56 and 57 were submerged (buried). As a result, the rotation support shaft fixing plates 56 and 57 do not protrude from the side wall members 54 and 55 (projections are not formed), so that the planetary gear reduction device 70 and the planetary gear reduction device 80 are placed in the first stage as shown in FIG. Even if they are connected and arranged as a planetary gear and a second stage planetary gear and the proximity length L (see FIG. 1) is set to zero, contact resistance between the rotation support shaft fixing plate 56 and the rotation support shaft fixing plate 57 is generated. High-precision rotation is possible without

  Next, the sixth feature will be described.

  The carrier 53 rotates at several tens to several hundreds (rotations / second), and forward / reverse rotation is added. Therefore, reducing the rotation weight as much as possible to reduce the inertia reduces the durability of the meshing gear tooth surfaces. It is important in raising.

  In order to reduce the rotational inertia of the rotation support shaft fixing plates 56 and 57 attached to the carrier 53, in FIGS. 8A and 8B, the rotation support shaft fixing plates 56 and 57 are positioned concentrically with the rotation shaft. In addition, at the equiangular positions, circular-thickening portions 56d and 57d are formed by thinning in a range that does not affect the strength.

  As described above, the planetary gear speed reduction device 50 according to the present embodiment is such that the metal rotation support shaft 52 of the planetary gear 51 that revolves while rotating is inserted and fixed to the resin carrier 53. The carrier 53 is provided with a rotation support shaft fixing plate 56 as a retaining member formed by punching out an inner diameter and an outer diameter by punching a thin metal plate and forming a disc shape. The rotation support shaft fixing plate 56 is provided with the rotation support shaft fixing plate 56. The ends are fixed concentrically.

  With this configuration, since the rotation support shaft 52 fixed to the rotation support shaft fixing plate 56 has a large sliding resistance at the contact portion with the carrier 53, the rotation support shaft 52 Even if the contact portion with the carrier 53 is loosened and the fit is within the desired tolerance, the rotation support shaft 52 can be prevented from falling off the carrier 53.

  Further, the load received by the rotation support shaft 52 due to the meshing rotation of the planetary gear 51 does not directly act on the support portion of the resin carrier 53, but is received by the metal rotation support shaft fixing plate 56. It is possible to prevent the occurrence of support play due to wear at the contact portion between the rotation support shaft 52 and the carrier 53 and maintain the rotation accuracy.

  Therefore, deformation of the resin carrier 53 can be prevented, and long-time driving performance can be ensured while ensuring high rotation accuracy and without bearing wear.

  Further, in the planetary gear speed reduction device 50 according to the present embodiment, the rotation support shaft fixing plate 56 is divided into press-fitting holes 56a into which the peripheral edge portion is divided by radial slits 56b and the end portion of the rotation support shaft 52 is press-fitted. The rotation support shaft 52 is fixed to the rotation support shaft fixing plate 56 by press-fitting.

  With this configuration, the rotation support shaft fixing plate 56 and the rotation support shaft 52 can be firmly coupled by a simple method. Further, the peripheral edge portion of the press-fitting hole 56 a divided by the slit is engaged with the rotation support shaft 52 during press-fitting, and a strong coupling force between the rotation support shaft fixing plate 56 and the rotation support shaft 52 can be obtained. Further, compared to the case where the rotation support shaft fixing plate 56 and the rotation support shaft 52 are fixed by adhesion, man-hours can be shortened and production efficiency can be increased.

  Further, in the planetary gear speed reduction device 60 according to the present embodiment, the carrier 53 has a cylindrical positioning portion 54b that is coaxial with the rotation shaft of the carrier 53, and the rotation support shaft fixing plate 56 has a positioning portion 54b. The rotation support shaft fixing plate 56 is fitted into the positioning portion 54b for positioning, and the end of the rotation support shaft 52 is concentrically fixed to the rotation support shaft fixing plate 56 by welding. It is characterized by that.

  With this configuration, the rotation support shaft fixing plate 56 and the rotation support shaft 52 can be firmly coupled by a simple method. Unlike the case where the press-fitting hole 56a is provided in the rotation support shaft fixing plate 56 and the rotation support shaft 52 is press-fitted with the position accurately adjusted, the fixed position of the rotation support shaft 52 in the revolving direction with respect to the rotation support shaft fixing plate 56 is different. Since it is allowed to some extent, the fixing operation of the rotation support shaft fixing plate 56 and the rotation support shaft 52 is simplified.

  In the planetary gear speed reduction devices 70 and 80 according to the present embodiment, two rotation support shaft fixing plates 56 and 57 are arranged so as to face each other with the carrier 53 interposed therebetween, and the rotation support shaft fixing plates 56 and 57 are arranged. The rotation support shaft 52 is fixed to both ends.

  With this configuration, the effect of preventing the rotation support shaft 52 from coming off can be improved, and the force from the planetary gear 51 acting on the fixed portion of the rotation support shaft 52 of the resin carrier 53 can be further reduced.

  Further, the planetary gear speed reduction devices 50, 60, 70, 80 according to the present embodiment have concave step portions in which the rotation support shaft fixing plate 56 is embedded on the side surface of the carrier 53 so as not to protrude from the surface of the carrier 53. 54c is provided.

  With this configuration, since the rotation support shaft fixing plate 56 does not protrude from the side surface of the carrier 53, the first-stage planetary gear mechanism and the second-stage planetary gear mechanism can be brought close to each other to shorten the axial length. Therefore, the size can be reduced. Further, it is possible to prevent the first stage planetary gear mechanism and the second stage planetary gear mechanism from coming into contact with each other and causing fluctuations in rotational speed.

  Further, in the planetary gear speed reduction devices 50, 60, 70, 80 according to the present embodiment, when the rotation support shaft fixing plate 56 is concentric with the rotation shaft and is at an equiangular position, 57d.

  With this configuration, the rotational inertia can be reduced along with the reduction in the mass of the rotation support shaft fixing plate 56, so that the tooth surface wear of the meshing planetary gear 51 when the forward / reverse rotation acts can be reduced and the durability can be improved.

  As described above, the planetary gear speed reduction device according to the present invention can prevent deformation of the resin carrier, and can ensure long-time operation performance that does not cause bearing wear while ensuring high rotational accuracy. This is effective and is useful as a planetary gear reduction device used in a drive transmission system of an electrophotographic image forming apparatus having a photosensitive drum.

50, 60, 70, 80 Planetary gear speed reducer 51 Planetary gear 52 Rotation support shaft 53 Carrier 54, 55 Side wall member 54a, 55a Rotation support shaft mounting hole 54b, 55b Positioning portion 54c, 55c Stepped portion 56, 57 Rotation support shaft fixed Plate (Retaining member)
56a Press-fit hole 56b Slit 56c, 57c Hole 56d, 57d Meat removal processing part 71 Die 72 Punch 73 Pressurizing member 81 Positive electrode 82 Negative electrode

Japanese Patent Laid-Open No. 6-200988 JP 2003-42238 A JP 2001-330087 A

Claims (6)

A planetary gear reduction device in which a metal rotation support shaft of a planetary gear that revolves while rotating is inserted and fixed to a resin carrier,
The carrier is provided with a retaining member formed by punching out an inner diameter and an outer diameter by punching a thin metal plate into a disk shape,
A planetary gear reduction device characterized in that an end of the rotation support shaft is concentrically fixed to the retaining member. The retaining member includes a press-fitting hole into which a peripheral edge is divided by a radial slit and an end of the rotation support shaft is press-fitted,
The planetary gear reduction device according to claim 1, wherein the rotation support shaft is fixed to the retaining member by press-fitting. The carrier has a cylindrical positioning portion that is coaxial with the rotation axis of the carrier;
The retaining member has an inner diameter that fits into the positioning portion;
2. The planetary gear according to claim 1, wherein the retaining member is positioned by being fitted to the positioning portion, and an end of the rotation support shaft is concentrically fixed to the retaining member by welding. Reducer. While disposing the two retaining members so as to face each other across the carrier,
The planetary gear reduction device according to any one of claims 1 to 3, wherein the retaining member is fixed to both ends of the rotation support shaft.   The planetary gear reduction according to any one of claims 1 to 4, wherein a concave step portion in which the retaining member is embedded so as not to protrude from the surface of the carrier is provided on a side surface of the carrier. apparatus.   The planetary gear reduction device according to any one of claims 1 to 5, wherein the retaining member has a thinning portion at a position concentric with the rotation shaft and at an equal angle.

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