JP2019052666A - Speed reduction gear and electric equipment with the same - Google Patents

Abstract

To provide a cycloid type speed reduction gear suitable for electric equipment which can reduce a noise level in a speed reduction mechanism while achieving miniaturization of the speed reduction mechanism, and the electric equipment with the speed reduction gear.SOLUTION: A cycloid type speed reduction gear includes an input shaft 5 receiving rotational power of a pre-stage device 3, an eccentric cam 6 fixed on the input shaft 5, a planetary gear 7 rotated and driven by the eccentric cam 6, an inner gear 8 meshed with the planetary gear 7 and allowing the planetary gear 7 to revolve while self-rotating, a passive disc 9 and an output shaft 10 receiving self-rotating power of the planetary gear 7, and a casing 4 for storing these members. The casing 4 includes a base end case 16 arranged on an end in the input shaft 5 side, a case 17 also used as the inner gear 8, and a distal end case 18 arranged on an end in the output shaft 10 side. The end in the input shaft 5 side of the casing 4 is closed by a base wall 20 provided on the base end case 16.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a cycloid reduction gear having a planetary gear and an inner gear as reduction elements, and an electric device such as an electric razor, a beauty instrument, or a chair type massage machine equipped with a reduction gear.

  The present applicant has previously proposed a rotary electric shaver including a sun gear, a planetary gear, and a speed reduction mechanism using an internal gear as a speed reduction element (Patent Document 1). There, a sun gear is fixed to the output shaft of the motor, and the rotational power (8000 rpm) of the output shaft is decelerated between the sun gear, the planetary gear, and the internal gear, and then transmitted to the inner blade through the winding transmission structure. doing.

  The planetary gear type reduction mechanism as described above can provide a high reduction ratio, but the overall structure is complicated and expensive, and there is room for improvement in that the noise level when the gears mesh with each other increases. . The present inventor studied to apply a cycloid type speed reducer with the aim of simplifying the structure of the speed reduction mechanism to reduce the cost and further reducing the noise level in the speed reduction mechanism. This type of speed reducer is disclosed in Patent Document 2, for example. In the reduction gear described in Patent Document 2, a transmission chamber is defined by a casing lid fixed to the casing body and the casing body, and a cycloid reduction mechanism is provided therein. The cycloid reduction mechanism is fixed to an eccentric shaft formed integrally with an input shaft, an eccentric wheel that is rotatably fitted to the eccentric shaft, an inner gear that is rotatably supported by the eccentric wheel, and a casing lid. The outer gear is provided and a driven member that inherits the rotation of the inner gear, and the rotation of the driven member is output from the output shaft. The cycloid reduction gear is advantageous in reducing the noise level because the reduction ratio is much larger than that of the involute gear reduction gear of Patent Document 1 and the number of gear teeth engaged at the same time is large.

JP 2005-198966 A (see FIG. 1) JP 2009-150416 A (see FIG. 1)

  For example, when the cycloid reduction gear of Patent Document 2 is applied to an electric device such as an electric razor, theoretically, the overall structure of the speed reduction mechanism should be simplified to reduce the cost, and the noise level in the speed reduction mechanism should be reduced. However, it is difficult to miniaturize the cycloid reducer to the same extent as, for example, an electric razor motor. As the speed reduction mechanism is miniaturized, the ratio of machining and assembly errors to the standard dimensions of each part increases, and assembly accuracy equivalent to a relatively large cycloid speed reducer that transmits large power is obtained. This is extremely difficult.

  An object of the present invention is to provide a cycloid type speed reducer suitable for an electric device and an electric device equipped with the speed reducer, which can reduce the noise level in the speed reduction mechanism while realizing a reduction in the size of the speed reduction mechanism.

  The speed reducer according to the present invention includes an input shaft 5 that inherits the rotational power of the upstream device 3, an eccentric cam 6 that is fixed to the input shaft 5, a planetary gear 7 that is rotationally driven by the eccentric cam 6, and a planetary gear 7. Of the planetary gear 7, a passive disk 9 and an output shaft 10 that inherit the rotational power of the planetary gear 7, and a casing 4 that accommodates these members. In the speed reducer, the casing 4 includes a base end case 16 disposed at the end on the input shaft 5 side, a case 17 serving also as the inner gear 8, and a front end case 18 disposed at the end on the output shaft 10 side. And. An end of the casing 4 on the input shaft 5 side is closed by a base wall 20 provided in the base end case 16.

  In the speed reducer according to the present invention, the base wall 20 of the base end case 16 is formed with a mounting seat 24 and a connection hole 22 that supports the front-stage device 3 in cooperation with the mounting seat 24. The housing 13 of the front-stage apparatus 3 is formed with a joining wall 14 joined to the proximal end case 16 and a bearing portion 15 that supports one end of the output shaft 3a. The joint wall 14 is joined to the mounting seat 24 in a state where the bearing portion 15 is fitted and supported by the connecting hole 22.

  In the speed reducer according to the present invention, the thickness E1 of the base wall 20 of the base end case 16 is set to be equal to or greater than the thickness E2 of the bearing portion 15.

  An electric device according to the present invention includes the above-described speed reducer and a motor 3 that rotationally drives the input shaft 5 of the speed reducer.

  In the speed reducer of the present invention, the end of the casing 4 on the input shaft 5 side is closed by the base wall 20 provided in the base end case 16. According to the speed reducer 2, the end of the casing 4 on the input shaft 5 side is sealed with the base wall 20, and the meshing noise between the planetary gear 7 and the inner gear 8 can be prevented from leaking to the outside. 2 can be silenced.

  The front-stage device 3 and the casing 4 are connected in a state in which the joint wall 14 and the bearing portion 15 provided in the housing 13 are joined to the mounting seat 24 and the connection hole 22 provided in the base wall 20 of the base end case 16. I fixed it. In this way, when the pre-stage device 3 and the casing 4 are joined via a plurality of joining planes, the connection objects 3 and 4 are firmly connected in a state of being positioned in a plurality of directions, and each other enhances the structural strength of the connection partner. Since it can do, the front | former stage apparatus 3 and the casing 4 can be connected still more firmly. There is also an advantage that the transmission loss of the rotational power transmitted from the front stage device 3 to the speed reducer 2 can be reduced.

  Further, if the thickness E1 of the base wall 20 of the base end case 16 is set to be equal to or larger than the thickness E2 of the bearing portion 15, the internal space of the casing 4 is reduced by the amount that the base wall 20 is formed thicker. Therefore, it is possible to further effectively suppress the meshing noise from resonating in the casing 4 and further promote the noise reduction of the speed reducer 2.

  Moreover, according to the electric device provided with the reduction gear 2 and the motor 3 described above, the noise level can be reduced and the electric device can be made quieter than the electric device including the involute gear type reduction gear.

It is a longitudinal cross-sectional view of the reduction gear which concerns on Example 1 of this invention. It is a longitudinal view of the power unit comprised with the reduction gear and the motor. It is a disassembled perspective view of a power unit. It is the sectional view on the AA line in FIG. It is the BB sectional view taken on the line in FIG. It is a longitudinal cross-sectional view which shows the fixing structure of a casing. It is a longitudinal cross-sectional view of a base end case. It is a longitudinal cross-sectional view of a front-end | tip case. It is a longitudinal cross-sectional view of the reduction gear which concerns on Example 2 of this invention. It is a longitudinal cross-sectional view of the reduction gear which concerns on Example 3 of this invention. 6 is an exploded perspective view of a power unit according to Embodiment 3. FIG. 6 is a longitudinal sectional view showing a casing fixing structure according to Embodiment 3. FIG. It is CC sectional view taken on the line in FIG. It is the DD sectional view taken on the line in FIG. It is a longitudinal cross-sectional view of the reduction gear which concerns on Example 4 of this invention. It is E arrow line view in FIG. It is the FF sectional view taken on the line in FIG. It is a schematic front view of the electric shaver which shows the example of application of a power unit. It is a schematic front view of the stick-type electric shaver which shows another example of application of a power unit. It is a schematic front view of the beauty instrument which shows another example of application of a power unit.

(Embodiment 1) FIGS. 1 to 8 show Embodiment 1 in which a cycloid type speed reducer 2 according to the present invention is directly connected to a motor (previous device) 3 and configured as a power unit 1. Note that front and rear, left and right, and up and down in the present embodiment follow the cross arrows shown in FIGS. 2 and 3 and the front and rear, left and right, and top and bottom displays written in the vicinity of each arrow.

  As shown in FIG. 2, the cycloid reducer 2 has a casing 4 as a basic structure, an input shaft 5 that inherits the rotational power of the motor 3 therein, and an eccentric made of brass that is fixed to the input shaft 5. A cam 6, a planetary gear 7 that is rotationally driven by the eccentric cam 6, an inner gear 8 that meshes with the planetary gear 7 and revolves while rotating, and a passive disk 9 that inherits the rotational power of the planetary gear 7. The output shaft 10 is configured. In this embodiment, the output shaft 3a of the motor 3 is also used as the input shaft 5 of the speed reducer 2. However, the output shaft 3a and the input shaft 5 may be provided separately and connected by coupling.

  The motor 3 is a brushed DC motor that is frequently used as a drive source for electric devices such as an electric razor and a beauty instrument for massage. The output speed of the output shaft 3a when no load is applied is 13000 rpm, and the maximum torque is 19 mN. -M. The motor 3 includes a drum-shaped metal housing 13 having a flat joint wall (fixed wall) 14 that is tightly joined to the casing 4 of the speed reducer 2 at the upper end thereof. Further, a boss-like bearing portion 15 that supports the upper portion of the output shaft 3a is bulged.

  In FIG. 3, the casing 4 includes a base case 16 disposed at the end on the input shaft 5 side, an intermediate case (case) 17 that also serves as the inner gear 8, and a tip case disposed at the end on the output shaft 10 side. 18 is provided. The outer shapes of the base end case 16 and the case 17 and the front end case 18 are each formed in a drum shape having the same size as the housing 13.

  The base case 16 is made of a molded product made of polyamide resin mixed with glass powder (filler), and includes a drum-shaped base wall 20 and a circumferential wall 21 projecting in a circumferential manner on the peripheral edge of the wall 20. In preparation. In the center of the base wall 20 surrounded by the circumferential wall 21, a connecting hole 22 for fitting and supporting the previous bearing portion 15 is formed, and screw insertion holes 23 are formed on the left and right thereof. The lower surface of the base wall 20 is a flat mounting seat 24 for tightly joining the motor 3. The positioning wall 21 is formed with four positioning holes 25 and two fastening holes 26 along the opposing arc edges.

  As shown in FIG. 2, two screws (screw shafts) 27 inserted through the screw insertion holes 23 in a state where the bearing portion 15 is fitted into the connection hole 22 and the joining wall 14 is tightly joined to the mounting seat 24. Is screwed into the screw hole 28 of the housing 13, whereby the proximal case 16 is integrated with the motor 3. In this way, when the motor 3 and the casing 4 are tightly joined through a plurality of joining planes, the connection objects 3 and 4 are firmly connected in a plurality of orientations, and the structural strength of each other is increased. As a result, the motor 3 and the casing 4 can be more firmly connected. There is also an advantage that the transmission loss of the rotational power transmitted from the motor 3 to the speed reducer 2 can be reduced.

  The case 17 is a flat precision press-molded product made of a stainless steel plate (metal material), and the inner gear 8 is constituted by a group of corrugated gear teeth 29 formed on the inner surface thereof. Four positioning holes 30 and two fastening holes 31 are formed along the arc edge of the case 17, and a positioning shaft 32 made of metal such as stainless steel is attached to each of the positioning holes 30. It is press-fitted and fixed prior to work. The number of teeth of the gear teeth 29 is one more than the number of teeth of the gear teeth 49 of the planetary gear 7 described later, and the number of teeth is 18. If the positioning shaft 32 is formed of a metal material as described above, the shaft strength can be increased and it is not necessary to consider aging deterioration as compared with the case where the coaxial shaft 32 is formed of a plastic material. It is preferable in that the durability of the casing 4 can be improved.

  As described above, when the case 17 that also serves as the inner gear 8 is formed of a metal material, the inner gear 8 can be formed more accurately than when the case 17 is formed of a plastic material. This is because when the case 17 is formed of a plastic material, shrinkage distortion during molding cannot be avoided, and there is a limit in increasing the shape and dimensional accuracy of the inner gear 8. On the other hand, when the case 17 is formed of a metal material, the inner gear 8 can be formed more precisely by machining the metal material, so that the shape and dimensional accuracy of the gear 8 can be reliably improved. The productivity of the case 17 can be improved by suppressing the occurrence frequency of defective products.

  The tip case 18 is a molded product made of polyacetal resin that integrally includes a boss portion 35 and an end wall 36 that surround the output shaft 10, and a peripheral wall 37 that protrudes in a peripheral manner from the peripheral edge of the end wall 36. The shaft hole 38 for the output shaft 10 is opened at the center of the boss portion 35. The circumferential wall 37 is formed with four positioning holes 39, two fastening holes 40, and fastening seats 41 (see FIG. 6) along the opposing arc edges.

  As shown in FIG. 3, a circular drive cam surface 44 is formed around the machined eccentric cam 6, and a mounting hole 45 is press-fitted and fixed to the input shaft 5 near the center of the eccentric cam 6. Is formed. The center of the drive cam surface 44 is eccentric with respect to the center of the mounting hole 45. A ball bearing (bearing body) 46 is mounted on the drive cam surface 44, and a planetary gear 7 described below is rotatably supported by the ball bearing 46. Further, the planetary gear 7 is positioned in the axial direction via the ball bearing 46 with the eccentric cam 6 in a state where the inner ring of the ball bearing 46 is fitted with the drive cam surface 44 and the outer ring is fitted with the passive cam surface 48. Thus, the planetary gear 7 is opposed to the base wall 20 and the passive disk 9 adjacent to the gear 7 through a gap.

  As described above, when the planetary gear 7 is rotatably supported by the bearing body 46 disposed between the eccentric cam 6 and the planetary gear 7, the relative movement between the eccentric cam 6 and the planetary gear 7 is absorbed by the bearing body 46. The rotational operation of the eccentric cam 6 can be smoothly transmitted to the planetary gear 7. Therefore, the transmission load of the rotational power between the eccentric cam 6 and the planetary gear 7 can be reduced, and the power transmission efficiency can be improved. Incidentally, when the planetary gear 7 is directly supported by the eccentric cam 6, a large frictional force is generated in the fitting portion between the two 6 and 7 due to the relative movement. Therefore, between the eccentric cam 6 and the planetary gear 7. It is inevitable that power loss will occur. Further, the planetary gear 7 is positioned in the axial direction via the bearing body 46 by the eccentric cam 6 so that the planetary gear 7 faces the adjacent base wall 20 and the passive disk 9 via a gap, so that the output When the shaft 10 is subjected to a strong load, the passive disk 9 is strongly brought into contact with the planetary gear 7 or the planetary gear 7 is strongly brought into contact with the base wall 20 to reliably eliminate the load on the speed reducer 2. Can be prevented from increasing.

  The planetary gear 7 is formed of a circular gear-shaped molded product made of polyamide resin. A passive cam surface 48 that is rotatably supported by the ball bearing 46 is formed at the center of the planetary gear 7, and a group of around the passive cam surface 48. Corrugated gear teeth 49 are formed to project outward in the radial direction. Further, a drive shaft 50 composed of eight round shafts is provided at regular intervals on the upper surface of the planetary gear 7, and a flange wall 51 is provided on the lower surface of the planetary gear 7 (tooth end surface on the input shaft 5 side). The gear teeth 49 are integrally formed with the gear teeth 49 in the same direction as the extension direction of the gear teeth 49 to block the lower surface side of the gear teeth 49. That is, the flange wall 51 is formed on the side surface of the planetary gear 7 so as to protrude in the same direction as the protruding direction of the gear teeth 49 of the planetary gear 7. Further, since the flange wall 51 is formed integrally with the gear teeth 49 so as to fill the gap between the teeth on the tooth end surfaces of the gear teeth 49, the strength of the gear teeth 49 can be increased. As the gear teeth 49 of the planetary gear 7 mesh with the gear teeth 29 of the inner gear 8 and revolve at a high speed while revolving at a low speed, the drive speed of the input shaft 5 can be reduced to 1/18.

  The passive disk 9 is made of a disk-shaped molded product made of polyacetal resin, and a stainless steel output shaft 10 is fixed at the center thereof. On the plate surface of the passive disk 9, eight passive holes 54 are formed at equal intervals corresponding to the previous drive shaft 50. The diameter of the passive hole 54 is set larger than the diameter of the drive shaft 50, and one place on the peripheral surface of the drive shaft 50 is always in contact with the inner surface of the passive hole 54. The rotational position of the planetary gear 7 is transmitted to the passive disk 9 by gradually shifting the contact position. The output shaft 10 is rotatably supported by a ball bearing (bearing body) 55 that is press-fitted to the boss portion 35 of the tip case 18. In addition, the passive disk 9 and the output shaft 10 are inserted through the ball bearing 55 in a state where the inner ring of the ball bearing 55 is fitted to the output shaft 10 and the outer ring is fitted to the bearing hole provided in the boss portion 36. The case 18 is positioned in the axial direction. Thereby, the passive disk 9 is directly opposed to the end wall 36 and the planetary gear 7 adjacent to the disk 9 through a gap.

  As described above, when the output shaft 10 is rotatably supported by the ball bearing 55 disposed between the tip case 18 and the output shaft 10, the frictional resistance between the tip case 18 and the output shaft 10 is reduced, and the planetary gear 7 can smoothly output the rotational power of the passive disk 9 inherited from the output shaft 10 without any power loss. Further, since the output shaft 10 is positioned in the axial direction via the ball bearing 55 by the tip case 18 so that the passive disk 9 faces the end wall 36 and the planetary gear 7 through a gap, the output shaft 10 When a strong load is applied, the passive disk 9 strongly contacts the end wall 36, or the passive disk 9 strongly contacts the planetary gear 7 is reliably eliminated, and the load of the speed reducer 2 increases. Can be prevented.

  The speed reducer 2 is assembled to the motor 3 by the following procedure, for example. First, the base end case 16 is assembled to the housing 13 as described above, and the eccentric cam 6, the ball bearing 46, and the planetary gear 7 that have been temporarily assembled are accommodated inside the base end case 16. The mounting hole 45 of the eccentric cam 6 is press-fitted and fixed to the input shaft 5. Next, while the inner gear 8 is engaged with the planetary gear 7, the positioning shaft 32 fixed to the case 17 is press-fitted into the positioning hole 25 of the base end case 16, and the inner gear 8 is assembled to the planetary gear 7. Further, in a state where the passive hole 54 of the passive disk 9 is engaged with the drive shaft 50 of the planetary gear 7, the positioning hole 39 of the tip case 18 is press-fitted to the positioning shaft 32, and at the same time, the ball temporarily assembled to the tip case 18. The bearing 55 is assembled to the output shaft 10. Finally, as shown in FIG. 6, screws (fastening shafts) 57 are inserted into the fastening holes 40 and 31 provided in the distal end case 18 and the case 17, and the screw shafts are screwed into the fastening holes 26 of the proximal end case 16. The speed reducer 2 can be integrated with the motor 3. Thus, in a state where the screw 57 is fastened to the base end case 16, a slight gap is formed between the screw shaft of the screw 57 and the fastening holes 40 and 31 of the tip case 18 and the case 17. Therefore, it is possible to prevent the positioning accuracy of the cases 16, 17, and 18 positioned by the positioning shaft 32 from being disturbed by fastening and fixing the screws 57. The screws 57 are provided only for fixing the cases 16, 17, and 18 in the axial direction of the casing 4, and the functions of the cases 16, 17, and 18 are divided so as to be performed only by the positioning shaft 32. Thus, the casing 4 can be assembled with high accuracy.

  As described above, when the casing 4 is configured by the three cases 16, 17, 18, the speed reducer 2 can be completed by assembling the cases 16, 17, 18 and the internal parts 6 to 10 in order. Compared with the case where the main part is formed in the shape of a hollow case, each part can be assembled accurately while confirming the operation status of the part being assembled. When the case 17 and the positioning shaft 32 formed of a metal material are used as a positioning reference, the meshing state of the inner gear 8 and the planetary gear 7 and the rotation state of the gear 7 are changed in the process of assembling the case 17 to the base case 16. Appropriateness can be confirmed. Therefore, it is possible to eliminate the troubles required for disassembling or reassembling the reduction gear 2 by finding a meshing failure between the two gears 7 and 8 at the initial stage of the assembly of the reduction gear 2.

  As described above, when the parts are assembled, the case 17, 17 and 18 can be positioned by the positioning shaft 32 with the positioning shaft 32 fixed to the case 17 and the case 17 formed of a stainless steel plate as a positioning reference. I did it. According to such a speed reducer 2, it is possible to eliminate the accumulation of errors as compared with the case 16, 17 and 18 that are positioned by engaging the concave and convex portions on the respective joint surfaces as will be described later. The assembly accuracy of the parts 5 to 10 accommodated in the casing 4 can be improved while realizing a reduction in the size of the speed reducer 2. Further, since the base case 16 and the tip case 18 are made of plastic molded products, even if there is a slight variation in the processing accuracy of the cases 16, 17, 18 and the positioning accuracy of the positioning holes 25, 30, 39, The previous variation can be absorbed by the deformation of the positioning holes 25 and 39. Therefore, the base end case 16 and the front end case 18 can be accurately assembled to the positioning shaft 32.

  Incidentally, when each case 16, 17, 18 is formed of a metal material, it is difficult to assemble each case 16, 17, 18 with only slight variations in processing accuracy and position accuracy, or positioning shafts. 32 may be plastically deformed so that the positioning function cannot be exhibited. In addition, when the base end case 16 and the case 17 or the case 17 and the front end case 18 are positioned by engaging the concave and convex portions at the respective joint surfaces, errors are likely to accumulate. Large variations in position accuracy may occur.

  As shown in FIG. 1, in the state where the speed reducer 2 is assembled, the end of the casing 4 on the input shaft 5 side is closed and sealed by the base wall 20 of the base end case 16. Further, the surrounding wall 21 cooperates with the base wall 20 to prevent the meshing noise from leaking outside. Therefore, the reduction noise can be reduced by preventing the meshing noise between the gear teeth 29 and 49 of the planetary gear 7 and the inner gear 8 from leaking to the outside. Dust does not enter the casing 4 and get caught in the previous meshing portion. Further, since the volume of the internal space surrounded by the casing 4 can be reduced by the amount of the base wall 20 provided, it is possible to suppress the meshing noise from resonating in the internal space of the casing 4. Further, when the thickness E1 of the base wall 20 of the base end case 16 is set to be the same as the thickness E2 of the bearing portion 15, the volume of the internal space surrounded by the casing 4 is further reduced, and the gear teeth 29. 49. It can suppress effectively that the meshing noise which arises between 49 resonates in the internal space of the casing 4. FIG.

  Since the lower surface side of the gear teeth 49 of the planetary gear 7 is closed by the flange wall 51, the engagement between the planetary gear 7 and the inner gear 8 and the base wall 20 of the base case 16 is divided by the flange wall 51. It has become a bottleneck, and the conduction path of meshing noise is complicated. That is, by making the gap between the meshing part of the planetary gear 7 and the inner gear 8 and the space S1 below the meshing part of both the gears 7 and 8 with the flange wall 51, the conduction path of the meshing noise is complicated, The noise level in the space S1 below the meshing part of both gears 7 and 8 is reduced. A similar noise countermeasure is taken on the tip case 18 side. Specifically, the meshing portion of the planetary gear 7 and the inner gear 8 and the tip case 18 are divided by the peripheral wall 53 of the passive disk 9 to form a bottleneck, and the conduction path of the meshing noise is complicated. In other words, the gap between the meshing part of the planetary gear 7 and the inner gear 8 and the space S2 above the meshing part of both the gears 7 and 8 is narrowed by the peripheral wall 53 of the passive disk 9, and the conduction path of the meshing noise is complicated. The noise level in the space S2 above the meshing portion of both gears 7 and 8 is reduced.

  The planetary gear 7 and the inner gear 8 mesh with each other only at the left meshing portion of both gears 7 and 8 as viewed in FIG. 1, and the flange wall 51 is located below the valley portion 99 of the gear teeth 29 of the inner gear 8. Covered. In this state, the radial dimension from the center of the input shaft 5 to the peripheral surface of the flange wall 51 may be set to be the same as the radial distance from the center of the input shaft 5 to the valley portion 99 of the gear teeth 29. More preferably, it is greater than the radial distance from the center of the input shaft 5 to the valley portion 99 of the gear tooth 29. In any case, the flange wall 51 can surely form a narrow path between the meshing part of both the gears 7 and 8 and the space S1 below the meshing part, and the conduction path of the meshing noise can be complicated. The noise level in the space S <b> 1 can be reliably reduced, and the noise reduction of the casing 4 can be promoted. The radial dimension to the peripheral surface of the flange wall 51 does not need to be set to be the same as the radial distance from the center of the input shaft 5 to the valley portion 99 of the gear tooth 29, and the peripheral surface of the flange wall 51 is the same for both gears. It may be configured to cover up to an intermediate position (near the pitch circle) of the valley portion 99 of the gear tooth 29 at the meshing portion of 7 · 8. Similarly, the radial dimension from the center of the output shaft 10 to the peripheral wall 53 of the passive disk 9 is set to be equal to or larger than the radial distance from the center of the input shaft 5 to the valley portion 99 of the gear tooth 29. Preferably, the peripheral wall 53 of the passive disk 9 may be configured to cover up to an intermediate position (near the pitch circle) of the valley portion 99 of the gear tooth 29 at the meshing portion of both the gears 7 and 8.

  In the present embodiment, in addition to the above-described noise countermeasures, the following noise countermeasures are taken to further reduce the noise level of the speed reducer 2 so as to reduce noise. As shown in FIG. 7, a proximal-side attenuation wall 60 composed of a group of uneven bodies 59 that reflect meshing noise is provided on the inner surface of the proximal case 16 (the inner surfaces of the base wall 20 and the rotating wall 21). Further, as shown in FIG. 8, on the inner surface (the inner surface of the boss portion 35, the end wall 36, and the rotating wall 37) of the tip case 18, a tip-side attenuation wall 62 configured by a group of concavo-convex bodies 61 that reflect meshing noises Provided. The concavo-convex bodies 59 and 61 are formed in a quadrangular pyramid shape, and the meshing noises reflected by the inclined peripheral surface can interfere with each other, so that the noise level can be effectively reduced and the speed reducer 2 can be silenced. Further, in addition to or instead of each of the attenuation walls 60 and 62, a sound insulating sheet can be attached to the inner surface of the base end case 16 and / or the inner surface of the front end case 18. The sound insulating sheet is composed of any one of a closed cell type sheet made of synthetic rubber, an open cell sheet made of synthetic rubber, a sound absorbing sheet made of urethane or the like, or each type. The sheets can be laminated by arbitrarily combining the different sheets. For example, a sound insulating sheet having a three-layer structure in which a closed cell sheet, an open cell sheet, and a fibrous sound absorbing sheet are combined is preferable. As a result, the noise level from the casing 4 can be greatly reduced to contribute to the noise reduction of the speed reducer 2. Further, the sound insulating sheet is provided on one of the base end case 16, the case 17, and the front end case 18 constituting the casing 4, or attached to the outer surface of all the cases to reduce the noise level from the casing 4. Can be made. At this time, it is possible to further reduce the noise level by configuring the casing 4 and another case body having a diameter larger than that of the casing 4 so as to sandwich the sound insulating sheet.

  According to the speed reducer 2 having the above-described configuration, the case 16 formed of a stainless steel plate is used as a positioning reference, and the cases 16, 17, and 18 are positioned with respect to each other by the positioning shaft 32. Assembling accuracy can be improved. Further, leakage of meshing noise from the base end case 16 and the front end case 18 facing the internal space of the casing 4 is prevented as much as possible, and the flange wall 51 of the planetary gear 7 and the peripheral wall of the passive disk 9 are used. The internal space is divided in a complicated manner, and the attenuation walls 60 and 62 are provided on the inner surfaces of the base end case 16 and the front end case 18, respectively. Furthermore, the base end case 16 is fastened to the joining wall 14 of the motor 3 with screws 27, and the base end case 16, the case 17, and the front end case 18 are fastened with screws 57 screwed into the base end case 16, and then the casing. 4 is prepared, a commercially available motor can be used as it is by preparing the base end case 16 corresponding to the structure of the motor 3. Therefore, the reduction gear 2 can be reduced in cost compared to the case where the custom motor 3 is used. In addition, since the screw shaft end of the fastening shaft 57 is fastened to the base end case 16 having no room for movement, the adjacent shafts 16, 17 and 18 are securely fixed by the fastening shaft 57 while being positioned accurately. Thus, the structural strength of the casing 4 can be improved.

  In the reduction gear 2 of the first embodiment, the planetary gear 7 is rotatably supported by the bearing body 46 disposed between the eccentric cam 6 and the planetary gear 7. According to such a speed reduction mechanism, the rotational movement of the eccentric cam 6 can be smoothly transmitted to the planetary gear 7 while absorbing the relative movement between the eccentric cam 6 and the planetary gear 7 by the bearing body 46. Therefore, the transmission load of the rotational power between the eccentric cam 6 and the planetary gear 7 can be reduced, and the power transmission efficiency can be improved. Further, since the output shaft 10 is rotatably supported by the bearing body 55 disposed between the tip case 18 and the output shaft 10, the frictional resistance between the tip case 18 and the output shaft 10 is reduced, and the planetary gear 7. The inherited rotational power of the passive disk 9 can be smoothly output from the output shaft 10 without any power loss.

(Example 2) FIG. 9: has shown the reduction gear 2 which concerns on Example 2 of this invention which changed a part of the reduction gear 2 which concerns on Example 1. FIG. In this case, the base case 16 is omitted, and a peripheral wall 64 is provided in a circular shape on the lower surface side of the case 17 so that the tip case 18 and the case 17 are screwed into the screw holes 28 of the housing 13 of the motor 3. The casing 4 was integrated with the motor 3 by fastening with 57. Further, a positioning shaft 32 for positioning the tip case 18 and the case 17 is fixed to a positioning hole (not shown) provided in the joining wall 14 of the housing 13, and the housing 3 (fixing wall of the preceding apparatus) 13 of the motor 3 is fixed. The casing 4 was assembled based on the positioning reference. The case 17 provided with the rotating wall 64 is made of a stainless steel material by a lost wax method.

  The reduction gear 2 described above uses a custom motor 3 in which a positioning hole is formed in the housing 13, but the structure of the reduction gear 2 is simplified and the cost is reduced to the extent that the base case 16 can be omitted. it can. Further, by fastening the shaft end of the fastening shaft 57 to the joint wall (fixed wall) 14 having no room for movement, the adjacent cases 17 and 18 are accurately fixed by the fastening shaft 57 while being positioned accurately. Therefore, the structural strength of the casing 4 can be improved. Since others are the same as the reduction gear 2 of Example 1, the same code | symbol is attached | subjected to the same member and the description is abbreviate | omitted. The same applies to the following embodiments. Even when the casing 4 is composed of the base end case 16, the case 17, and the front end case 18, the cases 16, 17, and 18 are fastened with screws 57 that are screwed into the screw holes 28 of the housing 13 in the same manner as described above. The positioning shaft 32 that fixes and positions the cases 16, 17, and 18 may be fixed to the positioning holes of the housing 13.

(Embodiment 3) FIGS. 10 to 14 show a reduction gear 2 according to Embodiment 3 of the present invention. In the present embodiment, the structure of the casing 4 is changed, the rattling of the planetary gear 7 and the passive disk 9 in the direction of the rotation center axis, the rotational power of the planetary gear 7 is controlled by the pair of drive shafts 50 and The point of transmission to the passive disk 9 through the passive hole 54 is different from the previous embodiments.

  Regarding the structural change of the casing 4, of the cases 16, 17, and 18 constituting the casing 4, the base end case 16 is constituted by a flat press-molded product made of a stainless steel plate (metal material), and a screw 27 The housing 13 is fastened and fixed. The connecting hole 22, the screw insertion hole 23, and the positioning hole 25 were formed by machining. The case 17 and the tip case 18 are each formed of a molded product made of polyamide resin, and the positioning shaft 32 fixed to the base case 16 prior to the assembly operation of the casing 4 with the base case 16 as a positioning reference. Thus, both cases 17 and 18 are positioned. The thickness E1 of the base wall 20 of the base end case 16 is set to be larger than the thickness E2 of the bearing portion 15 to further reduce the volume of the internal space surrounded by the casing 4 so that the meshing noise is generated in the internal space of the casing 4. The resonance can be effectively suppressed. The circulating wall 21 is omitted. A circumferential wall 64 is provided on the lower surface side of the case 17 so as to project around. The tip case 18 is formed in a dish shape with the end wall 36 and the rotating wall 37 without the boss portion 35. The output shaft 10 was supported by a plain bearing (bearing body) 55 fixed at the center of the end wall 36. The drive cam surface 44 of the eccentric cam 6 is fitted into the passive cam surface 48 of the planetary gear 7 and the ball bearing 46 is omitted.

  When the base end case 16 is formed of a metal material as described above, the case 17 and the planetary gear 7 can be formed of a resin material. Therefore, the meshing noise generated at the meshing portion of the planetary gear 7 and the inner gear 8 can be reduced, and the speed reducer 2 can be silenced. Further, since the base end case 16 made of a metal material and the positioning shaft 32 fixed to the case 16 serve as a positioning reference, the inner gear 8 and the planetary gear 7 are engaged with each other in the process of assembling the case 17 to the positioning shaft 32. In addition, it is possible to confirm whether the rotation state of the gear 7 is appropriate. Accordingly, as in the case where the case 17 is formed of a metal material, the meshing failure of both the gears 7 and 8 is discovered in the early stage of the assembling process of the speed reducer 2, and the speed reducer 2 is disassembled and reassembled. Can be saved.

  Regarding the regulation of the rattling of the planetary gear 7 and the passive disk 9, a flange-like regulation wall 68 facing the base wall 20 of the base end case 16 is formed on the inside of the inner surface of the case 17 so as to be regulated. The opposite end face of the planetary gear 7 is sandwiched between the wall 68 and the base wall 20 to regulate the rattling of the planetary gear 7 in the direction of the rotation center axis. Further, in order to reduce the contact friction between the base wall 20 and the regulating wall 68 and the planetary gear 7, ring-shaped protruding ribs 69 are bulged and formed on the upper end surface and the lower end surface of the planetary gear 7. A through hole 70 for the drive shaft 50 is formed in the center of the regulation wall 68. According to the speed reducer 2, when the planetary gear 7 rotates while revolving, it is possible to eliminate rattling along the rotation center axis, so that transmission of rotational power between the eccentric cam 6 and the planetary gear 7 can be efficiently performed. . There is also an advantage that the planetary gear 7 that revolves at a high speed rattles and can eliminate the occurrence of an annoying collision sound.

  Further, a passive ring 71 having a passive hole 54 is disposed on the lower surface of the passive disk 9, and both of these 9 and 71 are fixed by four connecting pins 72 so as to be able to rotate together. In addition, the upper surface of the passive disk 9 and the lower surface of the passive ring 71 are sandwiched between the restriction wall 68 and the end wall 36 of the tip case 18 facing the wall 68 in the direction of the rotation center axis of the passive disk 9. Regulated no rattling. Further, in order to reduce the contact friction between the end wall 36 and the regulating wall 68 and the passive disk 9, a thrust washer 73 is disposed between the upper surface of the passive disk 9 and the end wall 36. A protruding rib 74 having a shape was bulged. As described above, by restricting the backlash of the planetary gear 7 and the passive disk 9 in the direction of the rotation center axis, the transmission efficiency when the rotation power of the planetary gear 7 is transmitted to the passive ring 71 is improved. Power loss between the input shaft 5 and the output shaft 10 can be reduced. According to the speed reducer 2, the rotational power inherited from the planetary gear 7 can be smoothly output from the output shaft 10 through the passive disk 9 and the output shaft 10 without backlash.

  In order to transmit the rotational power of the planetary gear 7 to the passive disk 9, one cylindrical shaft-shaped drive shaft 50 projects from the center of the planetary gear 7 and engages with the drive shaft 50 on the inner surface of the passive ring 71. One passive hole 54 was provided. An air vent hole 75 is provided at the upper end of the drive shaft 50. Similarly to the first embodiment, the diameter of the passive hole 54 is formed to be larger than the diameter dimension of the drive shaft 50, and one place on the peripheral surface of the drive shaft 50 during power transmission contacts the inner surface of the passive hole 54. The passive ring 71 is rotated together with the planetary gear 7. 10 and 14, reference numeral P <b> 1 is the axis center of the input shaft 5 and the output shaft 10, and P <b> 2 is the hole center of the passive hole 54. As described above, when the rotational power of the planetary gear 7 is transmitted to the passive disk 9 through the pair of drive shafts 50 and the passive holes 54, the rotational power is transmitted to the passive disk 9 through the multiple drive shafts 50 and the passive holes 54. As compared with the above, the transmission noise (sliding contact sound) between the drive shaft 50 and the passive hole 54 can be reduced, and the speed reducer 2 can be silenced. Further, since the drive shaft 50 and the passive hole 54 are in contact with each other at one place to transmit the power, the rotational power can be efficiently transmitted to the passive disk 9 in a state where it is hardly affected by the processing accuracy.

(Embodiment 4) FIGS. 15 to 17 show a reduction gear 2 according to Embodiment 4 of the present invention. In the present embodiment, the planetary gear 7 is changed to the structure described below so that the noise of the casing 4 can be reduced more effectively. In this case, as shown in FIG. 15, the planetary gear 7 is constituted by a gear main body 95 and a flange wall 96 fixed to a surface (upper surface) of the gear main body 95 facing the passive disk 9. On the tooth end surface (lower surface) of the gear main body 95 on the input shaft 5 side, a flange wall 51 equivalent to that of the first embodiment projects. The flange wall 96 on the upper surface side is formed in a ring shape as shown in FIG. 16, and fastening seats 97 are provided at equal intervals at four locations on the inner edge. The flange wall 96 is assembled to the gear main body 95 with the planetary gear 7 assembled to the inner gear 8, and a screw 98 inserted through the fastening seat 97 is screwed into the gear main body 95, whereby the gear main body 95. And integrated. The forming material of the flange wall 96 may be either a plastic material or a metal material. In particular, when the flange wall 96 is formed of a metal material, the reinforcing action of the flange wall 96 allows the planetary gear 7 to be formed. The overall structural strength can be increased. The lower flange wall 51 may be formed of independent parts like the upper flange wall 96 and fastened and fixed to the gear body 95, or may be formed of a metal material.

  The planetary gear 7 and the inner gear 8 mesh with each other only at the meshing portion on the left side of both gears 7 and 8 as shown in FIG. 17, and the flange walls 61 and 96 are below the valley portions 99a of the gear teeth 29 of the inner gear 8. And covers the top. In this state, the radial dimension from the center of the input shaft 5 to the peripheral surfaces of the flange walls 51 and 96 is the relationship between the flange walls 51 and 96 and the inner gear 8. It can be said that it is set larger than the radial distance to the bottom of the valley portion 99 of the tooth 29. In terms of the relationship between the flange walls 51 and 96 and the planetary gear 7, it can be said that the previous radial dimension is set larger than the radial distance from the center of the input shaft 5 to the top of the peak portion 100 of the gear tooth 49. . The flange wall 51 described in the first embodiment is similarly set.

  As described above, if the peripheral edges of the flange walls 61 and 96 are overlapped with each other over the bottom of the trough portion 99 of the gear teeth 29 or the top of the crest portion 100 of the gear teeth 49, both gears 7 The meshing noise generated at the meshing portion 8 can be blocked by the upper and lower flange walls 61 and 96. In FIG. 17, the overlap amount between the peripheral edges of the flange walls 61 and 96 and the valley portions 99 of the gear teeth 29 is indicated by the symbol H. In this embodiment, the upper and lower surfaces of the five sets of gear teeth 29 and 49 facing the meshing portion are covered with the upper and lower flange walls 61 and 96. According to the speed reducer 2, the flange walls 51 and 96 can reliably provide a narrow path between the meshing portion of the planetary gear 7 and the inner gear 8, the space S <b> 1 below the meshing portion, and the space S <b> 2 above the meshing portion. Thus, the conduction path of the meshing noise can be complicated, the noise level in the upper and lower spaces S1 and S2 facing the meshing part can be reliably reduced, and the noise reduction of the casing 4 can be promoted. In the fourth embodiment, the upper and lower surfaces of the five sets of gear teeth 29 and 49 facing the meshing portion are covered with the flange walls 61 and 96, but this is not necessary, and at least one set of the upper and lower surfaces of the gear teeth 29 and 49 is provided. May be covered with the flange walls 61 and 96.

The speed reducer 2 described in the fourth embodiment can be implemented in the following manner.
The speed reducer 2 meshes with the input shaft 5 that inherits the rotational power of the upstream device 3, the eccentric cam 6 that is fixed to the input shaft 5, the planetary gear 7 that is rotationally driven by the eccentric cam 6, and the planetary gear 7. A cycloid speed reducer comprising an inner gear 8 that revolves while rotating the gear 7, a passive disk 9 and an output shaft 10 that inherit the rotational power of the planetary gear 7, and a casing 4 that accommodates these members. It is. The planetary gear 7 is characterized in that a flange wall 51 is formed so as to face the meshing surface of the gear tooth 49 of the planetary gear 7.

A flange wall 51 is formed to protrude from at least one tooth end surface of the gear teeth 49 of the planetary gear 7.
The peripheral edge of the flange wall 51 is projected radially outward from the top of the crest portion 100 of the gear tooth 49 of the planetary gear 7.
The peripheral edge of the flange wall 51 is protruded radially outward from the bottom of the valley portion 99 of the gear tooth 29 of the inner gear 8.

  As described above, when the flange wall 51 protrudes from the gear teeth 49 of the planetary gear 7 so as to face the meshing surface, the meshing portion of the planetary gear 7 and the inner gear 8 can be blocked by the flange wall 51. Along with this, a gap between the meshing portion of both gears 7 and 8 and the space S1 (or space S2) facing the meshing portion becomes a bottleneck at the flange wall 51, so that the meshing portion of both gears 7 and 8 and the previous space S1. The conduction path of the meshing noise between (or the space S2) can be complicated. Accordingly, the noise level of the meshing noise in the previous space S1 (or space S2) is reduced and the silencer of the speed reducer 2 is compared with the configuration in which the previous meshing portion faces the previous space S1 (or space S2). Can contribute to

  The power unit 1 described in the first to fourth embodiments can be used as a drive source for the electrical equipment shown in FIGS. FIG. 18 shows a rotary electric razor (electrical device). The power unit 1 is placed horizontally with the central axis of the motor 3 parallel to the center of rotation of the inner blade 81, and a winding transmission mechanism 82 is interposed therebetween. Thus, the deceleration power is transmitted to the inner blade 81. The winding transmission mechanism 82 includes a driving pulley 83 fixed to the output shaft 10, a driven pulley 84 fixed to the inner blade shaft, a timing belt 85 wound around these pulleys 83 and 84, and the like. In FIG. 18, reference numeral 86 is an outer blade, reference numeral 87 is a secondary battery, and reference numeral 88 is a power switch.

  FIG. 19 shows a stick-type electric shaver (electric device) in which an outer blade 86 is formed in a cylindrical shape. There, the power unit 1 is placed vertically with the central axis of the motor 3 positioned on the extension of the rotation center of the inner blade 81, and the output shaft 10 and the inner blade shaft of the speed reducer 2 are connected via the coupling 90. Connected. In FIG. 16, reference numeral 87 is a secondary battery, and reference numeral 88 is a power switch.

  FIG. 20 shows a beauty instrument (electrical device) for skin massage. The brush body 91 is rotationally driven by the decelerating power of the speed reducer 2 to foam the face washing liquid, and cleans and massages the facial skin. In this case, the power unit 1 is arranged vertically, and the output shaft 10 of the speed reducer 2 and the brush body 91 are connected by a coupling 90. The brush body 91 is configured by fixing the lower end of the brush bundle 93 with a ring-shaped brush base 94. At the time of use, the face-washing liquid is attached to the tip, pouring warm water in an appropriate amount in a foaming container (not shown), the cosmetic device is in a lying position, and the brush bundle 93 is rotated and driven while being immersed in hot water. The liquid can be bubbled.

  The speed reducer described in each embodiment can be implemented in the following form.

The present invention is engaged with the input shaft 5 that inherits the rotational power of the front stage device 3, the eccentric cam 6 that is fixed to the input shaft 5, the planetary gear 7 that is rotationally driven by the eccentric cam 6, and the planetary gear 7. A cycloid speed reducer comprising an inner gear 8 that revolves while rotating the gear 7, a passive disk 9 and an output shaft 10 that inherit the rotational power of the planetary gear 7, and a casing 4 that houses these members. set to target. The casing 4 includes a base case 16 disposed at the end on the input shaft 5 side, a case 17 serving also as the inner gear 8, and a tip case 18 disposed at the end on the output shaft 10 side. The base case 16, the case 17, and the tip case 18 are positioned by a positioning shaft 32 that simultaneously penetrates a plurality of locations around each case 16, 17, 18 with any one of the cases 16, 17, 18 as a positioning reference. It is fixed.
According to the speed reducer 2 configured as described above, it is possible to eliminate the accumulation of errors as compared to the case 16, 17, 18 that is positioned by engaging the concave and convex portions on the respective joint surfaces. Therefore, the assembly accuracy of the parts 5 to 10 accommodated in the casing 4 can be improved while realizing a reduction in the size of the speed reducer 2.

The distal end case 18 and the shaft end of the fastening shaft 57 inserted through the case 17 are fastened to the base end case 16 or the fixed wall 14 of the upstream device 3 that is in close contact with the base end case 16, and each case 16, 17, 18 is secured. Was fastened and fixed inseparably.
As described above, when the shaft end of the fastening shaft 57 is fastened to the base end case 16 or the fixed wall 14 having no room for movement, the adjacent cases 16, 17, and 18 are fastened while being accurately positioned. Since the shaft 57 can be securely fixed, the structural strength of the casing 4 can be improved.

A mounting seat 24 for tightly joining the upstream device 3 to the proximal case 16 is provided. The mounting seat 24 is formed on the basis of the shape and structure of the front stage device 3, and the base case 16 also serves as a connection adapter for fixing the front stage device 3. The proximal end of the positioning shaft 32 is engaged and fixed to the proximal end case 16.
According to the speed reducer 2, by preparing the base end case 16 having the mounting seat 24 corresponding to the shape and structure of the front stage device 3, the cost of the front stage device 3 is higher than that of the base end case 16. The front-stage apparatus 3 and the base end case 16 can be connected without changing the shape or structure of the side. For example, when the pre-stage device 3 is a motor, a commercially available motor can be directly connected to the base end case 16 serving as a connection adapter. Therefore, the reduction gear 2 can be reduced in cost as compared with the case where the attachment structure for the proximal case 16 and the engagement structure for the positioning shaft 32 are provided on the motor side, that is, the motor is a custom-made product.

The shaft end of the fastening shaft 57 inserted from the distal case 18 side is fastened to the proximal case 16.
According to such a reduction gear 2, since it is not necessary to provide a fastening structure for the fastening shaft 57 on the upstream side device 3 side, the reduction gear 2 can be reduced in cost as in the case of the base end case 16.

An end of the casing 4 on the input shaft 5 side is closed by a base wall 20 provided in the base end case 16.
According to the speed reducer 2, the end of the casing 4 on the input shaft 5 side is sealed with the base wall 20, and the meshing noise between the planetary gear 7 and the inner gear 8 can be prevented from leaking to the outside. 2 can be silenced. It is also possible to eliminate the intrusion of dust into the casing 4 and biting into the previous meshing portion.

  The base case 16 includes a base wall 20 and a peripheral wall 21 provided in a peripheral shape on the peripheral edge of the base wall 20. The positioning shaft 32 and the fastening shaft 57 are arranged in a state of engaging with a plurality of locations around the rotating wall 21. The base wall 20 of the proximal end case 16 is fastened and fixed to the joining wall 14 of the front-stage apparatus 3 with a screw shaft 27.

  According to the speed reducer 2, the internal space of the casing 4 can be reduced by the amount of the base wall 20, and the meshing noise can be prevented from resonating in the casing 4, and the rotating wall 21 cooperates with the base wall 20. It is possible to prevent the meshing noise from leaking outside. Furthermore, since the base end case 16 can be fastened and fixed to the joining wall 14 of the front-stage apparatus 3 and the resonance of the base wall 20 can be regulated, the overall reduction in the noise of the reduction gear 2 can be further promoted.

The base wall 20 of the base end case 16 is formed with a mounting seat 24 and a connecting hole 22 that supports the front-stage device 3 in cooperation with the mounting seat 24. The housing 13 of the upstream device 3 is formed with a joining wall 14 that is tightly joined to the proximal case 16 and a bearing portion 15 that supports one end of the output shaft 3a. The joint wall 14 is tightly joined to the mounting seat 24 in a state where the bearing portion 15 is fitted and supported by the connecting hole 22.
In the speed reducer having the above-described configuration, the front-stage device 3 and the casing 4 are configured such that the joint wall 14 and the bearing portion 15 provided in the housing 13 are connected to the mounting seat 24 and the connection hole 22 provided in the base wall 20 of the base end case 16. Are connected and fixed in a tightly bonded state. In this way, when the pre-stage device 3 and the casing 4 are intimately bonded via a plurality of bonding planes, the objects 3 and 4 are firmly connected in a state where they are positioned in a plurality of directions, and the structural strength of each other is increased. Since it can reinforce, the front | former stage apparatus 3 and the casing 4 can be connected still more firmly. There is also an advantage that the transmission loss of the rotational power transmitted from the front stage device 3 to the speed reducer 2 can be reduced.

A thickness E1 of the base wall 20 of the base case 16 is set to be equal to or larger than a thickness E2 of the bearing portion 15.
Thus, when the thickness E1 of the base wall 20 of the base end case 16 is set to be equal to or larger than the thickness E2 of the bearing portion 15, the internal space of the casing 4 is increased by the thickness of the base wall 20 formed. Therefore, it is possible to further effectively prevent the meshing noise from resonating in the casing 4 and further promote the noise reduction of the speed reducer 2.

A flange wall 51 is formed to protrude from the tooth end surface of the planetary gear 7 on the input shaft 5 side, and the space S1 between the meshing portion of the planetary gear 7 and the inner gear 8 and the meshing portion of both gears 7 and 8 is formed. The flange wall 51 forms a bottleneck.
As described above, when the flange wall 51 forms a path between the meshing portion of the planetary gear 7 and the inner gear 8 and the space S1 below the meshing portion of both the gears 7 and 8, the meshing portion of the both gears 7 and 8 and the tip of the gears 7 and 8 are pointed. The conduction path of the meshing noise between the spaces S1 can be complicated. Therefore, the noise level of the meshing noise in the previous space S1 can be reduced and the noise reduction of the speed reducer 2 can be reduced as compared with the configuration in which the previous meshing part faces the previous space S1.

A space between the meshing portion of the planetary gear 7 and the inner gear 8 and the space S2 above the meshing portions of both gears 7 and 8 is formed as a bottleneck at the peripheral wall 53 of the passive disk 9.
As described above, when the gap between the meshing portion of the planetary gear 7 and the inner gear 8 and the space S2 above the meshing portion of the two gears 7 and 8 is formed by the peripheral wall 53 of the passive disk 9, the two gears 7 and 8 are formed. The conduction path of the meshing noise between the meshing part and the previous space S2 can be complicated. Therefore, the noise level of the meshing noise in the space S2 above the meshing part can be reduced and the noise reduction of the speed reducer 2 can be contributed compared to the form in which the previous meshing part faces the space S2.

On the inner surface of the base end case 16, a base end side attenuation wall 60 constituted by a group of concavo-convex bodies 59 that reflect meshing noise is formed.
As described above, when the base end side attenuation wall 60 constituted by the group of uneven bodies 59 is formed on the inner surface of the base end case 16, the meshing noise can be reflected by the group of uneven bodies 59 and interfere with each other to attenuate. The reduction gear 2 can be silenced by lowering the sound pressure level of the meshing noise.

On the inner surface of the tip case 18, a tip side attenuation wall 62 composed of a group of concavo-convex bodies 61 that reflect meshing noise is formed.
As described above, when the tip-side attenuation wall 62 composed of the group of uneven bodies 61 is formed on the inner surface of the tip case 18, the meshing noise is reflected by the group of uneven bodies 61 and interferes with each other, as described above, and attenuated. As a result, the sound pressure level of the meshing noise can be reduced and the speed reducer 2 can be silenced.

Any one of the base end case 16, the case 17, and the front end case 18 is formed of a metal material, and the remaining case is formed of a plastic material. Each case 16, 17, 18 is positioned using a case formed of a metal material and a positioning shaft 32 fixed to the case as a positioning reference.
As described above, any one of the base end case 16, the case 17, and the front end case 18 is made of a metal material, the remaining case is made of a plastic material, and the case made of the metal material is fixed to the case. Each case 16, 17, 18 is positioned using the positioning shaft 32 as a positioning reference. According to the speed reducer 2, the case formed of the plastic material can be assembled with accuracy with respect to the case formed of the metal material, and thus the casing 4 constituted by the cases 16, 17, and 18 is assembled with high accuracy. be able to. In addition, even if there is a slight variation in the processing accuracy of the cases 16, 17, 18 and the positioning accuracy of the positioning holes 25, 30, 39, the positioning holes of the case made of plastic material are deformed, Since variations can be absorbed, a case formed of a plastic material can be accurately assembled to the positioning shaft 32.

The case 17 is formed of a metal material, and the proximal end case 16 and the distal end case 18 formed of a plastic material are positioned by a positioning shaft 32 fixed to the case 17.
As described above, when the case 17 that also serves as the inner gear 8 is formed of a metal material, the inner gear 8 can be formed with higher accuracy than when the case 17 is formed of a plastic material. This is because when the case 17 is formed of a plastic material, shrinkage distortion during molding cannot be avoided, and there is a limit in increasing the shape and dimensional accuracy of the inner gear 8. On the other hand, when the case 17 is formed of a metal material, the inner gear 8 can be formed more precisely by machining the metal material, so that the shape and dimensional accuracy of the gear 8 can be reliably improved. The productivity of the case 17 can be improved by suppressing the occurrence frequency of defective products. Further, since the case 17 and the positioning shaft 32 formed of a metal material serve as a positioning reference, the meshing state of the inner gear 8 and the planetary gear 7 and the rotation state of the gear 7 are obtained in the process of assembling the case 17 to the base case 16. Can be confirmed. That is, in the initial stage of the assembly process of the speed reducer 2, it is possible to find a meshing failure between the two gears 7 and 8 and to save time and labor required for disassembling and reassembling the speed reducer 2.

The base end case 16 is made of a metal material, and the case 17 and the tip case 18 made of a plastic material are positioned by a positioning shaft 32 fixed to the case 16.
As described above, when the base case 16 is formed of a metal material, the case 17 and the planetary gear 7 can be formed of a resin material. Therefore, the meshing noise generated at the meshing portion of the planetary gear 7 and the inner gear 8 can be reduced, and the speed reducer 2 can be silenced. Further, since the base end case 16 made of a metal material and the positioning shaft 32 fixed to the case 16 serve as a positioning reference, the inner gear 8 and the planetary gear 7 are engaged with each other in the process of assembling the case 17 to the positioning shaft 32. In addition, it is possible to confirm whether the rotation state of the gear 7 is appropriate. Therefore, as in the case where the case 17 is formed of a metal material, it is necessary to disassemble and reassemble the speed reducer 2 by discovering a meshing failure between the two gears 7 and 8 at an early stage of the assembly process of the speed reducer 2. Save time and effort.

The planetary gear 7 is rotatably supported by a bearing body 46 disposed between the eccentric cam 6 and the planetary gear 7. The planetary gear 7 is positioned in the axial direction by the eccentric cam 6 via the bearing body 46 and faces the base wall 20 adjacent to the planetary gear 7 and the passive disk 9 via a gap.
As described above, when the planetary gear 7 is rotatably supported by the bearing body 46 disposed between the eccentric cam 6 and the planetary gear 7, the relative movement between the eccentric cam 6 and the planetary gear 7 is absorbed by the bearing body 46. The rotational operation of the eccentric cam 6 can be smoothly transmitted to the planetary gear 7. Therefore, the transmission load of the rotational power between the eccentric cam 6 and the planetary gear 7 can be reduced, and the power transmission efficiency can be improved. Incidentally, when the planetary gear 7 is directly supported by the eccentric cam 6, a large frictional force is generated in the fitting portion between the two 6 and 7 due to the relative movement. Therefore, between the eccentric cam 6 and the planetary gear 7. It is inevitable that power loss will occur. Further, the planetary gear 7 is positioned in the axial direction via the bearing body 46 by the eccentric cam 6 so that the planetary gear 7 faces the adjacent base wall 20 and the passive disk 9 via a gap, so that the output When the shaft 10 is subjected to a strong load, the passive disk 9 is strongly brought into contact with the planetary gear 7 or the planetary gear 7 is strongly brought into contact with the base wall 20 to reliably eliminate the load on the speed reducer 2. Can be prevented from increasing.

The output shaft 10 provided on the passive disk 9 is rotatably supported by a bearing body 55 disposed between the tip case 18 and the output shaft 10. Further, the output shaft 10 is positioned in the axial direction by the tip case 18 via the bearing body 55 so that the passive disk 9 faces the end wall 36 adjacent to the disk 9 and the planetary gear 7 through a gap. ing.
As described above, if the output shaft 10 is rotatably supported by the bearing body 55 disposed between the tip case 18 and the output shaft 10, the frictional resistance between the tip case 18 and the output shaft 10 is reduced. The rotational power of the passive disk 9 inherited from the planetary gear 7 can be smoothly output from the output shaft 10 without any power loss. Further, the output shaft 10 is positioned in the axial direction in the tip case 18 via the bearing body 55 so that the passive disk 9 faces the end wall 36 adjacent to the disk 9 and the planetary gear 7 via a gap. Therefore, when a strong load is applied to the output shaft 10, the passive disk 9 strongly contacts the end wall 36, or the passive disk 9 strongly contacts the planetary gear 7 is reliably eliminated, and the deceleration is performed. It is possible to prevent the load on the machine 2 from increasing.

A flange-like restriction wall 68 that projects directly from the base wall 20 of the base end case 16 is formed on the inner surface of the case 17. The opposing end surface of the planetary gear 7 is sandwiched between the restriction wall 68 and the base wall 20, and rattling of the planetary gear 7 in the direction of the rotation center axis is restricted.
In the speed reducer 2 described above, a flange-like restriction wall 68 is formed to project on the inner surface of the case 17, and the opposite end face of the planetary gear 7 is sandwiched between the restriction wall 68 and the base wall 20 so that the planetary gear 7 is in the direction of the rotation center axis. It became possible to regulate the rattling. According to the speed reducer 2, when the planetary gear 7 rotates while revolving, it is possible to eliminate rattling along the rotation center axis. Therefore, it is possible to efficiently transmit the rotational power between the eccentric cam 6 and the planetary gear 7. . There is also an advantage that the planetary gear 7 that revolves at a high speed rattles and can eliminate the occurrence of harsh collision noise.

The opposing end surface of the passive disk 9 is sandwiched between the restriction wall 68 and the end case 18 facing the wall 68, and rattling of the passive disk 9 in the direction of the rotation center axis is restricted.
In the speed reducer 2 described above, the opposing end surface of the passive disk 9 is sandwiched between the restriction wall 68 and the end case 18 so that the passive disk 9 can be prevented from shaking in the direction of the rotation center axis. According to the speed reducer 2, the rotational power inherited from the planetary gear 7 can be smoothly output from the output shaft 10 through the passive disk 9 and the output shaft 10 without backlash.

The rotational power of the planetary gear 7 is transmitted to the passive disk 9 through a drive shaft 50 and a passive hole 54 that are provided at the center of the planetary gear 7 and the passive disk 9 and engage with each other. The diameter of the passive hole 54 is formed to be larger than the diameter dimension of the drive shaft 50, and one place on the peripheral surface of the drive shaft 50 during power transmission is in contact with the inner surface of the passive hole 54.
According to the above transmission structure, since the rotational power can be transmitted only by one set of the drive shaft 50 and the passive hole 54, the drive shaft is compared with the case where the rotational power is transmitted by the multiple sets of the drive shaft 50 and the passive hole 54. The transmission noise (sliding contact sound) between 50 and the passive hole 54 can be reduced, and the speed reducer 2 can be silenced.

An electric device according to the present invention includes the above-described speed reducer and a motor 3 that rotationally drives the input shaft 5 of the speed reducer.
According to the above-described electrical device including the speed reducer 2 and the motor 3, the noise level is reduced while realizing a reduction in the size of the speed reducer 2 having a large reduction ratio as compared with an electrical device including an involute gear type speed reducer. As a result, it is possible to reduce the size and noise of the electrical equipment.

  In the above embodiment, any one of the cases 16, 17, 18 constituting the casing 4 is made of a metal material. However, all the cases 16, 17, 18 may be made of a plastic material. Further, the positioning shaft 32 may be formed of a plastic material. The proximal case 16 can be configured as a motor holder (connection adapter). In this case, the mounting seat 24 may be formed in a cap shape that is fitted around the upper end surface of the motor 3 and the upper peripheral surface of the housing 13. The fastening shaft 57 can be easily disassembled and reassembled by forming it as a screw shaft. However, if this kind of maintenance is not required, the fastening shaft 57 may be formed by a caulking shaft.

  The bearing bodies 46 and 55 are preferably rolling bearings such as a ball bearing, a roller bearing, and a needle bearing in order to absorb the relative motion of the eccentric cam 6 and the planetary gear 7, but may be a plain bearing. However, when the bearing body 46 is constituted by a plain bearing, sliding friction is absorbed between the eccentric cam 6 and the bearing body 46 and between the bearing body 46 and the planetary gear 7, respectively, and the eccentric cam 6 and the planetary gear 7. It is necessary to absorb the relative movement of. The speed reducer 2 does not need to be directly connected to the motor 3 and configured as the power unit 1, and may be provided in the middle or in the final stage of the power transmission system. For example, the pre-stage device may be a clutch mechanism.

  The structure of the gear teeth of the inner gear 8 may be a structure in which a metal or plastic pin made of independent parts or a rotatable roller is externally fitted to the pin, as seen in Patent Document 2. . Further, in the power unit 1 of the first to fourth embodiments, the driving shaft 50 is provided on the planetary gear 8 side and the passive hole 54 is formed on the passive disk 9 side. As shown, a drive hole may be provided on the planetary gear 8 side, and a passive shaft may be provided on the passive disk 9 side.

1 Power unit 2 Reducer 3 Motor (previous device)
4 Casing 5 Input shaft 6 Eccentric cam 7 Planetary gear 8 Inner gear 9 Passive disk 10 Output shaft 16 Base end case 17 Intermediate case 18 Front end case 20 Base end case base wall 21 Base end case circumferential wall 24 Mounting seat 29 Inner gear Gear teeth 32 Positioning shaft 49 Planet gear gear teeth 57 Screw (fastening shaft)

Claims (4)

An input shaft (5) that inherits the rotational power of the upstream device (3), an eccentric cam (6) that is fixed to the input shaft (5), and a planetary gear (7) that is rotationally driven by the eccentric cam (6); An inner gear (8) that meshes with the planetary gear (7) and revolves while rotating, and a passive disk (9) and an output shaft (10) that inherit the rotation power of the planetary gear (7). A cycloid reducer comprising a casing (4) for accommodating these members,
The casing (4) includes a base end case (16) disposed at the end on the input shaft (5) side, a case (17) serving also as an inner gear (8), and an end on the output shaft (10) side. A tip case (18) to be arranged,
The speed reducer characterized in that an end of the casing (4) on the input shaft (5) side is closed by a base wall (20) provided in the base end case (16). The base wall (20) of the base case (16) is formed with a mounting seat (24) and a connection hole (22) for supporting the front device (3) in cooperation with the mounting seat (24),
The housing (13) of the front device (3) is formed with a joining wall (14) joined to the proximal case (16) and a bearing portion (15) supporting one end of the output shaft (3a),
The speed reducer according to claim 1, wherein the joint wall (14) is joined to the mounting seat (24) in a state in which the bearing portion (15) is fitted and supported by the connecting hole (22).   The speed reducer according to claim 2, wherein the thickness (E1) of the base wall (20) of the base end case (16) is set to be equal to or greater than the thickness (E2) of the bearing portion (15).   An electric device comprising the speed reducer according to any one of claims 1 to 3 and a motor (3) that rotationally drives an input shaft (5) of the speed reducer.

Images