JP6901943B2 - Reducer, and electrical equipment with reducer - Google Patents

Description

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

The applicant has previously proposed a rotary type electric razor including a sun gear, a planetary gear, and a reduction mechanism using an internal gear as a reduction element (Patent Document 1). There, the sun gear is fixed to the output shaft of the motor, 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 via the winding transmission structure. doing.

The planetary gear type reduction mechanism as described above can obtain a high reduction ratio, but the overall structure is complicated and costly, and there is room for improvement in that the noise level when the gears mesh with each other is high. .. The present inventor has studied the application of a cycloid type speed reducer with the aim of simplifying the structure of the speed reduction mechanism, reducing the cost, and further reducing the noise level in the speed reduction mechanism. This type of speed reducer is disclosed in, for example, Patent Document 2. In the speed reducer described in Patent Document 2, the transmission chamber is partitioned by the casing main body and the casing lid fixed to the main body, and a cycloid reduction mechanism is provided inside the transmission chamber. The cycloid reduction mechanism is fixed to the eccentric shaft formed integrally with the input shaft, the eccentric ring rotatably fitted to the eccentric shaft, the inner gear rotatably supported by the eccentric ring, and the casing lid. It is composed of an outer gear to be installed and a driven member that inherits the rotation operation of the inner gear, and outputs the rotational operation of the driven member from the output shaft. Compared to the involute gear type speed reducer of Patent Document 1, the cycloid type speed reducer has a significantly larger reduction ratio and has a large number of gear teeth that mesh with each other at the same time, which is advantageous in reducing the noise level.

Japanese Unexamined Patent Publication No. 2005-1989966 (see FIG. 1) JP-A-2009-150416 (see FIG. 1)

For example, if the cycloid speed reducer 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 reduce the size of a cycloid reducer to the same level as, for example, an electric razor motor. As the reduction mechanism becomes smaller, the ratio of machining error and assembly error to the standard dimensions of each part increases, and the assembly accuracy equivalent to that of a relatively large cycloid reducer that transmits a large amount of power is obtained. This is extremely difficult.

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

In the present invention, the input shaft 5 that inherits the rotational power of the pre-stage device 3, the eccentric cam 6 fixed to the input shaft 5, the planetary gear 7 that is rotationally driven by the eccentric cam 6, and the planetary gear 7 mesh with each other. A cycloid type speed reducer including 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. set to target. The casing 4 includes a base end case 16 arranged at the end on the input shaft 5 side, a case 17 that also serves as an inner gear 8, and a tip case 18 arranged at the end on the output shaft 10 side. The base end 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, and 18 with any one of the cases 16, 17, and 18 as a positioning reference. It is fixed.

The tip 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 front stage device 3 that is in close contact with the base end case 16, and each case 16.17.18 Is inseparably fastened and fixed. FIG. 6 shows a form in which the shaft end of the fastening shaft 57 is fastened to the base end case 16, and FIG. 9 shows a form in which the shaft end of the fastening shaft 57 is fastened to the fixed wall 14 of the front stage device 3. ..

A mounting seat 24 for tightly joining the front-stage device 3 to the base end case 16 is provided. The mounting seat 24 is formed with reference to the shape and structure of the front stage device 3, and the base end case 16 also serves as a connecting adapter for fixing the front stage device 3. The base end of the positioning shaft 32 is engaged and fixed to the base end case 16 (see FIG. 1).

The shaft end of the fastening shaft 57 inserted from the side of the tip case 18 is fastened to the base end case 16 (see FIG. 6).

The end of the casing 4 on the input shaft 5 side is closed by a base wall 20 provided on the base end case 16.

The base end case 16 includes a base wall 20 and a circumferential wall 21 provided in a circumferential shape on the peripheral edge of the base wall 20. The positioning shaft 32 and the fastening shaft 57 are arranged so as to engage with a plurality of locations around the peripheral wall 21. The base wall 20 of the base end case 16 is fastened and fixed to the joint wall 14 of the front stage device 3 with a screw shaft 27 (see FIG. 7).

The base wall 20 of the base end case 16 is formed with a mounting seat 24 and a connecting hole 22 for supporting the front stage device 3 in cooperation with the mounting seat 24. The housing 13 of the pre-stage device 3 is formed with a joint wall 14 that is tightly joined to the base end 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.

The thickness E1 of the base wall 20 of the base end case 16 is set to be the same as or larger than the thickness E2 of the bearing portion 15 (see FIGS. 7 and 10).

A flange wall 51 is overhanging on the tooth end surface of the planetary gear 7 on the input shaft 5 side, and a 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 is a bottleneck.

A bottleneck is formed between the meshing portions of the planetary gears 7 and the inner gear 8 and the space S2 above the meshing portions of the gears 7 and 8 by the peripheral wall 53 of the passive disc 9.

A base end side damping wall 60 composed of a group of uneven bodies 59 that reflect meshing noise is formed on the inner surface of the base end case 16 (see FIG. 7).

On the inner surface of the tip case 18, a tip-side damping wall 62 composed of a group of concavo-convex bodies 61 that reflect meshing noise is formed (see FIG. 8).

One of the base end case 16, the case 17, and the tip end case 18 is made of a metal material, and the remaining case is made of a plastic material. Each case 16, 17, 18 is positioned with the case made of a metal material and the positioning shaft 32 fixed to the case as a positioning reference.

The case 17 is made of a metal material, and a positioning shaft 32 fixed to the case 17 is used to place a base end case 16 and a tip end case 18 made of a plastic material.

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.

The planetary gear 7 is rotatably supported by a bearing body 46 arranged between the eccentric cam 6 and the planetary gear 7. Further, the planetary gear 7 is positioned in the axial direction via the bearing body 46 by the eccentric cam 6, and faces the base wall 20 adjacent to the planetary gear 7 and the passive disk 9 via a gap.

The output shaft 10 provided on the passive disk 9 is rotatably supported by a bearing body 55 arranged between the tip case 18 and the output shaft 10. Further, the output shaft 10 is positioned in the axial direction via the bearing body 55 in the tip case 18, and the passive disc 9 faces the end wall 36 and the planetary gear 7 adjacent to the disc 9 via a gap. ing.

A flange-shaped regulation wall 68 facing the base wall 20 of the base end case 16 is overhanging and formed on the inner surface of the case 17. The facing end faces of the planetary gears 7 are sandwiched between the regulation wall 68 and the base wall 20, and rattling of the planetary gears 7 in the direction of the center axis of rotation is restricted (see FIG. 10).

The facing end faces of the passive disc 9 are sandwiched between the regulating wall 68 and the tip case 18 facing the wall 68, and rattling of the passive disc 9 in the direction of the center axis of rotation is regulated (see FIG. 10).

The rotation power of the planetary gear 7 is transmitted to the passive disc 9 via a drive shaft 50 and a passive hole 54 provided in the center of the planetary gear 7 and the passive disc 9 and engaging 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 portion of the peripheral surface of the drive shaft 50 during power transmission is in contact with the inner surface of the passive hole 54.

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

In the present invention, the cycloid type speed reducer 2 is composed of an input shaft 5, an eccentric cam 6, a planetary gear 7, an inner gear 8, a passive disc 9, an output shaft 10, a casing 4 for accommodating these parts, and the like. Further, the casing 4 is composed of a base end case 16, a case 17, and a tip case 18, and penetrates each of the cases 16, 17, and 18 at the same time with any one of the cases 16, 17, and 18 as a positioning reference. Positioning can be performed by a plurality of positioning shafts 32. According to such a speed reducer 2, it is possible to eliminate the accumulation of errors as compared with the case where the cases 16, 17, and 18 are positioned by engaging with each other in a concavo-convex manner on their respective joint surfaces, so that the speed reduction can be reduced. While realizing the miniaturization of the machine 2, the assembly accuracy of each of the parts 5 to 10 housed in the casing 4 can be improved.

The tip case 18 and the shaft end of the fastening shaft 57 inserted into the case 17 were fastened to the base end case 16 or the fixing wall 14 of the front stage device 3, and the cases 16/17/18 were fastened and fixed inseparably. .. In this way, when the shaft end of the fastening shaft 57 is fastened to the base end case 16 or the fixed wall 14 which has no room for movement, the fastening shafts are kept in a state where the adjacent cases 16, 17, and 18 are accurately positioned. Since it can be firmly fixed by 57, the structural strength of the casing 4 can be improved.

The mounting seat 24 for the front stage device 3 provided in the base end case 16 is formed based on the shape and structure of the front stage device 3, so that the base end case 16 also serves as a connecting adapter for fixing the front stage device 3. did. Further, the base end of the positioning shaft 32 is engaged and fixed to the base end case 16. According to such a speed reducer 2, by preparing the base end case 16 provided with 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 device 3 and the base end case 16 can be connected without changing the shape or structure of the side. For example, when the front stage device 3 is a motor, a commercially available motor can be directly connected to the base end case 16 which is a connection adapter. Therefore, the cost of the speed reducer 2 can be reduced as compared with the case where the mounting structure of the base end case 16 and the engaging structure for the positioning shaft 32 are provided on the motor side, that is, the case where the motor is a custom-made product.

The shaft end of the fastening shaft 57 inserted from the side of the tip case 18 is fastened to the base end case 16 that also serves as a connecting adapter. According to such a speed reducer 2, since it is not necessary to provide a fastening structure for the fastening shaft 57 on the front stage device 3 side, the cost of the speed reducer 2 can be reduced as in the above-mentioned base end case 16.

The end of the casing 4 on the input shaft 5 side is closed by the base wall 20 provided on the base end case 16. According to such a speed reducer 2, the end portion of the casing 4 on the input shaft 5 side is sealed by the base wall 20 to prevent the meshing noise of the planetary gear 7 and the inner gear 8 from leaking to the outside. 2 can be made quieter. In addition, it is possible to eliminate dust from entering the casing 4 and being bitten into the meshed portion.

In the base end case 16 provided with the base wall 20 and the circumferential wall 21, the positioning shaft 32 and the fastening shaft 57 are arranged so as to engage with a plurality of locations around the circumferential wall 21, and the base wall 20 is arranged by a screw shaft 27 in the front stage device. It was fastened and fixed to the joint wall 14 of 3. According to such a speed reducer 2, the internal space of the casing 4 can be reduced by the amount of the base wall 20 to prevent the meshing noise from resonating in the casing 4, and the circumferential wall 21 cooperates with the base wall 20. It is possible to prevent the meshing noise from leaking to the outside. Further, since the base end case 16 can be fastened and fixed to the joint wall 14 of the front stage device 3 to regulate the resonance of the base wall 20, it is possible to further promote the noise reduction of the speed reducer 2 as a whole.

The front stage device 3 and the casing 4 are connected and fixed in a state where the joint wall 14 provided in the housing 13 and the bearing portion 15 are tightly joined to the mounting seat 24 provided in the base wall 20 of the base end case 16 and the connecting hole 22. I tried to do it. In this way, when the pre-stage device 3 and the casing 4 are tightly joined via a plurality of joining planes, the connecting targets 3 and 4 are firmly connected in a state of being positioned in a plurality of directions, and the structural strength of the connecting partner is increased. Since it can be strengthened, the front stage device 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 pre-stage device 3 to the speed reducer 2 can be reduced.

If the thickness E1 of the base wall 20 of the base end case 16 is set to be the same as or larger than the thickness E2 of the bearing portion 15, the internal space of the casing 4 can be reduced by the thickness of the base wall 20. , It is possible to more effectively suppress the meshing noise from resonating in the casing 4 and further promote the noise reduction of the speed reducer 2.

When the flange wall 51 creates a bottleneck between the meshing portion of the planetary gear 7 and the inner gear 8 and the space S1 below the meshing portion of both gears 7 and 8, the meshing portion of both gears 7 and 8 and the space S1 ahead of the meshing portion are formed. The conduction path of the meshing noise between them can be complicated. Therefore, the noise level of the meshing noise in the space S1 can be lowered to contribute to the noise reduction of the speed reducer 2 as compared with the form in which the meshing portion faces the space S1.

When the space S2 between the meshing portion of the planetary gear 7 and the inner gear 8 and the space S2 above the meshing portion of both gears 7 and 8 is made into a bottleneck by the peripheral wall 53 of the passive disc 9, the meshing portion of both gears 7 and 8 is formed. The conduction path of the meshing noise between the above spaces S2 can be complicated. Therefore, it is possible to reduce the noise level of the meshing noise in the space S2 above the meshing portion and contribute to the noise reduction of the speed reducer 2 as compared with the form in which the earlier meshing portion faces the previous space S2.

When the proximal end side damping wall 60 composed of a group of concave-convex bodies 59 is formed on the inner surface of the proximal end case 16, the meshing noise can be reflected by the group of concave-convex bodies 59 and interfere with each other to be attenuated, so that the sound pressure of the meshing noise can be attenuated. The level can be lowered to reduce the noise of the speed reducer 2.

When the tip side damping wall 62 composed of a group of concavo-convex bodies 61 is formed on the inner surface of the tip case 18, the meshing noise can be reflected by the group of concavo-convex bodies 61 and interfere with each other to be attenuated. The sound pressure level of the reducer 2 can be reduced to make the speed reducer 2 quieter.

One of the base end case 16, the case 17, and the tip case 18 is made of a metal material, the remaining case is made of a plastic material, and the case made of a metal material and the positioning shaft 32 fixed to the same case are formed. Each case 16, 17, and 18 is positioned as a positioning reference. According to such a speed reducer 2, a case made of a plastic material can be assembled accurately with respect to a case made of a metal material, so that a casing 4 composed of each case 16, 17, 18 can be assembled accurately. be able to. Further, even if there is a slight variation in the processing accuracy of each case 16/17/18 and the positional accuracy of the positioning holes 25/30/39, the positioning hole of the case made of the plastic material is deformed, so that the above Since the variation can be absorbed, the case made of the plastic material can be accurately assembled with respect to the positioning shaft 32.

The case 17 is made of a metal material, and the plastic base end case 16 and the tip end case 18 are positioned by a positioning shaft 32 fixed to the case 17. In this way, 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 in the case where the case 17 is formed of a plastic material. This is because when the case 17 is made of a plastic material, shrinkage distortion during molding cannot be avoided, and there is a limit in improving the shape and dimensional accuracy of the inner gear 8. On the other hand, when the case 17 is made 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 surely improved. The productivity of the case 17 can be improved by suppressing the frequency of occurrence of defective products. Further, since the case 17 and the positioning shaft 32 made of a metal material serve as a positioning reference, the meshing state of the inner gear 8 and the planetary gear 7 and the rotating state of the gear 7 in the process of assembling the case 17 to the base end case 16 It is possible to confirm the suitability of. That is, it is possible to find a poor meshing of both gears 7 and 8 at the initial stage of the assembly process of the speed reducer 2 and save the trouble required for disassembling and reassembling the speed reducer 2.

The base end case 16 is made of a metal material, and the plastic case 17 and the tip case 18 are positioned by a positioning shaft 32 fixed to the case 16. When the base end case 16 is formed of a metal material in this way, 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 made quieter. 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 in a meshed state in the process of assembling the case 17 to the positioning shaft 32. And the suitability of the rotational state of the gear 7 can be confirmed. Therefore, as in the case where the case 17 is made of a metal material, a poor meshing of both gears 7 and 8 is found at the initial stage of the assembly process of the speed reducer 2, and it is necessary to disassemble or reassemble the speed reducer 2. You can save time and effort.

When the planetary gear 7 is rotatably supported by the bearing body 46 arranged between the eccentric cam 6 and the planetary gear 7, the bearing body 46 absorbs the relative movement of the eccentric cam 6 and the planetary gear 7 while rotating the eccentric cam 6. The operation 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 at the fitting portion of both 6.7 due to the relative movement, so that between the eccentric cam 6 and the planetary gear 7. It is inevitable that power loss will occur. Further, since the planetary gear 7 is positioned by the eccentric cam 6 in the axial direction via the bearing body 46 so that the planetary gear 7 faces the adjacent base wall 20 and the passive disc 9 via a gap, the output is increased. When a strong load is applied to the shaft 10, the passive disc 9 is surely eliminated from strong contact with the planetary gear 7 or the planetary gear 7 is strongly contacted with the base wall 20, and the load of the speed reducer 2 is eliminated. Can be prevented from increasing.

When the output shaft 10 is rotatably supported by the bearing body 55 arranged 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 to reduce the frictional resistance from the planetary gear 7. The inherited rotational power of the passive disk 9 can be smoothly output from the output shaft 10 without causing power loss. Further, the output shaft 10 is positioned in the tip case 18 in the axial direction via the bearing body 55 so that the passive disc 9 faces the end wall 36 and the planetary gear 7 adjacent to the disc 9 with a gap. Therefore, when a strong load is applied to the output shaft 10, the passive disc 9 is surely eliminated from strong contact with the end wall 36 or the passive disc 9 is strongly contacted with the planetary gear 7, and the speed is reduced. It is possible to prevent the load of the machine 2 from increasing.

A flange-shaped regulation wall 68 is formed overhanging on the inner surface of the case 17, and the opposing end faces of the planetary gear 7 are sandwiched between the regulation wall 68 and the base wall 20 so that the planetary gear 7 can be regulated from rattling in the direction of the center axis of rotation. To. According to such a speed reducer 2, when the planetary gear 7 revolves and rotates, it is possible to eliminate the rattling along the rotation center axis, so that the rotational power can be efficiently transmitted between the eccentric cam 6 and the planetary gear 7. .. There is also an advantage that it is possible to eliminate the rattling of the planetary gear 7 that revolves at a high speed and the generation of annoying collision noise.

The regulating wall 68 and the tip case 18 sandwich the opposing end faces of the passive disc 9 so that the passive disc 9 can be restricted from rattling in the direction of the center axis of rotation. According to such a speed reducer 2, the rotational power inherited from the planetary gear 7 can be smoothly output from the output shaft 10 via the passive disc 9 and the output shaft 10 without rattling.

The rotation power of the planetary gear 7 can be transmitted to the passive disc 9 via the drive shaft 50 and the passive hole 54 that engage with each other. Further, the diameter of the passive hole 54 is formed to be larger than the diameter dimension of the drive shaft 50 so that the rotational power can be transmitted to the passive disk 9 in a state where one of the peripheral surfaces of the drive shaft 50 is in contact with the inner surface of the passive hole 54. To. According to such a transmission structure, the rotational power can be transmitted only by one set of the drive shaft 50 and the passive hole 54, so that the drive shaft 50 is compared with the case where the rotational power is transmitted by a large number of sets of the drive shaft 50 and the passive hole 54. The transmission noise (sliding contact noise) between the passive hole 54 and the passive hole 54 can be reduced to reduce the noise of the speed reducer 2.

According to the above-mentioned electric device equipped with the speed reducer 2 and the motor 3, the noise level is lowered while realizing the miniaturization of the speed reducer 2 having a large reduction ratio as compared with the electric device equipped with the involute gear type speed reducer. As a result, it is possible to reduce the size and noise of electrical equipment.

It is a vertical sectional view of the speed reducer which concerns on Example 1 of this invention. It is a vertical sectional view of a power unit composed of a speed reducer and a motor. It is an exploded perspective view of a power unit. FIG. 2 is a cross-sectional view taken along the line AA in FIG. FIG. 2 is a cross-sectional view taken along the line BB in FIG. It is a vertical cross-sectional view which shows the fixed structure of a casing. It is a vertical sectional view of a base end case. It is a vertical sectional view of the tip case. It is a vertical sectional view of the speed reducer which concerns on Example 2 of this invention. It is a vertical sectional view of the speed reducer which concerns on Example 3 of this invention. It is an exploded perspective view of the power unit which concerns on Example 3. FIG. It is a vertical sectional view which shows the fixing structure of the casing which concerns on Example 3. FIG. FIG. 10 is a cross-sectional view taken along the line CC in FIG. FIG. 10 is a cross-sectional view taken along the line DD in FIG. It is a vertical sectional view of the speed reducer which concerns on Example 4 of this invention. FIG. 15 is a view taken along the arrow E in FIG. FIG. 15 is a cross-sectional view taken along the line FF in FIG. It is the schematic front view of the electric razor which shows the application example of a power unit. It is the schematic front view of the stick type electric razor which shows another application example of a power unit. It is the schematic front view of the beauty device which shows still another application example of a power unit.

(Example 1) FIGS. 1 to 8 show Example 1 in which the cycloid type speed reducer 2 of the present invention is directly connected to a motor (pre-stage device) 3 to form a power unit 1. The front / rear, left / right, and up / down in this embodiment follow the crossing arrows shown in FIGS. 2 and 3 and the front / rear, left / right, and up / down indications shown in the vicinity of each arrow.

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

The motor 3 consists of a DC motor with a brush that is often used as a drive source for electric devices such as electric razors and beauty appliances for massage. The drive rotation speed of the output shaft 3a when there is no load is 13000 rpm, and the maximum torque is 19 mN.・ M. The motor 3 includes a metal housing 13 having a drum-shaped cross section, and has a flat joint wall (fixed wall) 14 at the upper end thereof which is closely joined to the casing 4 of the speed reducer 2, and is in the center of the joint wall 14. A boss-shaped bearing portion 15 that supports the upper portion of the output shaft 3a is formed in a bulge.

In FIG. 3, the casing 4 has a base end case 16 arranged at the end on the input shaft 5 side, an intermediate case (case) 17 also serving as an inner gear 8, and a tip case arranged at the end on the output shaft 10 side. It has 18. The outer shapes of the base end case 16, the case 17, and the tip case 18 are each formed into a drum shape having the same size as the previous housing 13.

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

As shown in FIG. 2, two screws (screw shafts) 27 inserted into the screw insertion hole 23 in a state where the bearing portion 15 is fitted into the connecting hole 22 and the joint wall 14 is tightly joined to the mounting seat 24. Is screwed into the screw hole 28 of the housing 13, so that the base end case 16 is integrated with the motor 3. In this way, when the motor 3 and the casing 4 are tightly joined via a plurality of joining planes, the connecting targets 3 and 4 are firmly connected in a state of being positioned in a plurality of directions, and the structural strength of the connecting partner is enhanced by each other. Therefore, 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 reduction gear 2 can be reduced.

The case 17 is made of a flat plate-shaped precision press-molded product made of a stainless plate material (metal material), and the inner gear 8 is composed of 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 metal positioning shaft 32 such as stainless steel is attached to each of the positioning holes 30 to assemble the casing 4. 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, which will be described later, and the number of teeth is 18. When the positioning shaft 32 is made of a metal material as described above, the shaft strength can be increased as compared with the case where the coaxial 32 is made of a plastic material, and it is not necessary to consider aging deterioration. , It is preferable in that the durability of the casing 4 can be improved.

As described above, when the case 17 also serving 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 made of a plastic material. This is because when the case 17 is made of a plastic material, shrinkage distortion during molding cannot be avoided, and there is a limit in improving the shape and dimensional accuracy of the inner gear 8. On the other hand, when the case 17 is made 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 surely improved. The productivity of the case 17 can be improved by suppressing the frequency of occurrence of defective products.

The tip case 18 is a molded product made of polyacetal resin, which integrally includes a boss portion 35 and an end wall 36 that surround the output shaft 10, and a circumferential wall 37 that is radially projected from the peripheral edge of the end wall 36. A shaft hole 38 for the output shaft 10 is opened in the center of the boss portion 35. The peripheral wall 37 is formed with four positioning holes 39, two fastening holes 40, and a fastening seat 41 (see FIG. 6) along the opposite 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 the planetary gear 7 described below is rotatably supported by the ball bearing 46. Further, 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 further fitted with the passive cam surface 48, the planetary gear 7 is positioned by the eccentric cam 6 in the axial direction via the ball bearing 46. Then, the planetary gear 7 faces 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 arranged between the eccentric cam 6 and the planetary gear 7, the bearing body 46 absorbs the relative movement of the eccentric cam 6 and the planetary gear 7 while absorbing the relative movement between the eccentric cam 6 and the planetary gear 7. 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 due to the relative movement is generated at the fitting portion of both 6.7, so that between the eccentric cam 6 and the planetary gear 7. It is inevitable that power loss will occur. Further, since the planetary gear 7 is positioned by the eccentric cam 6 in the axial direction via the bearing body 46 so that the planetary gear 7 faces the adjacent base wall 20 and the passive disc 9 via a gap, the output is increased. When a strong load is applied to the shaft 10, the passive disc 9 is surely eliminated from strong contact with the planetary gear 7 or the planetary gear 7 is strongly contacted with the base wall 20, and the load of the speed reducer 2 is eliminated. Can be prevented from increasing.

The planetary gear 7 is made of a circular gear-shaped molded product made of polyamide resin, and a passive cam surface 48 rotatably supported by the ball bearing 46 is formed in the center thereof, and a group of passive cam surfaces 48 are formed around the passive cam surface 48. Corrugated gear teeth 49 are formed. Further, drive shafts 50 composed of eight round shafts are projected at equal 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). It is overhanged and closes the lower surface side of the gear teeth 49. The gear teeth 49 of the planetary gear 7 mesh with the gear teeth 29 of the inner gear 8 and rotate at a low speed while revolving at a high speed, so that the drive rotation speed of the input shaft 5 can be reduced to 1/18.

The passive disc 9 is made of a disk-shaped molded product made of polyacetal resin, and a stainless steel output shaft 10 is fixed in the center thereof. On the plate surface of the passive disc 9, eight passive holes 54 are formed at equal intervals corresponding to the drive shaft 50. The diameter of the passive hole 54 is set to be larger than the diameter of the drive shaft 50, and one of the peripheral surfaces of the drive shaft 50 is always in contact with the inner surface of the passive hole 54. The rotation power of the planetary gear 7 is transmitted to the passive disc 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 and mounted on the boss portion 35 of the tip case 18. Further, with the inner ring of the ball bearing 55 fitted to the output shaft 10 and the outer ring fitted to the bearing hole provided in the boss portion 35, the passive disk 9 and the output shaft 10 are advanced via the ball bearing 55. The case 18 is positioned in the axial direction. As a result, the passive disc 9 faces the end wall 36 and the planetary gear 7 adjacent to the disc 9 via a gap.

As described above, when the output shaft 10 is rotatably supported by the ball bearing 55 arranged 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 The rotational power of the passive disk 9 inherited from 7 can be smoothly output from the output shaft 10 without causing power loss. Further, since the output shaft 10 is positioned in the tip case 18 in the axial direction via the ball bearing 55 so that the passive disc 9 faces the end wall 36 and the planetary gear 7 via a gap, the output shaft 10 is positioned. When a strong load is applied to the bearing, the passive disc 9 does not come into strong contact with the end wall 36, or the passive disc 9 comes into strong contact with the planetary gear 7, and the load on the speed reducer 2 increases. Can be prevented.

The speed reducer 2 is assembled to the motor 3 in the following procedure, for example. First, the base end case 16 is assembled to the housing 13 in the manner described above, and then the eccentric cam 6, the ball bearing 46, and the planetary gear 7 that have been temporarily assembled are housed 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 engaging the inner gear 8 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 to assemble the inner gear 8 to the planetary gear 7. Further, with the passive hole 54 of the passive disc 9 engaged with the drive shaft 50 of the planetary gear 7, the positioning hole 39 of the tip case 18 is press-fitted into the positioning shaft 32, and at the same time, the ball temporarily assembled in the tip case 18. Assemble the bearing 55 to the output shaft 10. Finally, as shown in FIG. 6, the screw (fastening shaft) 57 is inserted into the fastening holes 40 and 31 provided in the tip case 18 and the case 17, and the screw shaft is screwed into the fastening hole 26 of the base end case 16. , The speed reducer 2 can be integrated with the motor 3. As described above, in the 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 each of the cases 16, 17, and 18 positioned by the positioning shaft 32 from being disturbed by fastening and fixing the screw 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 and 17 and 18 are shared so that the positioning of each case 16 and 17 and 18 is performed only by the positioning shaft 32. As a result, the casing 4 can be assembled with high accuracy.

As described above, when the casing 4 is composed of 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 to the case where the main part is formed in the shape of a hollow case, each part can be assembled accurately while checking the operating status of the parts in the process of assembly. Further, assuming that the case 17 and the positioning shaft 32 made of a metal material are used as positioning references, in the process of assembling the case 17 to the base end case 16, the inner gear 8 and the planetary gear 7 are in a meshed state and the gear 7 is in a rotating state. You can check the suitability. Therefore, it is possible to find a poor meshing of both gears 7 and 8 at the initial stage of the assembly process of the speed reducer 2 and save the trouble required for disassembling and reassembling the speed reducer 2.

As described above, in the state where each part is assembled, each case 16, 17, and 18 can be positioned by the positioning shaft 32 with the case 17 formed of the stainless steel plate and the positioning shaft 32 fixed to the case 17 as the 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 where the cases 16, 17, and 18 are positioned by engaging with each other in a concavo-convex manner as described later. While realizing the miniaturization of the speed reducer 2, the assembly accuracy of each of the parts 5 to 10 housed in the casing 4 can be improved. Further, since the base end case 16 and the tip end case 18 are made of a plastic molded product, even if there is a slight variation in the processing accuracy of each case 16/17/18 and the positional accuracy of the positioning holes 25/30/39. By deforming the positioning holes 25 and 39, the variation can be absorbed. Therefore, the base end case 16 and the tip end case 18 can be accurately assembled with respect to the positioning shaft 32.

By the way, when each case 16/17/18 is made of a metal material, it becomes difficult to assemble each case 16/17/18 even if there is a slight variation in processing accuracy and position accuracy, or the positioning shaft. There is a risk that the 32 will be plastically deformed and will not be able to exert its positioning function. Further, when the base end case 16 and the case 17 or the case 17 and the tip end case 18 are positioned by being unevenly engaged with each other at the joint surfaces, errors are likely to be accumulated. For example, the base end case 16 and the tip end case 18 Large variations in position accuracy may occur.

As shown in FIG. 1, when the speed reducer 2 is assembled, the end portion of the casing 4 on the input shaft 5 side is closed by the base wall 20 of the base end case 16. Further, the circumferential wall 21 cooperates with the base wall 20 to prevent the meshing noise from leaking to the outside. Therefore, the meshing noise between the planetary gear 7 and the gear teeth 29 and 49 of the inner gear 8 can be prevented from leaking to the outside, and the speed reducer 2 can be made quiet. Dust does not enter the casing 4 and is not bitten into the meshed 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, 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. It is possible to effectively suppress the meshing noise generated between the 49s from resonating in the internal space of the casing 4.

Since the lower surface side of the gear teeth 49 of the planetary gear 7 is closed by the flange wall 51, the flange wall 51 separates the meshing portion of the planetary gear 7 and the inner gear 8 from the base wall 20 of the base end case 16. It has become a bottleneck, complicating the conduction path of meshing noise. That is, by forming a bottleneck between the meshing portion of the planetary gear 7 and the inner gear 8 and the space S1 below the meshing portion of both gears 7 and 8 by the flange wall 51, the conduction path of the meshing noise is complicated. The noise level in the space S1 below the meshing portions of both gears 7 and 8 is reduced. Similar noise countermeasures are taken on the side of the tip case 18. Specifically, the space between the meshing portion of the planetary gear 7 and the inner gear 8 and the tip case 18 is divided by the peripheral wall 53 of the passive disk 9 to form a bottleneck, which complicates the conduction path of the meshing noise. That is, a bottleneck is formed between the meshing portion of the planetary gear 7 and the inner gear 8 and the space S2 above the meshing portion of both gears 7 and 8 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 portions of both gears 7 and 8 is reduced.

The planetary gear 7 and the inner gear 8 are engaged only at the meshing portion on the left side of both gears 7 and 8 toward FIG. 1, and the flange wall 51 at the tip is below the valley portion 99 of the gear teeth 29 of the inner gear 8. I'm covering it up. The radial dimension from the center of the input shaft 5 to the peripheral surface of the flange wall 51 in this state 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. It is more preferable that the distance is larger than the radial distance from the center of the input shaft 5 to the valley portion 99 of the gear teeth 29. In either case, the flange wall 51 can surely form a bottleneck between the meshing portions of both gears 7 and 8 and the space S1 below the meshing portion, so that the conduction path of the meshing noise can be complicated and below the meshing portion. The noise level in the space S1 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 have 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 teeth 29, and the peripheral surface of the flange wall 51 is both gears. The meshing portion of 7 and 8 may be configured to cover up to the intermediate position (near the pitch circle) of the valley portion 99 of the gear teeth 29. Similarly, the radial dimension from the center of the output shaft 10 to the peripheral wall 53 of the passive disc 9 is set to be the same as or larger than the radial distance from the center of the input shaft 5 to the valley portion 99 of the gear teeth 29. However, the peripheral wall 53 of the passive disc 9 may be configured to cover the meshing portion of both gears 7 and 8 up to the intermediate position (near the pitch circle) of the valley portion 99 of the gear teeth 29.

In this embodiment, in addition to the above noise countermeasures, the following noise countermeasures are taken to further reduce the noise level of the speed reducer 2 to reduce noise. As shown in FIG. 7, on the inner surface of the base end case 16 (inner surface of the base wall 20 and the peripheral wall 21), a base end side damping wall 60 composed of a group of uneven bodies 59 that reflect meshing noise is provided. Further, as shown in FIG. 8, on the inner surface of the tip case 18 (boss portion 35, end wall 36, inner surface of the peripheral wall 37), a tip side damping wall 62 composed of a group of uneven bodies 61 that reflect meshing noise is provided. It is provided. The concave-convex bodies 59 and 61 are formed in a quadrangular pyramid shape, and the meshing noise reflected on the inclined peripheral surface thereof interfere with each other to effectively reduce the noise level and reduce the noise of the speed reducer 2.

According to the speed reducer 2 having the above configuration, since the cases 16, 17, and 18 are positioned with each other by the positioning shaft 32 with the case 17 formed of the stainless steel plate as a positioning reference, the casing 4 which is the core structure of the speed reducer 2 is used. Assembly accuracy can be improved. Further, the meshing noise is prevented from leaking from the base end case 16 and the tip end case 18 facing the internal space of the casing 4 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 to prevent the casing 4 from leaking. Since the internal space is complicatedly divided and the damping walls 60 and 62 are provided on the inner surfaces of the base end case 16 and the tip end case 18, respectively, the noise level in the speed reducer 2 can be reduced as a whole. Further, the base end case 16 is fastened to the joint wall 14 of the motor 3 with screws 27, and the base end case 16, the case 17 and the tip end case 18 are fastened with screws 57 screwed into the base end case 16 to form a casing. Since 4 is configured, a commercially available motor can be used as it is by preparing a base end case 16 corresponding to the structure of the motor 3. Therefore, the cost of the speed reducer 2 can be reduced as compared with the case of using the custom-made motor 3. In addition, since the screw shaft end of the fastening shaft 57 is fastened to the base end case 16 which has no room for movement, the adjacent cases 16, 17, and 18 are firmly fixed by the fastening shaft 57 while being accurately positioned. Therefore, the structural strength of the casing 4 can be improved.

In the speed reducer 2 of the first embodiment, the planetary gear 7 is rotatably supported by the bearing body 46 arranged between the eccentric cam 6 and the planetary gear 7. According to such a reduction mechanism, the rotational operation of the eccentric cam 6 can be smoothly transmitted to the planetary gear 7 while the bearing body 46 absorbs the relative operation of the eccentric cam 6 and 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. Further, since the output shaft 10 is rotatably supported by the bearing body 55 arranged 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 to reduce the frictional resistance from the planetary gear 7. The inherited rotational power of the passive disk 9 can be smoothly output from the output shaft 10 without causing power loss.

(Example 2) FIG. 9 shows a speed reducer 2 according to a second embodiment of the present invention, in which a part of the speed reducer 2 according to the first embodiment is modified. There, the base end case 16 is omitted, a peripheral wall 64 is projected on the lower surface side of the case 17 in a circumferential shape, and the tip case 18 and the case 17 are screwed into the screw holes 28 of the casing 13 of the motor 3. The casing 4 was integrated with the motor 3 by fastening and fixing at 57. Further, the positioning shaft 32 for positioning the tip case 18 and the case 17 is fixed to the positioning hole 65 provided in the joint wall 14 of the housing 13, and the housing (fixing wall of the front stage device) 13 of the motor 3 is used as a positioning reference for the casing. I tried to assemble 4. The case 17 provided with the circumferential wall 64 is made of a stainless steel material and is formed by a lost wax method.

The speed reducer 2 uses a custom-made motor 3 having a positioning hole 65 formed in the housing 13, but the structure of the speed reducer 2 is simplified by the amount that the base end case 16 can be omitted, and the cost is low. Can be converted. 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 firmly fixed by the fastening shaft 57 while being accurately positioned. Therefore, the structural strength of the casing 4 can be improved. Others are the same as the speed reducer 2 of the first embodiment, so the same members are designated by the same reference numerals and the description thereof will be omitted. The same shall apply in the following examples. Even when the casing 4 is composed of the base end case 16, the case 17, and the tip case 18, the cases 16, 17, and 18 are fastened with screws 57 screwed into the screw holes 28 of the housing 13 in the same manner as described above. The positioning shaft 32 that is fixed and positions the cases 16, 17, and 18 may be fixed to the positioning hole 65 of the casing 13.

(Example 3) FIGS. 10 to 14 show a speed reducer 2 according to a third embodiment of the present invention. In this embodiment, the structure of the casing 4 is changed, the rattling of the planetary gear 7 and the passive disc 9 in the direction of the center axis of rotation is regulated, and the rotational power of the planetary gear 7 is applied to the pair of drive shafts 50 and The point that the passive hole 54 transmits to the passive disk 9 is different from each of the above embodiments.

Regarding the structural change of the casing 4, among the cases 16, 17, and 18 constituting the casing 4, the base end case 16 is composed of a flat plate-shaped press-molded product made of a stainless plate material (metal material), and the screw 27 is used. It was fixed to the housing 13 with. The connecting hole 22, the screw insertion hole 23, and the positioning hole 25 were formed by machining. Further, the case 17 and the tip case 18 are each made of a molded product made of polyamide resin, and the positioning shaft 32 fixed to the base end case 16 prior to the assembling work of the casing 4 with the base end case 16 as a positioning reference. So, both cases 17 and 18 were 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, and the meshing noise is generated in the internal space of the casing 4. The resonance can be effectively suppressed. The circuit wall 21 is omitted. A circumferential wall 64 is provided on the lower surface side of the case 17 in a circumferential shape. The tip case 18 is formed in a dish shape by omitting the boss portion 35 and forming the end wall 36 and the peripheral wall 37 in a dish shape. Further, the output shaft 10 was pivotally supported by a spur bearing (bearing body) 55 fixed to the center of the end wall 36. The drive cam surface 44 of the eccentric cam 6 was internally fitted to the passive cam surface 48 of the planetary gear 7, and the ball bearing 46 was omitted.

When the base end case 16 is made of a metal material as described above, the case 17 and the planetary gear 7 can be made 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 made quieter. 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 in a meshed state in the process of assembling the case 17 to the positioning shaft 32. And the suitability of the rotational state of the gear 7 can be confirmed. Therefore, as in the case where the case 17 is made of a metal material, a poor meshing of both gears 7 and 8 is found at the initial stage of the assembly process of the speed reducer 2, and the speed reducer 2 is disassembled or reassembled. The time and effort required for this can be saved.

Regarding the regulation of rattling of the planetary gear 7 and the passive disc 9, a flange-shaped regulation wall 68 facing the base wall 20 of the base end case 16 is overhanging and formed on the inner surface of the case 17 to regulate the rattling. The opposite end faces of the planetary gears 7 are sandwiched between the wall 68 and the base wall 20 to regulate the rattling of the planetary gears 7 in the direction of the center axis of rotation. Further, in order to reduce the contact friction between the base wall 20 and the regulation wall 68 and the planetary gear 7, ring-shaped protruding ribs 69 are formed on the upper end surface and the lower end surface of the planetary gear 7. A through port 70 for the drive shaft 50 was formed in the center of the regulation wall 68. According to such a speed reducer 2, when the planetary gear 7 revolves and rotates, it is possible to eliminate rattling along the rotation center axis, so that the rotational power can be efficiently transmitted between the eccentric cam 6 and the planetary gear 7. .. There is also an advantage that the planetary gear 7 revolving at a high speed can be eliminated from rattling and annoying collision noise.

Further, a passive ring 71 provided with a passive hole 54 was arranged on the lower surface of the passive disk 9, and both of these 9.71 were fixed by four connecting pins 72 so as to be rotatable along with each other. Then, the upper surface of the passive disk 9 and the lower surface of the passive ring 71 are sandwiched between the regulation 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 rattling. Further, in order to reduce the contact friction between the end wall 36 and the regulation wall 68 and the passive disc 9, a thrust washer 73 is arranged between the upper surface of the passive disc 9 and the end wall 36, and a ring is placed on the lower surface of the passive ring 71. A protruding rib 74 in the shape of a bulge was formed. As described above, by restricting the rattling of the planetary gear 7 and the passive disc 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. The power loss between the input shaft 5 and the output shaft 10 can be reduced. According to such a speed reducer 2, the rotational power inherited from the planetary gear 7 can be smoothly output from the output shaft 10 via the passive disc 9 and the output shaft 10 without rattling.

In order to transmit the rotation power of the planetary gear 7 to the passive disc 9, one cylindrical drive shaft 50 is projected 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 is provided. An air vent hole 75 was provided at the upper end of the drive shaft 50. Similar 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 part of the peripheral surface of the drive shaft 50 during power transmission comes into contact with the inner surface of the passive hole 54. , The passive ring 71 is rotated along with the planetary gear 7. In FIGS. 10 and 14, reference numeral P1 is the center of the input shaft 5 and the output shaft 10, and P2 is the center of the passive hole 54. As described above, when the rotation power of the planetary gear 7 is transmitted to the passive disk 9 by the pair of drive shafts 50 and the passive holes 54, the rotation power is transmitted to the passive disk 9 by a large number of drive shafts 50 and the passive holes 54. The transmission noise (sliding contact noise) between the drive shaft 50 and the passive hole 54 can be reduced to reduce the noise of the speed reducer 2. Further, since the drive shaft 50 and the passive hole 54 are in contact with each other at only one place to transmit the power, the rotation power can be efficiently transmitted to the passive disk 9 in a state where it is not easily affected by the machining accuracy.

(Example 4) FIGS. 15 to 17 show a speed reducer 2 according to a fourth embodiment of the present invention. In this 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. There, as shown in FIG. 15, the planetary gear 7 is composed of a flange wall 96 fixed to a facing surface (upper surface) of the gear main body 95 and the passive disc 9 of the gear main body 95. A flange wall 51 equivalent to that of the first embodiment is projected on the tooth end surface (lower surface) of the gear body 95 on the input shaft 5 side. 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 four positions on the inner edge thereof at equal intervals. The flange wall 96 is assembled to the gear body 95 with the planetary gear 7 assembled to the inner gear 8, and the screw 98 inserted through the fastening seat 97 is screwed into the gear body 95 to form the gear body 95. Is integrated with. The material for forming the flange wall 96 may be either a plastic material or a metal material, but in particular, when the flange wall 96 is made of a metal material, the planetary gear 7 is formed by the reinforcing action of the flange wall 96. 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 may be fastened and fixed to the gear body portion 95, or may be formed of a metal material.

The planetary gear 7 and the inner gear 8 are meshed only at the meshing portion on the left side of both gears 7 and 8 toward FIG. 17, and the flange walls 51 and 96 are below the valley portion 99a of the gear teeth 29 of the inner gear 8. And cover the upper part. The radial dimension from the center of the input shaft 5 to the peripheral surface of the flange walls 51 and 96 in this state is the radial dimension of the tip from the center of the input shaft 5 to the gear teeth in terms of the relationship between the flange walls 51 and 96 and the inner gear. It can be said that the distance is set larger than the radial distance to the valley portion 99 of 29. Further, in relation to the flange walls 51 and 96 and the planetary gear 7, it can be said that the radial dimension of the tip is set to be larger than the radial distance from the center of the input shaft 5 to the mountain portion 100 of the gear teeth 49. The flange wall 51 described in the first embodiment is also set in the same manner.

As described above, when the peripheral edges of the flange walls 51 and 96 overlap each other so as to exceed the valley portion 99 of the gear teeth 29 or the peak portion 100 of the gear teeth 49, the meshing portions of both gears 7.8 are formed. The meshing noise generated in the above can be blocked by the upper and lower flange walls 51 and 96. In FIG. 17, the amount of overlap between the peripheral edges of the flange walls 51 and 96 and the valley portion 99 of the gear teeth 29 is indicated by reference numeral 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 51 and 96. According to such a speed reducer 2, the meshing portions of the planetary gear 7 and the inner gear 8 and the space S1 below the meshing portion and the space S2 above the meshing portion are surely squeezed by the flange walls 51 and 96. As a result, 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 portion can be surely lowered, 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 51 and 96, but it is not necessary to cover the upper and lower surfaces of at least one set of gear teeth 29 and 49. May be covered with flange walls 51 and 96.

The speed reducer 2 described in the fourth embodiment can be implemented in the following aspects.
The speed reducer 2 meshes with the input shaft 5 that inherits the rotational power of the preceding device 3, the eccentric cam 6 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 type speed reducer including 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. Is. A flange wall 51 is formed so as to face the meshing surface of the gear teeth 49 of the planetary gear 7.

A flange wall 51 is overhangingly formed on at least one tooth end surface of the gear teeth 49 of the planetary gear 7.
The peripheral edge of the flange wall 51 projects radially outward from the mountain portion 100 of the gear tooth 49 of the planetary gear 7.
The peripheral edge of the flange wall 51 projects radially outward from the valley portion 99 of the gear tooth 29 of the inner gear 8.

As described above, when the flange wall 51 is formed so as to face the meshing surface with the gear teeth 49 of the planetary gear 7, the meshing portion between the planetary gear 7 and the inner gear 8 can be blocked by the flange wall 51. Along with this, a bottleneck is formed between the meshing portion of both gears 7 and 8 and the space S1 (or space S2) facing the meshing portion by the flange wall 51, and the meshing portion of both gears 7 and 8 and the space S1 ahead are formed. The conduction path of meshing noise between (or space S2) can be complicated. Therefore, the noise level of the meshing noise in the space S1 (or space S2) is lowered as compared with the form in which the meshing portion faces the space S1 (or space S2), and the speed reducer 2 is quiet. Can contribute to the conversion.

The power unit 1 described in Examples 1 to 4 can be used as a drive source for the electrical equipment shown in FIGS. 18 to 20. FIG. 18 shows a rotary type electric razor (electrical device). The power unit 1 is arranged horizontally in a state where the central axis of the motor 3 is parallel to the rotation center of the inner blade 81, and the power unit 1 is arranged horizontally via the winding transmission mechanism 82. 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 both 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 razor (electrical device) in which the outer blade 86 is formed in a cylindrical shape. There, the power unit 1 is vertically arranged with the central shaft of the motor 3 located 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. I tried to connect. In FIG. 19, reference numeral 87 is a secondary battery, and reference numeral 88 is a power switch.

FIG. 20 shows a beauty device (electrical device) for skin massage, in which the deceleration power of the speed reducer 2 rotationally drives the brush body 91 to foam the facial cleansing liquid to cleanse and massage the facial skin. There, the power unit 1 was arranged vertically, and the output shaft 10 of the speed reducer 2 and the brush body 91 were 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 wash liquid is adhered to the tip, an appropriate amount of lukewarm water is poured into a whipping container (not shown), the beauty equipment is placed in a lying position, and the brush bundle 93 is rotationally driven in the hot water to wash the face. The liquid can be whipped.

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

In the present invention, the input shaft 5 that inherits the rotational power of the pre-stage device 3, the eccentric cam 6 fixed to the input shaft 5, the planetary gear 7 that is rotationally driven by the eccentric cam 6, and the planetary gear 7 mesh with each other. A cycloid type speed reducer including 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. set to target. The casing 4 includes a base end case 16 arranged at the end on the input shaft 5 side, a case 17 that also serves as an inner gear 8, and a tip case 18 arranged at the end on the output shaft 10 side. The base end 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, and 18 with any one of the cases 16, 17, and 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 with the case where the cases 16, 17, and 18 are positioned by engaging with each other in a concavo-convex manner on their respective joint surfaces. Therefore, it is possible to improve the assembly accuracy of each of the parts 5 to 10 housed in the casing 4 while realizing the miniaturization of the speed reducer 2.

The tip 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 front stage device 3 that is in close contact with the base end case 16, and each case 16.17.18 Was inseparably fastened and fixed.
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 which has no room for movement, the adjacent cases 16/17/18 are fastened while being accurately positioned. Since it can be firmly fixed by the shaft 57, the structural strength of the casing 4 can be improved.

A mounting seat 24 for tightly joining the front-stage device 3 to the base end case 16 is provided. The mounting seat 24 is formed with reference to the shape and structure of the front stage device 3, and the base end case 16 also serves as a connecting adapter for fixing the front stage device 3. The base end of the positioning shaft 32 is engaged and fixed to the base end case 16.
According to such a speed reducer 2, by preparing the base end case 16 provided with 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 device 3 and the base end case 16 can be connected without changing the shape or structure of the side. For example, when the front stage device 3 is a motor, a commercially available motor can be directly connected to the base end case 16 which is a connection adapter. Therefore, the cost of the speed reducer 2 can be reduced as compared with the case where the mounting structure of the base end case 16 and the engaging structure for the positioning shaft 32 are provided on the motor side, that is, the case where the motor is a custom-made product.

The shaft end of the fastening shaft 57 inserted from the side of the tip case 18 is fastened to the base end case 16.
According to such a speed reducer 2, since it is not necessary to provide a fastening structure for the fastening shaft 57 on the front stage device 3 side, the cost of the speed reducer 2 can be reduced as in the above-mentioned base end case 16.

The end of the casing 4 on the input shaft 5 side is closed by a base wall 20 provided on the base end case 16.
According to such a speed reducer 2, the end portion of the casing 4 on the input shaft 5 side is sealed by the base wall 20 to prevent the meshing noise of the planetary gear 7 and the inner gear 8 from leaking to the outside. 2 can be made quieter. In addition, it is possible to eliminate dust from entering the casing 4 and being bitten into the meshed portion.

The base end case 16 includes a base wall 20 and a circumferential wall 21 provided in a circumferential shape on the peripheral edge of the base wall 20. The positioning shaft 32 and the fastening shaft 57 are arranged so as to engage with a plurality of locations around the peripheral wall 21. The base wall 20 of the base end case 16 is fastened and fixed to the joint wall 14 of the front stage device 3 with a screw shaft 27.

According to such a speed reducer 2, the internal space of the casing 4 can be reduced by the amount of the base wall 20 to prevent the meshing noise from resonating in the casing 4, and the circumferential wall 21 cooperates with the base wall 20. It is possible to prevent the meshing noise from leaking to the outside. Further, since the base end case 16 can be fastened and fixed to the joint wall 14 of the front stage device 3 to regulate the resonance of the base wall 20, it is possible to further promote the noise reduction of the speed reducer 2 as a whole.

The base wall 20 of the base end case 16 is formed with a mounting seat 24 and a connecting hole 22 for supporting the front stage device 3 in cooperation with the mounting seat 24. The housing 13 of the pre-stage device 3 is formed with a joint wall 14 that is tightly joined to the base end 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 2 having the above configuration, in the front stage device 3 and the casing 4, the joint wall 14 and the bearing portion 15 provided in the housing 13 are provided in the mounting seat 24 and the connecting hole 22 provided in the base wall 20 of the base end case 16. On the other hand, it is connected and fixed in a state of tight junction. In this way, when the pre-stage device 3 and the casing 4 are tightly joined via a plurality of joining planes, the connecting targets 3 and 4 are firmly connected in a state of being positioned in a plurality of directions, and the structural strength of the connecting partner is increased. Since it can be strengthened, the front stage device 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 pre-stage device 3 to the speed reducer 2 can be reduced.

The thickness E1 of the base wall 20 of the base end case 16 is set to be the same as or larger than the thickness E2 of the bearing portion 15.
As described above, when the thickness E1 of the base wall 20 of the base end case 16 is set to be the same as 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. Therefore, it is possible to more effectively suppress 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 overhanging on the tooth end surface of the planetary gear 7 on the input shaft 5 side, and a 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 is a bottleneck.
In this way, when the meshing portion of the planetary gear 7 and the inner gear 8 and the space S1 below the meshing portion of both gears 7 and 8 are made into a bottleneck by the flange wall 51, the meshing portion of both gears 7 and 8 and the tip The conduction path of the meshing noise between the spaces S1 can be complicated. Therefore, the noise level of the meshing noise in the space S1 can be lowered to contribute to the noise reduction of the speed reducer 2 as compared with the form in which the meshing portion faces the space S1.

A bottleneck is formed between the meshing portions of the planetary gears 7 and the inner gear 8 and the space S2 above the meshing portions of the gears 7 and 8 by the peripheral wall 53 of the passive disc 9.
In this way, when the space S2 between the meshing portion of the planetary gear 7 and the inner gear 8 and the space S2 above the meshing portion of both gears 7 and 8 is made into a bottleneck by the peripheral wall 53 of the passive disc 9, both gears 7.8 It is possible to complicate the conduction path of the meshing noise between the meshing portion of the above and the space S2 above. Therefore, it is possible to reduce the noise level of the meshing noise in the space S2 above the meshing portion and contribute to the noise reduction of the speed reducer 2 as compared with the form in which the earlier meshing portion faces the previous space S2.

On the inner surface of the base end case 16, a base end side damping wall 60 composed of a group of uneven bodies 59 that reflect meshing noise is formed.
As described above, when the proximal end side damping wall 60 composed of a group of concave-convex bodies 59 is formed on the inner surface of the proximal end case 16, the meshing noise can be reflected by the group of concave-convex bodies 59 and interfere with each other to be attenuated. The sound pressure level of the meshing noise can be lowered to reduce the noise of the speed reducer 2.

On the inner surface of the tip case 18, a tip-side damping wall 62 composed of a group of concavo-convex bodies 61 that reflect meshing noise is formed.
As described above, when the tip side damping wall 62 composed of a group of concavo-convex bodies 61 is formed on the inner surface of the tip case 18, the meshing noise is reflected by the group of concavo-convex bodies 61 and attenuated by interfering with each other. Therefore, the sound pressure level of the meshing noise can be lowered to reduce the noise of the speed reducer 2.

One of the base end case 16, the case 17, and the tip end case 18 is made of a metal material, and the remaining case is made of a plastic material. Each case 16, 17, 18 is positioned with the case made of a metal material and the 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 tip case 18 is made of a metal material, the remaining case is made of a plastic material, and the case made of a metal material is fixed to the same case. Each case 16, 17, and 18 is positioned using the positioning shaft 32 as a positioning reference. According to such a speed reducer 2, a case made of a plastic material can be assembled accurately with respect to a case made of a metal material, so that a casing 4 composed of each case 16, 17, 18 can be assembled accurately. be able to. Further, even if there is a slight variation in the processing accuracy of each case 16/17/18 and the positional accuracy of the positioning holes 25/30/39, the positioning hole of the case made of the plastic material is deformed, so that the above Since the variation can be absorbed, the case made of the plastic material can be accurately assembled with respect to the positioning shaft 32.

The case 17 is made of a metal material, and the base end case 16 and the tip end case 18 made of a plastic material are positioned by a positioning shaft 32 fixed to the case 17.
As described above, when the case 17 also serving 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 made of a plastic material. This is because when the case 17 is made of a plastic material, shrinkage distortion during molding cannot be avoided, and there is a limit in improving the shape and dimensional accuracy of the inner gear 8. On the other hand, when the case 17 is made 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 surely improved. The productivity of the case 17 can be improved by suppressing the frequency of occurrence of defective products. Further, since the case 17 and the positioning shaft 32 made of a metal material serve as a positioning reference, the meshing state of the inner gear 8 and the planetary gear 7 and the rotating state of the gear 7 in the process of assembling the case 17 to the base end case 16 It is possible to confirm the suitability of. That is, it is possible to find a poor meshing of both gears 7 and 8 at the initial stage of the assembly process of the speed reducer 2 and save the trouble 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.
When the base end case 16 is made of a metal material as described above, the case 17 and the planetary gear 7 can be made 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 made quieter. 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 in a meshed state in the process of assembling the case 17 to the positioning shaft 32. And the suitability of the rotational state of the gear 7 can be confirmed. Therefore, as in the case where the case 17 is made of a metal material, a poor meshing of both gears 7 and 8 is found at the initial stage of the assembly process of the speed reducer 2, and it is necessary to disassemble or reassemble the speed reducer 2. You can save time and effort.

The planetary gear 7 is rotatably supported by a bearing body 46 arranged between the eccentric cam 6 and the planetary gear 7. Further, the planetary gear 7 is positioned in the axial direction via the bearing body 46 by the eccentric cam 6, 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 arranged between the eccentric cam 6 and the planetary gear 7, the bearing body 46 absorbs the relative movement of the eccentric cam 6 and the planetary gear 7 while absorbing the relative movement between the eccentric cam 6 and the planetary gear 7. 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 due to the relative movement is generated at the fitting portion of both 6.7, so that between the eccentric cam 6 and the planetary gear 7. It is inevitable that power loss will occur. Further, since the planetary gear 7 is positioned by the eccentric cam 6 in the axial direction via the bearing body 46 so that the planetary gear 7 faces the adjacent base wall 20 and the passive disc 9 via a gap, the output is increased. When a strong load is applied to the shaft 10, the passive disc 9 is surely eliminated from strong contact with the planetary gear 7 or the planetary gear 7 is strongly contacted with the base wall 20, and the load of the speed reducer 2 is eliminated. Can be prevented from increasing.

The output shaft 10 provided on the passive disk 9 is rotatably supported by a bearing body 55 arranged between the tip case 18 and the output shaft 10. Further, the output shaft 10 is positioned in the axial direction via the bearing body 55 in the tip case 18, and the passive disc 9 faces the end wall 36 and the planetary gear 7 adjacent to the disc 9 via a gap. ing.
As described above, when the output shaft 10 is rotatably supported by the bearing body 55 arranged 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 causing power loss. Further, the output shaft 10 is positioned in the tip case 18 in the axial direction via the bearing body 55 so that the passive disc 9 faces the end wall 36 and the planetary gear 7 adjacent to the disc 9 with a gap. Therefore, when a strong load is applied to the output shaft 10, the passive disc 9 is surely eliminated from strong contact with the end wall 36 or the passive disc 9 is strongly contacted with the planetary gear 7, and the speed is reduced. It is possible to prevent the load of the machine 2 from increasing.

A flange-shaped regulation wall 68 facing the base wall 20 of the base end case 16 is overhanging and formed on the inner surface of the case 17. The facing end faces of the planetary gears 7 are sandwiched between the regulation wall 68 and the base wall 20, and rattling of the planetary gears 7 in the direction of the center axis of rotation is restricted.
In the speed reducer 2, a flange-shaped regulation wall 68 is formed overhanging on the inner surface of the case 17, and the opposing end faces of the planetary gear 7 are sandwiched between the regulation wall 68 and the base wall 20, so that the planetary gear 7 moves in the direction of the central axis of rotation. Made it possible to regulate rattling. According to such a speed reducer 2, when the planetary gear 7 revolves and rotates, it is possible to eliminate the rattling along the rotation center axis, so that the rotational power can be efficiently transmitted between the eccentric cam 6 and the planetary gear 7. .. There is also an advantage that it is possible to eliminate the rattling of the planetary gear 7 that revolves at a high speed and the generation of annoying collision noise.

The facing end faces of the passive disc 9 are sandwiched between the regulating wall 68 and the tip case 18 facing the wall 68, and rattling of the passive disc 9 in the direction of the center axis of rotation is regulated.
In the speed reducer 2, the regulating wall 68 and the tip case 18 sandwich the opposite end faces of the passive disc 9 so that the passive disc 9 can be regulated from rattling in the direction of the center axis of rotation. According to such a speed reducer 2, the rotational power inherited from the planetary gear 7 can be smoothly output from the output shaft 10 via the passive disc 9 and the output shaft 10 without rattling.

The rotation power of the planetary gear 7 is transmitted to the passive disc 9 via a drive shaft 50 and a passive hole 54 provided in the center of the planetary gear 7 and the passive disc 9 and engaging 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 portion of 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, the rotational power can be transmitted only by one set of the drive shaft 50 and the passive hole 54, so that the drive shaft can transmit the rotational power only by the large number of sets of the drive shaft 50 and the passive hole 54. The transmission noise (sliding contact noise) between the 50 and the passive hole 54 can be reduced to reduce the noise of the speed reducer 2.

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

In the above embodiment, any one of the cases 16, 17, and 18 constituting the casing 4 is made of a metal material, but all the cases 16, 17, and 18 may be made of a plastic material. Further, the positioning shaft 32 may be made of a plastic material. The base end case 16 can be configured as a motor holder (connecting adapter). In that case, the mounting seat 24 may be formed in a cap shape that fits externally on 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 with a screw shaft, but when this kind of maintenance is not required, the fastening shaft 57 may be formed with a caulking shaft.

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

As seen in Patent Document 2, the structure of the gear teeth of the inner gear 8 may be a metal or plastic pin composed of independent parts, or a structure in which a rotatable roller is externally fitted to the pin. .. Further, in the power unit 1 of Examples 1 to 4, a drive shaft 50 is provided on the planetary gear 7 side and a passive hole 54 is formed on the passive disk 9 side, but it is not necessary and the present invention is disclosed in Patent Document 2. As shown above, a drive hole may be provided on the planetary gear 7 side, and a passive shaft may be provided on the passive disk 9 side.

1 Power unit 2 Reducer 3 Motor (pre-stage device)
4 Casing 5 Input shaft 6 Eccentric cam 7 Planetary gear 8 Inner gear 9 Passive disc 10 Output shaft 16 Base end case 17 Intermediate case (case)
18 Tip case 20 Base wall of base case 21 Circumferential wall of base case 24 Mounting seat 29 Gear teeth of inner gear 32 Positioning shaft 49 Gear teeth of planetary gear 57 Screws (fastening shaft)

Claims (5)

An input shaft (5) that inherits the rotational power of the pre-stage 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 the gear (7), and a passive disk (9) and an output shaft (10) that inherit the rotational power of the planetary gear (7). , A cycloidal speed reducer provided with a casing (4) for accommodating these members.
The casing (4) is provided at the base end case (16) arranged at the end on the input shaft (5) side, the case (17) also serving as the inner gear (8), and the end on the output shaft (10) side. It is equipped with a tip case (18) to be placed.
A plurality of base end cases (16), cases (17), and tip cases (18) are used around each case (16, 17, 18) with any one of the cases (16, 17, 18) as a positioning reference. It is positioned and fixed by a positioning shaft (32) that penetrates the points at the same time .
From the side of the tip case (18), the base end case (16) and the shaft end of the fastening shaft (57) inserted into the case (17) are brought into close contact with the base end case (16) or the base end case (16). A speed reducer characterized in that each case (16, 17, 18) is inseparably fastened and fixed by being fastened to a fixed wall (14) of the front stage device (3). A mounting seat (24) for tightly joining the front stage device (3) to the base end case (16) is provided.
The mounting seat (24) is formed based on the shape and structure of the front stage device (3), and the base end case (16) also serves as a connecting adapter for fixing the front stage device (3).
The speed reducer according to claim 1, wherein the base end of the positioning shaft (32) is engaged and fixed to the base end case (16). The base end case (16) includes a base wall (20) and a circumferential wall (21) provided in a circumferential shape on the peripheral edge of the base wall (20).
The positioning shaft (32) and the fastening shaft (57) are arranged so as to engage with a plurality of locations around the circumferential wall (21).
The speed reducer according to claim 1 or 2, wherein the base wall (20) of the base end case (16) is fastened and fixed to the joint wall (14) of the front stage device (3) with a screw shaft (27). The base wall (20) of the base end case (16) is formed with a mounting seat (24) and a connecting hole (22) for supporting the front stage device (3) in cooperation with the mounting seat (24).
The housing (13) of the pre-stage device (3) is formed with a joint wall (14) that is tightly joined to the base end case (16) and a bearing portion (15) that supports one end of the output shaft (3a). ,
The speed reducer according to claim 3, wherein 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). The speed reducer according to claim 4 , wherein the thickness (E1) of the base wall (20) of the base end case (16) is set to be the same as or larger than the thickness (E2) of the bearing portion (15).

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