JP2003207028A - Small toothed gear, small speed reducer furnished with it and geared motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small toothed gear durable against high torque even though it is extremely small, a small speed reducer furnished with it and a geared motor. <P>SOLUTION: The small toothed gear 11 is constituted by laminating a plurality of gear pieces 121, 122 of a thin plate gear shape in the axial direction in a state of matching their phases with each other. Additionally, the other small toothed gear 11 is constituted by inserting, installing and stacking a plurality of the gear pieces 121, 122 of the thin plate gear shape having shaft holes 128, 129 thereon, in and on the gear shaft 42 in the state of matching their phases with each other. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small speed reducer mounted in a small electronic device such as a camera or a mobile phone, and particularly to a small gear used in a small speed reducer having a large reduction ratio and a small speed reducer equipped with the same. Machines and geared motors.

[0002]

2. Description of the Related Art Heretofore, as a compact reducer and a geared motor of this type, those described in, for example, Japanese Patent Laid-Open No. 3-22547 have been known. This small reduction gear is composed of a planetary gear mechanism that is a main component and a case that houses the planetary gear mechanism, and is integrally attached to the motor through the case (geared motor). The planetary gear mechanism is a sun gear fixed to the main shaft of a motor, a plurality of planet gears that mesh with the sun gear, a carrier that rotatably supports the planet gears, a fixed internal gear that meshes with the planet gears, and a planet gear. And a movable internal gear integrally formed with the output shaft integrally with each other so as to obtain a large reduction ratio. These sun gears, planetary gears, fixed internal gears and movable internal gears are extremely small, and due to their complicated three-dimensional shape, they are molded of reinforced plastic in consideration of processing accuracy, processing easiness, cost, etc. It is composed of items.

[0003]

In such a conventional small speed reducer, by using the planetary gear mechanism, it is possible to obtain a relatively large speed reduction ratio in spite of its small size, but to obtain a further large speed reduction ratio. In such a case, the torque applied to each gear increases (especially the gear on the output side), and a reinforced plastic gear may be worn or damaged, which affects durability.

An object of the present invention is to provide a small gear which is extremely small and can withstand high torque, and a small reduction gear and a geared motor equipped with the small gear.

[0005]

The pinion gear of the present invention is characterized in that a plurality of thin plate gear-shaped gear pieces are axially laminated in a state of being in phase with each other.

Another pinion according to the present invention is characterized in that a plurality of thin plate gear-shaped gear pieces each having a shaft hole are inserted and mounted on a gear shaft in a phase-matched state and laminated. And

According to these structures, since the pinion gear itself is constituted by laminating a plurality of thin plate gear-shaped gear pieces in the axial direction, the thin plate-shaped gear piece is formed with high precision in machining. This makes it possible to create gears that are comparable to each other. In planar processing, press working on metals and etching on silicon wafers have been technically established.By applying these processing technologies, it is possible to easily form high-strength gears without impairing gear precision. can do.

In this case, it is preferable that the shaft hole of each gear piece is formed in a non-circular shape in plan view, and the gear piece mounting portion of the gear shaft has a sectional shape complementary to the sectional shape of the shaft hole. .

According to this structure, a plurality of gear pieces mounted on the gear piece mounting portion of the gear shaft can be laminated in the state of idling prevention and phase alignment, and the gear can be manufactured more easily and accurately. be able to.

In these cases, it is preferable that the plurality of gear pieces are welded to each other at the groove bottom portion of the tooth profile.

According to this structure, a plurality of gear pieces can be easily welded without sacrificing the proper meshing of the gears, and the integrity of the plurality of gear pieces as a single gear is ensured. can do.

Similarly, the gear shaft includes a gear piece mounting portion having a length of approximately the total thickness of the plurality of gear pieces, and one end of the gear piece mounting portion via a step portion for abutting the gear piece. A plurality of gear pieces, the gear piece located at one outer end in the axial direction is abutted against the step portion, and the gear piece located at the other outer end is the other of the gear piece mounting portions. It is preferable that the ends of the are fixed by crimping.

According to this structure, the other end of the gear piece mounting portion is caulked, and the gear piece located at the other outer end is fixed to the gear piece mounting portion. It is possible to secure the integrity of the gear piece as a single gear.

In these cases, it is preferable that an oil groove serving as a lubricant reservoir is formed on at least one of the front and back surfaces of each gear piece.

According to this structure, the oil groove can form a lubricant reservoir at the interface between the gear pieces, so that so-called oil shortage can be prevented and the durability of the gear can be improved without using a special material. Can be made.

In these cases, each gear piece is preferably formed by pressing a metal plate. Similarly, each gear piece is preferably formed by wire cutting a metal plate. Similarly, each gear piece is preferably formed by etching a silicon plate.

According to this structure, the metal gear piece or the silicon gear piece can be formed accurately and easily, and even if the gear is extremely small, it has high strength and high precision. It can be easily manufactured. Further, the surface roughness of the tooth surface can be easily improved by pressing or etching.

A small speed reducer of the present invention is characterized by including the above-described small gear.

Further, another small reduction gear of the present invention is a sun gear on the input side, a planet gear that meshes with the sun gear, a carrier that supports the planet gear so that it can rotate and revolve around the sun gear, and a planetary gear. A small reduction gear equipped with a planetary gear mechanism including a fixed internal gear that meshes with a gear and an output-side movable internal gear that meshes with a planetary gear, including a sun gear, a planetary gear, a fixed internal gear, and a movable internal gear. Among them, at least one gear is the pinion gear described above.

According to these configurations, a small gear having high strength and high precision can be incorporated, so that a reduction gear having an extremely small size and a large reduction ratio can be constructed.

The geared motor of the present invention is characterized by comprising the above-mentioned small reduction gear and a motor in which the small reduction gear is directly connected to the main shaft.

According to this structure, a small reducer having a large reduction ratio can be formed compactly and accurately, and a geared motor with high accuracy as a whole can be provided.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION A compact speed reducer and a geared motor including the same according to an embodiment of the present invention will be described below with reference to the accompanying drawings. 1 is an external perspective view of a geared motor, FIG. 2 is an exploded perspective view thereof, and FIG. 3 is a sectional view thereof. As shown in these figures, the geared motor 1 is composed of an ultra-small motor 2 and a small reducer 3 directly connected to the motor 2, and the motor 2 is, for example, a DC motor having a nominal diameter of about 6 mm. It is configured.

The small reducer 3 is provided in a substantially cylindrical case 4,
It is configured by incorporating the planetary gear mechanism 5 that forms the main body. The case 4 is an input side case 7 fixed to the motor 2.
And the output side case 8 that is joined to the input side case 7 in a snap-in manner are configured in two parts. On the other hand, the planetary gear mechanism 5 includes the input sun gear 1 directly connected to the motor 2.
0 and three planetary gears 11, 1 that mesh with the sun gear 10.
1, 11, a carrier 12 that supports the planetary gears 11 so as to be rotatable and revolvable around the sun gear 10, a fixed internal gear 13 that meshes with the planetary gears 11, and an output shaft 15 that meshes with the planetary gears 11. The movable internal gear 14 is formed integrally with the movable internal gear 14.

The input case 7 has a cross groove 21 having a substantially cross shape in plan view inside and is integrally formed in a block shape. The input case 7 is formed around the main shaft 2a of the motor 2 in the central portion thereof. A fitting opening 22 that fits into the boss 2b is formed. In the cross groove 21, a pair of counterbore grooves 24, 24 for machine screws 23, 23 and a pair of fitting grooves 25, 25 for fixing the fixed internal gear 13 are alternately formed in the circumferential direction. (See FIG. 2). Then, the input side case 7 is screwed and fixed to the motor 2 by two machine screws 23, 23 screwed into the end surface 2c of the motor 2 via the pair of counterbore grooves 24, 24.

On the other hand, on the outer peripheral surface of the input side case 7, four locking projections 26 for snap-in, and a pair of counterbore grooves 24, 24 and a pair of fitting grooves 25, 25 are provided. Two rectangular convex portions 27 are formed alternately in the circumferential direction. Each locking projection 26 is formed in a square spire shape having a guide slope, and locking holes 3 of the output side case 8 described later are provided.
4 is adapted to be locked in a snap-in form.
Further, the four notches 32 of the output side case 8 are fitted into the four rectangular convex portions 27, and the output side case 8 is positioned in the axial direction and the circumferential direction.

The output side case 8 is integrally molded into a substantially cylindrical shape by a peripheral wall portion 8a and a cover wall portion 8b on the tip side, and a movable internal gear 14 is rotated at the center of the cover wall portion 8b. A circular sliding contact opening 31 is formed so as to freely support it. At the joint portion of the output side case 8 in the peripheral wall portion 8a, the four protrusions 3 are provided by the four notch portions 32 evenly arranged in the circumferential direction.
3 is formed, and a locking hole 34 for locking the locking projection 26 of the input side case 7 is formed in each of the projecting pieces 22.

The sun gear 10 includes a sun gear forming portion 37,
Shaft hole forming part 3 connected to the motor 2 side of the sun gear forming part 37
8 has a laminated structure of thin plates (details will be described later). The shaft hole forming portion 38 is formed to have a diameter slightly larger than that of the sun gear forming portion so as to support the sun gear forming portion, and a main shaft (input shaft) of the motor 2 is inserted through a shaft hole 39 having a substantially semicircular cross section.
It is mounted so as to be driven into 2a. Further, the sun gear forming portion 37 meshes with a large gear forming portion 44 of each planetary gear 11, which will be described later.

Each planetary gear 11 is composed of a gear body 41 and a support shaft 42 that coaxially penetrates the gear body 41. The gear body 41 has a laminated structure of thin plates (details will be described later). The gear body 41 is the movable internal gear 1
4 is integrally formed with a small gear forming portion 43 meshing with 4 and a large gear forming portion 44 connected to the motor 2 side of the small gear forming portion 43. The large gear forming portion 44 meshes with the sun gear 10 and has fixed internal teeth. The gear 13 is meshed.

The small gear forming portion 43 and the large gear forming portion 44 have the same number of teeth and the same phase of each tooth, but different modules. Therefore, the pinion forming portion 43
Has a pitch circle diameter smaller than that of the large gear forming portion 44,
Moreover, the contour line is contained within the contour line of the large gear forming portion 44 (see FIG. 6). The tooth shapes of the small gear forming portion 43 and the large gear forming portion 44 may have the same or different pitch circle diameters, or the tooth shapes may be the same one original tooth shape. Furthermore, the number of teeth and the phase of both gear forming portions 43 and 44 do not necessarily have to be the same.

The three planetary gears 11, 11, 11 thus configured are arranged at 120 ° point symmetric positions with respect to each other and their axes are parallel to each other.
2, the carrier 12 is rotatably supported by the carrier 12 with both ends. As a result, each planetary gear 11 is connected to the carrier 12
It revolves around the sun gear 10 via the and rotates.

The carrier 12 is 2 at a substantially intermediate position in the axial direction.
The divided input side piece 12a and output side piece 12b are joined to each other. More specifically,
The carrier 12 is the large gear forming portion 4 of the planetary gear 11.
4 at the position corresponding to the boundary between the pinion 4 and the pinion forming portion 43
The input side piece 12a is divided and the output side piece 12b faces the small gear forming portion 43.

The input side piece 12a includes a thick disk-shaped bearing portion 51 and three columnar connecting portions 52, 52, 52 extending from the bearing portion 51 toward the output side piece 12b.
It is configured. A circular escape opening 53 into which the sun gear 10 is loosely inserted is formed in the center of the bearing portion 51. The three columnar connecting portions 52 are evenly arranged by alternately sandwiching the three planetary gears 11 in the circumferential direction (120 ° point symmetry), and the bearing portion 51 has the respective columnar connecting portions 52, 52.
Three bearing holes 54, 54, 54 that rotatably support the planetary gear (spindle 42) 11 are formed between them.

At the tip of each columnar connecting portion 52, a columnar joining pin 55 for joining to the output side piece 12b is projected. The end of the bearing portion 51 on the side of the motor 2 is an annular protrusion 56 that is thinly formed, and the carrier 12 has the annular protrusion 56 at the fixed internal gear 1.
It is rotatably supported by the annular stepped portion 76 and is positioned in the axial direction.

Similarly, the output side piece 12b includes a thick-walled disc-shaped bearing portion 61, and the input side piece 1 from the bearing portion 61.
Three columnar connecting portions 62, 62, 6 extending toward 2a
2 and. The three columnar connecting portions 62 of the output-side piece 12b are evenly arranged with the three planetary gears 11 alternately sandwiched in the circumferential direction (120 ° point symmetry), and the bearing portion 61 has each columnar connecting portion 62, Located between 62,
3 which rotatably supports the planetary gear (spindle 42b) 11
One bearing hole 65, 65, 65 is formed. A joint hole 66 into which the joint pin 55 of the input side piece 12a is joined is formed through the axis of each columnar connecting portion 62.

After assembling the three planetary gears 11, the input side piece 12a and the output side piece 12b are joined to each other to form bearings 51, 6 having the same diameter.
The ones face each other in parallel with each other, and the planetary gears 11 are rotatably supported by the ones. Further, in this state, the carrier 12 has the output side coaxial with the movable internal gear 1
4 is rotatably supported by the shaft projection 84, and the input side is rotatably supported by the annular step portion 76 of the fixed internal gear 13 coaxially.

The fixed internal gear 13 is composed of a fixed gear forming portion 71 that meshes with the large gear forming portion 44 of each planetary gear 11, and a gear support portion 72 connected to the motor 2 side of the fixed gear forming portion 71. There is. The axial length (tooth width) of the fixed gear formation portion 71 is formed sufficiently larger than the length of the large gear formation portion 44 of the planetary gear 11 that meshes with the fixed gear formation portion 71. Further, on the movable internal gear 14 side of the fixed gear forming portion 71, a thin fixed-side annular sliding contact portion 73 with which the movable internal gear 14 is rotatably engaged is formed via a step portion.

The gear supporting portion 72 has a shape like an end face wall connected to the fixed gear forming portion 71, and its central portion has
A circular opening 75 that escapes the shaft hole forming portion 38 of the sun gear 10 is formed. Further, an annular step portion 76 is formed on the inner peripheral surface of the gear support portion 72, and the carrier (the annular protrusion 56 thereof) 12 is rotatable in the annular step portion 76 while being axially positioned. Supported by.

On the other hand, on the motor 2 side of the gear support 72,
The pair of fitting protrusions 77 (only one is shown (FIG. 2)) is 180
The protrusions are formed so as to be point-symmetrical. As described above, the pair of fitting grooves 25, 25 is formed in the input side case 7, and the pair of fitting protrusions 77 are fitted into the pair of fitting grooves 25, 25 to fix the fixed internal gear. By seating 13 on the input side case 7, the fixed internal gear 13 is fixed to the input side case 7 in a rotationally stopped state.

The movable internal gear 14 is composed of a bottomed cylindrical gear body 81 and an output shaft 15 projecting axially forward from the gear body 81. The gear main body 81 includes a cylindrical movable gear forming portion 82, an end face wall portion 83 continuous with the movable gear forming portion 82, and a shaft protrusion 84 formed inside the end face wall portion 83. Carrier 12
Is rotatably supported.

Like the fixed gear forming portion 71, the movable gear forming portion 82 has an axial length (tooth width) sufficiently larger than that of the small gear forming portion 43 of the planetary gear 11 meshing with the movable gear forming portion 82. Has been formed. Further, on the fixed internal gear 13 side of the movable gear forming portion 82, a thin-walled movable side annular sliding contact portion 86 with which the fixed side annular sliding contact portion 73 is rotatably engaged is formed via a step portion. Has been done.

On the other hand, the shoulder portion of the end face wall portion 83 on the output shaft 15 side is an annular step portion, and this end face wall step portion 87 is
It is rotatably engaged with the sliding contact opening 31 of the output side case 8. That is, in the movable internal gear 14, the movable side annular slide contact portion 86 is rotatably brought into sliding contact with the fixed side annular slide contact portion 73 of the fixed internal gear 13, and the end face wall stepped portion 87.
Rotatably slidably contacts the sliding contact opening 31 of the output side case 8,
It is rotatably supported at two locations in the axial direction.

Here, the sun gear 10 which is an essential part of the present invention.
The structure (laminated structure) of the planetary gear 11 will be described in detail.

As shown in the external perspective view of FIG. 4 and the exploded perspective view of FIG. 5, the sun gear 10 has the sun gear forming portion 3 thereof.
7 is formed by stacking a plurality of sun gear pieces 101, and the shaft hole forming portion 38 includes two shaft hole disk pieces 102 and a connecting disk piece 1.
And 03 are laminated. That is, in the sun gear 10, the plurality of sun gear pieces 101 are mounted on the mounting shaft portion 105 formed on one end surface of the connecting disc piece 102, and the two pair of mounting pin portions 106 formed on the other end surface are mounted on the mounting shaft portion 105. A single shaft hole disc piece 102 is mounted, and these are integrated.

The connecting disc piece 103 is made of metal or the like,
The disk piece body 107, a mounting shaft portion 105 having a semicircular cross section that projects from the center of one end surface of the disk piece body 107, and a pair of mounting pin portions that have a circular cross section that projects from the other end surface of the disk piece body 107. 106 and 106 are integrally formed. A plurality of sun gear pieces 101 are mounted on the semi-circular mounting shaft portion 105 in a state in which the phases (tooth) are aligned and idle rotation is prevented.
The shaft hole disc pieces 102 are mounted in the same phase (shaft hole) and in a state of idling prevention.

Each sun gear piece 101 has a semicircular mounting hole (shaft hole) 109 in the center thereof and is formed in a thin plate gear shape. For example, a steel plate or a stainless plate (metal plate).
Is formed by pressing (punching) or wire cutting, or by etching a silicon wafer (silicon plate). Each sun gear piece 10
1 has a thickness of, for example, 0.2 mm to 0.5 mm, and the sun gear forming portion 37 is configured by stacking about 5 to 10 of these.

In this case, the plurality of sun gear pieces 101 are
The semicircular mounting holes 109 are aligned and mounted (fitted) so as to overlap the mounting shaft portion 105 of the connecting disc piece 103 without a gap, and in this state, they are integrated by welding or the like of the tooth bottom portion (mounting). Also welded to the shaft 105 at the end). However, it is also possible to integrally integrate the mounting shaft portion 105 by caulking the end surface of the mounting shaft portion 105 with a punch or the like and expanding the end portion to fix the outermost sun gear piece 101.

Each shaft hole disc piece 102 is formed with a semicircular shaft hole portion 111 which becomes the shaft hole 39 of the sun gear 10 at the center thereof, and the shaft hole portion 111 is sandwiched between both sides of the above-mentioned shaft hole portion 111. A pair of pin hole portions 11 into which a pair of mounting pin portions 106 are fitted
2, 112 are formed. Also in this case, the shaft hole disc pieces 102 are, for example, pressed (punched) or wire cut on a steel plate or a stainless steel plate (metal plate) or etched on a silicon wafer (silicon plate) in the same manner as described above. And is formed.

The two shaft hole disc pieces 102 are mounted such that the shaft hole portions 111 and the pin hole portions 112 are aligned and overlapped with the pair of mounting pin portions 106, 106 of the connecting disc piece 103 without a gap. (Fit), and in this state, they are integrated by welding the outer peripheral surface (welding also to the connecting disc piece 103). In this case as well, it is possible to crimp the end faces of the respective mounting pin portions 106 with a punch or the like and integrate them as a whole. In addition, in the case of silicon, it is also possible to adopt a form of welding at the interface such as anodic bonding.

On the other hand, as shown in the external perspective view of FIG. 6 and the exploded perspective view of FIG. 7, each planetary gear 11 has a small gear forming portion 43 formed by laminating a plurality of small gear pieces 121. The large gear forming portion 44 is configured by laminating a plurality of large gear pieces 122. That is, in the planetary gear 11, a plurality of small gear pieces 121 are mounted on a small diameter mounting shaft portion 124 formed on one half of the support shaft 42, and a large diameter mounting shaft portion 125 formed on the other half portion. It has a structure in which a plurality of large gear pieces 122 are mounted and these are integrated.

The support shaft 42 is made of metal or the like, and has a small-diameter mounting shaft portion 124 having a "D" -shaped cross section, a large-diameter mounting shaft portion 125 having a "D" -shaped cross section and a small-diameter mounting shaft portion 12 connected to the small-diameter mounting shaft portion 124.
4 and a pair of rotating shaft portions 126, 126 each having a circular cross section and connected to the outer ends of the large-diameter mounting shaft portion 125, respectively, are integrally formed. A plurality of small gear pieces 121 are mounted on the small-diameter mounting shaft portion 124 in the same phase (tooth) and in a non-idling state. Similarly, on the large-diameter mounting shaft portion 125, a plurality of large gear pieces 122 are mounted. Are mounted in the same phase (tooth) and in a state of idling prevention. Note that the pair of rotating shaft portions 126, 126
Is a portion rotatably supported by the bearing holes 54 and 65.

Each pinion 121 has a cross section "D" at the center.
It has a V-shaped mounting hole (shaft hole) 128 and is formed in a thin plate gear shape. For example, a steel plate or a stainless plate (metal plate) is pressed (punched) or wire cut, or a silicon wafer ( It is formed by etching a silicon plate). Each pinion 121 has a thickness of, for example, 0.2 mm to 0.5 mm, and the pinion forming portion 43 is configured by stacking about 5 to 8 of these.

Similarly, each large gear piece 122 has a mounting hole (shaft hole) 129 having a "D" -shaped cross section at the center thereof, and is formed in a thin plate gear shape. For example, a steel plate or a stainless plate ( It is formed by pressing (punching) or wire cutting a metal plate) or etching a silicon wafer (silicon plate).
Each large gear piece 122 has a thickness of, for example, 0.2 mm to 0.5 mm, and by stacking about 5 to 8 of these,
The large gear forming portion 44 is configured.

Also in this case, a plurality of small gear pieces 1
21 and the large gear piece 122, the mounting holes 128,
129 are aligned and mounted (fitted) on the mounting shaft portions 124 and 125 of the support shaft 42 so as to be overlapped with each other without a gap, and in this state, they are integrated by welding or the like at the tooth bottom portion (both mounting shaft portions 1
Welded at the end for 24 and 125).

As shown in FIG. 8, the sun gear piece 10
It is preferable to form a plurality of oil grooves 131 serving as oil reservoirs on one surface of each of the small gear piece 121 and the large gear piece 122. Each oil groove 131 corresponds to each tooth profile and includes a main oil groove 131a extending in the radial direction and a pair of sub oil grooves 131 branched from the main oil groove 131a.
b, 131b, and is capable of supplying oil to the meshing portion. However, the oil groove 131 may be formed by surface processing like a hairline. In addition, the oil groove 131 is formed in the gear piece 10
You may form on both surfaces of 1,121,122.

Here, the above-mentioned laminated structure gear (sun gear 1
The Young's modulus (flexural elastic modulus) of a material which is an index for the strength of 0 and the star gear 11) is compared with that of a conventional gear material such as reinforced plastic. Among various reinforced plastics that are conventional gear materials, for example, POM non-reinforced plastic: 2.4 [GPa] PA non-reinforced plastic: 2.7 POM potassium titanate 30% reinforced plastic: 8.8 Special PA titanic acid Potassium 30% reinforced plastic: 11.2, whereas in the metal material of this embodiment, for example, aluminum: 70 [GPa] steel: 200 silicon: 150, it is expected that the strength will be remarkably increased. To be done.

As described above, the sun gear forming portion 37 of the sun gear 10 and the small gear forming portion 43 and the large gear forming portion 44 of the planetary gear 11 are respectively formed into a plurality of sun gear pieces 1.
Since 01, the small gear piece 121, and the large gear piece 122 are formed by stacking them, they can be easily manufactured by punching a metal plate or the like. That is,
Ultra-compact and high-strength gear without sacrificing accuracy
Can be easily created. Therefore, the small speed reducer 3 which requires a high torque output with a large reduction ratio can be easily manufactured at low cost.

In the present embodiment, the sun gear 10 and the planetary gear 11 have a laminated structure, but the fixed internal gear 13 and the movable internal gear 14 are not the same as the carrier 12
Also, it is possible to have a laminated structure as described above.

[0059]

As described above, according to the pinion gear of the present invention,
Since it is configured by laminating a plurality of thin plate gear-shaped gear pieces, it can be easily processed even by using metal or silicon. Therefore, a high-strength and high-precision gear can be easily formed, and it is possible to endure high torque while being extremely small.

Further, according to the small speed reducer and the geared motor of the present invention, since a high-strength and high-precision small gear can be incorporated, an extremely small speed reducer having a large reduction ratio can be constructed. Therefore, a compact and highly accurate geared motor can be provided.

[Brief description of drawings]

FIG. 1 is an external perspective view of a geared motor according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the geared motor according to the embodiment.

FIG. 3 is a vertical cross-sectional view of the small reduction gear according to the embodiment.

FIG. 4 is an external perspective view of the sun gear according to the embodiment.

FIG. 5 is an exploded perspective view of the sun gear according to the embodiment.

FIG. 6 is an external perspective view of the planetary gear according to the embodiment.

FIG. 7 is an exploded perspective view of the planetary gear according to the embodiment.

FIG. 8 is a partial perspective view showing an oil groove formed in each gear piece.

[Explanation of symbols]

1 Geared Motor 2 Motor 3 Small Reducer 4 Case 5 Planetary Gear Mechanism 10 Sun Gear 11 Planetary Gear 12 Carrier 13 Fixed Internal Toothed Gear 14 Movable Internal Toothed Gear 15 Output Shaft 37 Sun Gear Formation 38 Shaft Hole Formation 39 Shaft Hole 41 Gear main body 42 Spindle 43 Small gear forming portion 44 Large gear forming portion 101 Sun gear piece 102 Sun gear piece 102 Shaft hole disk piece 103 Connecting disk piece 105 Mounting shaft portion 109 Mounting hole 112 Pin hole portion 121 Small gear piece 122 Large gear piece 124 Small diameter mounting shaft 125 Large diameter mounting shaft 128 Mounting hole 129 Mounting hole 131 Oil groove

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3J027 FA36 FA37 FB28 FB34 GB03                       GC13 GC24 GC26 GC28 GD04                       GD07 GD12 GE17 GE21                 3J030 AC01 AC10 BA01 BB03 BB17                       BC03 BC05

Claims (12)

[Claims] 1. A pinion gear comprising a plurality of thin plate gear-shaped gear pieces laminated in the axial direction in a phase-matched state. 2. A pinion gear comprising a plurality of thin plate gear-shaped gear pieces each having an axial hole formed therein, the gear pieces being inserted and mounted on a gear shaft in a phase-matched state and laminated. 3. The shaft hole of each gear piece is formed in a non-circular shape in plan view, and the gear piece mounting portion of the gear shaft has a cross-sectional shape complementary to the cross-sectional shape of the shaft hole. Claim 2 characterized by the above-mentioned.
Small gear described in. 4. The pinion gear according to claim 1, wherein the plurality of gear pieces are welded to each other at a tooth bottom groove bottom portion. 5. The gear shaft includes a gear piece mounting portion having a length of approximately the total thickness of the plurality of gear pieces, and a step portion for abutting the gear piece, and a gear piece mounting portion of the gear piece mounting portion. And a plurality of gear pieces, the gear piece located at one outer end in the axial direction is abutted against the step portion, and the gear piece located at the other outer end. The pinion according to claim 2 or 3, wherein said pin is attached by caulking the other end of said gear piece mounting part. 6. The pinion gear according to claim 1, wherein an oil groove serving as a lubricant reservoir is formed on at least one of the front and back surfaces of each gear piece. 7. The pinion gear according to claim 1, wherein each gear piece is formed by pressing a metal plate. 8. The pinion gear according to claim 1, wherein each of the gear pieces is formed by wire cutting a metal plate. 9. The pinion gear according to claim 1, wherein each of the gear pieces is formed by etching a silicon plate. 10. A small speed reducer comprising the pinion according to claim 1. Description: 11. A sun gear on the input side, a planetary gear that meshes with the sun gear, a carrier that rotatably supports the planetary gear and revolves around the sun gear, and fixed internal teeth that mesh with the planetary gear. In a small reduction gear provided with a planetary gear mechanism consisting of a gear and an output-side movable internal gear that meshes with the planetary gear, the sun gear, the planetary gear, the fixed internal gear and the movable internal gear Among them, at least one gear is the small gear according to any one of claims 1 to 9, wherein the small reduction gear is characterized. 12. A geared motor comprising the small reducer according to claim 11 and a motor in which the small reducer is directly connected to a main shaft.