JP2549917B2 - Planetary gear unit that does not require spacers - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a planetary gear device that has wide applications as a speed reducer and a speed increaser. In particular, it relates to an improvement in which a spacer is unnecessary when a plurality of planetary gear devices are vertically connected and housed in a casing.

[Prior art]

The planetary gear device is composed of a sun gear, a proper number of planetary gears, an outer shell internal gear, a carrier and the like. A planetary gear device in which a disk larger than the addendum circle is provided on both sides of the planetary gear and a cylindrical portion larger than the root circle is provided on both sides of the outer shell internal gear (JP-A-58-94656, S58.6.4 published). Is a unit integrated by the action of the disc, so it is extremely convenient for all handling such as transportation, storage and installation. Or, one of the planetary gears has a disk larger than the tip circle and the other has a disk smaller than the bottom circle, and the cylindrical portion of the outer shell internal gear is larger than one bottom circle, and the other has a circle larger than the tip circle. Asymmetrical planetary gear set with a small cylinder (Japanese Patent Laid-Open No. 60-252845, S6
0.12.13 published, JP-A-61-27337, S61.2.6 published) is also an integrated unit due to the action of the disc and the shape of the carrier. These are created by the applicant. By the way, the planetary gear device has an excellent feature that it can be vertically connected in multiple stages due to its central symmetry. However, in the conventional planetary gears, the axial direction of the outer shell internal gear is narrower than the axial width of the carrier. The carrier rotatably supports the planetary gears. Since the planetary gear meshes with the outer shell internal gear, the tooth width is the same. The carrier naturally has a width greater than the tooth width of the planet gears. Therefore, the width of the outer shell internal gear is generally narrower than that of the carrier. Therefore, conventionally, the carrier is not covered by the outer shell internal gear, but projects in the axial direction. When such a planetary gear device is connected in multiple stages, it becomes as shown in FIG. The first stage carrier and the second stage sun gear are connected by a joint shaft 40. Further, since a gap is generated between the outer shell internal gear, the cylindrical spacer 41 is required. The spacer 41 is a cylinder having the same outer diameter as the outer shell internal gear.

[Problems to be Solved by the Invention]

If two or more planetary gear units are connected in cascade, two adjacent
Two members, a joint shaft and a spacer, are required to connect the two devices. A cylindrical spacer is placed on the end surface of the outer shell internal gear of one device, and the joint shaft is inserted into the carrier shaft hole. Then, the other end of the joint shaft is inserted into the shaft hole of the sun gear of the other device so that the spacer is sandwiched between the end faces of the two outer shell internal gears. This is a troublesome work because the spacer and the joint shaft must be sandwiched at the same time. Further, since another member called a spacer is required, there is a problem that the material cost is increased. Further, in order to prevent the casing from rotating, it is necessary to form an axial groove in the casing and to form one or more protrusions that fit in the groove on the outer circumference of the outer shell internal gear. Through the spacer, it is difficult to axially align the protrusions of the two devices. It is an object of the present invention to provide a planetary gear device that can be easily connected in cascade and is suitable for multistage connection.

Means for Solving the Problems In the present invention, the width of the outer shell internal gear is expanded in the axial direction so that the carrier does not project outward from the end surface of the outer shell internal gear, and the adjacent planet gears are provided. The end surfaces of the outer shell internal gear of the device are in direct contact with each other.

[Action]

When the outer shell internal gear is wide in the axial direction and is connected in multiple stages, a spacer is not required between two adjacent outer shell internal gears. For this reason, the work of putting it in the casing becomes easy. It is possible to reduce the component cost for the spacer.

【Example】

A planetary gear device according to an embodiment of the present invention will be described with reference to the drawings. 1 is a front view, FIG. 2 is a rear view, FIG. 3 is a III-III sectional view in FIG. 2, and FIG. 4 is a IV-IV sectional view of FIG. FIG. 5 is a sectional view showing a state in which the casings are cascade-connected. Around the central sun gear 1 are four planet gears 2 that mesh with it. The number of planetary gears is 2 to 2 depending on the purpose and reduction ratio.
It can be 6 pieces. There is a shell internal gear 3 that surrounds and meshes with all planet gears 2. The carrier 4 is a combination of a main carrier disc 4a and a sub carrier disc 4b. The carrier 4 rotatably supports the planetary gear 2 by means of a planetary shaft 5. The main carrier board 4a has four first protrusions 10 on its inner surface. Corresponding to this, the sub-carrier disc 4b has four second inner discs.
It has a convex portion 11. A plug 12 is formed at the tip of the first convex portion 10 of the main carrier board 4a. A socket hole 13 is formed at the tip of the second convex portion 11 of the sub carrier board 4b. The main carrier board 4a and the sub carrier board 4b are integrated as follows. After mounting the gears and planetary shafts, insert the plug part of the main carrier board 4a into the socket hole 13 of the sub carrier board 4b.
Insert 12. Since the tip of the plug part 12 projects to the outside of the sub carrier board 4b, it is pressed and crimped by a machine. The caulking end portion 28 integrally fixes the main carrier board 4a and the sub carrier board 4b. This is the case when the carrier discs 4a, 4b are made of a metal capable of being plastically deformed, for example, sinter-bonded gold, aluminum die cast, zinc. When the carrier board is made of plastic, the end portion of the plug portion 12 can be welded to the socket hole 13 by the ultrasonic welding method. Planetary shaft stop holes 16 are formed in the back surfaces of the main carrier board 4a and the sub carrier board 4b. Both ends of the planet shaft 5 are fixed by the planet shaft stop holes 16. The planetary gear 2 has a planetary gear portion 8 at the center and planetary disk portions 6 and 7 on both sides. This is a tip circle method (JP-A-58-9)
4656), the outer diameter of the disk portions of the planetary disk portions 6 and 7 is larger than the diameter of the addendum circle of the planetary gear. Although the tip circle method is shown here, one of the disks may be larger than the tip circle and the other disk may be smaller than the root circle instead (Japanese Patent Laid-Open No. 60-252845, JP-A-60-252845). 61-2733
7). A shaft through hole 21 is formed in each of the planetary disk portions 6 and 7, and the planetary shaft 5 is inserted therein. The outer shell internal gear 3 has an outer shell gear portion 25 in the center, and outer shell large cylindrical portions 26, 27 having an inner diameter larger than the root circle of the outer shell internal gear, on both sides thereof. The outer shell gear portion 25 meshes with the planetary gear portion 8. Outer shell large cylindrical part
26 and 27 can contact the outer peripheral surface of the planetary disk portion 6. The outer shell internal gear 3 can also have an asymmetrical structure. As described above, when the planetary gear is asymmetric, a cylindrical portion with an inner diameter narrower than the tip circle is formed on the side of the outer shell gear portion 25, and a cylindrical portion with an inner diameter wider than the root circle is formed on the other side. It should be done. A sun shaft hole 14 is bored in the center of the sun gear 1.
Here, a detent mechanism such as a spline, serration or D-shaped hole is provided. The boss portion of the main carrier board 4a of the carrier 4 is thick and has a carrier shaft hole 15 formed therein. Carrier shaft hole 15
Also, anti-rotation mechanisms such as splines and serrations are provided. What is important is that the outer shell internal gear 3 is long in the axial direction and the carrier 4 is included therein. In the outer shell internal gear 3, the outer shell large cylindrical portions 26, 27 are formed as outer shell gear portions.
Although it is provided on both sides of 25, outer width portions 29 and 30 which are smooth cylindrical surfaces are further provided outside the outer shell large cylindrical portions 26 and 27. Since the extra width portions 29 and 30 are wide, the carrier discs 4a and 4b are included therein and do not project to the outside. That is, a plane including the end surface of the outer shell internal gear 3 is defined by P and Q.
Then, the carrier 4 is sandwiched between the planes P and Q. In this example, the end of the carrier board 4a is flush with the plane Q, but this is also acceptable. Plane Q
It's better not to go outside. A state in which two planetary gear units A and B are placed in a casing C and are cascade-connected will be described with reference to FIG. Actually, multi-step deceleration of three steps or more may be used, but since the same thing is applied, two-step deceleration will be described. The planetary gear devices A and B both have the same outer circumference and have a detent protrusion 31. The casing C is a long cylindrical container, but has a rotation stop groove 35 cut in the vertical direction. The sun gear 1 of the planetary gear sets A and B and the carrier 4 are connected by a joint shaft 40. The outer circumference of the outer shell internal gear 3 of the planetary gear units A and B is slightly smaller than the inner diameter of the casing C. The anti-rotation protrusions 31 of A and B are fitted into the anti-rotation groove 35, and the planetary gear devices A and B are pushed in in the axial direction. In FIG. 5, the planetary gear units A and B have no spacers between them, and the outer shell internal gears 3 and 3 are
The edges of are in direct contact. Thus, it is a feature of the present invention that the spacer is unnecessary.

【The invention's effect】

When two or more planetary gear units are combined to achieve multi-stage deceleration, a spacer is not required between adjacent units.
The work of combining two planetary gear units becomes easy.
Also, the positioning of the detents becomes easier when it is put in the casing. Also, since there is no spacer, the amount of parts can be reduced.

[Brief description of drawings]

FIG. 1 is a front view of a planetary gear device according to an embodiment of the present invention. FIG. 2 is a rear view of the same thing. FIG. 3 is a sectional view taken along the line III-III in FIG. FIG. 4 is a sectional view taken along the line IV-IV in FIG. FIG. 5 is a vertical cross-sectional view of two planetary gear devices (A, B) of the present invention placed in a casing and connected in cascade. FIG. 6 is a schematic vertical cross-sectional view of two planetary gear devices according to a conventional example, which are cascade-connected and placed in a case. 1 …… Sun gear 2 …… Planetary gear 3 …… Outer shell internal gear 4 …… Carrier 4a …… Main carrier board 4b …… Sub carrier board 5 …… Planetary shaft 6,7 …… Planetary disk 8… … Planetary gear part 10 …… First convex part 11 …… Second convex part 12 …… Plug part 13 …… Socket part 14 …… Sun shaft hole 15 …… Carrier shaft hole 16 …… Planet shaft stop hole 21 …… Shaft through hole 25 …… Outer shell gear section 26 …… Outer shell large cylindrical section 27 …… Outer shell large cylindrical section 28 …… Caulking end 29 …… Excessive width section 30 …… Excessive width section 31 …… Rotation stop protrusion Part P, Q ... Plane including the ends of the outer shell internal gear

Claims (1)

(57) [Claims] 1. A sun gear 1, an appropriate number of planet gears 2 which should mesh with the sun gear 1, and an outer shell internal gear 3 which meshes with these.
And a carrier 4 rotatably supporting the planetary gear 2 by a planetary shaft 5, and the planetary gear 2 has a disk larger than its tip circle on both sides, or one side of which has a tip circle A large disk and a disk smaller than the root circle on the other side, and having a cylindrical portion larger than the root circle on both sides of the outer shell internal gear 3, or a cylinder larger than the root circle on one side. And a cylindrical portion smaller than the tip circle on the other side, the carrier is composed of a main carrier disc and a sub carrier disc, both of which are connected, and both ends of the planetary shaft are supported by both the main carrier disc and the sub carrier disc. The outer shell internal gear is open at both ends, and the outer shell internal gear 3 has a rotation preventing projection 31 formed on the outer surface for preventing rotation, and an end surface of the outer shell internal gear 3 is formed. Between the two planes P and Q including Unnecessary planetary gear spacer, characterized in that was as rare.