JPS5829321Y2 - Lubrication mechanism of planetary gear system - Google Patents

Description

[Detailed explanation of the idea] This invention relates to a lubrication mechanism for a planetary gear system.

A planetary gear system consists of a central sun gear, a plurality of planetary gears arranged around the sun gear that mesh with the sun gear, an external internal gear that meshes with the outer circumference of the planetary gear, and a planetary gear that is attached to the shaft. It consists of a carrier.

Planetary gears are highly symmetrical, have excellent force balance, and have extremely high power transmission efficiency.

If the input and output shafts are on the same straight line and are unitized, an ideal transmission (reduction,
speed increase).

On the other hand, in a planetary gear system, the gears mesh with each other at many points at the same time, so high processing accuracy was required for the division accuracy of the gears and carriers, the position of the shaft hole, etc.

In order to solve this problem, a planetary gear device was devised in which a disk or ring having a pitch circle equal to the pitch circle of the planetary gear and the outer shell internal gear is attached to both sides of the planetary gear and the outer shell internal gear.

Since the pitch circles of the disks and rings are equal to each other, they roll into contact with each other and exert pressure on each other in the radial direction.

The gear only transmits rotational torque in the tangential direction.

The mesh is smooth and generates little vibration and noise.

Furthermore, it becomes possible to lower the machining accuracy of gears.

You can also reduce the price significantly.

Conventionally, planetary gears have generally been made of metal.

However, the requirements for machining accuracy are relaxed for structures that include a pitch disk and a pitch ring.

It can also be made from plastic.

Plastics cannot be expected to have exact dimensional accuracy during manufacturing.

Although thermal expansion and distortion may occur, it is often still usable.

In mechanical equipment, sufficient attention must be paid to the lubrication mechanism.

A planetary gear system having a structure in which a pitch disk and a pitch ring are added to both sides as described above can provide new benefits in terms of lubrication.

This is because the planetary gear and the outer shell internal gear have a triple structure instead of a single member, and a grease reservoir space can be easily provided.

An object of the present invention is to provide a planetary gear device that has a lubrication mechanism using a grease reservoir in the internal space of the planetary gear and the internal space of the external internal gear.

Another object of the present invention is to provide a planetary gear device in which a resting area is provided in the internal space of the planetary shaft or the inner surface of the carrier to serve as a grease reservoir.

Another object of the present invention is to provide a planetary gear device in which the inner peripheral end of the disk portion of the planetary gear is chamfered.

Embodiments will be described below with reference to drawings showing examples.

FIG. 1 is a partially cutaway front view of a planetary gear device according to an embodiment of the present invention, and FIG. 2 is a partially cutaway rear view.

FIG. 3 is a sectional view taken along the line ■-■ in FIG. 1, FIG. 4 is an enlarged sectional view of the vicinity of the planetary gear, and FIG. 5 is a partially enlarged view of the outer shell gear.

This planetary gear system consists of a central sun gear 1, four planetary gears meshing with four planetary gears 2, 2. . . ., includes an outer shell internal gear 3 outside the planetary gear, and a carrier 4 that holds the planetary gear between two plates.

An (input) shaft hole 6 is bored in the center of the sun gear 1 .

A D-shaped hole is used to prevent rotation. In this example, there are four planetary gears 2, which are evenly spaced at 90° intervals.

The planetary gear 2 consists of an intermediate planetary gear part 12 and a planetary disk part 13 sandwiching the gear part 12 from both sides and having a circumference having an outer diameter equal to the pitch circle.

The planetary gear part 12 and the disc part 13 only need to be loosely inserted.

The planetary shaft 5 perpendicularly passes through the boss portion of the disk portion 13 and is fixed to the carrier 4 at both ends.

Two disc parts 13, 13 and a gear part 12. An internal space is created which is surrounded by the planetary shaft 5.

This is because the sum of the thicknesses of the small diameter portions of the disc portion is smaller than the thickness of the gear portion.

This internal space is filled with grease in advance to form a grease reservoir A.

Grease from the planetary gear grease reservoir A constantly circulates between the planetary shaft and the disc part 1 to reduce friction between the two.

The lubricating action of grease can suppress heat generation, wear, vibration, and noise.

The outer shell internal gear 3 includes an outer shell gear portion 14 and an outer shell ring 15.

Corresponding to the triple structure of the planetary gear, the outer shell ring 15 has an inner diameter equal to the pitch circle.

It is attached to both sides of the gear section 140.

In this example, the ring portion 15 and the gear portion 14 of the external internal gear
It has a snap fit structure.

That is, the protrusion of the ring part is fitted into the hole of the gear part.

However, you can simply overlap them without making them snap-fit.

When fixed to the casing (not shown) with bolts and screws,
This is because the ring portion and the gear portion are properly overlapped and fixed.

Arc-shaped depressions are formed on both sides of the ring portion 140, avoiding the mounting screw holes 16.

In the arc-shaped depression. The outer shell gear grease reservoir B is filled with grease.

As shown in FIG. 5, the outer shell gear grease reservoir B is also provided with a thin outer shell gear communication hole 20 that reaches the tooth surface of the outer shell gear.

The grease may be in grease reservoir B. It is constantly supplied to the teeth of the outer shell gear.

In this example, the outer shell gear grease reservoirs B are provided at 16 locations, 8 locations on the front and back sides.

The carrier 4 consists of a carrier base 4a and a carrier sub-base 4b.

A carrier shaft hole 7 is opened in the center of the carrier base 4a.

The carrier shaft hole 7 is provided with serrations to prevent rotation.

The anti-rotation mechanism, together with the sun gear shaft hole 6, can be any spline, serration, D-shape, square-shape, star-shape, or the like.

In this example, the carrier base 4a and the carrier sub-base 4b are connected by a snap fit.

A raised connecting part 11 having a protrusion 8 is provided on the inner surface of the carrier platform 4a, and a raised connecting part 10 with a fitting hole 9 is formed on the inner surface of the sub-plate 4b. 9 firmly fit and connect.

As shown in FIG. 4, the planetary shaft 5 has a cavity extending in the axial direction.

Grease is injected here in advance to form the planetary shaft grease reservoir C.

The planetary shaft grease reservoir C passes through the planetary shaft communication hole 19 reaching the planetary shaft surface, and the grease gradually leaks onto the planetary shaft surface to lubricate the space between the shaft and the planetary disk portion 130.

A thrust washer 18 is inserted through the shaft 5 and interposed between the disk portion 13 of the planetary gear and the inner surface of the carrier 4a t 4b.

It is a good idea to apply grease to the thrust washer 18 as well.
This avoids friction between the planetary gear and the inner surface of the carrier.

Frictional resistance of planetary gears can be reduced.

Six-chamfered chamfers 24 and 25 are provided on both ends of the inner peripheral surface of the planetary gear disc portion 13 that contacts the planetary shaft 5.

Because of the chamfer 24.250, the grease in grease reservoirs A and C is
It moves along the planetary axis and easily penetrates between the disk portion 13 and the shaft 50.

FIG. 6 is an enlarged sectional view of the vicinity of a planetary gear showing another embodiment.

On the inner surfaces of the carriers 4a and 4b, an annular resting area centered around the planetary shaft is formed, and this is filled with grease to form a carrier grease reservoir D.

A carrier communication hole 21 extending from the carrier grease reservoir D to the surface of the planetary shaft is formed so that grease gradually advances from the carrier grease reservoir D to the planetary shaft.

The grease that has advanced into the carrier grease reservoir D mainly contributes to lubrication between the inner surface of the carrier and the planetary gear.

In this example, although the thrust washer is missing, the lubricating action of the grease in the carrier grease reservoir is effective, so the thrust washer can be omitted.

According to the present invention, since the planetary gear grease reservoir A and the outer shell gear grease reservoir B are filled with grease in advance, there is no contact between the planetary gear and the shaft, and between the planetary gear and the outer shell internal gear and the sun gear. The condition is always in a suitable lubrication state.

Furthermore, planetary shaft grease reservoir C, carrier grease reservoir D,
If a thrust washer on the planetary shaft and a chamfer on the planetary gear disk are used together, the lubrication conditions will be further improved.

This is a useful idea.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view of a planetary gear device according to an embodiment of the present invention, and FIG. 2 is a partially cutaway rear view. Fig. 3 is a sectional view taken along the line ■-■ in Fig. 1, Fig. 4 is an enlarged sectional view of the vicinity of the planetary gear, Fig. 5 is a partially enlarged view of the outer shell gear, and Fig. 6 shows another embodiment. FIG. 3 is an enlarged sectional view of the vicinity of the planetary gear shown in FIG. 1 is a sun gear, 2 is a planetary gear, 3 is an outer shell internal gear, 4 is a carrier, 5 is a planetary shaft, 6 is a sun gear shaft hole, 7 is a carrier shaft hole, 8 is a protrusion, 9 is a fitting hole, 10 is a connecting portion, 11 is a connecting portion, 12 is a planetary gear portion, 13 is a planetary disk portion, 14 is an outer shell gear portion, 15 is an outer shell ring portion, 16 is a mounting screw hole,
18 is a thrust washer, 19 is a planetary shaft communication hole, 20 is an outer gear communication hole, 21 is a carrier communication hole, 24 and 25 are chamfers, A is a planetary gear grease reservoir, B is an outer shell gear grease reservoir, and C is a planetary gear. Shaft grease reservoir, D is carrier grease reservoir.

Claims (1)

[Scope of utility model registration request] A sun gear 1, planetary gears 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 3, 3, 4 being being provided as well. ...and the planetary gear 2,
2. an outer shell internal gear 3 that surrounds and meshes with the outer shell ring provided on both sides with an outer shell ring having an inner diameter equal to the pitch circle;
Planetary gear 2, 2. In a planetary gear device consisting of a carrier 4 that supports . A reservoir A is provided between the outer shell gear part 14 and the outer shell ring part 15 and filled with grease to form an outer shell gear grease reservoir B, between the outer shell gear grease reservoir B and the tooth surface of the outer shell gear. A lubrication mechanism for a planetary gear device, characterized in that an outer shell gear communication hole 20 is formed in the lubrication mechanism.