JPH0220529Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a planetary gear system, particularly a planetary gear system that transmits large torque and is suitable for high-load applications.

Planetary gear systems have the advantage of being able to obtain a large reduction or speed increase ratio with a small and lightweight device, and have been widely used in various industrial fields.
As is well known, a planetary gear system consists of a sun gear, an internal gear disposed coaxially with the sun gear, a planetary gear that meshes with the sun gear and the internal gear at the same time, and the planetary gear. When a high reduction ratio or speed increase ratio is desired, the internal gear is fixed and
One of the sun gear and carrier is often used as an input member and the other as an output member. In this case, the planetary gear revolves due to the rotation of the carrier and rotates around its own axis, which tends to lead to insufficient lubrication and failure due to heat generation, especially when the transmitted torque is large.

This invention was devised in view of the above circumstances.
A sun gear, a fixed internal gear disposed coaxially with the sun gear, a planetary gear that meshes with the sun gear and the internal gear at the same time, and a planetary gear shaft that rotatably supports the planetary gear. , and a carrier that supports the planetary gear shaft and rotates coaxially with the sun gear, wherein one end is open to the outer circumferential surface of the gear shaft and the other end is open to the outer peripheral surface of the gear shaft. By drilling an oil hole that opens at the end face in the axial direction, fitting the rotor of the screw pump into the oil hole, and rotating the pump rotor in conjunction with the rotation of the carrier, The gist of the present invention is a planetary gear device characterized in that it is configured such that lubricating oil is sucked in and forced into an opening in the outer peripheral surface of the planetary gear shaft.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a hub reduction device for a vehicle such as a tractor for transporting heavy goods will be specifically described below with reference to the accompanying drawings. Reference numeral 10 in the figure indicates a drive axle shaft for a heavy goods transport vehicle, which is rotatably supported within an axle housing 12 connected to a vehicle body (not shown) via a suspension device. 14 is a sun gear mounted on the axle shaft 10 via a spline, a key, etc. so as not to rotate relative to each other, and 16 is an internal tooth connected to the outer periphery of the axle housing 12 via a spline so as not to rotate relative to each other. The gear support flange 18 is an annular ring connected to the internal gear support flange 16 through spline teeth provided on the outer periphery of the internal gear support flange 16 so as not to rotate relative to the flange 16, and is arranged concentrically with respect to the sun gear 14. The internal gear 20 is the sun gear 1.
4 and the internal gear 18, and is rotatably supported on a planetary gear shaft 24 via a sleeve or bush 22.

Reference numeral 26 denotes a carrier that supports the planetary gear shaft 24, and in this embodiment, its outer circumferential surface is cylindrical, and a foil cover 28 is fixed to the open end surface on the outside of the vehicle body, and Flange part 30
is the brake drum 32 and wheel disc 3
4 (only a portion of which is shown) are fixed to the flange portion 38 of the wheel hub 36 by bolts (not shown). 40 is a hub bearing that rotatably supports the wheel hub 36 on the axle housing 12.

42 is coaxially bored in the planetary gear shaft 24, one end thereof is bent in the radial direction and opens on the outer peripheral surface of the gear shaft, and the other end is an internal gear support flange of the same gear shaft. 16 is an oil hole opened in the end face opposite to 16, and 44 is a screw pump rotor fitted in the oil hole 42 so as to be rotatable, and as is well known in the art, around a rod-shaped shaft. A spiral thread or a spiral vane is formed on the shaft, and the lubricating oil around the planetary gear shaft is sucked into the oil hole 42 by rotation in one direction, and is pumped from the outer peripheral surface of the planetary gear shaft toward the sleeve 22. ing. Reference numeral 46 denotes a pump drive pinion connected to the end of the screw pump rotor 44 via a well-known one-way clutch device 48 (for example, a simple structure consisting of a ball and a wedge-shaped groove). , an internal gear 5 provided on the inner peripheral surface of the internal gear support flange 16
It meshes with 0. 52 is a rotor supporting bush fitted into the open end of the oil hole 42 on the pump drive pinion 46 side, and as shown in FIGS. 2 and 3, the end on the pinion 46 side is filled with lubricating oil. It is provided with a plurality of notches 54 to allow smooth circulation.

In the above device, when the axle shaft 10 of the heavy goods transport vehicle is driven in the forward direction, the sun gear 14 rotates, and the planet gear 20 meshes with the sun gear and the relatively fixed internal gear 18 at the same time. Because of this, it revolves while rotating on its axis. This revolution is transmitted to the wheel hub 36 via the gear shaft 24 and the carrier 26, and the wheel disk 34 fixed to the wheel hub 36 and the tire (not shown) attached to the outer circumference of the wheel disk move at a low speed. The vehicle rotates at low speeds, generating the high torque needed to transport heavy objects while moving forward at low speeds. At this time, as the planetary gear shaft 24 revolves, the pump drive pinion 46 rotates in one direction by meshing with the internal gear 50, and this rotation is controlled by the screw pump via the one-way clutch device 48. Rotor 44
is transmitted to. On the other hand, lubricating oil is sealed and stored in the cylindrical carrier 26, which also serves as the casing of the planetary gear set, to a level slightly below the center line OO in FIG. 1, so that the planetary gear shaft 24 revolves. When the screw pump rotor 44 rotates, the lubricating oil is actively sucked into the oil hole 42, and the gear It is fed under pressure toward the sleeve 22 from an opening on the outer periphery of the shaft 24 . Therefore, the planetary gear shaft 24, which supports the planetary gear 20 rotating and revolving around its axis and transmits large torque, and the sleeve 22 that cooperates with the planetary gear shaft 24 are sufficiently lubricated, and it is ensured that the planetary gear device will not seize due to poor lubrication. It is possible to prevent this and ensure the running safety of vehicles for transporting heavy goods. In the above embodiment, when the vehicle is reversing, the pinion 46 idles due to the operation of the one-way clutch device 48, and the pump rotor 44 does not rotate. Therefore, the lubricating oil in the oil hole 42 prevents the pump rotor 44 from rotating in reverse. The problems caused by this problem are now avoided. However, in the case of a vehicle for transporting heavy objects, the one-way clutch device 48 can be omitted since it is unlikely that the vehicle will be traveling backwards for a long time or a long distance. Further, in the above embodiment, the pump driving pinion 46 is configured to mesh with the internal gear 50 of the internal gear support flange 16. An external gear may be formed on the outer periphery, or an external gear may be interposed between the two lock nuts 56 and meshed therewith. In this case, since the direction of rotation of the screw pump rotor 44 is opposite to that in the illustrated embodiment, the spiral direction of the screw must naturally be formed in the opposite direction.

Further, in the above embodiment, the present invention is applied to a hub reduction device for a vehicle for transporting heavy goods, but the present invention is not limited to this, and can be applied to planetary gear devices used in various industrial fields, especially planetary gear devices. It is expected that it will be widely adopted in planetary gear systems that operate under high loads and provide excellent effects.

As mentioned above, the planetary gear device according to the present invention is
A sun gear, a fixed internal gear disposed coaxially with the sun gear, a planetary gear that meshes with the sun gear and the internal gear at the same time, and a planetary gear shaft that rotatably supports the planetary gear. and a carrier that supports the planetary gear shaft and rotates coaxially with the sun gear, wherein one end is open to the outer circumferential surface of the gear shaft and the other end is open to the outer circumferential surface of the gear shaft. By drilling an oil hole that opens at the end face in the axial direction, fitting the rotor of the screw pump into the oil hole, and rotating the pump rotor in conjunction with the rotation of the carrier, The lubricating oil is sucked in and forced into the opening on the outer circumferential surface of the planetary gear shaft, which prevents seizure due to poor lubrication of the planetary gear device operated under high load and improves its durability. This is extremely beneficial as it can improve safety.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of essential parts showing an embodiment of the present invention;
Figure 2 shows rotor support bushing 5 in Figure 1.
2 is an enlarged side view of FIG. 2, and FIG. 3 is a sectional view taken along the line - in FIG. 10... Axle shaft, 12... Axle housing, 14... Sun gear, 18... Internal gear, 20... Planet gear, 24... Planet gear shaft, 2
6...Carrier, 42...Oil hole, 44...Screw pump rotor, 46...Pump drive pinion.

Claims (1)

[Scope of utility model registration request] A sun gear, a fixed internal gear disposed coaxially with the sun gear, a planetary gear that meshes with the sun gear and the internal gear at the same time, and a planetary gear shaft that rotatably supports the planetary gear. and a carrier that supports the planetary gear shaft and rotates coaxially with the sun gear, wherein one end is open to the outer circumferential surface of the gear shaft and the other end is open to the outer circumferential surface of the gear shaft. By drilling an oil hole that opens at the end face in the axial direction, fitting the rotor of the screw pump into the oil hole, and rotating the pump rotor in conjunction with the rotation of the carrier, A planetary gear device characterized in that lubricating oil is sucked in and forced into an opening in the outer peripheral surface of the planetary gear shaft.