JPH0144820Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is applicable to forklifts and other industrial vehicles,
This invention relates to a wet brake cooling mechanism that can be used in construction machinery, agricultural machinery, etc.

(Prior Art) A conventional axle wet brake structure is shown in FIG.

In the conventional structure shown in FIG. 5, the right end of the axle shaft 5 is connected to a differential (not shown),
A sun gear 7 provided at the left end meshes with an internal gear 9 via a planetary gear 8, and the internal gear 9 is fixed to an axle pipe 11 via an internal gear hub 10. The axle pipe 11 and the brake case 13 are fastened to the housing 6 with bolts 12. The support shaft 14 of the planetary gear 8 is connected to the wheel hub 17 via a carrier 16 that also serves as a side wall of the reduction gear chamber 15, and a boss cylinder 18 that projects toward the wet brake chamber 1 is provided on the inner circumference of the wheel hub 17.
are integrally provided, and the boss tube 18 is provided with a bearing 19.
to the axle pipe 11 via the bearing 2
0 and is supported by an axle pipe 11 via an internal gear hub 10. 21 is a cover.

The axle pipe 11 has a brake case 13,
13' is integrally attached, and plate 3
The back plate 23 and the pressure plate 25 fit into the brake case 13' at the notch groove 24 (spline teeth) so that they can slide only in the axial direction, and the brake disc 2 fits into the notch groove 26 of the boss tube 18. The brake discs 2 and plates 3 are arranged alternately between the back plate 23 and the pressure plate 25. Each brake disc 2 has an oil introduction hole 27 on its inner periphery, so that the inner periphery of the brake disc 2 is connected to the axle shaft 5 through the inner periphery of the wet brake chamber 1 and the hole 28 of the axle pipe 11. Housing 6
It communicates with an oil passage 29 between the two. 30 is the oil level. The friction material on both sides of the brake disc 2 has a large number of grooves 3 penetrating from the inner circumference to the outer circumference.
1 is provided, so that the oil in the groove 31 receives centrifugal force during rotation of the brake disc 2 and collects in the notched groove 24 on the outer periphery. A groove 32 penetrating from the outer periphery to the inner periphery is provided on the back surface of the back plate 23 (left side surface in FIG. 5).
Therefore, the pressurized oil in the notched groove 24 passes through the inner peripheral edge of the back plate 23 and flows toward the introduction hole 27 side. 33 is a floating seal, which is attached to brake case 1 by the outer lip.
3' and the wheel hub 17, and the floating seal chamber 34 communicates with the introduction hole 27. An annular piston 35 is fitted into an annular cylinder 4 provided in the brake case 13, and the cylinder 4 is connected to a brake master cylinder (not shown) via an oil passage 36.

In such a conventional structure, the wet brake chamber 1
The oil inside is in the groove 3 of the rotating brake disc 2.
The oil in the notch groove 24 is discharged radially outward by centrifugal force within the groove 1, and collects in the spline tooth removal portion of the notch groove 24. The oil in the notch groove 24 is returned to the introduction hole 27 side through the groove 32, as shown in FIG. It circulates in a small loop shown by the arrow.

(Problem to be solved by the invention) However, according to the structure shown in FIG. Since the absorption capacity for heat generated by friction is small and the heat dissipation area is also small, the friction material on both sides of the brake disc 2 wears out quickly, and under severe usage conditions, the plate 3 may bend or the friction material may burn out. Floating seal 33
There was a problem in that the O-ring 33a constituting the O-ring 33a hardened due to high temperatures. As a countermeasure to this problem, some devices are equipped with oil coolers and pumps to perform forced cooling, but this increases the cost significantly. The purpose of this invention is to improve the flow of brake oil and improve its cooling capacity.

(Means for solving the problem) In the present invention, a wheel hub is connected to the end of the axle shaft via a final reducer, and a boss cylinder protrudes from the inner circumference of the wheel hub in the opposite direction to the reducer. A brake case surrounding the boss tube is attached to a fixed axle pipe that supports the tube, and a brake disc attached to the wheel hub boss tube, a plate and a back plate attached to the brake case, and a hydraulic pressure built in the brake case. The piston forms a wet brake,
In a vehicle in which a floating seal is interposed between a wheel hub and a brake case, an oil storage chamber that partially opens into the reduction gear chamber is formed on the vertical wall surface of the wheel hub on the side of the reduction gear chamber, and the oil storage chamber is partially opened to the reduction gear chamber. This wet brake cooling mechanism is characterized by having a through hole that guides the oil from the wet brake chamber to the wet brake chamber via a floating seal, and a return oil passage that guides the oil in the wet brake chamber to the reduction gear chamber.

(Example) An example of the present invention is shown in FIGS. 1 and 2. In FIGS. 1 and 2, the same symbols as those in FIG. 5 indicate corresponding parts, and there are two changes, A and B. First, in part A, a lip part 40 shaped like a ring-shaped member is partially cut out is provided on the vertical wall surface 17a of the wheel hub 17, and this lip part 40
A lid member 41 is integrally formed to cover the oil storage chamber 43, and the lip portion 40, the lid member 41, and the vertical wall surface 17a form an oil storage chamber 43. As shown in FIG. 2, a plurality of oil storage chambers 43, for example six, are formed, each having an opening 42 that opens into the reduction gear chamber 15, and this opening 42 is connected to the wheel hub 17.
It is open toward the outer circumferential side. Although FIG. 2 shows a case in which the lip portion 40 and the lid member 41 are integrally molded on the wheel hub 17, in another embodiment, as shown in FIG.
6, the lip portion 40, and the lid member 41 as a separate member 47 of integral sheet metal, and this separate member 47 is welded or bolted (not shown) to a predetermined location on the wheel hub 17. It may be a configuration.

Further, a through hole 48 is formed in the wheel hub 17 substantially parallel to the axial direction, and one end of this through hole 48 is connected to the oil storage chamber 4.
3, and the other end opens to the floating seal chamber 34 in the wet brake chamber 1, and this through hole 48 connects the oil storage chamber 43 side and the wet brake chamber 1 side. As the wheel hub 17 rotates, the oil storage chamber 4
The oil pumped up into the wet brake chamber 3 can flow into the wet brake chamber 1 side through the through hole 48.

In part B, there is an oil groove 50 at the end of the axle pipe 11.
(return oil passage) is formed, and this oil groove 50 allows the oil passage 29 side and the reduction gear chamber 15 side to communicate with each other, and the structure allows oil from the oil passage 29 side to flow into the reduction gear chamber 15 side. It is becoming. 51
is a spacer.

Next, the operation will be explained. Since the brake disc 2 rotates not only while the vehicle is driving but also when braking force is applied, the oil in the groove 31 of the brake disc 2 is discharged into the notch groove 24 (spline tooth removal part) under the influence of centrifugal force. The pressurized oil in the notched groove 24 passes through the groove 32 and circulates to the floating seal chamber 34 side.

On the other hand, as the wheel hub 17 rotates, the low-temperature oil in the reducer chamber 15 is pumped up into the oil storage chamber 43, and as the oil storage chamber 43 is positioned upward, the oil flows from the oil storage chamber 43 through the through hole 48 into the wet type. It flows into the brake chamber 1 and cools the brake disc 2 and the like inside the wet brake chamber 1. The oil in the wet brake chamber 1 flows out from the hole 28 to the oil passage 29 side and enters the oil groove 5.
0 into the reducer chamber 15 or through the bearings 19 and 20, forming a large loop-shaped circulation path shown by the solid arrow.

At this time, heat is absorbed between the brake disc 2 and the plate 3, and the high-temperature oil is cooled while circulating in the large loop. In particular, the wheel hub 17 has a large heat dissipation area, and since it rotates, it has a high heat dissipation effect. The oil cooled in the reducer chamber 15 is pumped up into the oil storage chamber 43 and forced into the wet brake chamber 1.
returned to the side.

In another embodiment shown in FIG. 4, the oil storage chamber 43'
The openings 42' are open toward the circumferential direction R, and the openings 42' are formed to face each other in consideration of the case where the wheel hub 17 rotates in the opposite direction. The overall shape of the oil storage chamber 43' is a long cylindrical shape along the circumferential direction, and the through hole 48 is opened on the opposite side of the opening 42' of the oil storage chamber 43', so that the oil can be absorbed more actively. The structure allows for a large amount of oil to be pumped and a large amount of oil to be stored.

Note that the lip portion 40' in this embodiment may be integrally molded with the wheel hub 17, or may be fixed to a separate member.

(Effects of the invention) As explained above, in the present invention, the oil storage chamber 43 partially opened to the reduction gear chamber 15 is formed on the vertical wall surface 17a of the wheel hub on the reduction gear chamber side, and the oil in the oil storage chamber 43 is A through hole 48 that guides the oil from the wet brake chamber 1 to the reduction gear chamber 15 via the floating seal 33, and a return oil path (for example, the hole 28, the oil passage 29, the oil groove 5) that leads the oil in the wet brake chamber 1 to the reducer chamber 15
0) is formed, and in particular, an oil storage chamber 43 is provided in the wheel hub 17, which is a rotating body, and this oil storage chamber 4
3 actively pumps up the oil in the reducer chamber 15 and causes the oil storage chamber 43 to function as a water wheel, so the oil in the reducer chamber 15 is directed into the wet brake chamber 1, which tends to become hot. It can be sent forcefully and reliably. That is, the well-cooled, low-temperature oil from the speed reducer chamber 15 side is pumped up into the oil storage chamber 43 as the wheel hub 17 rotates, passes through the through hole 48 to the floating seal chamber 34, and then
It is forcibly sent to the wet brake chamber 1 side where a large amount of heat is generated. Therefore, it is possible to reliably prevent the wear of the friction materials on both sides of the disc brake 2, the bending of the plate 3 under severe usage conditions, and the occurrence of accidents such as burnout of the friction materials. Furthermore, since the O-ring 33a constituting the floating seal 33 is actively lubricated and cooled, it is possible to eliminate the problem of itching when it hardens.

In the embodiment shown in FIG. 1, an oil groove 50 is formed as a part of the return oil passage, and the oil in the wet brake chamber 1 flows out from the hole 28 to the oil passage 29 side and passes through the oil groove 50 to the reducer. A large loop-shaped circulation path shown by the solid arrow that flows into the chamber 15 is formed, so the heat radiation area of the oil can be increased, the oil is cooled more smoothly, and the wet brake chamber 1 has a lower temperature. It becomes possible to send oil.

Furthermore, in the embodiment shown in FIG. 4, since the opening 42' is open toward the circumferential direction R, the oil in the reduction gear chamber 15 is more actively stored as the wheel hub 17 rotates. The oil can be pumped up into the oil chamber 43', and a larger amount of cooled oil can be supplied into the wet brake chamber 1.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view of the brake cooling mechanism according to the present invention, FIG. 2 is a view of the main part in the direction of the arrow in FIG. 1, FIG. 3 is a front and side view of the main part showing another embodiment, and FIG. FIG. 4 is a drawing corresponding to FIG. 2 showing yet another embodiment, and FIG. 5 is a longitudinal sectional side view showing a conventional example. 1... Wet brake chamber, 2... Brake disc, 3... Plate, 5... Axle shaft, 11... Axle pipe, 13, 13'
...Brake case, 15...Reduction gear room, 17...
...Wheel hub, 17a... Vertical wall surface, 18...
Boss tube, 23... Back plate, 33... Floating seal, 35... Piston, 42...
Opening, 43...Oil storage chamber, 47...Separate member, 48
...Through hole, 50...Oil groove (return oil path), R...Circumferential direction.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A wheel hub is connected to the end of the axle shaft via a final reducer, and a boss cylinder protrudes from the inner circumference of the wheel hub in the opposite direction to the reducer. A brake case surrounding a boss tube is attached to the fixed axle pipe supporting the wheel hub, and a brake disc attached to the wheel hub boss tube, a plate and a back plate attached to the brake case, and a hydraulic piston built into the brake case In a vehicle in which a wet brake is formed and a floating seal is interposed between a wheel hub and a brake case, an oil storage chamber that partially opens into the reduction gear chamber is formed on a vertical wall surface of the wheel hub on the reduction gear chamber side. a through hole that guides the oil in the oil storage chamber to the wet brake chamber via a floating seal;
A wet brake cooling mechanism characterized in that a return oil passage is formed to guide oil in a wet brake chamber to a reduction gear chamber. (2) The wet brake cooling mechanism according to claim 1, wherein the oil storage chamber is formed by a part integrally molded with the wheel hub. (3) The wet brake cooling mechanism according to claim 1, wherein the oil storage chamber is formed by fixing a separate member to the wheel hub. (4) The wet brake cooling mechanism according to any one of claims 1 to 3, wherein the oil storage chamber opens on the outer peripheral side of the wheel hub. (5) The wet brake cooling mechanism according to any one of claims 1 to 3, wherein the oil storage chamber opens toward a substantially circumferential direction of the wheel hub.