JPS5828059Y2 - Structure for shortening the rear end turning radius of wheel-type hydraulic excavators - Google Patents

Description

[Detailed description of the invention] This invention relates to a wheeled hydraulic excavator in which the driving power train is sequentially mechanically connected from the engine to the drive wheels by gears, shafts, shaft joints, etc., and in particular shortens the turning radius of the rear end. The present invention relates to the structure of an upper bevel gearbox suitable for

Compared to crawler-type hydraulic excavators, wheel-type hydraulic excavators have much better running maneuverability than crawler-type hydraulic excavators because they use rubber tires and are 10 times or more faster than crawler-type hydraulic excavators. They are especially popular in urban areas because they are suitable for paved roads that are unsuitable for crawler hydraulic excavators because they cause road surface damage.

Therefore, unlike in the field, the work space is inevitably narrow,
During work, there is a high risk of collision or contact with surrounding workers, buildings, trees, etc.

On the other hand, due to the nature of the work, this is true not only for wheeled hydraulic excavators but also for general hydraulic excavators. The operator must confirm that there is no contact with the rear and side surroundings each time.

In such a case, a large rear end turning radius not only increases the above-mentioned danger but is also extremely disadvantageous in terms of work efficiency, which is not desirable.

Therefore, a small aircraft size, especially a small trailing turning radius, provides good visibility to the rear and sides during work, which is particularly advantageous against the aforementioned collision and contact risks, and allows for tighter working areas. work is also possible.

Incidentally, the rear end turning radius of the wheeled hydraulic excavator is limited by the configuration and arrangement of the running power train, and below, FIGS. The upper bevel gearbox in the power train will be explained.

The driving powertrain is a radiator 1a on the rotating structure A,
An engine 1, a clutch 2, a transmission 3, and an upper bevel gearbox 4 are arranged in series from the rear, and the output shaft from the upper bevel gearbox 4 and the vertical shaft 5 are arranged so that the rotating body A can turn 360 degrees. Figure 2 shows the turning center P.
Arrange them so that they are connected at the top.

The vertical shaft 5 extends vertically downward from the turning center P and is connected to a lower bevel gear box 6 provided on the traveling body B, and is further connected to a propeller shaft 7, a driving wheel shaft 8, and a driving wheel 9 in this order.

Then, the power of the engine 1 is transmitted in the above-mentioned order of configuration to rotate the driving wheels 8 to the final driving wheels 9.

Further, a driver's cab 19 and a front attachment 11 are installed at the front of the revolving body A, and a counterweight 10 for the front attachment 11 is installed at the rear end.

Next, Fig. 2 shows a plan view showing the power train and rear end turning radius of a wheeled hydraulic excavator on revolving structure A, and Fig. 3 shows the engine and rear end turning radius of a general crawler type hydraulic excavator. FIG.

In the figure, the same reference numerals as in FIG. 1 represent the same or equivalent parts.

In FIG. 2, as mentioned above, the radiator 1a, engine 1, clutch 2, transmission 3, and upper bevel gearbox 4 are arranged in series from the rear, and the vertical axis center on the output side of the upper bevel gearbox 4 is the turning center. Since the rear end turning radius Rw is made to match P, the rear end turning radius Rw is from the turning center P to the corner of the counterweight 10 located at approximately the same position as the radiator 1a.

On the other hand, in Fig. 3, there is no upper bevel gearbox because hydraulic pressure is used in the power train for driving, and therefore there is no need to align the shaft center on the output side of the upper bevel gearbox with the turning center P, and it is natural that the engine 1 The arrangement can be freely selected so that the rear end turning radius R6 is minimized.

Comparing the rear end turning radius Rw and R6, there is a difference depending on the capacity of the hydraulic excavator, but Rw = 1.2Rc, and when turning 360 degrees, the difference in radius becomes the difference in diameter, and the difference becomes even larger.

For wheel-type hydraulic excavators that use hydraulic pressure for the power train, the engine placement can be freely selected as shown in Figure 3, and the rear end turning radius Rw can be reduced to improve workability and operation. Of course, it can be advantageous in terms of performance, etc., but in the case of using hydraulic pressure,
It is not possible to provide the same or similar operability as general mechanical freight vehicles, which is most strongly and widely desired by users, especially operability during acceleration and deceleration.

Next, a conventional upper bevel gearbox will be described with reference to FIGS. 4 and 5.

In the figure, the same reference numerals as in FIG. 1 represent the same or equivalent parts.

In FIG. 4, an output shaft 3a of a transmission 3 enters an upper bevel gear box 4, a bevel gear 4b is fixed together, and a shaft 4C, which is horizontally supported on both sides of the bevel gear by bearings 4C and 4d, and a flange joint 3b are connected to the output shaft. Coaxially connected to the shaft 3a.

A bevel gear 4f meshing orthogonally with the bevel gear 4b is fixed to a vertical shaft 4C that supports the bevel gear at its upper and lower ends by bearings 4g and 4h.

In this case, the axis of the vertical shaft 4e coincides with the rotation center axis P-Q, which is spaced from the transmission end face 3C by a certain amount so that the rotating body A can rotate 360 degrees, and the bevel gear 4b is aligned with the rotation center axis P-Q. It is placed on the ridance transmission 3 side and meshes with it.

Further, the vertical shaft 4e has a lower portion protruding outside the lower surface of the upper bevel gear box 4 to securely fix a brake drum 12 for braking during parking, and further connects its lower end to the vertical shaft 5 by a joint 14.

Next, an upper bevel gear box 4' in FIG. 5 has the configuration of the upper bevel gear box 4 in FIG. 4, but the mounting position of the brake drum 12 is mainly changed.

The shaft 4'a, bevel gear 4'b, and bearings 4'C, 4'd in the upper bevel gear box 4' have the same structure as the conventional example shown in FIG. Vertical shaft 4'e fixed with matching bevel gear 4'f
However, in order to protrude outside the top surface of the bevel gear box 4' and fix the brake drum 12, an oil seal 18 is provided at the top opening of the bevel gear box, and an oil sump device 17 is provided to prevent the oil seal from running out of oil. Attach.

On the other hand, a joint 16 for connecting to the vertical shaft 5 is fixed to the portion protruding from the bottom surface.

Note that the vertical axis 4'e coincides with the pivot axis P-Q.

Conventional upper bevel gearbox 4 configured as above,
4' is relatively advantageous in terms of strength and manufacturing because it is small in size and can be made into a simple shape, but it has the following drawbacks including the above-mentioned rear end turning radius.

First, as mentioned above, if the driving power train is configured to mechanically transmit the power of the engine to the drive wheels and the rotating body rotates 360 degrees, the center of the vertical axis of the upper bevel gearbox should be the center of the vertical axis of the upper bevel gearbox. The driving powertrain must be arranged in series as shown in Figure 2.In this case, the driving powertrain includes engine 1, clutch 2, and transmission 3. are virtually unchangeable and cannot be shortened enough to affect the rear end turning radius;
After all, from the transmission end face 3C to the vertical axis 4e or 4
Since the dimension up to 'e is large, the rear end turning radius RW cannot be made small.

Second, in order to repair any one part when repairing the upper bevel gearbox 4, 4', in the case of FIG. In the case of Figure 5, bolt 1
3 and the joint 16, the entire bevel gearbox 4' must be removed from the joint 15, and vice versa.

The third problem is that the position of the brake drum 12 in Fig. 4 is on the lower surface of the upper bevel gear box 4, which is narrow and difficult to visually inspect. Brake adjustment work is difficult because the brakes are insufficient.

On the other hand, as shown in FIG. 5, this is improved and the upper surface of the upper bevel gear box 4' is provided with an oil seal 18 at the upper surface opening of the bevel gear box, as described above. An oil sump device 17 that requires precise machining accuracy to keep the seal in an oil-free state at all times is required, which increases both machining costs and the number of parts.

This invention was made in consideration of the above-mentioned problems, and by changing the meshing arrangement of the bevel gears in the upper bevel gearbox of the power train for traveling in a wheeled hydraulic excavator, it is possible to The rear end turning radius is reduced by reducing the distance to the vertical axis center, that is, the turning center of the rotating body,
It is also intended to facilitate the assembly and disassembly of the upper bevel gearbox.

The feature of this invention is that the turning radius of the rear end of a wheeled hydraulic excavator is limited by the configuration and arrangement of the power train for running the wheeled hydraulic excavator. The meshing arrangement of the inner bevel gears is configured such that the rear end turning radius is shortened.

An embodiment of this invention will be explained in detail below with reference to FIG.

In the drawings, the same reference numerals as in FIGS. 4 and 5 represent the same or equivalent parts.

In the upper bevel gear box 40, a boss 3d having a spline on the outer periphery is fixed to the shaft end of the output shaft 3a of the transmission 3, and a shaft 40a having the same spline as the spline at the shaft end adjacent to the output shaft 3a. are arranged coaxially, and the splines at both wheel ends are connected by a sleeve 3b.

A bevel gear 40b is fixed to the middle of the shaft 40a and supported on both sides by bearings 40C and 40d.

Then, a shaft 40a is made to protrude from the outer surface of the upper bevel gear box 40 on the side of the bearing 40d, and the brake drum 12 is fixed to the end of the shaft.

An oil seal 20 is attached to this opening to prevent oil from leaking inside the upper bevel gear box 40.

Bevel gear 40 that meshes directly with bevel gear 40 b
f is integrally fixed to the upper end of a vertical shaft 40e, and the shaft is supported by bearings 40g and 40h at the base of the bevel gear 40f and below.

A joint 16 for connecting to the vertical shaft 5 is fixed to the lower end of the bearing 40h, projecting downward.

In this case, the axis of the vertical shaft 40e is aligned with the rotation center axis PQ, and the bevel gear 40b is disposed on the opposite side of the transmission than the rotation center axis P-Q so that they mesh with each other.

Also, just by removing or tightening the bolt 13, the seam 15
From shaft 40a, bevel gear 40b, bearings 40C, 40
d. The parts of the brake drum 12 can be disassembled together with the housing independently of the vertical axis 5, and conversely can be reassembled.

In this embodiment with such a configuration, the dimension 1 from the end surface 3C of the transmission 3 to the center of the vertical axis 40e or the vertical axis 5, that is, the pivot axis P-Q, is approximately equal to that of the bevel gear 40.
It can be made as small as the outer diameter of f.

Therefore, the center of gravity Gp of the driving power train in Figure 1
Since the dimension l becomes much smaller than the conventional dimension, it approaches the center of gravity G of the entire aircraft, and at the same time, the center of gravity G also moves to the right in the figure, that is, to the front, by a corresponding amount.

This means that the operability of wheeled hydraulic excavators is
This means more understeer.

Further, since the brake drum 12 is fixed to the outer end of the shaft 40e as described above, the space is wide and visual inspection is sufficient, making adjustment work easy.

There is no need to worry about the oil seal 20 running out of oil, and there is no need to provide a special oil reservoir device 17.

Although the above description has been made regarding bevel gears whose axes are perpendicular to each other, they do not necessarily have to be perpendicular to each other, and the same explanation can be applied to hypoid gears whose axes are different from each other.

As described above, according to this invention, in the upper bevel gearbox in the power train for running a wheeled hydraulic excavator, the meshing of the bevel gear is between the bevel gear fixed to the shaft disposed on the rotation center axis of the rotating body and the transmission. The bevel gear fixed to a shaft coaxially arranged adjacent to the end of the output shaft is configured to mesh at a position on the opposite side of the transmission from the center axis of rotation, thereby reducing the dimension from the end face of the transmission to the center axis of rotation. This has the effect of reducing the turning radius of the rear end of the wheeled hydraulic excavator and making it easier to assemble and disassemble the upper bevel gearbox.

[Brief explanation of the drawing]

Figure 1 is a side view of the layout of the conventional running powertrain of a wheeled hydraulic excavator, which is mechanically connected sequentially from the engine to the driving wheels. Figure 2 is a plan view of the main parts of Figure 1, with the rear end turning. Fig. 3 is a diagram showing the engine arrangement and rear end turning radius of a general hydraulic excavator, and Fig. 4 is a diagram showing the radius.
FIG. 5 is an explanatory vertical cross-sectional view of a conventional upper bevel gearbox, FIG. 6 is an explanatory vertical cross-sectional view of another conventional upper bevel gearbox, and FIG. 6 is an explanatory vertical cross-sectional view of an upper bevel gearbox according to the present invention. be. A...Rotating body, 1...Engine, 2.
...Clutch, 3...Transmission, 3a...Output shaft, 3C...Transmission end face, 4.4', 40...Upper bevel gear box, 4 b , 4'b , 40 b , 4
f, 4'f, 40 f...bevel gear,
4 a, 4'a, 40 a...axis, 4e,
4'e, 4Qe... Vertical axis, 5... Vertical axis, 9... Drive wheel, 12... Brake drum, P...・Turning center, Rw. Rc...Rear end turning radius.

Claims (1)

[Scope of utility model registration request] In the upper bevel gearbox of a wheeled hydraulic excavator in which the driving power train is sequentially mechanically connected from the engine to the clutch, transmission, upper bevel gearbox, and drive wheels by a vertical shaft, etc.,
A bevel gear fixed to a shaft disposed coaxially adjacent to the end of the output shaft of the transmission, and a bevel gear fixed to a shaft disposed perpendicularly with the center of rotation of the rotating body aligned with the center of rotation, are arranged on the opposite side of the transmission from the center of rotation. A structure for shortening the rear end turning radius of a wheeled hydraulic excavator, characterized in that the wheels are arranged so as to mesh at the position.