JPS6318253Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a traveling drive device for an industrial vehicle such as a forklift or a construction machine.

Conventionally, for example, in a forklift, as shown in FIGS. 1 and 2, axle tubes 2 are rotatably supported on vehicle body frames 1 on both left and right sides, and a differential lens is installed between both axle tubes 2. A transmission 4, a clutch 5, and an engine 6 are sequentially fixed to the differential gear 3, and the engine 6 is elastically supported on the vehicle body frame 1 by a mount 7.
A front axle 8 rotated by a differential device 3 is inserted into the axle tube 2, and a front wheel 9 is attached to the front axle 8. By transmitting the force acting on the fork to the front wheel 9 as a driving wheel via the axle tube 2 and the front axle 8 without using a cushion member, it is possible to stably support the load on the fork. However, in this type of traveling drive device, the vibrations of the engine 6 are transmitted to the vehicle body frame 1 via the clutch 5, transmission 4, differential device 3, and axle tube 2, so that vibrations in various parts of the machine are transmitted. There was a defect that caused vibration.

In addition, in order to eliminate the above-mentioned defects, conventionally, as shown in FIG. 3, the clutch 5 and engine 6 are separated from the transmission 4, and the clutch 5 and engine 6 are supported on the body frame 1 via a mount 7. A drive device has been proposed in which the transmission 4 is also supported on the vehicle body frame 1 via a mount 7, and the output shaft 10 of the engine 6 and the input shaft 11 of the transmission 4 are connected by a universal joint 12. However, with this drive system, it is necessary to provide a large space between the transmission 4 and the clutch 5 to accommodate the universal joint 12, which not only increases the wheelbase (distance between axles) but also increases the The vibrations are transmitted to the transmission 4 via the output shaft 10 and the universal joint 12 which does not have vibration absorption ability, and irregular vibrations act on the output shaft 10, the universal joint 12, and the input shaft 11. However, the disadvantage was that it accelerated the wear of the power transmission system.

Purpose of the invention The present invention was made in order to eliminate the deficiencies existing in the above-mentioned prior art. In addition to significantly reducing the vibration of
It is an object of the present invention to provide a traveling drive device for an industrial vehicle that can absorb this and protect the power transmission system and extend its life.

Structure of the Invention In order to achieve the above-mentioned object, the present invention includes an engine which is elastically mounted to a vehicle body frame via an elastic member, separated from a transmission, and an input shaft provided to the transmission. The input shaft is loosely inserted into a cylindrical shaft rotatably supported by the transmission so that its inner end extends in a direction away from the engine, and the outer end of the input shaft protruding from the cylindrical shaft is connected to the output shaft of the engine. The gist of the invention is that the inner end of the input shaft located within the cylindrical shaft is connected to the inner end of the cylindrical shaft via a second flexible joint. That is.

Embodiment Hereinafter, an embodiment in which the present invention is embodied in a traveling drive device for a forklift will be described with reference to FIGS. 4 and 5. Incidentally, in this embodiment, members having the same functions as those of the conventional traveling drive device shown in FIGS. 1 to 3 described above are given the same reference numerals, and the explanation thereof will be omitted, and only the differences will be described.

A first flexible joint 13 is connected between the tip of the output shaft 10 of the engine 6 and the outer end of the input shaft 11. As shown in FIG. 5a, this first flexible joint 13 includes a flexible iron plate 14 welded and fixed to the tip of the output shaft 10, a flexible iron plate 15 welded and fixed to the outer end of the input shaft 11, and a flexible iron plate 15 welded and fixed to the outer end of the input shaft 11. It is comprised of bolts 16 and nuts 17 that tighten and fix the outer peripheries of flexible iron plates 14 and 15. The input shaft 11 is loosely inserted in a cylindrical shaft 19 rotatably supported by a bearing 18 into the case of the transmission 4 so as to be movable in the radial direction, i.e.
The input shaft 11 is arranged so that the inner end thereof extends in the direction away from the engine, and the inner end of the input shaft 11 and the cylindrical shaft 1
It is connected to the inner end of 9 by a second flexible joint 20. This second flexible joint 20 includes a flexible iron plate 21 welded and fixed to the inner end of the input shaft 11, and a flexible iron plate 21 fixed to the inner end of the input shaft 11.
A seal plate 23 is provided between the flexible iron plate 21 and the inner end surface of the cylindrical shaft 19.
is crimped.

A reduction gear 24 is fitted and fixed to the outer peripheral surface of the cylindrical shaft 19 so as to be able to rotate integrally with the transmission 4.
The reduction gear 24 is meshed with a reduction gear 27 that is fitted and fixed to the outer periphery of a reverse idler shaft 26 which is rotatably supported in the case of the reverse idler shaft 26 via a bearing 25. The rotational motion of the reduction gear 27 is transmitted to the differential gear 3 and the front axle 8 by another gear drive mechanism (not shown) provided within the transmission 4. A cover 28 is provided outside the case of the transmission 4 so as to cover the bearings 18 and 25.

Next, the operation of the forklift traveling drive device configured as described above will be explained.

Now, the engine 6 is started and its output shaft 10
When the output shaft 10 is rotated, the rotation of the output shaft 10 is transmitted to the input shaft 11 via the first flexible joint 13, transmitted to the cylindrical shaft 19 via the second flexible joint 20, and further transmitted to the reduction gear 24, 27, gear mechanism (not shown) in the transmission 4, differential device 3
The power is transmitted to the front wheels 9 via the internal gear mechanism and the front axle 8, and the forklift is driven.

While the forklift is running, engine 6
The vibration of Since most of it is absorbed by the flexible joints 13, 20, the transmission 4,
Vibrations of the engine 6 transmitted to the vehicle body frame 1 via the differential device 3 and the axle tube 2 can be significantly reduced. To explain this point in detail, the vibration of the engine 6 causes the output shaft 1 to
0 is displaced by a certain distance e from the central axis L of the cylindrical shaft 19, as shown in FIG.
and is easily absorbed by the first and second flexible joints 13 and 20. That is, the inclination angle of the central axis L1 (same as the central axis of the input shaft 11) of the second flexible joint 20 with respect to the central axis L is the displacement angle α1, and the central axis of the first flexible joint 13 with respect to the central axis L When the inclination angle of L2 is the displacement angle α2, both displacement angles α1 and α2 are suppressed from becoming extremely large, and the eccentric (revolution) movement of the output shaft 10 is controlled by the cylindrical shaft 19.
The second flexible joint 20 and the input shaft 11 absorb the eccentricity e1 of the eccentricity c, and the first flexible joint 13 absorbs the remaining eccentricity e2. Therefore, the vibration absorption capacity increases.

If two flexible joints 13, 2 are used as in the present invention,
0, output shaft 1 as shown in Figure 6.
0 and the input shaft 11 are connected by one flexible joint 13, the displacement angle α becomes too large and an unreasonable force acts on the flexible joint 13, which increases the generation of vibration. This is a problem because it significantly reduces the durability of flexible joints, etc.

In addition, in the present invention, the output shaft 10 of the engine 6
and the input shaft 11 of the transmission 4 are connected by the first flexible joint 13, which has a high degree of freedom in design, compared to a conventional drive device that uses a universal joint 12, which has a low degree of freedom in design. There is an advantage that the distance between the transmission 4 and the clutch 5 can be reduced to shorten the wheelbase.

Furthermore, in the present invention, the power transmission system from the crankshaft of the engine 6 to the front axle 8 has a first
and the second flexible joints 13 and 20 are connected,
Even if an excessive load is applied to the power transmission system, it can be absorbed to protect the power transmission system and extend its life.

Note that the present invention can also be embodied in the following embodiments.

(1) As shown in FIG. 7, an elastic member 30 such as rubber is interposed between the flexible iron plates 14 and 15.

(2) In the above embodiment, the differential device 3 and the transmission 4 are fixed to the axle tube 2, and the axle tube 2 is supported by the vehicle body frame 1. 3 and transmission 4 to be embodied in a forklift of a type that elastically supports the vehicle body frame 1 via a mount 7 or various industrial vehicles.

Effects As detailed above, the vibration absorption capacity of the present invention is increased by the first flexible joint and the second flexible joint. Transmitted engine vibrations can be significantly reduced.
In addition, because the engine output shaft and transmission input shaft are connected by the first flexible joint, which has a high degree of freedom in design, the transmission The wheelbase can be shortened by shortening the distance between the syon and the clutch, which is particularly advantageous for vehicles such as forklifts that require the ability to have a small turning radius. Furthermore, when an excessive load is applied to the power transmission system from the engine crankshaft to the drive shaft, the first and second flexible joints absorb it, protecting the power transmission system and extending its life. It has excellent effects.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a conventional traveling drive device for a forklift, FIG. 2 is a schematic plan sectional view, FIG. 3 is a side view showing a conventional traveling drive device, and FIG. 4 is a side view showing a conventional traveling drive device. A partially cutaway side view showing an embodiment of a traveling drive device for a forklift, FIG. 5a is an enlarged sectional view of the main part, and FIG. 5b is an enlarged sectional view of the main part showing the eccentric state of the output shaft. FIG. 6 is a partial sectional view showing an embodiment of the present invention to be compared with the embodiment of the present invention, and FIG. 7 is a sectional view showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Body frame, 2... Axle tube, 3... Differential device, 4... Transmission, 5... Clutch, 6... Engine, 7... Mount, 10... Output shaft, 11... ...Input shaft, 1
3, 20...first (second) flexible joint, 19...cylindrical shaft.

Claims (1)

[Scope of utility model registration request] The engine is elastically mounted to the vehicle body frame via an elastic member, separated from the transmission, and the input shaft provided to the transmission has its inner end rotatably supported by the transmission. The input shaft is loosely inserted into the cylindrical shaft so as to extend in a direction opposite to the engine, and the outer end of the input shaft protruding from the cylindrical shaft is connected to the first output shaft of the engine.
An industrial vehicle characterized in that the input shaft is connected via a flexible joint, and further, the inner end of the input shaft located within the cylindrical shaft is connected to the inner end of the cylindrical shaft via a second flexible joint. Travel drive device.