JPH025633B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to, for example, a shaft drive type motor tricycle, and particularly to a structure around a gear case that transmits engine power to a rear wheel shaft.

[Prior art]

Conventionally, in automatic tricycles called ATVs that travel on sandy or rough terrain, the left and right rear wheels are driven by shafts, as seen in ``Utility Model Publication No. 56-152790''. Are known.

When the rear wheels are driven by a shaft in this way, one of the left and right rear arms is formed hollow, and the transmission shaft that transmits the engine power is inserted into this one rear arm, in consideration of the location where the engine power is taken out. At the same time, a gear case supporting the rear wheel axle is connected to the rear end opening of the rear arm by abutting against each other from the rear, and a driving bevel gear driven by the transmission shaft and a driven bevel gear on the rear wheel axle are housed in the gear case. It is possible that bevel gears are accommodated and meshed with each other, and the rear arm is used as a case for a power transmission path.

On the other hand, because this type of tricycle travels on extremely uneven terrain such as sandy or rough ground, the impact applied to the support portion of the rear wheel axle is quite large. Therefore, by connecting the gear case and the rear end of the other rear arm through a hollow hub, and passing the rear wheel shaft through the hub and gear case, the rear arm and the rear wheel support section can be connected. It is thought to increase stiffness and strength.

[Problem that the invention seeks to solve]

Incidentally, since a driving bevel gear and a driven bevel gear that mesh with each other are housed in the gear case, it is necessary to remove the gear case from the rear arm and hub when performing maintenance and inspection of these bevel gears.

In this case, since the rear end of the transmission shaft is introduced into the gear case through the rear arm, in order to remove the gear case from the rear arm, it is necessary to shift the gear case backward and pull out the transmission shaft from the gear case.

However, since this gear case is also connected to the rear end of the other rear arm via a hub that extends in the left-right direction, for example, if the gear case and the hub are made into a so-called spigot joint by fitting the gear case with a concave and convex shape, the gear case becomes It becomes impossible to pull it out backwards, which causes problems such as the need for effort and effort to attach and detach the gear case.

Therefore, the present invention provides a shaft drive equipped with two rear wheels in which the gear case can be pulled out rearward as it is, no effort is required to attach and detach the gear case, and the mating surface between the gear case and the hub can be easily processed. The purpose is to provide type vehicles.

[Means for solving problems]

Therefore, in the present invention, a pair of left and right rear arms are provided that extend toward the rear of the engine, one of the rear arms is formed in a hollow shape, and a transmission shaft through which engine power is transmitted is inserted and disposed inside the rear arm. Connect the gear case to the rear end opening of one of the rear arms from the rear,
A drive bevel gear driven by the transmission shaft is housed in this gear case, and the transmission shaft is configured to be separably connected in the axial direction at a connecting portion between the rear arm and the gear case, and the other The rear end of the rear arm and the gear case are connected by a hollow hub, and a rear wheel shaft that supports the left and right rear wheels is inserted through these hubs and the gear case. Assuming that the vehicle is a shaft drive type vehicle with two rear wheels that are driven by a driven bevel gear that meshes with the driving bevel gear in the gear case, the mating surface of the gear case and the hub should be aligned approximately parallel to the direction in which the rear arm extends. It is characterized by being formed on the same flat surface.

[Function] According to this configuration, since the mating surfaces of the gear case and the hub are formed on the same flat surface extending in the front-rear direction along the extending direction of the rear arm, there is no difference between the mating surfaces of the gear case and the hub. There are no parts that protrude or fit into each other on this mating surface, and if the gear case is disconnected from the rear arm and hub while the rear wheel axle is pulled out, the gear case can be pulled out rearward.

Therefore, maintenance and inspection work inside the gear case can be easily performed without requiring any effort to attach or detach the gear case.

In addition, since the mating surface between the gear case and the hub can be simply formed as a flat surface, the mating surface between the gear case and the hub can be easily
Compared to the so-called spigot structure, it can be processed more easily and can be provided at a lower cost.

〔Example〕

The present invention will be explained below based on an embodiment shown in the drawings.

The vehicle body indicated by reference numeral 1 in the figure has a main pipe 3 extending rearward from a steering head pipe 2, and a pair of left and right down tubes 4 extending downward. A pair of left and right seat pillar tubes 5 extending downward are connected in the middle of the main pipe 3, and the seat pillar tubes 5 and the down tubes 4 are connected to each other at the lower rear end. An engine 6 is mounted in a space surrounded by the main pipe 3, down tube 4, and seat pillar tube 5.

The steering head pipe 2 includes a front fork 8 that is steered by a bar handle 7.
is supported. A front wheel 9 is pivotally supported at the lower end of the front fork 8, and this front wheel 9 is equipped with ultra-low pressure wide balloon tires 10.

A pair of left and right seat rails 12 that support the seat 11 and extend rearward are connected to the upper end of the seat pillar tube 5.
2 is down tube 4 and seat pillar tube 5
It is supported by a pair of left and right backstays 13 extended by the joint portions of the backstays 13.

Further, a rear arm assembly 15 is swingably supported at the joint portion of the down tube 4 and the seat pillar tube 5 via a pivot shaft 14.

Regarding this rear arm assembly 15,
To explain with reference to the drawings, the rear arm assembly 15 includes a pair of left and right rear arms 16a, 16b that extend toward the rear of the engine 6, and the front ends of these rear arms 16a, 16b are connected to the front cross member 17. connected together. One rear arm 16a has a hollow pipe 1
8 and 19 are connected in the axial direction to form a hollow shape, and the rear end opening of this hollow pipe 19 is abutted against the front end opening of the gear case 20 from the rear. The gear case 20 is fixed to the rear arm 16a by screwing bolts 21 into the joints with the hollow pipes 19 and tightening them with nuts 22.
The joint surface A between the rear arm 1 and the gear case 20 is
It is formed on a flat surface perpendicular to 6a.

A transmission shaft 23 for transmitting engine power is inserted through the rear arm 16a. The transmission shaft 23 is divided into three parts: a front shaft 24, an intermediate shaft 25, and a rear shaft 26.
4 is an output shaft 27 in the engine case 6a.
It is linked with. In other words, the engine case 6a
Inside, a bevel gear 28 rotates together with the output shaft 27.
and a bevel gear 29 on the front shaft 24 are meshed with each other, and the bevel gear 29 is connected to the front shaft 2 through a buffer mechanism 30.
It is connected to 4. The buffer mechanism 30 is a bevel gear 29
via the cam surface 31a, and the front shaft 2
4, and another sleeve 32 rotatably fitted onto the front shaft 24.
When excessive back torque is applied from the front shaft 24 side toward the output shaft 27, the sleeve 31 moves against the spring 33 to the other sleeve 32 side. The power transmission to the bevel gear 29 is cut off.

Further, the front shaft 24 and the intermediate shaft 25 are connected via a universal joint 34 on the axis of the pivot shaft 14, so that power can be transmitted even if the rear arm 16a swings.

In addition, the rear arm 16a and the engine case 6a
A rubber boot 35 is installed between the two.

The rear shaft 26 of the transmission shaft 23 is connected to the rear arm 16a.
The rear shaft 26 is led out from the rear end opening into the gear case 20, and is rotatably supported by the gear case 20 via a bearing 36. A cylindrical internal gear 37 is provided at the front end of the rear shaft 26.
The internal gear 37 is located at the joint between the gear case 20 and the rear arm 16a, and its front end enters into the rear arm 16a. An external gear 38 formed at the rear end of the intermediate shaft 25 is meshed with this internal gear 37. Therefore, the intermediate shaft 25 and the rear shaft 26 are connected to each other at the joint between the rear arm 16a and the gear case 20. , are axially separably coupled.

A drive bevel gear 40 is formed on the rear shaft of the rear shaft 26 . This drive bevel gear 40 is the gear case 2
It meshes with the driven bevel gear 41 housed in the
This driven bevel gear 41 has a boss portion 41a that bears the bearing 4.
It is pivotally supported within the gear case 20 via 2.
A sleeve 43 having a straight spline groove formed on the inner surface is welded into the boss portion 41a of the driven bevel gear 41, and this sleeve 43 is connected to the roller bearing 4.
4 and is pivotally supported by the gear case 20. Further, on the inner surface of the gear case 20, a cover 45 that also serves as a bearing case that supports the bearing 42 is attached to the bolt 46.
It is fixed by tightening it through.

In addition, at the rear end of the other rear arm 16b,
A bearing case 50 is welded. Bearing case 5
0 faces the cover 45 of the gear case 20, and the bearing case 50 and cover 45 are connected by a hollow hub 51. That is, one end of the hub 51 is welded to the bearing case 50, and a cylindrical bracket 52 is welded to the other end of the hub 51. The bracket 52 has a flange portion 53 overlaid on the side surface of the cover 45.
This flange portion 53 is removably fastened to the cover 45 via bolts 54. The mating surface B between the flange portion 53 and the cover 45 is between the gear case 20 and the rear arm 1.
The rear arms 16a and 16b are machined to have the same flat surface in the front-rear direction, which is perpendicular to the joint surface A with the rear arms 16a, ie, substantially parallel to the extending direction of the rear arms 16a and 16b.

Therefore, the left and right rear arms 16a, 16
b, front cross member 17, gear case 20
The hub 51 is framed in a rectangular shape to constitute the rear arm assembly 15.

Note that a hydraulic shock absorber 5 is installed between the under bracket 55 welded to the upper surface of the hub 51 and the upper bracket 56 welded to the rear end of the main pipe 3.
7 is being bridged.

On the other hand, a rear wheel portion 60 is horizontally suspended between the rear end portions of the rear arms 16a and 16b, passing through the bearing case 50, the hub 51, and the gear case 20. Left and right rear wheels 61 are attached to both ends of the rear wheel section 60 so as to rotate together with the rear wheel shaft 60, and the rear wheels 61 are equipped with balloon tires 62 similar to the front wheels 9. .

One end of the rear wheel shaft 60 is pivotally supported by the gear case 20 via a bearing 63, and the other end is pivotally supported by the bearing case 50 via another bearing 64, and the rear wheel shaft 60 passes through the gear case 20. A straight spline groove 65 that engages with the sleeve 43 is formed on the outer peripheral surface of the portion where the sleeve 43 engages. Therefore, the rear wheel shaft 60 is rotationally driven integrally with the sleeve 43.

In this way, the rear wheel shaft 60 is inserted from the bearing case 50 side and assembled between the rear ends of the rear arms 16a and 16b as shown by the arrow C in FIG. It is designed to be pulled out in the opposite direction to the C direction.

According to this embodiment of the present invention, when performing maintenance inspection inside the gear case 20, the rear wheel shaft 60 is pulled out from the rear end of the rear arms 16a, 16b, and then the nut 22 is loosened. The connection between the rear arm 16a and the gear case 20 is released, and the bolt 54 is loosened to release the connection between the hub 51 and the gear case 20. At this time, gear case 2
0 includes a transmission shaft 23 that passes through the rear arm 16a.
Since the rear end is inserted, the gear case 20
Therefore, the gear case 20 is shifted to the rear of the rear arm 16a as shown by arrow D in FIG. 1, and the internal gear 37 is separated from the external gear 38. It is necessary to pull it out, that is, to separate the intermediate shaft 25 and the rear shaft 26 in the axial direction.

By the way, in the above configuration, the mating surface B between the hub 51 and the gear case 20 is connected to the rear arms 16a, 16b.
Since they are formed on the same flat surface in the front-rear direction that is approximately parallel to the extending direction of the If the gear case 20 is disconnected from the rear arm 16a and the hub 51 as shown in FIG.
Move the entire gear case 20 to the rear (arrow D
direction) and remove the rear arm assembly 1.
It can be removed from 5.

Therefore, the troublesome work of shifting the gear case 20 in the front-rear and left-right directions is not necessary, so the work of attaching and detaching the gear case 20 can be easily performed without the need for labor.

Also, the mating surface B between the gear case 20 and the hub 51
Since it is sufficient to form a simple flat surface, it is easier to process than a so-called spigot structure in which projections and recesses fit into each other, and it also has the advantage of contributing to a reduction in manufacturing costs.

In the above-described embodiment, the rear arm assembly is pivotably supported relative to the vehicle body, but in some cases, it may be rigidly fixed to the vehicle body.

〔Effect of the invention〕

According to the present invention described in detail above, if the gear case is disconnected from the rear arm and hub while the rear wheel axle is pulled out, the entire gear case can be pulled out rearward as it is. It does not require much effort and can be easily attached and detached.

Further, the mating surface between the gear case and the hub can be easily machined, which has the advantage of contributing to a reduction in manufacturing costs.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a sectional view of a rear arm assembly and a power transmission path, FIG. 2 is a plan view showing the body structure of a tricycle, and FIG. 3 is a side view thereof. . 6...Engine, 16a, 16b...Rear arm,
20... Gear case, 23... Transmission shaft, 40... Drive bevel gear, 41... Driven bevel gear, 51... Hub, 60... Rear wheel shaft, 61... Rear wheel, B... Matching surface.

Claims (1)

[Scope of Claims] 1. A vehicle is provided with a pair of left and right rear arms extending toward the rear of the engine, one of the rear arms is formed into a hollow shape, and a transmission shaft through which engine power is transmitted is inserted through the rear arm, and A gear case is connected from behind to the rear end opening of one of the rear arms, and a drive bevel gear driven by the transmission shaft is accommodated in this gear case, and the transmission shaft is connected to the rear arm and the gear case. Constructed by connecting separably in the axial direction at the connecting part,
Further, the rear end of the other rear arm and the gear case are connected by a hollow hub, and a rear wheel shaft that supports the left and right rear wheels is inserted through the hub and the gear case. A shaft drive type vehicle comprising two rear wheels in which the rear wheel shaft is driven by a driven bevel gear meshing with the driving bevel gear within the gear case, the mating surface of the gear case and the hub being an extension of the rear arm. A shaft drive vehicle having two rear wheels formed on the same flat surface substantially parallel to the direction.