JPS604426A - Power transmission of small-sized vehicle having two rear wheels - Google Patents

Abstract

PURPOSE:To contrive compactness of the whole of a power transmission by contriving miniaturization of a transmission case, by providing a rear axle shaft by making the same penetrate through a part surrounded by three parts such as a driving shaft, a driven shaft and a winding transmission body. CONSTITUTION:A crankcase 6 in an engine 5 is divided into a right and left two cases 7, 8 and a transmission case 17 extending toward the rear of a car body is formed on a rear end part of the left case 7 unitarily, in a small-sized vehicle whose fixed seating capacity is one person. A left end part of a crankshaft 11 and a driven shaft 20 are arranged on a front and rear end parts of a transmission chamber 19 of the inside of the transmission case 17, and both the shaft 11, 20 are connected by a V belt stepless speed change gears 21 with each other. In addition to the above, a first gear chamber 32 is formed on the rear of the transmission chamber 19 and at the same time a second gear chamber 40 is formed of a recessed part 38 provided on the transmission case 17 in a recessed state and a cover 39. Then a differential gear 53 is arranged in front of a gear chamber 40 and a right and left axle shafts 47 are penetrated through the transmission case 17.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to, for example, a small vehicle with a passenger capacity of one person and two rear wheels intended for driving mainly in urban areas, and particularly relates to a power transmission device for driving the rear wheels. .

In this type of small vehicle, the body itself is a converter. Therefore, the engine and the transmission device that transmits its power to the rear wheels also need to be made as small as possible.

The present invention was made based on these circumstances, and
The purpose of the present invention is to provide a power transmission device for a small vehicle having two rear wheels, in which the axle of the rear wheels can be effectively arranged by utilizing dead space within a transmission case, and the overall size can be reduced.

That is, in order to achieve the above object, the present invention accommodates a drive shaft and a driven shaft spaced apart in the front and back in a transmission case, and also accommodates a drive-side rotating member attached to the drive shaft and a driven-side rotation member attached to the driven shaft. A wrapped transmission body such as a V-belt is wound around the rotating member to form a unit, and a part of the transmission case surrounded by the drive shaft, driven shaft, and wrapped transmission body is parallel to the drive shaft and driven shaft. An axle driven by power transmission from the driven shaft is inserted through the axle, and rear wheels are provided at both ends of the axle passing through the transmission case.

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

1 in Fig. 1 is a box-shaped vehicle body, and left and right front wheels 2, 2 are arranged at the front of this vehicle body 1, and left and right rear wheels 3, 3 are arranged at the rear. There is. The rear wheels 3, 3 are rotationally driven by an engine unit 4 provided between these rear wheels 3, 3. The front end of the cooled engine 4 is swingably connected to the vehicle body 1, and the rear end is suspended via a shock absorber (not shown).The details of this engine unit 4 will be described below. This will be explained with reference to FIGS. 2 and 3.

That is, 5 is a two-stroke engine, and its crankcase 6 has a two-part structure in which a left case 7 and a right case 8 are abutted against each other.

A crankshaft 11 driven by a piston 10 in a cylinder 9 is housed in the crankcase 6, and a generator 12 and a fan 13 are attached to the right end of the crankshaft 11. The fan 13 inhales outside air from the suction port 14 and sends it to the air shroud 15 that covers the cylinder 9.
The engine 5 is forcedly cooled by blowing air inside the engine 5, and the outside air after cooling the engine 5 is discharged from the discharge port 16.

By the way, a transmission case 17 is integrally formed at the rear end of the left case 7 and extends toward the rear of the vehicle body 1.
The left side openings of the left case 7 and the transmission case 17 are integrally closed by a transmission case cover 18. In this case, the left side openings of the left case 7 and the transmission case 17 are machined into the same plane, and therefore the base surfaces of the left case 7 and the transmission case 17 and the base surface of the transmission case cover 18 are on the same plane. It is collided above. The left end portion of the crankshaft 11 is led out to the front end of the transmission chamber 19 in the transmission case 17, and therefore, in this embodiment, the crankshaft 11 constitutes a drive shaft. A driven shaft 2 is provided at the rear end of the transmission chamber 19 in parallel with the crankshaft 11.
0 is pivotally supported, and this driven shaft 20 and crankshaft 11
are provided at a fixed distance apart from each other in the longitudinal direction of the vehicle body 1, and are interlocked by a V-belt type continuously variable transmission 21. This V-belt type continuously variable transmission 21 is constructed by passing a V-belt 24 as a wrapped transmission body between a primary sheave 22 on the crankshaft 11 side and a secondary sheave 23 on the driven shaft 20 side. Ru. ! Primary sieve 2
2 is spline-engaged with the left end of the crankshaft 11, and as the rotational speed of the crankshaft 11 increases, the flyweight 25 moves in the outer radial direction due to centrifugal force.

The groove width of the V-shaped groove 26 is automatically reduced, and the V-belt 2
4 is moved in the outer radial direction of the primary sheave 22. Further, the secondary sheave 23 is relatively rotatably mounted on a sleeve 22 rotatably inserted on the outer periphery of the driven shaft 20, and the groove width of the V-shaped groove 29 is constantly controlled by the biasing force of a spring 28. It is biased in the direction of decrease. Therefore, when the V-belt 24 is moved in the outer radial direction due to the speed increase of the crankshaft 11 as described above, the secondary sheave 23 conversely moves the V-belt 24
4 is drawn inward in the radial direction, and the width of the V-shaped groove 29 is expanded. Therefore, the rotation of the crankshaft 11 is transmitted to the secondary sheave 23 in an accelerated state. When the rotation speed of the secondary sheave 23 exceeds a predetermined value, the centrifugal clutch 30 is activated to transmit the rotation of each secondary sheave 23 to the sleeve 27.

At the rear of the transmission chamber 19, a first gear chamber 32 is defined by a partition wall 31, and the driven shaft 20 and the right end of the sleeve 27 are introduced into the first gear chamber 32.
An intermediate shaft 33 supported in the first gear chamber 32 has a large gear 35 that meshes with a small gear 34 provided at the introduction end of the sleeve 27.
A reduction gear 37 that meshes with the reduction gear 36 fixed to the introduction end of the driven shaft 20 is fixed, so that the rotation of the sleeve 21 is controlled by the pinion 34, the large gear 35, the intermediate shaft 33, the reduction gear 37, and the rotation of the sleeve 21. Driven shaft 2 via reducing gear 36
0 that is transmitted while being decelerated to 0. Also, the transmission case 1
The right side surface of 7 is recessed toward the inside of the transmission chamber 19,
The opening of this recess 38 is covered by another cover 39. A second gear chamber 40 separated from the transmission chamber 19 is formed between the cover 39 and the recess 38, and the second gear chamber 40 is located on the side of the transmission chamber 19 and is located in the recess. The bottom surface 41 of 38 is the bridging sheave 2.
2 and the secondary sheave 23.
The maximum space 42 is secured in this part. The right end of the driven shaft 20 is introduced into the second gear chamber 40 through the bottom surface 41, and an intermediate shaft 43 is pivotally supported in front of this introduction end.

A drive gear 44 is fixed to the introduction end of the driven shaft 20, and this drive gear 44 is connected to the driven gear 4 fixed to the intermediate shaft 43.
5 to drive a transmission gear 46 on this intermediate shaft 43.

By the way, the transmission case J71C has an axle 47 installed parallel to the crankshaft 1 and the driven shaft 20. It is inserted through a portion surrounded by the slack side 24a and the slack side 24b and the largest space 42 of the second gear chamber 40. Both ends of the axle 47 are connected to the transmission rear wheels 3.
, 3 are attached. The axle 47 is divided into two parts: a left axle part 48 that supports the left rear wheel 3 and a right axle part 49 that supports the right rear wheel 3.
8 is pivotally supported in the penetration portion of the transmission case 17 and the transmission case cover 18 via bearings 5'0 and 50, respectively, and the right axle portion 49 is pivotally supported in the penetration portion of the cover 39 via a bearing 51. ing. Further, both axle portions 48.
49 is interlocked within the second gear chamber 40 via a differential gear 52. That is, a differential case 53 is rotatably attached between the divided ends of both axle portions 48 and 49, and this differential case 53 is rotationally driven by a ring gear 54 that meshes with the driven gear 45. A pair of differential binions 55.55 that rotate together with the differential case 53 are accommodated in the differential case 53, and these differential binions 55.55
It meshes with side gears 56, 56 fixed to the ends of the 8°490 split. Therefore, when the differential case 53 rotates, the differential binions 55, 55 are connected to the side gears 56 and 56.
Since it revolves while meshing with the side gear 5,
6.56 is rotated at the same speed. For example, if a large road resistance is applied to the left rear wheel 3 due to turning, the differential 2 onion 56,55 revolves on its own axis on the left side gear 56, so the rotation of the partial pressure side axle 48 decreases, and The rotation of the right axle portion 49 is increased.

The second gear chamber 40 is filled with lubricating oil for lubricating various gears.

Further, in the figure, reference numeral 57 is a carburetor, 58 is an air cleaner, and 5
9 indicates a cell starter.

However, in the engine unit 4 having such a configuration,
In order to secure the winding diameter of the V-belt 240 for the primary sheave 22 and the secondary sheave 23, the crankshaft 11 and the driven shaft 20 must be arranged with some distance from each other, and there is a large space between these two shafts. do. In this case, the axle 47 of the rear wheels 3, 3 should be arranged between the crankshaft 11 and the driven shaft 20 and surrounded by the tension side 24a and slack side 24b of the V-belt 24, as in the above configuration. For example, the axle 42 can be disposed by effectively utilizing the unused space within the transmission chamber 19. Therefore, axle 47
There is no need to secure a special space for inserting the engine unit 4, and the engine unit 4 is located just between the rear wheels 3 and 3.
The positional relationship allows the entire device to be made compact.

Furthermore, in this embodiment, the left case 7 of the crankcase 6 and the left side opening of the transmission case 17 are on the same plane, and the base surface of the transmission case cover 18 that covers this opening is flush with each other. can be processed in one step, improving workability.

In addition, when assembling the differential gear 52 into the transmission case 17, the right side of the transmission case 17 is inserted into the transmission chamber 19.
By concave to the side and covering the opening of the four parts 38 with a cover 39, a second gear chamber 40 which is partitioned and independent from the transmission chamber 19 is formed between these concave parts 38 and the cover 39. Since the differential gear 52 is disposed within the two-gear chamber 40, a space for disposing the gear 52 can be easily obtained. Still transmission case 17
By attaching the cover 39 to the transmission case 17
The rigidity of the rear wheels 3, 3 is improved, and the axle 47 of the rear wheels 3, 3 is connected to the transmission case cover 18, the transmission case 17 and the cover 39.
Since the axle 47 passes through the main part of the shaft 47, the insertion area of the axle 47 becomes wider. As a result, the axle 47 is supported at a position closer to the rear wheels 3, 3, so the bearing bracket 4 becomes longer and the axle 47
As the bending moment applied to the bearing 5 becomes smaller,
0゜50,. 51 has the advantage of reducing the burden.

Note that the present invention is not limited to the embodiments described above. For example, in the above embodiment, a belt is used as the wrapping power transmission body, but
A sprocket may be attached to each of the crankshaft and the driven shaft, and a chain or a toothed belt may be passed between these two sprockets.

Alternatively, the differential gear may be omitted and the axle and driven shaft may be directly connected, and the engine may be fixed to the vehicle body.
Alternatively, only the transmission case may be swung.

According to the present invention described in detail above, the axle of the rear wheel is inserted through the portion surrounded by the drive shaft, driven shaft, and the wrapped transmission body, so that the axle can be inserted into the portion that is surrounded by the king of the transmission case. It can be used and placed. therefore,
There is no need to secure space for the axle to pass through the transmission case, so the transmission case does not become large, and the transmission case is positioned exactly where the IC between the rear wheels will fit, so the overall size can be made more compact. There are some advantages.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which FIG. 1 is a side view of a small vehicle, FIG. 2 is a sectional view of a power transmission device, and FIG. 3 is a partially sectional side view. 1... Vehicle body, 3... Rear wheel, 5... Engine, 11
... Drive shaft (crankshaft), 17... Transmission case,
20... Driven shaft, 22... Driving side rotating member (Zoraimary sheep), 23... Driven side rotating member (secondary sheep), 24... Wrap conductor, 47... Axle . Applicant's agent Patent attorney Takehiko Suzue Figure 1

Claims (1)

[Claims] A drive shaft driven by the engine is housed in the front end of a transmission case extending from the engine toward the rear of the vehicle body, and a driven shaft is housed in the rear end of the transmission case parallel to the drive shaft. The frame passes an endless wrap-around transmission member between the drive-side rotating member attached to the drive shaft and the driven-side rotation member attached to the driven shaft, and the drive shaft, driven shaft, and wrap-around power transmission body in the transmission case An axle that is parallel to the drive shaft and driven shaft and rotationally driven by power transmission from the driven shaft is inserted into the enclosed area, and this axle passes through the transmission case, and both ends of the axle are inserted. A power transmission device for a small vehicle having two rear wheels, characterized in that a rear wheel is provided in the rear wheels.