JPH0349934Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power unit suitable for use in vehicles, particularly rear engine vehicles.

Recently, in relatively small buses and the like, in order to ensure a sufficient wheelbase within a certain overall length of the vehicle body, the engine and transmission assembly is mounted at the rear of the vehicle body in the width direction, that is, placed horizontally. hand,
A power unit has already been proposed that is configured to drive the rear wheels and is configured to minimize the dimension in the longitudinal direction of the vehicle body from the rear axle to the rearmost end of the vehicle body, that is, the rear overhang. In this type of rear-engine bus power unit, a well-known chain type transfer is connected to the output end of a transmission located near the side wall of the vehicle body, and a transfer output shaft extending in the width direction of the vehicle is connected. and the end of the transfer output shaft on the inside of the vehicle body, that is, on the center line side in the longitudinal direction;
The front end is connected to the rear axle differential,
The rear end of the propeller shaft, which extends generally in the longitudinal direction of the vehicle body, is drivingly connected to the rear end of the propeller shaft by a direction changer containing a pair of bevel gears. Furthermore, many bus power units are based on truck power units with necessary modifications, in order to reduce product and service costs by standardizing parts. A transmission equipped with a parking brake device, usually called a center brake, at the end of the output shaft of the transmission is widely used. When such a transmission with a center brake is combined with the above-mentioned transfer to form the above-mentioned power unit for a rear engine bus, the radiator located in front of the engine, that is, on one side of the vehicle body, is connected to the other side of the vehicle body. The length up to the transfer tube disposed in the section has become significantly longer, making it difficult, or in the worst case, impossible to accommodate it within a certain permissible width of a small vehicle.

This invention was devised in view of the above circumstances.
The engine and transmission assembly are mounted across the width of the vehicle at the rear of the vehicle, and the drive sprocket wheel is fixed to the output shaft of the transmission and is connected to the drive sprocket wheel via a chain or other transmission member. a first bevel gear drivingly connected to the driven sprocket wheel; and a first bevel gear drivingly connected to a propeller shaft extending in the longitudinal direction of the vehicle body and meshing with the first bevel gear. A parking brake device is provided at an appropriate position in the transmission system from the driven sprocket wheel of the transfer gear to the first bevel gear of the shifting machine, and The present invention is directed to a power system for a rear engine vehicle, characterized in that the rim portion of the drive sprocket wheel of the transfer drive is supported by a transfer housing via a bearing. According to the present invention, the drive sprocket wheel of the transfer gear is directly connected to the output end of the transmission, and the transmission system between the driven sprocket wheel of the transfer gear and the input bevel gear, that is, the first bevel gear of the change gear, is connected directly to the output end of the transmission. By arranging the parking brake device at the appropriate location, the overall length in the vehicle width direction of the main part of the power plant, which includes the engine, transmission assembly, and transfer, can be reduced at least as much as a power plant for a truck. The time can be shortened by the amount equivalent to the parking brake device. Furthermore, when mounting the transfer drive sprocket wheel on the output shaft of the transmission,
According to normal technical knowledge, the output shaft end of the transmission is supported by the transfer housing via a bearing, but according to the present invention, the rim portion of the drive sprocket wheel is supported by the transfer housing via a bearing. Therefore, the total length of the output shaft of the transmission can be shortened by approximately the equivalent of the bearing, and as a result, combined with the special arrangement of the parking brake device mentioned above, the power output within a certain limited vehicle width can be reduced. This has the advantage of making it extremely easy to mount the device horizontally.Furthermore, since the main shaft (output shaft) of an existing truck transmission can be used as is, it is possible to reduce manufacturing costs. This has the advantage of increasing capacity and improving reliability.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. First, in FIG. 1, the reference numeral 10 conceptually indicates the rear body of the bus, and the rear body has the following parts:
A rear wheel 12 as a driving wheel and a differential 14 for driving the rear wheel via a rear axle are provided,
In this embodiment, the differential 14 is arranged approximately near the center line in the longitudinal direction of the vehicle body. Further, an engine 16 is placed horizontally in the vehicle width direction at the rear of the vehicle body behind the rear axle, that is, in the rear overhang portion, and a transmission 22 is assembled to the flywheel housing 18 of the engine via a clutch device 20, and the engine and A transmission assembly is configured. As shown in an enlarged view in FIG. 2, the output shaft 221 of the transmission 22, usually called the main shaft, ^includes :
A transfer 30, which is known per se, is connected to the drive sprocket wheel 24, the driven sprocket wheel 26, and a wrapped transmission member, such as a chain 28, suspended between the two sprocket wheels 24 and 26. Driven sprocket axle 3 of transfer shaft 30
2 includes a parking brake device 34 and a pair of universal joints 3, the configuration of which will be described in detail later.
An output bevel gear or second bevel gear 42 that meshes with the input bevel gear 40 of the diverter 38 through a universal joint 44 is connected to the propeller shaft 46 through a universal joint 44. is connected to the rear end of the Furthermore, the same propeller shaft 4
The front end of 6 is connected to the rear wheel drive differential 14 via a universal joint 48.

The parking brake device 34 is of a well-known drum brake type, and the parking brake device 34 is of a well-known drum brake type.
2, a brake drum 54 fixed to the hollow shaft 50 with bolts 52, and a pair of arc-shaped friction surfaces housed inside the brake drum 54. 56. brake shoe 56
is supported on a support plate 60 fixed to an extension housing 58 that is made integrally with the housing 30 ¹ of the transferor 30 or is made separately and fixed integrally. Further, one edge of the pair of brake shoes 56 adjacent to each other is
It abuts against a well-known screw type shoe gap adjuster 62, and the other mutually adjacent end edges abut against a drive cam 66 fixed to one end of a camshaft 64 by means of a return spring 68. Further, an operating lever 70 is fixed to the other end of the camshaft 64, and the lever is connected to a handbrake lever 72 via a cable or rod. A return spring (not shown) is connected to the operating lever 70, which constantly biases the camshaft in the brake release direction.
In addition to the hollow shaft 50 and the brake drum 54, the companion flange 76 of the intermediate transmission shaft 74
is fixed.

On the other hand, the drive sprocket wheel 24 of the transfer shaft 30 is connected to the output shaft 22 ¹ of the transmission.
A bearing 80 is interposed in the rim portion 78 of the bearing 80.
0 is further supported by a transfer housing ³⁰¹ . In addition, 82 in the figure is a radiator, 8
4 indicates an air breather.

In the above configuration, while the bus is running, the power of the engine 16 is transmitted from the clutch device 20, transmission 22, and transfer 30 to the intermediate transmission shaft 74, universal joint 36, and the universal joint 36 that constitute the output shaft system of the transfer. The signal is transmitted to the propeller shaft 46 through the change gear 38, and further transmitted from the differential 14 to the rear wheel 12, which serves as a driving wheel, via the rear axle. When the parking brake device 34 is not in operation, the brake shoe 56 is not pressed against the inner circumferential surface of the brake drum 54, and the shaft 32 of the driven sprocket vehicle 26, the hollow shaft 50 spline-coupled to the shaft 32, and the bolt 52 The brake drum 54 as well as the intermediate transmission shaft 74, which are integrally connected to the hollow shaft, can rotate freely.
When the hand brake lever 72 is operated, the operating lever 70 is rotated via a cable or rod in a direction perpendicular to the plane of the drawing in FIG. 2, and the drive cam 66 is rotated via the cam shaft 64. The brake shoe 56 is expanded in the radial direction by the drive cam 66 and is brought into frictional contact with the inner peripheral surface of the brake drum 54, thereby applying the parking brake. According to such a configuration, the overall length of the engine 16, transmission 22, and transfer 30 in the vehicle width direction can be shortened by at least the equivalent of the parking brake device 34 compared to the same type of truck power unit. I can do it. Additionally, the rim portion 7 of the drive sprocket wheel 24 of the transfer shaft 30
8 is supported on the housing 30 ¹ by the bearing 80, so that the transmission output shaft 22 ¹
The overall length of the output shaft 22 ^{1 can be reduced compared to the usual case where the free end of the output shaft 22 1} is supported by the housing 30 ¹ . As a result of the above, there is an advantage that the power unit can be horizontally mounted without any problem even in a small bus or the like with limited vehicle width. Furthermore, according to the above configuration, the main shaft, that is, the output shaft 22 ¹ of the existing truck transmission can be used as is without modification, so manufacturing costs can be reduced and the large tension of the chain 28 can be reduced. The diameter of the bearing 80 supported is the output shaft 22 ¹
Since it is larger than the case of a bearing that supports the shaft, reliability in terms of durability can be improved. In the above embodiment, the support plate 60 of the parking brake device is transferred to the transfer 3.
0 housing, but the direction changer 38
Of course, it is also possible to fix it to the housing. Furthermore, although the present invention is particularly advantageous when applied to small buses that require a sufficient wheelbase within a limited overall body length, it can of course be widely applied to rear-engine vehicles other than buses. It is something.

As mentioned above, the power unit for a rear engine vehicle according to the present invention includes an engine and a transmission assembly mounted in the width direction at the rear of the vehicle body,
A transfer comprising a driving sprocket wheel fixed to the output shaft of the transmission and a driven sprocket wheel connected to the driving sprocket wheel via a winding transmission member such as a chain; a first bevel gear connected to the first bevel gear; and a second bevel gear drivingly connected to the propeller shaft extending in the longitudinal direction of the vehicle and meshing with the first bevel gear.
A parking brake device is provided at an appropriate position in the transmission system from the driven sprocket wheel of the transfer gear to the first bevel gear of the shift gear, and The rim part of the drive sprocket vehicle is supported by the transfer housing via bearings, and the overall length of the engine, transmission, and transfer in the width direction is shortened, making it easy to install horizontally in small vehicles. It has the advantage of being easy to install, and it also allows the use of existing truck transmissions, which reduces manufacturing costs.It also improves the reliability of the bearings that support the drive sprocket wheels of the transfer. There are benefits that can be improved.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view of a rear body of a bus showing an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing the main parts of FIG. 1. 10... Bus rear body, 12... Rear wheels, 14...
...differential, 16...engine, 22
...transmission, 24...driving sprocket vehicle, 26...driven sprocket vehicle, 28...
Wrap transmission member, 30...transfer, 34...
Parking brake device, 38... Turning device, 46... Propeller shaft, 78... Driving sprocket vehicle rim portion, 80... Bearing.

Claims (1)

[Scope of utility model registration request] The engine and transmission assembly are mounted across the width of the vehicle at the rear of the vehicle, and the drive sprocket wheel is fixed to the output shaft of the transmission and is connected to the drive sprocket wheel via a chain or other transmission member. a first bevel gear drivingly connected to the driven sprocket wheel; and a first bevel gear drivingly connected to a propeller shaft extending in the longitudinal direction of the vehicle body. and a second bevel gear meshing with the gear, wherein the transmission gear is connected from the driven sprocket wheel of the transfer gear to the first bevel gear of the gear shifter.
A rear engine vehicle characterized in that a parking brake device is disposed at an appropriate position in the transmission system leading to the bevel gear, and the rim portion of the drive sprocket wheel of the transfer is supported by the transfer housing via a bearing. power plant.