JP2001277866A - Drive unit for electric vehicles - Google Patents

Abstract

(57) [Problem] To provide a compact drive device for an electric transport vehicle having excellent mechanical strength and high handleability. SOLUTION: In a driving device, a gear reduction mechanism is arranged so as to overlap and balance right and left with respect to a center of width of a tire which is a steering center. [Effect] By arranging the equipment driving device almost in the left and right directions with respect to the turning center of the tire, the driving device for an electric transport vehicle having excellent mechanical strength and high handleability can be made compact.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive device for an electric carrier suitable for use in a so-called hand lift truck or the like.

[0002]

2. Description of the Related Art A technique for driving a hand lift truck, which lifts and transports a pallet on which goods are loaded, by using an electric motor is known, for example, from Japanese Patent Application Laid-Open No. 6-99864.

On the other hand, the output of an electric motor is transmitted to driving wheels (wheels) via a reduction gear mechanism.
No. 44 is known.

[0004]

However, in the case of an electric drive device such as the former in the prior art, it is common to simply dispose the speed reduction mechanism and the electric motor in the axial direction with respect to the drive rear wheel. There has been a problem that the length from the center of the wheel, which is the rudder center, to the end of the motor is long, and the turning radius of the motor is inevitably large. In particular, this type of transport machine requires a small turn and a sense of running stability (straightness). However, if the motor protrudes too much on one side, it needs to be devised to install it in the center of the chassis, and versatility It becomes a device to be applied to.

[0005] In the latter device, since the distance between the center of mounting the drive device and the center of the wheel is long, bending stress when a load is applied is applied to the shaft and spokes.
In order to withstand this, it is necessary to devise a method of increasing the design strength by changing the material, structure, and the like, so that disadvantages in terms of cost are inevitable.

An object of the present invention is to provide a compact drive device for an electric transport vehicle which has excellent mechanical strength and high handleability.

[0007]

According to the present invention, there is provided a drive unit for an electric transport vehicle which is mounted on a chassis and receives the propulsive force of the chassis by the rotating force of an electric motor, wherein the drive unit forms a chassis mounting base around the drive unit. Cylindrical gear case,
A bowl-shaped wheel rotatably disposed via a bearing between the outer peripheral base and the distal end of the gear case, one end of which is engaged with and held at the center of the wheel, and the other end of which is disposed on the inner peripheral portion of the distal end of the gear case via a bearing. A drive shaft, a gear reduction mechanism disposed on a cylindrical portion of the gear case and transmitting output to the drive shaft, an input shaft end of the gear reduction mechanism, and the cylinder holding one end of the drive shaft. An electric transport vehicle comprising: a front bracket for closing an open end of a shaped part; and an electric motor having a rotor rotatably held on the front bracket and a stator case butted and fixed. This is achieved by a driving device.

Preferably, the present invention is attained by arranging the gear reduction mechanism so as to be located within the width of the tire.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings shown in FIGS.

In FIG. 1, a gear case 1 made of iron has a cylindrical shape with a substantially convex cross section, and a chassis mounting base 2 is integrally formed therearound. A bowl-shaped wheel 7 is rotatably disposed between the outer peripheral base 3 and the distal end 4 of the gear case via a pair of bearings 5 and 6, and a tire 71 made of urethane or the like is mounted on the large diameter portion. ing.

One end of a key 8 is provided at the center of the bottom of the wheel 7.
A drive shaft 10 is provided, the other end of which is held at the inner periphery of the front end of the gear case 1 via a bearing 9. Further, the other end of the drive shaft 10 is rotatably held by a front bracket 12 of an electric motor 11 that closes the open end of the cylindrical portion of the gear case 1.

Next, the gear reduction mechanism, which is one of the features of the present invention, will be described in detail with reference to FIG. The pinion 1 at the end of the rotor shaft of the electric motor 11 in the gear case space
3, a first gear 14 meshed with the pinion 13 and supported by the gear case 1 and the front bracket 12, and a small gear 16 arranged in parallel with the gear and meshed with a second gear 15
And a small gear 18 arranged in parallel with the second gear 15 and meshing with a drive gear 17 mounted on the drive shaft 10.

In the driving device having such a configuration, the gear reduction mechanism is disposed so as to overlap and balance right and left with respect to the width center of the tire 71, which is the steering center, so that it is compact in the radial and axial directions. In addition to the unity, the left and right balance is good even when viewed from the whole device, the motor is also shorter than the center of steering, and when mounted on the chassis, the center of the chassis is stable without worrying about the rotation range. It is easy to mount and a highly versatile drive device.

[0014]

According to the present invention, there is provided a drive device for an electric transport vehicle which has excellent mechanical strength and is easy to handle by arranging the drive device in a substantially balanced manner on the left and right with respect to the turning center of the tire. It can be provided in a compact form.

[Brief description of the drawings]

FIG. 1 is a perspective view of an electric vehicle driving device according to an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of FIG. 1;

FIG. 3 is a sectional view of the gears taken along the line AA of FIG. 2;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Gear case 2 ... Chassis mounting base 3 ... Gear case outer peripheral base 4 ... Gear case tip 7 ... Wheel 1
0: drive shaft 11: electric motor 12: front bracket 13: pinion 14: first gear 15: second gear
17 Drive gear

Continued on the front page (72) Inventor Kazuhisa Ishizaki 2477 Takaba, Hitachinaka, Ibaraki Prefecture Inside Hitachi Car Engineering Co., Ltd. (72) Inventor Hironori Watanabe 2477 Takaba, Hitachinaka City, Ibaraki Prefecture Hitachi Car Engineering F Terms (Reference) 3D035 DA03 3J009 DA16 DA17 EA01 EA11 EA21 EA44 EC05 EC10 FA30

Claims (2)

[Claims] 1. A driving device for an electric transport vehicle, which is mounted on an undercarriage and obtains a propulsive force of the undercarriage by a rotating force of an electric motor, wherein the driving device has a cylindrical gear case having a chassis mounting base formed therearound; A bowl-shaped wheel rotatably disposed via a bearing between the outer peripheral base and the distal end of the gear case, one end of which is engaged with and held at the center of the wheel, and the other end of which is disposed on the inner peripheral portion of the distal end of the gear case via a bearing. A drive shaft, a gear reduction mechanism disposed on a cylindrical portion of the gear case and transmitting output to the drive shaft, an input shaft end of the gear reduction mechanism, and the cylinder holding one end of the drive shaft. A front bracket that closes the open end of the shaped portion, and an electric motor that holds the rotor rotatably on the front bracket and abuts and fixes the stator case. Drive for electric vehicles. 2. The driving device for an electric transport vehicle according to claim 1, wherein the gear reduction mechanism is disposed so as to be located within the width of the tire.