LT6334B - Friction gear for for wheelchair - Google Patents

Abstract

This invention relates to electric wheelchair power train construction. Proposed is a friction coupling of drive motor to wheelchair wheel with very simple construction. This coupling consists of an electric motor with roller fixed onto motor axle mounted so that roller is pressed against wheelchair wheel. In this way, electric motor power is transferred directly to the wheelchair wheel. The maximum speed and torque of the wheelchair is changed by selecting appropriate roll diameter. The full wheelchair drive train comprises two friction couplings, one per each wheel. Drive mechanism is designed so that the user can install it to the active type of wheelchair himself and mechanism serves as attachment to the wheelchair.

Description

Technical field

The present invention relates to an electric drive design for electric wheelchairs.

State of the art

Most electric wheelchairs use direct power transmission mechanisms to connect the electric motor to the drive wheels via a gearbox. These designs use massive electric motors with metal construction drives. Trolleys use massive batteries for long distances (> 1 km). The weight of a typical bogie is well over 100 kg. An example of this type of actuator may be the design disclosed in US 20050077790 A1.

In most cases, the high weight of the drive mechanism results in a high total weight of the bogie, which limits the user's mobility due to the low maneuverability of the bogie. In addition, the large mass requires adapted vehicles to transport the cart. The ultra-light friction drive proposed in this patent is mounted as an accessory to an active-type wheelchair. The proposed design ensures a very low trolley weight and high maneuverability.

The essence of the invention

The present invention seeks to provide an extremely lightweight, high maneuverability wheelchair. The essence of the invention is the creation of a friction drive. This drive consists of a roller mounted on the electric motor axle, which is pressed against the wheel of the wheelchair by means of a mounting mechanism. In this way, the power of the electric motor is transmitted directly to the wheel of the bogie. This design eliminates the need for sophisticated power transmission mechanisms on the j wheel and simplifies all gear up to one engine (no gear) per wheel. The roller, which is mounted on the motor shaft, is made of a material that ensures good adhesion to the wheel tire, and its diameter is chosen to ensure proper torque and maximum trolley speed. The complete trolley drive consists of two electric motors, one per wheel. The motors are controlled by a reverse current controller that allows independent control of both motors power and direction of rotation. In addition to the usual forward, reverse and twisting movements, this arrangement allows you to make turns while standing still and turning in very narrow spaces. The user controls the current controller along with the entire trolley by means of a joystick or similar manipulator.

The drive mechanism shall be designed in such a way that the disabled person can mount it on the active wheelchair and is an accessory.

The typical weight of such a wheelchair drive is about 8-9 kg, in addition to the mass of a 912 kg active type wheelchair, thus a total weight of about 20 kg, which is significantly less than a conventional electric wheelchair (typically> 100 kg).

The friction drive design requires significantly less detail compared to conventional bogie designs, resulting in a significantly lower total cost.

Brief description of the drawing figures

The drawings accompanying the description show:

Fig. 1 Friction Drive Design.

Fig. 2 Schematic diagram of a wheelchair disabled wheelchair.

The friction drive consists of an electric motor 1 attached to the bogie frame by a bracket 2. A tire-shaped drive roller 3 is mounted on the motor axis 3. The roller 3 and the electric motor 3 are pressed against the bogie wheel 4 by spring tension 5 wheel. The auxiliary and control elements are mounted at certain positions of the trolley: the control joystick 7, mounted conveniently in the armrest, the reverse current control 8 under the seat, the battery 9 mounted on the rear axle 6 of the trolley without changing the balance of the trolley.

Preferred embodiments

One embodiment of the friction drive is shown in Figs.

1. A metal rod is attached to the trolley frame, to which two 150 W, 24 V (may be other) electric motors are mounted, each on different wheels of the bogie. The engine is pressed against the tire by a spring tensioner. Since only the roller compression force is important for correct drive operation, the design of the tire pressurization may be different. The motors are connected to a reverse current controller mounted conveniently on the bogie frame. The power supply battery is mounted on the rear axle of the trolley, thus not changing the balance of the trolley, which is very important for the user. In turn, the current controller is connected to a joystick mounted on the bogie armrest.

Claims (3)

Definition of the invention 1. An electric drive for a wheelchair consists of an electric motor and a mechanical gearbox, characterized in that the gear unit consists of a roller mounted on the motor shaft pressed against the wheel of the bogie. 2. An electric drive for a wheelchair according to claim 1, characterized in that a frictional method is used to transmit the power of the electric motor to the wheels of the wheelchair. 3. An electric drive for a wheelchair according to claim 1, characterized in that the user is mounted on a standard active type wheelchair and is an accessory thereto.