Mechanical Engineering Wheelchair Project Idea - 1 | Hand-Driven Recliner Wheelchair

DESIGN AND FABRICATION  OF HAND DRIVEN  RECLINER WHEELCHAIR

1)Mayur Vishwakarma 2)Rishikesh Nagalkar 3)Sanket Bhendarkar 

4)Satyam Kumar 5)Sandeep Sarojkar 6)Pritam Dhobale

Final Year BE Mechanical Engineering, 2020

📜 Table of Content 👉  Abstract 👉  Introduction 👉  Literature Review 👉  Problem Statement 👉 Working Mechanism   👉  Calculations 👉  Conclusion

Abstract:

Hundreds of billions of people are troubled through the disabilities. This topic faced with the challenges to manoeuvre people with disabilities by easing mobility topics. After communicating with users, the final image of the wheelchair is aimed which is lighter, less costly and more efficient than similar creations commercially usable. The wheelchair has two major modification, to the existing wheelchair the first one is recliner mechanism which gives seating and relaxing comfort to the user and other is the pivoted lever mechanism that helps in receiving the best mechanical advantage. Levers have to be perceived more efficient than hand rim, their purpose seems reasonable in modern wheelchairs. This research and findings serves as a foundation for our proposed prototype.

Introduction:

Mechanical advantage which also affects the cardiorespiratory and musculoskeletal systems causing high strain. These both factors in combination lead the wheelchair confined population to high physical strain which may cause them further disabilities and an inactive lifestyle.  Wheelchair user who uses a push-rim wheelchair to go out of home, their Hands and Nails often get dirty, and sometimes they end up having blisters on their palms. There might be some situations when users get shoulder injuries and rotator cuff tear. The lever propelled wheelchair seems a less straining form of locomotion, considering the long and continuous stroke pattern. Flexor and extensor muscles in the arms are used with a less complex coupling of hands.

Long continuous motion serves as a major contributing positive factor. In a lever propelled wheelchair, arms are seen to be in a more natural segmental position under which the user is capable of transmitting more human power. The passenger’s seating comfort is considered by including the Recliner mechanism, which allows the seat back to rotate forward & rearward direction from a pivot point at the base of the seat back according to the user. Thus, the well-being of the person using the lever propelled wheelchair and having a recliner in it is preserved. Manual wheelchair propulsion using push-rim is not a reliable form of human locomotion. Push-rim wheelchair comes with a poor.

Literature Review:

Currently, scientists are so better in class and step by step they are unwrapping the advancement in each section. Thus, there is an immense improvement in the structure of wheelchair. Some kinds of literature which includes such developments are discussed.

• Manual Wheelchair:

The manual wheelchair has great indoor mobility what's more, it is anything but difficult to control forward way however for turning it requires more power likewise it requires high starting power to move. It might cause harm in the shoulder area of the user. It can't be utilized for outside works. These wheelchairs are unfit to be driven on the harsh surfaces like grass, rough places, rocky surfaces, inclines, and sand surfaces.

• Lever Propelled Wheelchair:

This paper helps to make reasonable and adaptable in utilization in complex diversity like India.

• Electric Wheelchairs:

The electric wheelchairs can be utilized by the individual who has more disabilities other than legs. 

•  Joystick Controlled Wheelchair:

There are numerous individuals who have a lower body is paralysed. For such individuals, there are electric wheelchairs and some of them utilize a joystick controller. These wheelchairs make their life simple. 

Objectives (Problem Statements)

• Dirty Hands With Swelling:

Any wheelchair user who uses the manual wheelchair to go out of gets harm by moving the wheels which is already rotates continuously with some speed. Hands and nails often get dirty and there are times when they have two deals with blisters on the palms.

• Shoulder Injuries & Wrist Pain:

Regrettably, as the shoulder is the primary joint for propelling a device or transposing to/from a wheelchair. It’s a leading pain point for lots of wheelchair users. The most common issue of wheelchair user face is a rotator cuff tear. Tears are caused by imbalances of muscles in your shoulder.

Working Mechanism:

• Lever Mechanism

The primary objectives of lever mechanism are to obtain maximum load carrying capacity with applying minimum effort. So it will be helpful for the patient to propel the wheelchair.

Using our designed mechanism for propulsion of wheelchair user will be required less effort to attain maximum distance in less time interval. It is nothing but increase the velocity of wheelchair also another advantage is that rack and pinion mechanism which is driven by hand operated lever offers less cost, easy for maintenance and ease for propulsion the reason behind for selection of this mechanism is that it contain wheels of wheelchair chain used as rack and the sprocket use as pinion. The main advantage of this mechanism is the patient can move the wheelchair on rough and uneven rocky surfaces easily.

The lever mechanism is nothing but mild steel rods which are pivoted at the end of the another link where the small piece of roller chair is used at the rack the braking levers are attached at the end of  the primary lever to command the speed of wheels and stipulate the direction to the wheelchair. By applying the brakes on any one wheel and moving the other lever, the patient can change the direction of the wheelchair.

 

• Rack and Pinion Mechanism

A rack and pinion gear mechanism is used to convert rotational motion into linear motion. In general mechanism a bar of rectangular cross-section having teeth cut on one side that will mesh with teeth on a pinion .but such teeth cut bar and pinion compatible to that bar is not easily available in market, and it is costly, hence to reduce the cost of mechanism and for the convenience and maintenance point of view we use bicycle chain welded on other link use as the rack which work similar to the rack and pinion mechanism.

There are two basic components of this rack and pinion mechanism:

1) Bicycle chain welded on connecting link.

2) Bicycle sprocket.

• Recliner Mechanism

Recliner Mechanism chair is a chair that tilts to the back rest of the chair to achieved comfort position to the person who is sited on the chair. According to W.H.O. the comfort position for the wheelchair is at about 140 degrees.

In current market scenario the reclining is present, but the secondary person required for reclining of that chair, so our main aim is to eliminate the necessity of a secondary person.

There are three basic components of this recliner mechanism:

1) Adjustable Hand rest

2) Spring

3) Back rest

The mechanism containing various parts i.e. adjustable hand rest, backrest, and spring. Proper slots are formed on the adjustable hand rest. So first in case of working the Upper side of the adjustable hand rest is move to backward direction so due to this backrest tilts to backside of chair with help of slots (it is just like a gear mechanism)

After reclining if a person (handicapped) try to move for certain work in a forward direction then same adjustable hand rest is move in a forward direction with similar meshing of slots.

Calculations:

Standard Measurements

Length of Handle = 530 mm

Average Human Force = 500 N

• With Mechanism 

Torque occurred on the Sprocket = Force Applied to Handle * Length of the Pivoted Handle

= 500 * 0.53T = 265 N-m

We have,

Power

P = 2* π *NT/60

P = 666.01 W (Rated)

• Without Mechanism

Torque Occurred on the Wheel = Force Applied on the Rim * Wheel Radius

= 500 * 0.35 = 175 N-m

Power,

P = 2* π *NT/60 

P =  439.82 W (Rated)

Reading taken

X-distance travelled  & θ-angle covered

Without Mechanism

With Mechanism

Conclusion:

The centreline of this project is to design a wheelchair to provide “THE WELFARE OF ALL” The census 2011 report said that in India 20% of the disabled person all having disabilities in movement. In this project, we work on two things: - To modified existing wheelchair by providing recliner mechanism in seat & lever mechanism for movement instead of rotation mechanism for rotation of the wheel.  The recliner mechanism provides comfort for the rides.

In case of the lever mechanism, the lever is attached to the frame and one end attached to the horizontal mounting having chain acts as a rack which is sliding over the sprocket acts as a pinion .so the motion of the lever is provided to chain (Rack) to the sprocket (pinion), the sliding motion converted into rotational motion. This project is capable to move the wheelchair of the handicapped person in their direction without the assistance of any other person. In general the application we can use a recliner to provide comfort by itself. 

For Working Model Video : Click Here

For Working Model AutoCAD Video: Click Here

Full Research Paper : IjIrt

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