Manual & Electrical Winding Machines

Introduction

A winding machine is a mechanical or electro-mechanical equipment that curls a strand of material e.g. wire round a carrier object. Typically, a winding machine winds a material, such as metal wire, thread, or paper, onto a core, spool, or bobbin. A winding machine could be manually driven and fed (hand-operated) or electrically driven and manually fed (semi-automatic) or electrically driven and fed (automatic) with input wire that it uses to form the required coil. Winding machines can be used in producing the coils for ceiling fans, light choke & transformer coil etc.

 

 

 

 

Some of the more common uses for winding machines are coil winding, rope winding, and continuous filament winding. Many industries use these devices, including textile, electronics, and wire industries.

A motor coil winding machine allows you to make an electromagnetic coil that can be used for a variety of purposes. A coil winding machine takes a copper or aluminium wire and winds it around a core or sometimes around air. The coils are usually wound around reels. During this process, the wires can be coated with a variety of materials that can provide some form of insulation. The types of wire, coiling, and insulation needed depends upon the particular application.

RPM & SPEEDS OF WINDING

Winding can occur only when there is a difference between the circumferential speed of the bobbin and that of the spindle (or flyer). At each instant, this difference must correspond to the delivery speed, since the length delivered and the length wound up must be the same. As roving layers are deposited on the bobbin, however, their diameters increase. Hence, in the absence of intervention, the circumferential speeds (and finally their difference) would increase. There would be a constant increase in the length wound up, and a roving break would occur. To avoid this the bobbin speed V_bo must continuously be reduced in a precisely controlled manner in order to maintain the speed difference continually equal to the constant delivered length. The following general principle can therefore be derived. If the circumferential speeds (bo = bobbin, spi = spindle) are given by:

V_bo = d_bo x π x n_bo

V_spi = d_spi x π x n_spi

Then since delivery is given by:

L = V_bo – V_spi

L =  d_bo x π x n_bo – d_spi x π x n_spi

 

By transforming the equation, the bobbin speed corresponding to any given bobbin diameter can be derived:

Components of a Winding

Coil winding machine is having two major functional parts.

First is the rotating spindle and the second is the wire layering traverse. In short Spindle assembly and traverse mechanism are two major parts of winding machine while other parts may be part of the machine but its optional.

Spindle assembly can be rotated by various forces like hand or by motor. When the spindle is rotated by hand, it is generally called as hand winding machine or manual winding machine and when the motor is used to rotate the spindle, it is termed as motorized coil winding machine. The main function of the spindle is to rotate the bobbin or core on which wire is been wound which is called coiling of the wire. Now depending on the wire size and final coil weight along with the production required, either it can be hand rotated or with motor. Various HP motors are selected depending on the weight of the coil after winding. When the production required is too low then manually rotated spindle is generally preferred.

Whether a machine is manual or automatic, they key components a winding machine must have include:

1. A Main Drive Mechanism: this provides the turning effect to roll the surface on which the coil is run. The main drive may be a manual crank connected to a spindle to which the coil bobbin is mounted as in Fig.1 above or an electric motor controlled by switches or CNC system as in Fig.2
2. The Spindle: this is shaft end on which the Bobbin or Spool for winding the coil is mounted.

• Winding head or Layering Traverse fitted with a chuck: this is where the bobbin or spool is mounted and coil run on the device.

1. Tensioner or Tension Control: this is the device that enables coil tension to be adjusted. In manual machines this is not present as the operator regulates the coil tensioning.
2. Speed Control: this may be a switch, clutch, gear or CNC circuit that controls the main spindle speed and hence the feed speed. Manual machines do not have this.

 

CLASSIFICATION OF WINDING MACHINES

Winding machines can be classified in various ways. Two popular classification categories are:

• By capacity
• By degree of automation.

CLASSIFICATION BY CAPACITY

Under this classification, there are the following types:

Basic Coil Winders

Coil winders are generally used for smaller jobs. They can be hand operated or have a winding drive that is controlled by a foot pedal. These coil winding machines are used in the production of solenoid coils, multi-section coils, and other such complex coils. Though they are small, they can reach up to speeds of 9000 RPM.

Medium-Duty Coil Winding Machines

These machines are more powerful than coil winders and take on higher production demands. Most of them are driven by potentiometers. They can wind various types of wires.

Heavy-Duty Coil Winding Machines

Heavy-duty motor coil winding machines are able to take care of extremely large amounts and are also very versatile in nature. For higher precision, most of these machines are equipped with LCD touch-screen monitors. These screens allow operators to have more control over speed.

CLASSIFICATION BY DEGREE OF AUTOMATION

Under this classification, there are several different types of winding machines, from simple manual feed machines to Semi-Automatic to complex computer-numeric-control (CNC) machines.

Manual Winding Machine

A manual winding machine usually has a core on a spindle and the user feeds wire, rope, or other material onto the core. The user controls the spindle speed and feeds the material through his or her hand, guiding it to control the tension and load pattern. These simple machines may be of a bench-top size or large stand-alone winders.

In the manual machine the shaft on which bobbin is mounted is rotated manually with paddle assembly as shown in Fig.1 while the other hand feeds in the wire. Rotating paddle with one and then providing wire feed by another hand makes the process hectic.

Semi-Automatic Winding Machine

This was developed to mitigate the tedious paddling job in the manual machine. So new machine was developed around 1965 in France and this machine was widely accepted all over the world and with some modifications is used today as well. Though this machine was accepted worldwide still it needs the skilled worker to operate it as it just eliminated the hurdle of paddling but the providing to & fro horizontal motion to ensure uniform winding per layer remained as it was in manually operated machine.

As shown in Fig 3. the winding process is still depends on the skilled labour as he has to take care of 4 different things simultaneously such as controlling speed of induction motor, providing horizontal to & fro motion to ensure uniform winding, previously setting tension in the wire in accordance with the speed of induction motor & also he has to see the counter for number of turns completed & how many turns remained. Also the operator has to take care of number of turns per layer should not exceed the predefined value for that particular gauge of wire and as this varies as per gauge of wire ultimately this makes the whole process tedious.

Advanced Semi-automatic Transformer winding Machine (Existing) have also been developed.  This is more advanced method of semi-automatic transformer winding machine as it provides horizontal to & fro motion automatically. But the main drawback of this machine is that it can only be used for manufacturing LV transformers & there also for specific range of bobbin size.

The advanced automatic transformer winding machine fails to provide automatic paper isolation as per requirement. The main drawback of this machine is that it is very costly and it cannot be used for manufacturing of HV transformers.

Fig.4: Advanced Semi-Automatic Transformer winding machine

Fully Automatic Electric Winding Machines

Most winding machines are CNC controlled or are a combination of manual and automatic. The CNC controls can regulate the tension of the material, the amount that is wound on the base, and the pattern in which the material is wound onto the base. For example, the machine will not stretch wire unduly. An example of CNC controlled winding machine is shown in Fig.2 above.

Automatic winding machine relies mainly on CNC control system controls the interaction between the spindle motor and cable system to achieve automatic winding, works as follows: every revolution of the spindle motor, cable and wire drive mechanism to move a wire diameter speed position, traversing mechanism may vary depending on the spindle speed adjustment at any time to ensure the precise amount of movement, the control system cable reversal signal to cable systems reverse movement when moving to the width of the position, and so on to achieve multi-automatic Rao line effect of cable.

To achieve the function of automatic winding machine, not only rely on CNC control system or other co-operation of the various components to complete.

Constituting the automatic winding machine, CNC controller is the core control equipment, as well as composite applications spindle systems, cable systems, accessory systems, their integrated control various functions to achieve the desired automatic winding machine there are many processes to meet the special automatic winding machine is also equipped with a special mechanism to assist other to achieve functional.

Advantages of Automatic Electrical Winding machines

There are a number of advantages that a coil winding machine can provide. With the right materials and components, coils can be excellent conductors of heat. Coils also have the ability to distribute electric field strength with ease. Equipment that contains coils can often operate more smoothly and efficiently than equipment without coils. Reducing the size of coils with an appropriate winding machine can reduce the risk of the coils burning out due to high voltage amounts.

For transformer manufacturing quality, not only requires the electrical performance and reliable, mechanical stability, anti-short circuit ability should be more reliable. This is provided by automatic winders.

Machines also provide the right speed of feed and tension of coil during production. This ensures the electrical characteristics of the coil are optimal for usage.

Advantages of Programmable / CNC winding machine for motor stator coils are

• 0.05 turns accuracy
• 16 coils per winding cycle
• 100% repeatability
• Soft start and soft stop avoids wire breaking
• Minimum setup time with 50 program memory
• Independent of operator’s skill
• Very high production
• Constant tension to avoid elongation of wire
• Equal resistance of every coil
• Ease in insertion of coil in stator due to layer wound coils
• Reduction in joints of coil
• Flexibility to use various formers on single mandrel

 

Bibliography

ACME Mechatronics (2017). Coil winding machines. Retrieved from: https://acmemechatronics.wordpress.com/tag/winding-machine/

Minebea Co. Ltd. (2014). Motor coil winding machines. Retrieved from: http://www.nmbtc.com/nmb-component-applications/industrial/motor-coil-winding-machine/index.html

Rikipedia (2017). The winding principle.  Retrieved from: http://www.rieter.com/cn/rikipedia/articles/technology-ofshort-staple-spinning/handling-material/winding-on-flyer-bobbins/the-winding-principle/

Zhongshan Shili Wire Winder Equipment Co., Ltd. (2017). Analytic principle of automatic winding machine.  Retrieved from: http://www.zsshili.com/en/newsshow-58-1459.html

Wisegeek.com (2017).  What is a Winding Machine?. Retrieved from: http://www.wisegeek.com/what-is-a-winding-machine.htm