Pullers

GGHYD Series - A Definitive Guide on Hydraulic Pullers.

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INDEX

 

 

 

Removing Press-Fit Components

While the term puller sounds general, pullers are made to perform specific purposes. If you have worked in any mechanical field, you will be aware of the fact that there are many cases where you are required to remove a stuck stubborn component. Sometimes, this may only take your hands and a little force. In other cases, you may find it humanly impossible to provide the required force with your own hands. Pullers afford the perfect grip and the required force to pull specific types of objects.

Evenly Distribute Force When Dealing With Precision Components

A solid grip and ample force are what you want when using a puller. The tool ensures that your components are safe during the removal. Some mechanical components, although often times made of metal, are made with precision and any uneven pressure may impair them. Pullers provide a well-spread grip and even force that allows you to pull out components without damaging them.

Remove Small Components from Hard-to Reach Spots

How many times have you had to reach for a small component awkwardly stuck in a crevice or hole that is too small for your fingers let alone your hands? That is another scenario where pullers come in handy. There are some that have been specifically designed to get to most hard-to-reach spaces and firmly hold your component.

Easily and Safely Manipulate Small Components

Small components may be hard to manipulate when performing actions such as soldering or coating. It would be cumbersome and even dangerous to hold a tiny component as you solder it. With a puller, not only will the process be safer, but it will be more efficient to pull items for preparation rather than trying to accomplish your task while the item is attached. Pull the item to properly solder, chrome plate, etc.  

Not all pullers are used to pull components apart. Some are designed to firmly grip wires for forceful pulling, something that would be impossible with your bare hands.

 

 

It all comes down to your application. Here are the available types.

Manual vs. Hydraulic Pullers

At the very top of the classification tree of pullers are two types: mechanical and hydraulic pullers. Both of these are further divided into different types suited for all sorts of applications.

Hydraulic pullers come with a fluid-filled ram as opposed to the threaded rod of manual pullers. One advantage of choosing a hydraulic puller over a mechanical one is the ease of operation that it comes with. If you are faced with a component that requires extra force to be removed, you would do well to get yourself a hydraulic puller. It is more convenient and can exert much more force than a manual one would, but these benefits are more costly. Hydraulic pullers typically, cost more than their mechanical counterparts.

Hydraulic pullers can be operated manually by hand pumping, or by electricity with a motor pump. The electric type will obviously be more convenient and faster to use.

Types of Pullers by Purpose

Bearing Pullers

Bearings are precision components and dealing with them may require delicate, skilled, and patient handling. To assemble or dismantle ball bearings a bearing puller is used. Currently, the majority of bearing pullers on the market are handheld. Although, there is a growing popularity of a manually powered type which by far reduces the amount of force needed to pull apart components.

Some bearing pullers are meant to perform technical tasks. These range from more precise aerospace component assembly to putting together bearing systems in printers. These are precise operations, and the components can be tiny, sometimes as small as a lead pencil point. Such bearings can also be found in small motors, fishing reels and similar items.

On the cruder side are the bearing pullers used by mechanics. These are non-precise since the components they deal with are much bigger. You can use them to pull out worn bearings, or to adjust any similar component in a machine.

Apart from the degree of precision, bearing pullers can also be differentiated by the nature of job they are needed for. The internal bearing puller is designed to handle small components with diameters ranging from 2.5 millimeters to 11 mm. Some bearings may be lodged inside blind holes that do not go through the other end, this is where internal bearing pullers shine.

Gear Pullers

Gear pullers are designed specifically to separate gears from crankshafts. This is a more general definition because there are different types suited for different jobs. You can classify gear pullers by the number of jaws and the size of gears they are meant to handle. For some, the gears are gripped by jaws, while some come with bolts that are attached to the gears. Whatever type used, bolt or jaw, the mechanisms are about the same. Both of these have a rod with threads. When in operation, the rod presses against the shaft. The pressure is increased by turning the forcing screw using a wrench until the gear is detached from its shaft.

The most popular are the two-jaw and three-jaw gear pullers. When faced with a task where you’re required to pull out a small gear from a narrow space, the two jaw gear puller is the perfect choice. What happens is  the threaded rod meets the shaft as the two jaws grip the gear. The rod then exerts force on the shaft and once the operator turns the jaws, the gear is detached from the shaft. In some cases, the gear can be so tight that it would need too much force to be removed. The best way to deal with such a situation is to let the threaded rod apply some force on the shaft and leave it on for some minutes. The gear will slowly get loose, until you can comfortably remove it.

While the two-jaw puller may be expedient for use on small tight gears that call for considerable force, large gears will need something bigger. This is where the three-jaw gear puller comes in handy. Since it has three jaws, it can easily spread its pressure across the diameter of the gear. This allows safe removal without damaging either the shaft or the gear itself.

It is not uncommon for a large gear to require a little, or even serious hammering for it to move. This is one other reason why three-jaw gear pullers are preferred for handling large components. Their durability allows them to withstand hammering when the gears are too tight.

Hydraulic Push-Pullers

An ordinary puller can be used to extract components like gears, bearings, pulleys, etc. But what if you are faced with a situation where you need to install a component like a gear where much force is required? This is where hydraulic push-pullers come in. They are able to supply both a pull and push force. The fact that these are powered by hydraulics makes the job much easier. Hydraulic push-pullers require less force than the mechanical ones. There are different tonnages available, and all you have to do is select one suited for your task.

Blind Hole Pullers

One of the worst nightmares a machinist or mechanic could face is a bearing or similar component that is stuck in a hole. Not just any hole, a blind one, meaning there is no through way. It has been drilled to a certain depth without penetrating to the other side. There were ways to go about this before the development of blind hole pullers. One involved using a sharp prying tool which would be inserted through the center hole of the stuck component, then placed between the component and bottom of the hole. The idea was to force the sharp part of the prying tool in whatever clearance would be found between the component and the bottom wall of the hole. Once this is achieved, several methods would then be used to pull the prying tool along with the bearing or other component.

The problem is that sometimes there was no clearance of any significance to insert the prying tool. The operation would be so cumbersome that it would leave the hole and the bearing damaged.

Blind hole pullers are able to achieve the same purpose more easily, and without damaging either the component or the hole in any way. Their construction may be complex, but the premise of their operation is simple. They have wedged fingers that are able to extend outwards in a radial fashion. The wedge shape of the fingers means they are able to force their way behind any bearing stuck in a blind hole. They don’t even need any clearance at all. The only necessity is the radius found on the edges of any bearing. That is enough to give the puller fingers something to hold on to.

Once the radial fingers have managed to fit behind the bearing, all you have to do is continue rotating the rod until the puller has a secure hold. The next thing to do is simply to pull it up using any suitable method. Most of them come with a sliding hammer which you attach to the puller. You then thrust the hammer in the direction you would like the bearing to move.

Multipurpose Pullers

Multipurpose pullers are just as the name suggests. They are able to work in a wide range of situations. This usually means buying a puller set that comes with multiple parts and all you have to do is swap the parts to fit the job at hand. The set includes different size jaws to fit across different radius components. Some even come with different sliding hammer sizes, meaning any job will be taken care of no matter how much force is needed to pull out the bearing.

Hydraulic Master Pullers

Hydraulic master pullers come with different types of parts to fit all sorts of purposes. But, to make the job less taxing on the operator, they come with hydraulic systems. Hydraulic master pullers can produce massive pulling force to dislodge gears, bearings, pulleys, and other components. The parts are usually made of forged steel to allow the puller to withstand any punishment the job might dish out.

Manual Pullers

Most things are drifting towards automation, electrical power, and other forms of operation that make the job easy for operators of machines. But once in a while you need a good old hand operated tool. That’s where manual pullers come in. You can operate them by hand meaning there won't be any need for extra components for power. This makes them cheap, and their simplistic build often times means they will be more durable. The only disadvantage, of course, is that they may be energy draining on the operator.

Manual pullers can be used for many applications: pull out gears, pulleys, or any press-fit component that goes onto a shaft. They are best suited for jobs that do not require substantial force. Larger components would be best dealt with using hydraulic pullers.

Hydraulic/Manual (Hybrid)

So there are manual and there are hydraulic pullers, but what if you need a little of both worlds? Then you need a tool that you could operate manually, on jobs that do not require much force, and with hydraulics, on jobs that need substantial force. This is exactly what hydraulic/manual pullers are designed for. They are versatile tools that combine the advantages of both manual and hydraulic pullers.

 

 

To remove a gear, bearing, or any component successfully without injuring yourself or damaging either the puller or the gear, you will need to follow a few steps. Also, there are a few care tips you will need to heed for your puller. 

1.    Choose the Right Tool

It should go without mention that your puller should be the right size. Its jaws should be able to fit the diameter of the gear, bearing, or other component easily. It is easy to get this wrong since most pullers come with cross arms that are used to adjust the span of the jaws. However, you should note that each puller is designed with a particular maximum diameter in mind. Make sure the puller has a longer span than the diameter of the component you intend to use it on. Furthermore, you have to make sure the puller you choose comes with a threaded rod that can fit on the shaft.

Now, you won't be able to wind the threaded rod with your hands. You will need a socket wrench that squarely fits the nut that comes at the top of the puller’s rod. Avoid using the wrong size even if it seems to do the job. If the wrench and puller nut are not the same size, you will grind the nut away and this will make it hard to grip.

2.    Adjust the Puller’s Arms

After picking the right size of puller, you now have to adjust the span of the jaws to make them fit the diameter of the gear. You do this using the cross arms. The whole purpose of a puller is to make sure there is uniform pressure across the gear being pulled out. Therefore, you should make sure that the arms are evenly placed. This especially applies to the two-jaw gear puller. The pair should both be in the same line with the gear shaft. The fact that you need to aim the threaded rod in the center of the gear makes it easy to place the jaws evenly.

3.    Tighten the Threaded Rod to Pull Out the Gear

The next thing to do is to apply pressure on the shaft using the forcing screw, or the threaded rod. You will have to use the socket wrench for this, and basically, you will turn the nut on the rod until it is touching the shaft. Do not proceed to tighten the nut until you have made sure everything is securely gripped: the jaws are in a secure position, and the rod is squarely on the gear shaft. Once you have checked, continue turning the wrench until you have loosened the gear. The gear should be in the pullers hold even after it is fully removed.

 

Picking the right puller for the job is essential, but it's only one part of all you have to do to use the tool successfully. Apart from the operation steps, you also have to be aware of the precautionary measures necessary for your own safety, that of the puller, and the component you are working on.

1.    Make Sure There Is Enough Lubrication

The puller has a number of parts that work in friction conditions. For this, you will need to lubricate them with a suitable lubricant to prevent any parts from getting stuck. The part that needs the lubrication is the forcing screw. The cross bar that is used to adjust the span of the jaws will also need some lubrication, although this does not play a direct role during the actual gear pulling. The best lubricant is machine oil, as it has just the right viscosity to withstand the intense friction in the puller mechanism. Should you still find yourself with a stuck gear even after adequate lubrication, a larger puller might be needed.

2.    Replace Deformed Parts

It is important that the puller remains in top-notch working condition; with usage, some parts may develop deformation. This is something you cannot get away with. The puller needs to be precise in its operation, and deformities will hinder this. It needs to exert uniform force across the component being removed or there will be risk of damage. That is something you can only achieve if all the parts are fully functional.

The part most susceptible to damage is the threaded rod. After prolonged usage, the rod may develop a split end on the part that exerts force on the shaft. Sometimes the end may mushroom, meaning it will be wider at the base. This may make the puller incapable of handling some of the jobs it was meant for on account of its inability to go through the bearing or gear center-hole and fit on the shaft.

Sometimes, especially if you are using the wrong size wrench to turn the nut on the forcing screw, the nut’s polygonal faces may become rounded. This is why it is important to use the right wrench for the nut.

3.    Use protective wear

This is a fundamental workshop rule, and its importance when using pullers is obvious. Especially if you working on large components, be sure to put on steel toed boots. They will save your dear toes in case the pulley or some other component falls onto your foot. Your eyes might also need protection because of the possibility of flying particles and components. Use appropriate goggles when operating a puller in such eye-threatening conditions.

Don't forget to protect your hands. If you are handling items that have been exposed to dangerous chemicals or have sharp edges, your will have to protect your hands with the right gloves. This also applies if you are handling large components, or when you need to exert much force on the puller enough to harm your hands.

4.    Store Your Pullers Properly

Store the puller properly to ensure that it lasts long. Keep it in dry conditions, away from excess moisture and heat.

 

 

1.    What Is the Capacity Required?

The capacity is simply the amount of force the puller is capable of producing. You need to know how much force will be necessary to pull the pulley, gear, or whatever component it is that you are working on. Each puller will have its own limit as to how much force it can bear.

One of the ways you can determine whether a puller has enough capacity for a particular job is by checking the diameter of the shaft from where you are pulling a component. When choosing a manual puller, make sure the threaded rod has a diameter at least half that of the shaft you are dealing with.

2.    What Is The Required Reach?

The reach of a puller is simply how long the jaws extend from their intersection. For cases where you need to remove bearings lodged in a hole, this will be determined by how deep the hole goes. Pullers meant to extract components stuck in tight spaces will have to be slender.

3.    What Spread Do I need?

The spread of your pulley is the largest diameter it can span. If you are working on wide components, go for a large spread. You also have to consider that the spread can be adjusted using the cross bars, but definitely not beyond its maximum.

If the diameter of the gear you are trying to pull is large, you will also have to go for a puller with 3 jaws. They are better at distributing force across the surface than the two-jaw type. This will not only make the job easier but will also ensure the safety of your components.

4.    Is the Component Lodged in a Through Hole?

If you have a bearing stuck in a bore, the kind of puller you will need depends on whether the hole is a blind one or if it goes through. If you have a blind hole, get yourself a blind hole puller. These are designed to extract components in such space limited conditions.

5.    What are the working conditions?

You also have to consider the working environment. Sometimes you may have to work on components that have been exposed to corrosive chemicals. Make sure the puller you choose is built from material that can withstand such conditions.