Neometrix / Hydraulic Tools / Hydraulic Puller System / NMX-HPS-100

NMX-HPS-100 · ENGINEERED-TO-ORDER CLASS — DUTY · CYLINDER AND PUMP · LEGS AND JAWS · ALIGNMENT AND GUARD · BUILD · PROVE

Hydraulic Puller System. Pull the part that is tight.

Name: Hydraulic Puller System
Brand: Neometrix
SKU: NMX-HPS-100

A hydraulic puller draws a tight-fitted part off a shaft or out of a bore: a bearing, a coupling, a gear, a wheel. A hydraulic cylinder makes the force, legs with jaws grip behind the part, and a pump drives the cylinder. Neometrix engineers it as a system: the cylinder and pump, the legs and jaws, the alignment, the guard and the proof.

So the system has to pull the part that is tight, pull in line with the shaft, and keep people clear of the stored force.

Discuss a hydraulic puller Capability note (PDF)

A trolley-mounted hydraulic puller on a plain white studio background: a pale grey welded trolley on four wheels with a towing handle and a vertical column, a horizontal hydraulic cylinder with a bright body and a black end cap held on the column and facing a short steel shaft stub, a crosshead plate, two long steel puller legs with hooked jaws that hook behind a thick steel ring pressed on the shaft, the shaft resting on a pale grey support block, a hand pump with a lever on the trolley joined to the cylinder by a black hose, and no people

Fig · 01 — A trolley-mounted hydraulic puller: a cylinder held on the centreline of the shaft, legs with jaws hooked behind the ring, and a pump on the trolley — illustrative render.

The result

the part off its shaftthe part and the shaft undamaged

The pull

on the tight partnever through the rolling elements

The line

in line with the shaftthe legs set square and equal

The load

put on graduallythe part gives a little at a time

Status

engineered to orderno delivery is claimed

ISO 9001ISO 14001ISO 4413 reference for hydraulic systemsISO 12100 reference for machinery safety

Overview

What a hydraulic puller has to get right, and what goes wrong when it does not.

Because a part that is tight on a shaft can be drawn off cleanly, or torn off with damage to the part and to the shaft.

The gripping end of a hydraulic puller on a plain white studio background: two bright steel legs with hooked jaws behind a thick steel ring pressed on a steel shaft, a pale grey crosshead plate, a short hydraulic cylinder with a black end cap and its ram on the shaft end, a black hose with a quick coupling, and no people

Fig · 02 — The grip: legs with hooked jaws behind a ring that is pressed on a shaft, and a cylinder in the middle with its ram on the shaft end — illustrative render.

Pull the part that is tight.

What the system is for

It draws a tight-fitted part off a shaft or out of a bore, when hand tools and heat are not enough: a bearing, a coupling, a gear, a wheel or a sleeve. It serves power stations, process plants and maintenance workshops.

Why a hydraulic cylinder

A part that is pressed on a shaft is held by the grip of the fit, and the force needed to move it is large. A hydraulic cylinder gives that force steadily from a small pump, and without hammering.

Why the pull goes on the tight part

A bearing has an inner ring and an outer ring, and only one of them is fitted tight. If the pull goes through the other ring, the force passes through the rolling elements and marks the raceways. So the jaws grip behind the ring that is tight, and for a bearing on a shaft that is the inner ring.

Why the pull is in line with the shaft

If the pull is off the line of the shaft, the part cocks and jams, and the shaft or the bore is scored. So the cylinder is set on the centreline of the shaft.

Why the legs and jaws are set equal

The jaws share the load. If one takes more than its share, it slips or bends, and the part comes off crooked. So the jaws are set for flat, square contact, and the legs are set equal.

Why the puller is rated as a whole

A puller is as strong as its weakest part. The rating of the whole puller can be lower than the rating of the cylinder alone, so the legs, the crosshead and the cylinder are chosen together.

Why the force goes on gradually

The part gives a little at a time. So the pump raises the force gradually, and the operator watches the part move, and does not force it.

Why a guard, and why the operator stands to one side

A puller holds a large force, and a slip or a break releases it at once. So a guard stands between the puller and the operator, and the operator stands to one side, never in line with the pull.

Why heat and oil are not ruled out

Some tight fits are eased by heating the part, or by oil forced between the surfaces. The puller works with those methods, and does not replace them.

The method

Duty, cylinder and pump, legs and jaws, alignment, build and prove.

Six steps in a fixed order. The alignment and the proof are the two that a quick job skips.

1 · Duty

The parts to be drawn off, the shafts they sit on, how tight the fit is judged to be, how much room there is behind the part, and where the work is done are noted.

2 · Cylinder and pump

A cylinder is chosen for the pull, and a hand or electric pump is matched to it, with a relief valve that limits the force and hoses suited to it.

3 · Legs and jaws

The legs reach behind the part, and the jaws hook behind the tight ring. The legs are set equal, and are rated with the crosshead for the whole pull.

4 · Alignment and guard

The cylinder is set on the centreline of the shaft, so that the pull is in line, and a guard stands between the puller and the operator.

5 · Build

The cylinder, the crosshead, the legs, the jaws, the pump and the hoses are built and fitted together, with adapters for the parts the customer names.

6 · Prove

The system is run on a test shaft with a fitted part, the alignment and the load are checked, the relief valve and the guard are tested, and the record goes with it.

Which hazard, which safeguard

What can go wrong	Why it happens	What the system does about it
The raceways are marked	the pull went through the rolling elements	jaws that grip the tight ring, and a split plate that sits behind the inner ring
The part jams on the shaft	the pull is off the line of the shaft	a cylinder on the centreline, and legs set square and equal
The shaft or the bore is scored	the part cocks as it comes off	alignment, and a pull that is gradual and steady
A leg slips or bends	one leg takes more than its share	jaws set for flat contact, and legs rated for the whole pull
The force is released suddenly	a slip or a break frees the stored force	a guard in front of the puller, and the operator to one side
The puller is overloaded	the pump is stronger than the puller	a relief valve set for the rating of the whole puller

The step people underrate is the line of the pull. A strong cylinder pulling off the line of the shaft does more harm than good.

Work content

What the system contains, element by element.

Read it as a checklist: a system missing a row will pull a part, but it will not pull it cleanly or safely.

A hydraulic puller set laid out on a plain white studio background: a hand pump with a lever on a pale grey reservoir, a black hose with a quick coupling, a hydraulic cylinder with a black end cap and a chrome ram, a crosshead plate, steel puller legs with hooked jaws, extension rods and a steel split plate in two halves, and no people

Fig · 03 — A puller set laid out: a hand pump with its hose, a cylinder, a crosshead, legs with jaws, extension rods and a split plate — illustrative render.

Element	What it does	What matters
Hydraulic cylinder	makes the force	a cylinder chosen for the pull, with a ram that bears on the centre of the shaft end, and a return that is controlled
Pump	drives the cylinder	a hand or electric pump matched to the cylinder, with a relief valve that limits the force and a release that lets the load off slowly
Hoses and couplings	join the pump to the cylinder	hoses suited to the pressure, and self-sealing couplings that keep the oil in when a hose is disconnected
Crosshead	carries the legs	a stiff plate that holds the legs parallel to the shaft and shares the pull between them
Legs	reach behind the part	legs of the right length, set equal and parallel to the shaft, and rated with the crosshead for the whole pull
Jaws	grip the tight part	jaws that hook behind the ring that is fitted tight, and make flat, square contact
Split plate	takes a bearing ring	two halves that sit behind the inner ring, so that the pull does not pass through the rolling elements
Adapters and rods	fit the system to the job	adapters and extension rods for the parts the customer names, and for shafts with limited room
Trolley	carries the heavy version	a trolley that holds the cylinder at the height of the shaft and on its centreline, so that no one has to hold it
Guard	keeps people clear	a guard between the puller and the operator, and a place to stand to one side of the pull
Testing & documentation	prove the system first	a run on a test shaft with a fitted part, a check of the alignment and the load, a test of the relief valve and the guard, and a record the customer can inspect

The elements that decide the result are the jaws and the alignment. The first puts the pull on the tight part, and the second keeps it in line with the shaft.

Full specification — expand

System	A hydraulic cylinder with a relief valve and a hand or electric pump; a crosshead; legs and jaws that hook behind the part to be drawn off; a split plate for a bearing ring; adapters and extension rods; hoses and self-sealing couplings; a trolley for the heavy version; a guard between the puller and the operator; and trials on a test shaft and documentation before handover
The One Idea	Pull the part that is tight.
Why The Tight Part	A bearing has an inner ring and an outer ring and only one of them is fitted tight; if the pull goes through the other ring the force passes through the rolling elements and marks the raceways, so the jaws grip behind the ring that is tight, which for a bearing on a shaft is the inner ring
Why In Line	If the pull is off the line of the shaft the part cocks and jams and the shaft or the bore is scored, so the cylinder is set on the centreline of the shaft and the legs are set square and equal
Standards	ISO 4413 covers the general rules and safety requirements for hydraulic systems and their components, and ISO 12100 covers the general principles of design, risk assessment and risk reduction for machinery. This page prints none of their requirements, and no edition year. Approval of a system rests with the customer and the authority they name; none is claimed here
Configurations	A portable puller set, a trolley-mounted puller, and a push-pull set
Scope Boundary	This page is the hydraulic puller system, which draws a tight-fitted part off a shaft or out of a bore. It is not a jack, which lifts or moves a load (see hydraulic jack machine), not a spreader, which opens a gap (see hydraulic spreader machine), not a torque wrench, which tightens a bolted joint (see hydraulic torque wrench system) and not a press, which forms a part between dies (see hydraulic press machine). It does not decide the method of dismantling a machine, and it does not replace the operator's own judgement. No certification or accreditation is claimed here
Status	Neometrix has quoted against successive hydraulic puller and bearing puller requirements, and no delivered hydraulic puller system is claimed.

Configurations

One method, three ways to build the system.

The method, the alignment, the guarding and the proof are shared. What changes is how the cylinder is carried, and whether it pulls only or pulls and pushes.

Portable puller set

A cylinder, a pump, legs and jaws in a set, carried to the machine

For a maintenance team that works at many machines: the whole set is carried to the shaft, and the legs and jaws are chosen for the part in front of it.

Trolley-mounted puller

A cylinder on a trolley, held on the centreline of the shaft

For large machines with heavy parts on long shafts: the trolley holds the cylinder at the height of the shaft, so that the pull is in line without anyone holding it.

Push-pull set

A set that draws a part off, and presses a part on

For a shop that fits as well as removes: the same cylinder pulls a part off, and with the right adapters presses a new part on, square and gradually.

And the part that is not equipment at all, yet decides all three: the duty and the dismantling method. They are written from the customer's own machine and work, not from the puller.

The drawings

A reference set, drawn as real CAD sheets.

Two sheets of one reference configuration: the arrangement of a hydraulic puller system with three details, and its hydraulic circuit with the trolley-mounted version. They show the legs and jaws behind the tight ring, the cylinder on the centreline, the guard and the operator's place, the hand pump, the relief and release valves and the trolley. They carry tags and letters only. Every force, pressure, stroke, shaft size and quantity is fixed by design for the customer's duty.

Reference drawing sheet one, the puller arrangement and details of a hydraulic puller system. A section through a shaft shows a bearing fitted tight near the shaft end, two legs whose jaws hook behind the inner ring, a crosshead, a hydraulic cylinder on the centreline with its ram on the shaft end, and the hose to the pump. Detail A shows the pull going on the tight ring against a pull on the other ring that passes through the rolling elements, Detail B a cylinder on the centreline against one off the line, and Detail C a guard and the place where the operator stands. An item list numbers eight parts. A title block stamped reference configuration, not for construction

Fig · 04 — Sheet 01, the puller arrangement: a section through the shaft with the puller in position, the pull on the tight ring, the line of the pull, and the guard. Reference configuration, letters only.

Reference drawing sheet two, the hydraulic circuit and the trolley-mounted puller of a hydraulic puller system. A reservoir, a hand pump with a suction and a delivery check valve, a relief valve that returns to the reservoir, a gauge, a release valve, a self-sealing coupling, a hose and a single-acting spring-return cylinder. A table of what each step does, and an elevation of the trolley with its column and carriage, cylinder, crosshead, leg and jaw, a shaft with a ring, the hand pump and its hose. An item list numbers eight parts. A title block stamped reference configuration, not for construction

Fig · 05 — Sheet 02, the hydraulic circuit and the trolley-mounted puller: the hand pump, the relief and release valves, the spring-return cylinder, and the trolley that holds the cylinder on the centreline. Reference configuration, tags and letters only.

Every real puller is drawn for its own part, its own shaft and its own work. These sheets are the arrangement and the order of working that a project set starts from. Approval of any drawing rests with the customer and the authority they name; none is claimed here.

PDF · two sheets

Reference drawings — puller arrangement and hydraulic circuit

PDF · capability sheet

hydraulic puller system — what Neometrix engineers

Where it is used

Wherever a tight part has to come off, and the shaft has to stay sound.

The common thread is a part pressed on a shaft, a shaft that is worth more than the part, and a need to draw the part off without harm.

Power stations

Where large pumps, fans, motors and generators carry heavy bearings and couplings on long shafts, and a pull must be in line.

Process plants

Where pumps, compressors and gearboxes run for years, and a seized bearing or coupling has to come off without damage to the shaft.

Maintenance workshops

Where many kinds of parts come in, and one set has to be set up quickly for each of them.

Remote sites

Where the machine is far from a workshop, and the set has to come to the machine and be used safely there.

Watch

See it in motion.

A short walkthrough video of the Hydraulic Puller System.

FAQ

Common questions.

Longer answers, for readers who want the reasoning.

Q · 01 What does a hydraulic puller actually do?

It draws a part that is pressed tight on a shaft, or in a bore, off its seat. The legs reach behind the part and the jaws hook behind the ring that is fitted tight. The cylinder stands in the middle, on the centreline of the shaft, with its ram on the shaft end. A pump drives the cylinder, and the force goes on gradually until the part gives. A relief valve limits the force, and a guard stands between the puller and the operator. The puller does not decide how a machine is dismantled. That comes from the maker's method and the customer's own procedure, and the system is built, set and proved to carry it out.

Q · 02 Why must the pull go on the tight part?

Because the force has to reach the part that is held, by the shortest path. A bearing has an inner ring and an outer ring, and only one of them is fitted tight. If the pull is applied to the other ring, the force passes through the rolling elements, which are small contact points, and it marks the raceways and can crack a ring. So the jaws grip behind the ring that is fitted tight, which for a bearing on a shaft is the inner ring, and when the jaws cannot reach it, a split plate sits behind it. A bearing that is drawn off the wrong way is often a bearing that cannot be used again.

Q · 03 Why does the pull have to be in line with the shaft?

Because a part that is pulled off the line of the shaft cocks on its seat and jams, and as it jams it scores the shaft or the bore. So the cylinder is set on the centreline of the shaft, the legs are set parallel to it, and the jaws are set to make flat, square contact. The force goes on gradually, because the part gives a little at a time, and the operator watches it move. A trolley is a way of holding the cylinder on the centreline for a heavy part, so that the line does not depend on a person holding it.

Q · 04 Why does the puller need a guard, and where does the operator stand?

Because a puller under load holds a large force, and a leg that slips or a part that breaks releases it at once. So a guard stands between the puller and the operator, and the operator stands to one side of the pull and never in line with it. The relief valve limits the force that the pump can put on, and the rating of the puller is the rating of the whole puller, not of the cylinder alone. A puller is not serviced while it is under load.

Q · 05 Is this the same as a jack, a spreader, a torque wrench or a press?

No, and the differences are worth stating precisely. The hydraulic jack machine page covers lifting and moving a load. The hydraulic spreader machine page covers opening a gap. The hydraulic torque wrench system page covers tightening a bolted joint. The hydraulic press machine page covers forming a part between dies. This page is the hydraulic puller system, which draws a tight-fitted part off a shaft or out of a bore. It does not replace any of them, and it does not claim what they claim a second time.

Q · 06 Has Neometrix built one of these?

We would rather answer this plainly than let a page imply otherwise. Neometrix has quoted against successive hydraulic puller and bearing puller requirements, and no delivered hydraulic puller system is claimed. What stands behind the offer is adjacent: Neometrix engineers a hydraulic torque wrench system (see the hydraulic torque wrench system page), a hydraulic jack machine (see the hydraulic jack machine page) and a hydraulic spreader machine (see the hydraulic spreader machine page). The cylinders, pumps, hoses, couplings, legs, jaws and adapters are catalogue items, bought in, not invented. What Neometrix engineers is the system around them: the match of cylinder, legs and pump, the alignment, the guard and the proof. So the honest position is that the system is engineered to order, the neighbouring disciplines are in the building, and the first system of this exact kind will be built around the customer's own parts and work rather than taken off a shelf.

Q · 07 Which standard applies, and what can the system not do?

ISO 4413 covers the general rules and safety requirements for hydraulic systems and their components, and ISO 12100 covers the general principles of design, risk assessment and risk reduction for machinery. This page prints none of their requirements, and no edition year: those come from the standard the customer names. The system draws a tight-fitted part off a shaft or out of a bore. It does not decide the method of dismantling a machine, it does not lift or tighten anything, and it does not replace the operator's own judgement. This page claims no certification or accreditation. No force, pressure, stroke, capacity, shaft size or fit figure is printed here, and approval of a system rests with the customer and the authority they name; none is claimed here.

Q · 08 What do you need from us to quote?

Six things, and most of them describe your machine rather than the puller. First, the parts: what is to be drawn off, a bearing, a coupling, a gear or a wheel. Second, the shafts: what the parts sit on, and how much room there is behind them. Third, the fit: how tight the part is judged to be, and whether heat or oil is used. Fourth, the reach: how far the part has to be drawn. Fifth, the place: a workshop, a plant floor or a remote site, and how the set is moved. Sixth, the supply: whether a hand pump will do or an electric pump is wanted. From that we come back with a system concept, a test plan you can check, and a budgetary price.

The neighbouring pages, and how they differ from this one.

Three neighbours: one moves a load, one opens a gap, one tightens a bolt.

↗ The jack

Hydraulic Jack Machine

Lifts and moves a load - where this page draws a tight-fitted part off a shaft.

↗ The spreader

Hydraulic Spreader Machine

Opens a gap - a different job from drawing a part along a shaft.

↗ The torque wrench

Hydraulic Torque Wrench System

Tightens a bolted joint - where this page takes a tight fit apart.

Browse all Neometrix product lines.

Get a quotation

Tell us the part,
and the shaft it sits on.

The projects desk replies within two working days with a system concept, a test plan you can check, and a budgetary quotation. Write to [email protected] or use the form.

Enquire — hydraulic puller Capability sheet (PDF) +91 7777 876 876

ISO 9001 / 14001 ENGINEERED-TO-ORDER CLASS — HYDRAULIC PULLER SYSTEM DUTY · CYLINDER AND PUMP · LEGS AND JAWS · ALIGNMENT AND GUARD · BUILD · PROVE — PULL THE PART THAT IS TIGHT. ENGINEERED IN NOIDA · INDIA