Selection of Chucks |
|
To help you select the right chuck for your application and achieve optimum performance, AIRTECH gives a thumb sketch of its family of Power Chucks. This wedge type chuck is actuated by a rear mounted hydraulic or pneumatic cylinder via a draw bar passing though the machine spindle bore. Offered with standard or long jaw stroke, this compact and high rigid chuck, offers powerful gripping and high repeatability. Ideal for CNC applications, this chuck has a self-locking design.
Ultra High Speed Power Operated Hollow Chuck - Model WHCB.
Front Operated Self Contained Power Chuck - Model WHFO Eccentric Compensating Power Chuck - Model CC This Wedge Type Closed Centre Chuck has a small float (compensation) in the jaws, to take care of the irregularities in the job geometry. The job must be held between centers for which a spring load / dead centre is provided in the chuck. The Chuck has to be coupled with Closed Centre Hydraulic / Pneumatic Cylinder.
Quick Change Jaw Power Chuck - Model QCJ This Open Centre Chuck has two special features one, the wedge design is modified to give better gripping force and second, the jaws are modified to facilitate quick change over. No allen keys or wrenches are required for unscrewing the top jaws from the base jaws. Only a turn of the key enables you to pull out the jaw.
Ball Fulcrum Power Chuck - Model BFC This Chuck is ideal for forgings and castings. The jaws are designed to exert a pulling action on the job. The totally sealed construction ensures negligible maintenance or attention. However, the Chuck being a closed center design, has to be coupled to a closed center hydraulic / pneumatic cylinder.
Power Operated Collet Chuck - Model PCCDLR/A This hollow type chuck, manufactured to suit standard or specific collets available with the customer, is ideal for machining components susceptible to deformation or surface damage. This chuck needs to be coupled to hollow hydraulic cylinders for bar stock or closed center hydraulic / pneumatic cylinders for short length components.
2+2+2 Compensating Chuck - Model SCC These chucks are specifically designed to hold large diameter thin walled components. Aluminium components of turbines and couplings, precision bigger size wheels and large size gear blanks.
Manual Indexing Chuck - Model ICM Suitable for machining jobs at 90 , 120 , 180 or any other angle in one clamping, this Manual indexing chuck is ideal for machining automobile transmission cross, hydraulic fittings and valve bodies. Also the operator has to only clamp the job once. He just has to pull and push a lever to index the next operation.
Auto Indexing Chuck - Model ICA To reduce the long change hours times or even avoid investing in expensive Special Purpose Machines, Airtech introduced Auto Indexing Chucks. With this chuck, clamping, indexing, locking and opening of the chuck is performed hydraulically to pre-set programmes. This chuck is ideal for machining components like universal joint bodies, spiders, gate valve bodies, hydraulic fittings etc.
Lever Type Big Bore Chuck - Model LCB This chuck is manufactured to accommodate large diameter jobs, which have to be machined by keeping only the portion to be machined in front of the chuck. The remaining portion could go inside the machine spindle.Ideal applications are bomb shell, short length large diameter pipes etc. This chuck comes in sizes 400mm to 1000mm dia. with bores above 200mm.
Pull Grip Chuck - Model PG The chuck works on the principle of master jaw collets. Its interchangeable jaw inserts exert radial force as well as axial pull, thus drawing the job against the face of the chuck. The chuck can operate at very high speeds without any appreciable loss of grip due to centrifugal forces. However like the collet chuck, this chuck is also useful for only external gripping. Gear blank turning, bearing race turning and short cut piece bar work on medium or small batch size, are ideal applications for this chuck.
2+2 Compensating Chuck - Model WWC/S These chucks are specifically designed to hold square and rectangular components where standard four Jaw chuck dose not always clamp on all four sides.
Expandable Jaw Chuck Expandable jaw chucks are used for clamping in bore for clamping in bore of tube shaped components. Wedge principle is employed for moving multi-jaws in one or multiple planes. Concentricity and ovality of component OD can be achieved by selection and placement of expandable jaws.
Stationary Power Chuck - Model PSCA/PSCH This chuck is exclusively designed for drilling machines, milling machines and vertical CNC machining centers. The compact construction not only offers maximum working space, but also allows inspection of components in clamped or unclamped positions. It can be operated hydraulically or pneumatically.
Diaphragm Chuck - Model SD/SCD Mainly used for secondary operations like grinding, facing and boring where a high degree of concentricity control is required, this chuck utilizes the inherent strength of the spring action of steel to achieve chucking pressure on the job. The absence of sliding parts to clamp the job ensures higher reliability and longer life.
Swiveling Jaw Face Clamping Chuck - Model SFC This chuck is mainly used for machining components by clamping them on the face. The large swivel angle facilitates easy loading and unloading of the components. The modular design and the fact that the swiveling jaws are mounted on compensating spider, lend flexibility and versatility to this chuck. It can be operated either hydraulically or pneumatically.
Expanding Mandrill Collet type expanding mandrill is used for holding components in previously finished bores for grinding or finish turning where extreme concentricity are needed.
Combined Diaphragm Chuck - Model DAFC This chuck is developed for machining components that require location and clamping both on outside diameter and the face. Interchangeable jaws, arms and radial clamps ensure accommodation of various sizes of components. The modular design also ensures reduction in the work holding fixture inventory.
Bevel Gear Chuck - Model BGC This chuck locates the bevel gear with respect to the pitch-line of the teeth, thus providing a high degree of concentricity and accuracy. The angular moving jaws are used to clamp the gear against the butting surface. The length of the arm and the height of the jaws can also be changed. The modular design thus helps in accommodating various sizes of components.
Manual Cam Operated Coventry Concentric Chuck - Model CCM Remarkable for its gripping power and adaptability, this chuck is ideal for all concentric and every type of irregular applications. Moreover, by removing the jaws, the chuck body could be used as a faceplate too.
Pull Clamp Chuck - Model WPC This concentric wedge type chuck uses wedges to carry the jaws. The clamping motion coupled with axial displacement tends to pull back the work piece against the locating stops. The jaws are interchangeable and must be ground in situs. It is mainly used for internal and face grinding applications.
High Speed & Ultra High Speed Hydraulic Cylinders Open Centre - Models HOHSA These cylinders are designed for high speed CNC bar and chucking lathes. They can also be offered with nonreturn valves on request.
Pneumatic Cylinders - Models AC/ACH/ACMK Made from high quality aluminum alloy, these cylinders are not only light but are specially treated to take large loads. They are ideal for special applications such as finger chucks, clamp applications and special chucks. They are offered in three types: Single Chamber Air Cylinder for limited power, Tandem Cylinder for limited space or added power and High Speed Cylinder for high speed applications with provision for fitting the proximity switch.
High Speed Hydraulic Cylinders Closed Centre - Models HCHSA/HCHSLA
Rotating Tandem Air Cylinder - Model ACT This cylinder has two pistons working in two different chambers but having a common piston rod. They are ideal for machines without hydraulic systems. Lightweight aluminum alloy is used for almost all components except the pistons and piston rod, which are made from alloy steel.
|
Guide to Cutting and Gripping ForcesWith the advancement of cutting tool technology, machines need to have ultra high speeds to make the optimum use of the changing technology. To match this age of high speeds, work holding for rotating machines needs high gripping power, even at very high cutting speeds. Therefore it is very important to know:
|
Elements of Power Chucking System
Power chucking system consists of:
a. Power chuck
b. Power source an actuating source i.e. Rotating Hydraulic / Pneumatic Cylinder or Electromechanical device
C. Draw bar or draw pipe connecting chuck to power source (Item b and c are not required in the case of self-contained chucks)
The chuck is mounted at the front end and the hydraulic/ pneumatic cylinder or electro-mechanical actuatingdevice is mounted at the rear end of the headstock spindle of the lathe. The chuck and cylinder/actuator areconnected to each other by a draw bar or draw pipe.
The cylinder is connected to two pressure pipes, each supplying oil under pressure or compressed air to each of the two chambers of the cylinder. The cylinder piston exerts pull or push force when oil or air is fed to the two chambers of the cylinder via a control valve. In case of Hydraulic Cylinders, a drainpipe is also connected to the cylinder to return the leakage oil to the reservoir. Electro-mechanical actuator has an in-built three phase
tapered brake motor, the rotary motion of which is converted into axial motion by a set of planetary gears to push or pull the draw bar/pipe at the required operating force. Schematic arrangement of Hydraulic and Pneumatic operation is shown in figures G1 and G2.
Generally, Open Centre Chuck (Model WH) is used with an Open Centre Hollow Cylinder (Model HOH) for free passage of bar stock through the spindle. However, WH chucks can also be used with Closed Centre Cylinders to accommodate short length bar stock. The following illustrations show a few combinations of chucks and cylinders.
