Part i - spindle facts

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HSK-Clamping Unit / Design B • A newly designed coating optimizes the life span 50 times in the case of insufficient lubrication. • The guiding of the gripper is done by means of a specially formed locating sleeve, which sits the tool directly into the taper. • New also are the geometry and the coating of the spacer. The position of the individual gripper fingers are securely held and guided to ensure a perfect balance at high speed. Quickest clamping now depends only on the machine tool control and its software With regard to spindle design, the drawbar presents some challenges. A drawbar is a movable device, and with each actuation the springs may end up in slightly different locations. This can create a balance problem, which could cause unwanted vibration at high speeds. To overcome this, drawbar components should be manufactured to close tolerances, and with guide bushings positioned internally. Also, as speeds increase, the holding force required also increases. It is not practical to increase the holding force by simply increasing the number of washers, as this would require a longer spindle shaft. It is also not always practical to increase the diameter of the washers, as this may require the shaft to be larger imposing on spindle speed. Mechanical locking systems Figure 43. HSK Clamping unit – Design B The mechanical clamping system offers the highest pull forces. Special features of the power drawbar are the amplification mechanism for transmission of the pull force and locking the universal spindle’s inside shape. The drawbar uses belleville washers to pull the toolholder into the taper. Once seated, however, a mechanical locking system then is actuated. The locking components may be small balls or cams. Figure 44. Mechanical locking system - 39 -
After the locking mechanism is in place, all cutting forces are directed against the solid steel shaft, not against the belleville washers. This system provides very high holding force and rigidity, which is critical to the high speed cutting process. As the spindle will be used with an ATC (Automatic Tool Change) magazine, it is necessary to have electronic sensors or switches built-in to indicate to the control logic when a tool is clamped, unclamped, or missing. These signals must be derived by monitoring the position of the drawbar. Unclamping Units Figure 45. Pneumatic unclamping unit Figure 46. Hydraulic unclamping unit • low bearing load • enclosed housing • modular • RPM independent • purge passage • low bearing load • easy mounting • RPM independent - 40 -
Page 2 and 3: PART I - SPINDLE FACTS 1. Introduct
Page 4 and 5: 2. Precision Spindle Design 2.1 Lis
Page 6 and 7: otate up to the maximum speed, and
Page 8 and 9: Bearing Contact Angle Angular conta
Page 10 and 11: Back to Back Configuration The most
Page 12 and 13: Motor-Spindle with Tandem Bearing P
Page 14 and 15: Bearing Lubrication Methods Angular
Page 16 and 17: There are many oils available on th
Page 18 and 19: 2.5 Spindles with Integral Motors S
Page 20 and 21: Synchronous Spindle Motor : AC asyn
Page 22 and 23: The synchronous motor built in spin
Page 24 and 25: Torque: This is the most critical a
Page 26 and 27: 2.7 Spindle Cooling Systems Heat is
Page 28 and 29: 2.8 Seal Types High precision beari
Page 30 and 31: The values are valid for spring-loa
Page 32 and 33: and the influence of higher tempera
Page 34 and 35: 2.9 Tool Retention System A high sp
Page 36 and 37: Assuming that equivalent force is a
Page 38 and 39: of tooling. This means that users m
Page 42: 3. Conclusion and Future trends A h
Page 45 and 46: Dynomax’s dedication to new spind

Part i - spindle facts

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