UPSPL : Manufacturing spindles clearance grinding spindles hydrodynamic spindle pune flute grinding spindle thread grinding spindle india

Conversion of Hydrodynamic Bearing Spindle to Antifriction Bearing Spindle.

Today’s drills and taps manufacturing industry is well equipped with different flute grinding, clearance grinding and thread grinding machines. The most popular make of these machines are

	Reishauer		Normac
	Hartline		Guhring

Many of these machines are using hydrodynamic spindles for different applications. Needless to mention the ruggedness and accuracy of hydrodynamic spindles, it normally gives lot of trouble to refurbish after its first failure. It is just because the skill required maintaining radial clearances between bush bearings and shaft diameters, which very few maintenance crews possess.

Ultra Precision Spindles Pvt Ltd (UPSPL) has successfully manufactured spindles, which would replace these hydrodynamic spindles with antifriction bearing spindles. We have observed that these spindles run at relatively at low rpm but calls for high degree of radial and axial rigidity. We have used double row cylindrical roller bearings with taper bore and double row angular contact thrust bearings to achieve this rigidity factor.

UPSPL can offer you standard spindles, custom built spindle to meet your requirements. Apart from this we also have established state of art spindle room, which would cater requirements of reconditioning of spindles. Boneham & Turner is not a new name for engineering industry. We have set close association with this company and can get full support from them.

The schematic sketch of the spindle is shown below

The spindle has met all the quality parameters of end product and more over it would give maintenance friendliness while reconditioning the spindle keeping low downtime of the machine.
In case if you have any this kind of requirement, please contact

ULTRA PRECISION SPINDLES PVT LTD

S. No. 166, Pune Sinhagad Road, Nanded Phata,
Pune 411 041

Phone	:	0091 20 24391881/ 2372/0444
Fax	:	0091 20 24390700 / 1645

Cell	:	09822454204 / 09822458694
Email	:	rajesh@svispm.com, pradeep@svispm.com

Remanufacturing of HMC Spindle of Super Max 500 A.

	Objective
	This spindle which is running on HMC at leading diesel engine manufacturer. This spindle was having problem of early failure of bearing and hence was leading to heavy downtime of the machine. The task was given to rectify the problem and enhance the bearing life. Before repairs the spindle was failing in 3 months and the needs to prolong this life to minimum 1 year.

General observations before dismantling of spindle

Bearings used	:	7017 ACD HCP4ADBA SKF make: 01 pair NN 3012 KTN/SP W 33 SKF Make: 01 no
Lubrication	:	8000 rpm.
Axial play	:	Grease packed.
Radial Play	:	0.2 mm
Quill bore run out	:	0.015 mm
After opening spindle heavy coolant and dust was found inside the spindle. O rings which are used to prevent coolant seepage in spindle, were found to be worn out.

Activities carried out to recondition the spindle

	Spindle shaft bore, which is BT 40 in size, and having run out of 0.015 mm was first ground with respect to bearing diameters and 90% blue matching. A due care is taken to maintain gauge length of spindle, which is mandatory for proper fitment of tool shank.
	Spindle shaft is dynamically balanced to the level of 0.2 gm cm per plane.
	The first thing which was observed that bearing failure was caused because of fatigue failure. This led us to conclusion that using only pair in the front end may not be sufficient to take cutting forces which are generated while machining. Hence we have taken decision to use a set of three in front side, instead of a pair.
	Necessary modifications carried out in the existing spindle itself to accommodate a set of three and bearing no for the same was 7017 ACD/HCP4 ATBTB: SKF make.
	Rear side bearing which is NN 3012 KTN/SP W33 which is unchanged. This is double row cylindrical roller bearings with taper bore. This type of bearing needs special skill to gain zero clearance which can be achieved by proper sizing of spacer. Our technical personnel possess skill to maintain the zero clearance because of hands on experience. The same zero clearance is maintained in this spindle as well.
	A careful assembly practice is maintained while carrying out the assembly of this spindle in our temperature controlled clean spindle room.

Results achieved after assembly of spindle

	Quill bore run out	: 1 micron
	Radial play	: Nil

	Axial play	: Nil
	Run out on test mandrel of 200 mm in length	: 5 micron

Remanufacturing of MAKINO S 33 VMC Spindle

	Objective
	This spindle which is running on VMC at leading automobile component manufacturer. This spindle was heavily damaged due to accident on the machine. We found cracks developed at spindle nose which was penetrated for 20 mm from the face of the spindle.

General observations before dismantling of spindle

Bearings used

HCS 71914CTP4SUL: 04 nos B 7011 E 2RSD TP4SUL: 01 no

Max speed

10000 rpm.

Lubrication

Grease packed.

Axial play

Rigid

Radial Play

Rigid

Quill bore run out

Not measurable due to heavy damage

We found that spindle nose BT 40 was heavily damaged.

Activities carried out to recondition the spindle

Results achieved after assembly of spindle

We rebuilt the spindle by machining BT 40 taper and converted it to cylindrical bore. We produced insert with BT 40 taper and fitted it on the shaft by ensuring heavy interference. Find below the photographs of remanufactured spindle after grinding.

	Quill bore run out	: 2 micron
	Radial play	: Nil

	Axial play	: Nil
	Run out on test mandrel of 200 mm in length	: 10 micron