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Keyless bushing
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Trantorque
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Tollok TLK200 Series, Ringfeder RfN 7012 Series, Bikon 4000 Series, U.S. Tsubaki
AS Series, Peter PSV 2001 Series, B-Loc 400 Series
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QD or EPT (Browning) Split Taper Bushing
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Keyless mounting
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Yes
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Yes
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Not recommended.
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Principle design
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Single locking nut, opposing tapers
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All are multi-screw opposing tapered rings.
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Opposing tapers, multiple capscrews
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How they work
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An inner, collet-like sleeve with a tapered O.D. and an outer sleeve with a tapered
I.D. The tapers are identical but opposing to one another. The inner sleeve fits
around the shaft while the outer fits inside the hub bore of the component. Tightening
the single nut forces the inner to clamp the shaft and the outer to expand outward
against the component hub bore.
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Four tapered rings, inner ring has a straight ID and twin opposing taper OD with
single split. Outer ring has a straight OD and twin opposing taper ID with single
split. Outboard rings have ID and OD opposing tapers that when pulled together expand
outer ring and contact inner ring. Multiple socket head capscrews through a series
of threaded and clearance holes are used to pull outboard rings together and generate
pressure on component bore and shaft.
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Equal, but opposing tapers. Split tapered OD fits into tapered mounting hub. ID
is keyed to shaft. Multiple capscrews are used to pull the tapers together. Threaded
push off holes are provided to remove bushing from the mounted component.
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Means of transmitting torque
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Coefficient of friction, developed through the engagement of opposing tapers, developing
evenly distributed pressure on the shaft and component bore.
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Coefficient of friction, developed through the engagement of opposing tapers, developing
evenly distributed pressure on the shaft and component bore.
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QD ... through shaft key and mounting capscrews. EPT ... through shaft key,mounting
capscrews and external key.
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Shaft range
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3/16 to 3 inches and 5mm to 75mm
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3/4 to 7 7/8 inches and 20mm to 500mm
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Varies with bushing size.
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Component material
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Any metallic material providing sufficient yield strength to withstand the outward
forces (psi) generated.
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Any metallic material providing sufficient yield strength to withstand the outward
forces (psi) generated.
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Irons (gray and ductile) or steel. The required hub diameter is a function of bushing
size.
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Machining Requirements
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No special machining required just a simple straight bore with a liberal tolerance.
Example: 1 inch unit is + or - .003 inches.
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Must machine a counter-bore for centering the mounted component. The component bore
must be tightly controlled. Example: 1 inch unit -.000 +.002
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Tapered bore to match bushing taper, 3/4" per foot. Must drill and tap mounted component.
Cut keyway for external key.
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Shaft tolerance
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1 inch unit is + or - .003 inches
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1 inch unit is +.000, -.002
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Varies with bushing size and shaft.
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Self centering
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Yes .... concentric to .001 maximum T.I.R.
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No .... tolerance for runout is not specified by the manufacturers.
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No .... tolerance for runout is not specified by the manufacturers.
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Backlash
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Zero
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Zero
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Yes ... amount depends on fit of key.
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Radial adjustment
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Infinite
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Infinite
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None
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Repositioning along shaft
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Unlimited
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Unlimited
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Limited ... length of key dictates amount of lateral repositioning.
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Ease of assembly
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Excellent! Simply tighten the single locking nut. The self-centering action maintains
perpendicularity between mounted component and centerline of axis.
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Awkward. Multiple screws must be tightened evenly and progressively in diametrically
opposite sequence to prevent cocking of the component and introducing runout.
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Awkward. Multiple screws must be tightened evenly and progressively in diametrically
opposite sequence to prevent cocking of the component and introducing runout.
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Ease of disassembly
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Excellent! Simply unloosen the single locking nut which pulls the outer and component
from the inner ... unlocking the assembly.
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Awkward. Multiple screws must be removed and push off bolts must be threaded into
the push off holes, then tightened to loosen the assembly. May require special long
metric push off bolts which some manufacturers do not supply.
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Difficult. The multiple screws must be loosened and threaded into the push off holes.
Because of shaft to bushing bore clearances, unit often has fretted to shaft.
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Tools required
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Torque wrench, standard socket or crowfoot wrench.
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Torque wrench, hex bit socket.
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Torque wrench, standard socket or crowfoot wrench.
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