Bevel Gear Screw Jack
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BEVEL GEAR JACKS BEVEL GEAR SCREW JACK SYSTEMS JACK MODELS Nook Bevel Gear Screw Jack systems are ruggedly designed using a ground spiral bevel gear and produced in standard models with load handling capacities from 12.3kN to 117kN. They may be used individually or in multiple arrangements. There are no “standard” travel lengths and each bevel gear screw jack is built to specification. All bevel gear screw jacks are equipped with hardened and sharpened spiral toothed bevel gear transmissions for high lifting speed and greater duty cycle. The Bevel Gear Screw jack housings are made from AISI...

DEFINITIONS AND TECHNICAL DATA BEVEL GEAR JACKS DESIGN CONSIDERATIONS TRAVEL LENGTH DUTY CYCLE BALL SCREW  VS. MACHINE SCREW JACK KILOWATT RATINGS Jacks are not pre-assembled or stocked with standard length screws. Each jack is made to order based on travel length. Nook Industries has the capability to manufacture long screws for special applications, limited only by the availability of raw materials. Rotating screw jacks may be assembled with a larger diameter lift screw for greater column strength. Duty cycle is the ratio of run time to total cycle time. Some of the mechanical energy...

BEVEL GEAR JACKS COLUMN STRENGTH CHARTS BALL SCREW JACKS MACHINE SCREW JACKS Column strength is the ability of the lift shaft to hold compressive loads without buckling. With longer screw lengths, column strength may be substantially lower than nominal jack capacity. To use this chart: Find a point at which the maximum length “L” intersects the maximum load. Be sure the jack selected is above and to the right of that point. Column strength is the ability of the lift shaft to hold compressive loads without buckling. With longer screw lengths, column strength may be substantially lower than...

DUTY CYCLE CHARTS BALL SCREW JACKS *Chart is based on 20°C Ambient Temp. To calculate the operating time for other speeds and temperatures, multiply the duty cycle in % by fn and ft. SPEED AMBIENT TEMP 'f different speeds determine the average of speed: SPEED FACTOR f„ TEMP(C) FACTOR f, 25QQ 06 IQO 12 nr n2, ...= Each incremental speed movement in rpm 2000 0.75 20° 1.0 qr q2, ...= Percentage of move time NOOK BEVEL GEAR JACKS BEVEL GEAR JACKS MACHINE SCREW JACKS *Chart is based on 20°C Ambient Temp. To calculate the operating time for other speeds and temperatures, multiply the duty cycle...

DESIGN CONSIDERATIONS (CONTINUED) CRITICAL SPEED REQUIRED APPLICATION DATA The speed that excites the natural frequency of the screw is referred to as the critical speed. Resonance at the natural frequency of the screw will occur regardless of the screw orientation or configurations of the jack (vertical, horizontal, translating, rotating, etc.). The critical speed will vary with the diameter, unsupported length, end fixity and rpm of the screw. Since critical speed can also be affected by the shaft straightness and assembly alignment, it is recommended that the maximum speed be limited to...

QUICK REFERENCE BALL SCREW BEVEL GEAR JACKS Raise for One Torque to Back Drive Tare Drag Dynamic Gear Lifting Screw Screw lead Turn of Worm Max Input Raise 1 kN Holding Torque Load Ca Ratio Capacity (kN) Dia (mm) (mm) (mm) Torque (N-m) (N-m) Torque(N-m) (N-m) (kN) MACHINE SCREW BEVEL GEAR JACKS Raise for One Torque to Back Drive Tare Drag Gear Lifting Screw Screw lead Turn of Worm Max Input Raise 1 kN Holding Torque Torque Ratio Capacity (kN) Dia (mm) (mm) (mm) Torque (N-m) (N-m) (N-m) (N-m) REFERENCE NUMBER SYSTEM BEVEL GEAR JACKS Upright Rotating Upright Keyed GEAR RATIO - Refer to...

BEVEL GEAR JACKS DESIGN CONSIDERATIONS (CONTINUED) For multiple jack arrangements, total kilowatts required depends on horsepower per jack, number of jacks, the efficiency of the gear box(es) and the efficiency of the arrangement. If the application duty cycle exceeds the allowable duty cycle as illustrated on pages 8 and 9 for the jack selected, several solutions are possible. • Two jacks = 95% • Three jacks = 90% • Four jacks = 85% • Six to eight jacks = 80% The efficiency of each miter gearbox is 90%. Therefore, motor kilowatts requirement for the arrangement: kW per jack Arrangement...

BEVEL GEAR JACKS G1-BSJ TOP VIEW (2:1 GEAR RATIO) Counterclockwise rotation raises load G1-BSJ-UR UPRIGHT ROTATING For ordering, specify “L” dimension L(min) = Travel + 249 Ball nut position A Specify position B for opposite G1-BSJ TOP VIEW (3:1 GEAR RATIO) Travel + 35 42 Sq Backdrive holding torque (N·m) Tare Drag Torque (N·m) Gear Ratio Raise for One Turn of Worm (mm) MALE CLEVIS ROD-EYE CLEVIS FEMALE CLEVIS Screw Specs: Screw Dia: 25 mm Lead: 5 mm Start torque = 1.5 × Running Torque Approximate weight (kg) “0” Travel: 7.7 Per inch travel: 0.32 Grease: 0.22 Caution: Jack is self-lowering....

BEVEL GEAR JACKS Counterclockwise rotation raises load G2-BSJ-UR UPRIGHT ROTATING For ordering, specify “L” dimension L(min) = Travel + 331 Ball nut position A Specify position B for opposite Raise for One Turn of Worm (mm) Backdrive holding torque (N·m) Tare Drag Torque (N·m) Screw Specs: Screw Dia: 40 mm Lead: 5 mm Start torque = 1.5 × Running Torque Approximate weight (kg) “0” Travel: 15.9 Per 100mm travel: 0.81 Grease: 0.45 ROD-EYE CLEVIS MALE CLEVIS Caution: Jack is self-lowering. Lifting screw must be secured to prevent rotation for non-keyed units. MALE CLEVIS NOOK BEVEL GEAR JACKS...

BEVEL GEAR JACKS 0.5C-BSJ-UR & 0.5CHL-BSJ-UR UPRIGHT OR INVERTED ROTATING For ordering, specify “L” dimension L(min) = Travel + 331 Counterclockwise rotation raises load Ball nut position A Specify position B for opposite Gear Ratio Raise for One Turn of Worm (mm) Backdrive holding torque (N·m) Tare Drag Torque (N·m) Screw Specs: Screw Dia: 32 mm Lead: 10 mm Start torque = 1.5 × Running Torque Approximate weight (kg) “0” Travel: 15.9 Per 100mm travel: 0.81 Grease: 0.45 ROD-EYE CLEVIS FEMALE CLEVIS Caution: Jack is self-lowering. Lifting screw must be secured to prevent rotation for...