PRECISION METRIC & MINIATURE BALL SCREW ASSEMBLIES
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PRECISION METRIC & MINIATURE BALL SCREW ASSEMBLIES Ve r s i o n 1 . 0 2 . 0 2

Ball Splines Linear Slides Electric Cylinders Worm Gear Screw Jacks Profile Rails Planetary Roller Screws EZZE Mounts™ Modular Linear Actuators In 1969, Joseph H. Nook Jr. founded Nook Industries, Inc., intent on becoming a global supplier of Linear Motion products. Ball screws, both rolled and ground, were the cornerstone products in the early 1970’s, putting Nook Industries on the map as a successful business and a trusted company. screws to the latest technologies, Nook Industries strives to provide customers with high quality products and engineered solutions. Companies around the world...

INTRODUCTION Nook Industries has always been a leader in developing highquality linear motion components and systems to meet the everincreasing demand for precision linear motion. Precision-rolled ball screws have long been a hallmark of Nook Industries, and the latest innovations from Nook Industries are Precision Metric Ball Screws (PMBS™). They are manufactured in the United States to meet the increasing demand for metric ball screws in the global market. The PMBS™ product line offers linear lead accuracy classes of T10, T7, T5, and T3, which comply with the ISO 3408 ball screw standard....

TECHNICAL DATA TECHNICAL DATA TECHNICAL DATA NOOK PRECISION METRIC AND MINIATURE BALL SCREWS The specifications and data in this publication are believed to be accurate and reliable. However, it is the responsibility of the product user to determine the suitability of Nook Industries products for a specific application. While defective products will be replaced without charge if promptly returned, no liability is assumed beyond such replacement.

TECHNICAL DATA PRECISION METRIC AND MINIATURE BALL SCREWS TECHNICAL DEFINITIONS LEAD ACCURACY The selection of the correct ball screw and nut for a particular application involves five interrelated factors. Before attempting to determine the ball screw and nut combination, the following values must be known: • Load measured in newtons • Speed measured in millimeters per minute • Length between bearings measured in millimeters OVERTURNING LOAD - A load that tends to rotate the nut radially around the longitudinal axis of the screw. SIDE LOAD - A load that is applied radially to the nut....

TECHNICAL DATA When considering the total torque required for a given screw assembly, you must consider several factors. If Preload is applied to the ball screw assembly, Drag Torque is added to either the Driving Torque or Backdriving Torque. DRIVING TORQUE When rotation is converted into linear motion (Normal Operation), the torque can be obtained from the following formula: Ttotal driving torque = Td + Tp Ttotal backdriving torque = Tb + Tp Ttotal holding torque = Tb - Tp Lead Angle Tp = Drag torque (N·m) Tb = Backdriving torque (N·m) BACKDRIVING TORQUE When linear motion is converted...

TECHNICAL DATA PRECISION METRIC AND MINIATURE BALL SCREWS LIFE EXPECTANCY Fm = equivalent axial load (N) Indirect Vibration Direct Vibration AND High Cyclical Impact nj = rotational speed at load Fj (rpm) nm = equivalent rotational speed (rpm) and is given by the following equation: n DIRECT VIBRATION - Any vibration directly linked to the screw assembly which influences the stability of the assembly. LIFE (ADJUST TO RELIABILITY) If operation reliability higher than 90% is required, then the theoretical life must be corrected by using a reliability factor (far) according to the table. Lar =...

TECHNICAL DATA PRECISION METRIC AND MINIATURE BALL SCREWS Assuming Earth gravity at Sea Level, a simplified formula for calculating critical speed is available: END FIXITY - End fixity refers to the method by which the ends of the screw are supported. The degree of end fixity is related to the amount of restraint of the ends of the screw. It is important to determine the proper end fixity in order to determine the appropriate screw size for a give application. COLUMN STRENGTH - When a screw is loaded in compression (see compression load definition on page 6), its limit of elastic stability...

PRECISION METRIC BALL SCREWS BALL SCREW ASSEMBLIES PRECISION METRIC BALL SCREWS PRECISION METRIC BALL SCREWS PRECISION METRIC BALL SCREWS NOOK PRECISION METRIC BALL SCREWS The specifications and data in this publication are believed to be accurate and reliable. However, it is the responsibility of the product user to determine the suitability of Nook Industries products for a specific application. While defective products will be replaced without charge if promptly returned, no liability is assumed beyond such replacement.

PRECISION METRIC BALL SCREW SIZES Nook Precision Metric Ball Screw Assemblies are available in four separate classes of accuracy determined by the manufacturing techniques used to produce the screws, the precision rolled (T5,T7, T10) accuracies are a product of state-of-the-art thread rolling and heat-treat technology. Very precise rolled thread screws offer the design engineer the option of obtaining high accuracy at reduced costs. High-lead precision rolled ball screws acheive maximum travel rates with repeatable positioning accuracy. Nook also offers PMBS™ ball nuts with precision ground...

PRECISION METRIC BALL SCREWS REFERENCE NUMBER SYSTEM PRECISION METRIC BALL SCREW ASSEMBLIES ISO LEAD ACCURACY GRADE Rolled Thread Ground Thread Right Hand Thread ACTIVE TURNS Number of Active Turns Flanged V-Thread Cylindrical No Nut Wipers None Clearance Ball Nut Reduced Clearance Ball Nut 1% - 2% Preload 3% - 5% Preload NOTE: Preload percentage value as measured without wipers T10 T7 T5 (T3 is available upon request for limited sizes and lengths) FIRST END CONFIGURATION See next page for configuration codes. NOTE: Both Ends must be specified. SECOND END CONFIGURATION See next page for...

PRECISION METRIC BALL SCREWS PMBS BALL SCREW ASSEMBLIES SINGLE NUT WITH FLANGE (12MM DIA) FOUR-HOLE FLANGE Ball nuts are provided clearance or preloaded fit To be used with all accuracy classes (precision rolled T10, T7, T5 and precision ground T3) Mounting dimensions per DIN69 051 Part 5 Type C PRECISION METRIC BALL SCREWS Part Number Active Turns Dynamic Static Load Load Ca(N) C0a(N) Linear Speed* (mm/min) Screw Dimensions (mm) Size NOOK PRECISION METRIC BALL SCREWS The specifications and data in this publication are believed to be accurate and reliable. However, it is the responsibility...