BALL SCREW JACKS
132Pages

BALL SCREW JACKS Made In Italy products 100% Made in SERVOMECH SpA Via Calari, 1 • 40011 Anzola dell’Emilia (BO) • Italy • T. +39.051.6501711 • sales@servomech.com BALL SCREW JACKS

© Copyright SERVOMECH This catalogue contents are under publisher copyright and may not be reproduced unless permission is agreed. Every care has been taken to ensure the accuracy of the information contained in this catalogue, but no liability can be accepted for any errors or omissions. The data shown in this catalog are in any case indicative and do not constitute any commitment. SERVOMECH reserves the right, at any time, to make changes at its discretion without notice.

2 / Ball screw jacks

1 / PRODUCT DESCRIPTION Screw jacks transform a rotary motion of an electric, hydraulic or pneumatic motor or even a manual operation into a vertical linear lifting motion (push or pull) or into a horizontal positioning motion. Screw jacks can be installed as a single unit or in lifting systems with different layouts connected by transmission shafts, couplings and bevel gearboxes. Screw jacks enable the synchronized constant movement of lifting systems even with a not uniformly distributed load. Ball screw jacks combine the gear unit with a linear drive performed by a ball screw that, in...

PRODUCT DESCRIPTION /I 1.1 Product overview SERVOMECH ball screw jacks range consist of three main series: MA BS Series, SJ BS Series and HS Series. Each family is designed and developed to represent a series of sizes with an adequate reciprocal gauge, to allow an easier selection of the most suitable size in terms of performances and costs for each application. MA BS Series High efficiency screw jacks • Recommended for continuous operation, duty cycle up to 100% • Lifelong synthetic oil lubricated worm gear • High precision worm gearbox, reduced angular backlash • Gearbox housing shape for...

1 / PRODUCT DESCRIPTION 1.2 Materials and Components MA BS Series and SJ BS Series screw jacks Input drive with precision worm gearbox, high efficiency design, ZI involute profile, reduced angular backlash. Bronze wormwheel, hardened and ground steel wormshaft, with true involute worm thread and shaft ground. Monobloc housing designed for a more compact and robust shape, able to carry heavy loads and ensure a high precision level of machining. • Housing: casting in hardened and tempered aluminium alloy EN 1706 AC-Al Si10Mg-S-T6 casting in grey cast iron EN-GJL-250 (UNI EN 1561:2011) casting...

PRODUCT DESCRIPTION /1 1.3 Size overview Ball screw jacks 6 / Ball screw jacks

1.4 Models and design Ball screw jacks are available in two different models: • travelling screw (Model A) • travelling nut (Model B) The ball nut is integral with the worm wheel. The linear motion is performed by the ball screw being driven by the nut through the screw jack housing, therefore there must be enough space on both screw jack sides. In operation, the screw does not rotate and its translation is possible only if the reacting torque is applied. Accessories: • protective tube • protective bellows • safety nut • various screw end attachments • limit switches • anti-turn device •...

PRODUCT DESCRIPTION / 1 1.4 Models and design MA BS Series screw jacks are available in both models (Model A and Model B), while SJ BS Series and HS Series are available only with travelling nut (Model B). SERVOMECH screw jacks can operate in vertical, horizontal or inclined plane. Different input options are available, such as: • MA BS Series and SJ BS Series: single or double solid shaft, motor flange or motor flange with second input shaft. • HS Series: single solid shaft or flange and hollow shaft All screw jacks are available with flange + hollow shaft or bell housing + coupling for: • AC...

MOUNTING POSITION DOWNWARD (D)

PRODUCT DESCRIPTION /1 1.6 HS Series - Models and Design KINEMATICS SCHEME Scheme 20 Bevel gear wheel on nut side Scheme 10 Bevel gear wheel on side opposite to nut solid shaft with key, standard diameter solid shaft with key, larger diameter flange and hollow shaft for IEC / servo motor 10 / Ball screw jacks

ADDITIONAL OUTPUT SHAFT Screw jacks HS Series can be equipped with one or more additional output shafts. Available versions are: • S: solid shaft with key, standard diameter • R: solid shaft with key, larger diameter The shafts position refers to the main input shaft and is expressed by an angle with counter-clockwise positive direction and screw jack top view (ball nut side). S 180 or R 180 WARNING! The rotating speed of the additional output shaft is always the same as the input shaft rotating speed, independently from the screw jack ratio. * - not available with transmission ratio R1...

SIZING AND SELECTION / 2 2.1 Self-locking conditions A ball screw jack is in self-locking condition when: • a push or pull load applied on a not working screw jack does not cause the linear motion (static self-locking condition); • by stopping the motor power supply of a working screw jack with push or pull load, the motion stops (dynamic self-locking condition). Due to the high efficiency of ball screw jacks, it is not possible to ensure the static or dynamic self-locking condition without using a brake motor. According to the total direct efficiency value of the screw jack the following...

2 / SIZING AND SELECTION 2.2 Ball screw buckling Euler I: screw jack housing firmly fixed to the base - free travelling screw end screw jack housing firmly fixed to the base - free travelling nut Example: with a push load of 7 kN applied on a screw length of 1 000 mm, the right selection is a screw with nominal diameter 40 mm, mounted on a screw jack MA 50 BS or SJ 50 BS or HS 50. Euler I Safety factor: 4 Ball screw length L [m]

SIZING AND SELECTION / 2 2.2 Ball screw buckling Euler II: screw jack housing and travelling screw end fixed to pivoting supports screw jack housing and travelling nut fixed to pivoting supports Example: with a push load of 8 kN applied on a screw length of 1 000 mm, the right selection is a screw with nominal diameter 32, mounted on a screw jack MA 25 BS or SJ 25 BS or HS 25. Euler II Safety factor: 4 Ball screw length L [m]