- Ball screw assembly is a high-precise mechanical drive part made up of screw, nut, ball bearing, sealing washer and other components, for there are ball bearing rolling between the screw and nut, the ball screw can receive high movement efficiency, compared with slide guide screw, the drive torque is under 1/3. So that it is easy to translate turning movement to straight-line movement, also, it is easy to translate straight-line movement to turning movement. It is a kind of further expansion and development of traditional slide guide screw. The profound significance of this development is the same as the transformation brought by rolling bearing to slide bearing. Due to its fine friction character, ball screw assembly is widely used in various industrial equipments, precise apparatus and precise numerically-controlled machine tool. Especially in recent years, work as executive unit of straight-line drive of numerically-controlled machine tool, it is broadly used in machine tool industry, and greatly promotes the numerically-controlled development of machine tool industry. All of these lie on several fine characters as follows:
High drive efficiency, high orientation precision, reversibility of drive, long service life, good synchronous performance
Because the ball screw assembly has smooth operation, eliminates axial clearance, with consistency of production, when it adopts several sets of ball screw assembly projects to drive a same device or several same parts, it can receive excellent synchronous working.
- It not only can feed slightly, but also can feed at high speed. Because of ball bearing’s rolling, ball screw has tiny starting torque, will not cause crawl or creepage phenomena, which are easy to come forth in slide movement, so that it can guarantee to realize precise micro feeding. On the other hand, with high efficiency, small friction and low heat, the ball screw assembly can carry out high-speed feeding at the same time.
- Without clearance and with high rigidity. Adopt Gothic groove shape (refer to following picture), the axial clearance is regulated to infinitesimal and can not turn randomly. Besides, as the ball screw assembly can be added pressure in advance, the axial clearance can achieve zero or below zero even more after adding, thus high rigidity is received.
Gothic groove
- Adopt inner circulation mode to work (refer to following picture)
This method is to make steel balls roll along the groove of inner circulator, get across the tooth peak of screw sidelong and return to origin. Generally speaking, a circle of steel ball implements a circulation. One end of the screw should be at least if using this circulation method, used in small screw diameter, adopt metal circulator.
- Material and heat treatment
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Material |
Heat treatment |
Rigidity |
|
Screw |
S55C |
High-frequency quench |
HRC56～62 |
|
Screw cap |
SCM420 |
Cementite quench |
HRC56～62 |
|
Steel ball |
SCM420 |
Heat treatment |
HRC60 more than |
|
