Low-clearance lead screw nuts for linear motion

What options does the igus product range offer for reducing clearance?

To reduce the unwanted axial clearance, in addition to the correct choice of material, a preload mechanism has proven to be an effective measure. There are four variants with pretension for our dryspin® high helix thread and trapezoidal threads: zero-backlash, low clearance, preload and AB lead screw nut. Here you will find all the advantages and assembly instructions for our clearance-reduced lead screw nuts.
 
For applications with high loads, high temperatures or in heavily polluted environments, a standard lead screw nut should always be used. The reason for this is that all three principles are cancelled out by high loads. For this reason, the maximum static axial loads are specified separately for each lead screw nut model.

The zero-backlash lead screw nut

One of the most precise solutions is the ZB lead screw nut. It consists of several components and is self-adjusting to the service life. It is particularly suitable for lead screw drives with high helix threads for quick adjustment of small loads. The clearance-free principle ensures minimum clearance over the entire service life. Ideal for precise positioning and feed movements in medical, laboratory and printing technology as well as in the wide range of life sciences. The lead screw nut consists of a support nut, a fixing collar with torsion spring, a friction disc and the axial element. The torsion spring is used to apply pretension to the thread system.

• Lifelong minimal axial backlash
• More precise positioning and infeed movements
• In dryspin high helix threads
• Flange lead screw nut
• Thread direction: RH
• Material: iglidur J

The pre-load lead screw nut

The pre-load lead screw nut convinces with minimal axial clearance and highest positioning accuracy. It is the cost-effective alternative to the zero-backlash and perfectly suited for small pitches. This is the proven pre-load principle from SHT-PL. Typical application areas include 3D printers.

• For high helix threads up to a thread diameter of 6.35mm
• Cylindrical lead screw nut with flange
• Thread direction: right-hand thread
• Material: iglidur J

The low-clearance lead screw nut

Our LC lead screw nuts are all equipped with two elastomer O-rings. The functional principle is similar to the AB lead screw nut. However, with the help of the LC lead screw nut, a reduction in clearance can be achieved in this case. The O-rings apply a circumferential radial pretension in the thread system, pressing the flanks of the lead screw nut and the threads of the lead screw. This ensures a constant axial and radial pretension of the nut. The high operational smoothness and cost-effective purchase are further advantages of the LC lead screw nut.

• Reduced axial clearance due to circumferential radial pretension
• Very quiet operation due to reduction of possible vibrations
• Cost-effective alternative to the zero-backlash nut
• In dryspin high helix and trapezoidal thread up to thread diameter 14mm
• Flange lead screw nut
• Thread direction: RH
• Material: iglidur J

The anti-backlash lead screw nut

Lead screw drives can generally produce noise and vibrations. In particular, long lead screws and great travel distances can cause self-induced vibrations in the sliding system. Due to their good sliding properties, lead screw nuts made from the tribologically optimised iglidur materials tend to develop significantly less noise than conventional plastics or metals, such as bronze or brass.

To reduce noise, a preloading mechanism is also an effective measure in addition to the right choice of material. In the case of the AB lead screw nut, an elastomer ring applies a force on an insert with a matching thread, which is pressed into the threads of the lead screw. It is important that this pretension is not present over the entire length and not all around. This ensures low axial clearance only in a small range. The functional principle of this lead screw nut differs significantly from that of the zero-backlash lead screw nut.

• Reduction of noise and vibrations
• For trapezoidal threads up to a thread diameter of 24mm
• Cylindrical and flange lead screw nuts
• Thread direction: RH and LH
• Material: iglidur J and iglidur R