采煤机液压螺母与上海天地、上海创立、无锡盛达、鸡西煤机等配套

液压螺母产品介绍

　　Hydraulic nuts and super-pressure pump

　　一、概述

　　液压螺母和螺栓是一种新型紧固件。普通螺母的锁紧是靠转动扳手来产生扭矩来锁紧的，因此90%以上的力量浪费在克服摩擦力上，而作用在螺栓上的预紧力很小，特别对于大直径，高强度螺母，在受人力，工具和场地等因素的影响时，预紧力根本达不到设计要求，容易造成螺母松动。液压螺母的锁紧和普通螺母不同，液压螺母在锁紧过程中，是靠液压力(约200 MPa)直接作用于螺母而产生超高预紧力，接近螺栓屈服点，即使在振动工况条件下，也不会松动。

　　液压螺母特别适合在煤矿井下狭窄空间，对采煤机，掘进机等煤矿设备进行部件连接紧固，也可用于冶金，化工及工程机械上。

　　二、工作原理和加压系统

　　液压螺母是靠高预紧力对连接螺栓进行拔长后的锁紧，因此必须使用10.9级以上的高强度双头螺栓。

　　液压螺母的安装方式及加压示意图(见图一)。液压螺母先进行预紧，进口超高压手动泵通过进口超高压软管对液压螺母的缸体注入高压油，使螺栓伸长，背帽和缸体之间 产生一个间隙(图2-2)，转动背帽使其紧靠缸体(图2-3)，然后拧紧背帽以及卸载泵的压力。由于拉长的螺栓无法回缩，因此可以保证对连接螺栓施加相当高的紧固力。

　　三、液压螺母的加压系统

　　液压螺母的加压系统是主要由超高压手动油泵(进口)，超高压软管，液压螺母和高强度螺栓组成(见图3)

　　1. 超高压手动油泵，

　　超高压手动油泵是提供液压螺母高压油的动力设备，主要由柱塞泵，储油箱，超高压压力表，高压卸载阀，低压卸载阀，油过滤器等组成。

　　2. 超高压软管组成

　　由超高压软管，过滤接头，快速接头组成。

　　3. 液压螺母与超高压软管连接

　　通过快速接头和过滤接头，实现快速连接，操作和搬运非常方便。

产品应用 

产品原理图 

　　Overview

　　Hydraulic nut and bolt is a kind of new fastener, to common nuts locking, they can fasten the nuts by turning spanner so that it can cause a torsion, so, 90% strength is wasted in Overcoming the friction of the spaaner, but the pretightening force used in the bolts is too small. especially for some big diameter and high strength nuts, when they are affected by manual force,tools and position, the pretightening force can not meet the demand at all, which can cause the nuts loosen. The locking for hydraulic nuts is different from common nuts, whenthe hydraulic nut is locking, it causes Ultra-high pre-tightening force by hydraulic pressure(about 200 MPa), which can get close to the yield point of the bolts, it will not loosen even if it is in vibrating condition, hydraulic nut is especially suitable in the fastening for the coal miners and roadheaders

　　underground the mine when the space is very narrow. It can also be used in the machines for metallurgy , chemical industry and engineering machinery.

　　Working principle and forcing system

　　Hydraulic nut is a kind of locking device which relies on pretightening force that can make the connection nuts longer. So, the high strength two heads nuts above 10.9 grade must be used. The installation way and forcing schematic diagram ( picture 1). Firstly, the hrdarulic nut Pretightens, imported ultrahigh pressure manual pump injects the high pressure oil to the cylinder block of hydraulic nuts by imported ultrahigh pressure hosepipe. Which will make the bolt longer, there will be a gap between the back bolt and the cylinder(picture 2-2),turn the back bolt so that it will get very close to the cylinder(picture 2-3),and then tighten the back bolt. The pressure unloading pump will not recover, so it can definitely put very high tightening force on connecting bolts.

　　The forcing system of hydraulic nuts

　　The forcing system of hydraulic nuts are mainly made up of ultrahigh pressure Manual oil pump

　　(imported), ultrahigh pressure flexible pipe, hydraulic nuts and high-strength bolt(picture 3)

　　1. ultrahigh pressure manual oil pump

　　ultrahigh pressure manual oil pump is a power equipment which offers hydraulic nut high pressure oil, it is mainly made up of plunger pump,oil storage tank, ultrahigh pressure gage, high-pressure unloading valve, low-pressure unloading valve, oil filter.

　　2. the composition of ultrahigh-pressure hosepipe.

　　It is made up of ultrahigh-pressure hosepipe, filter joint, quick coupling.

　　3. The connection of hydraulic nuts and ultrahigh pressure hosepipe

　　It connects very quickly by quick joint and filter joint, it is very convenient in operating and moving.