What is the structure of horizontal double suction three screw pump? What are its characteristics?

卧式双吸三螺杆泵，它的主要构件有主动螺杆1、两个从动螺杆2和7、衬套3、泵体4、填料箱5和轴承6等。衬套外表面是圆形，与泵体配合形成吸油腔与排油腔，衬套内有三个相互连接的圆孔与三个螺杆相配合。主动螺杆比从动螺杆粗，因为它在工作过程中承受主要负荷，从动螺杆只作阻止液体从排出室漏回吸入室的密封元件，即与主动螺杆啮合而形成密闭容积，将排出室和吸入室隔开。为了使轴端便于密封并减小由伸出端引起的不平衡轴向力，通常都是两边吸油中间排油，轴向力基本上得到平衡。

Horizontal double suction three screw pump, its main components are active screw 1, two driven screw 2 and 7, bushing 3, pump body 4, packing box 5 and bearing 6. The outer surface of the bushing is circular, and is matched with the pump body to form an oil suction cavity and an oil discharging cavity, and three interconnected circular holes are arranged in the bushing to cooperate with the three screws. The active screw is thicker than the driven screw, because it bears the main load in the working process. The driven screw is only the sealing element that prevents the liquid from leaking back into the suction chamber from the discharge chamber, that is, the closed volume is formed with the active screw, and the discharge chamber is separated from the suction chamber. In order to make the shaft end easy to seal and reduce the unbalanced axial force caused by the extended end, the two sides usually suck the oil in the middle, and the axial force is basically balanced.

卧式双吸三螺杆泵主要有以下几方面的特点。

The horizontal double suction three screw pump has the following characteristics.

1.受力情况良好 多数螺杆泵的主螺杆不受径向力，所有从动螺杆不受扭转力矩的作用。因此，泵的使用寿命较长。双吸结构的螺杆泵，还可以平衡轴向力。

1. the force is in good condition. Most of the main screws of the screw pump are free from radial force, and all driven screws are not affected by torsional moment. Therefore, the service life of the pump is longer. The double suction structure of the screw pump can also balance the axial force.

2.螺杆泵流量均匀 当螺杆旋转时，密封腔连续向前推进，各瞬时排出量相同。因此，它的流量比往复泵、齿轮泵要均匀。

The flow rate of the 2. screw pump is uniform. When the screw rotates, the sealing cavity keeps pushing forward,lvhua.71ix.com fangshui.07858.nethsmumen.89ix.com hskongtiao.89ix.com hschugui.75ix.com hsyuesao.75ix.com and the instantaneous discharge volume is the same. Therefore, its flow rate is more uniform than that of reciprocating pumps and gear pumps.

3.适用范围广 螺杆泵可输送黏度较大的液体。

3. wide range of applications. Screw pumps can transport large viscosity liquids.

4.运转情况良好 运转平稳、噪音小、被输送液体不受搅拌作用;螺杆泵密封腔空间较大，有少量杂质颗粒也不妨碍工作。

4. operation is good running smoothly, the noise is small, the conveyed liquid is not agitated; the cavity of the screw pump has a large space, and a small amount of impurity particles does not interfere with the work.

5.具有良好的自吸能力 因螺杆泵密封性好，可以排送气体，启动时可不用灌泵，可用作气液混合物的输送。

5. good self-priming capacity. Because of the good sealing performance of the screw pump, the gas can be discharged, and the pump can not be pumped when starting, so it can be used for conveying gas liquid mixture.

卧式双吸三螺杆泵的密封性能好、效率高，因而适用于压力较高的场合。但制造成本高，对输送液体要求比较严格，常用于输送比较清洁而又具有自润滑性的液体，广泛应用于中等黏度的润滑系统和液压传动等场合，其流量可通过改变转速来调节。

The horizontal double suction three screw pump has good sealing performance and high efficiency, so it is suitable for occasions with high pressure. But the cost of manufacturing is high, and it is very strict for the delivery of liquid. It is often used to deliver a clean and self lubricated liquid, which is widely used in medium viscosity lubrication and hydraulic transmission, and its flow can be adjusted by changing the speed.