German SKF pump SKF model SKF price

The most basic form of an SKF pump consists of two gears of identical size meshing and rotating within a closely fitted housing. The interior of this housing resembles the shape of the number "8", with the two gears installed inside. The outer diameters and sides of the gears fit tightly against the housing. Material from the extruder enters between the two gears at the suction inlet, fills this space, moves along the housing as the teeth rotate, and is finally discharged when the two teeth mesh.

SKF pump working principle

The concept of a gear pump is very simple. Its most basic form consists of two gears of identical size meshing and rotating within a closely fitted housing. The interior of this housing resembles the shape of the number "8", with the two gears installed inside. The outer diameters and sides of the gears fit tightly against the housing. Material from the extruder enters between the two gears at the suction inlet, fills this space, moves along the housing as the teeth rotate, and is finally discharged when the two teeth mesh. A gear pump is also known as a positive displacement device. Like a piston in a cylinder, when one tooth enters the fluid space of another tooth, the liquid and the tooth cannot occupy the same space simultaneously because the liquid is incompressible. Thus, the liquid is mechanically squeezed out. Due to the continuous meshing of the teeth, this phenomenon occurs continuously, providing a continuous discharge volume at the pump outlet. The discharged volume per revolution is constant. As the drive shaft rotates continuously, the pump discharges fluid without interruption. The pump flow rate is directly related to the pump speed. In practice, there is a small amount of fluid loss within the pump because this fluid is used to lubricate the bearings and the sides of the gears. Since the pump body cannot have a gap-free fit, it is impossible for the fluid to be discharged from the outlet 100%. Therefore, a small amount of fluid loss is inevitable, preventing the pump's operating efficiency from reaching 100%. However, the pump can still operate well, achieving an efficiency of 93% to 98% for most extruded materials. This type of pump is not significantly affected by changes in fluid viscosity or density during the process. If a damper, such as a filter screen or restrictor, is placed on the discharge side, the pump will push the fluid through them. If this damper changes during operation—for example, if the filter becomes dirty or clogged, or if the back pressure of the restrictor increases—the pump will maintain a constant flow rate until the mechanical limit of the weakest component in the system is reached (a torque limiter is usually installed). There is actually a limit to the speed of a pump, which mainly depends on the process fluid. If oil is being conveyed, the pump can rotate at high speeds, but this limit increases significantly when the fluid is a high-viscosity polymer melt. It is crucial to fill the space between the two teeth on the suction inlet side with high-viscosity fluid. If this space is not fully filled, the pump cannot discharge an accurate flow rate. Therefore, the PV value (pressure × flow velocity) is another limiting factor and a process variable. Due to these limitations, gear pump manufacturers offer a range of products with different specifications and displacements (volume discharged per revolution). These pumps are matched to specific application processes to optimize system capacity and price.

Precautions for using SKF pumps

Gear pumps are suitable for various industries and handle a wide range of media. These gear pumps offer advantages such as robust construction, easy installation, simple disassembly, straightforward maintenance, uniform and continuous flow, minimal wear, and long service life. 1) During the use of gear pumps, frequent greasing is required. Since lubricating grease evaporates relatively easily, attention must be paid to replenishment and replacement. Additionally, keep the bearing area clean. 2) When using or after using the electric oil extraction pump, place it in a dry, non-corrosive, and clean environment. 3) Frequently inspect and maintain the gear pump during use. Check the electric oil drum, including the power cord, internal wiring, plug, and switch, to ensure they function normally. Inspect bearing components for any damage. 4) Preserve every component of the gear pump. During disassembly and inspection, keep all parts clean and stored properly.

SKF pump maintenance

When using a gear pump, wear of the gear pump is unavoidable, therefore many problems will arise, so it is necessary to learn the most common maintenance technique for gear pumps. This enables accurate diagnosis when problems occur. Routine maintenance techniques are as follows: 1) Maintenance of the working surface: If the wear on the pump cover working surface is slight, you can manually remove the wear marks by lapping, that is, place a small amount of valve grinding compound on a surface plate or thick glass plate, then place the pump cover on top and lap it, until the wear marks are removed and the working surface is flat. If the wear depth on the working surface of the pump cover exceeds zero point one millimeter, it must be repaired by turning first and then lapping. 2) Maintenance of the drive shaft bushing bore: The repair method for wear of the drive shaft bushing bore on the pump cover is the same as that for wear of the drive shaft bushing bore in the housing. Repair of the pump housing bore: After the pump housing bore wears, the bore lining method is always used for repair, that is, enlarge the bore by boring and then fit a cast iron or steel liner. After fitting the liner, bore the inner cavity to the required dimensions, and grind off the liner protruding from the end face so that it is flush with the pump housing mating surface. 3) Maintenance of the valve seat: Pressure-limiting valves come in two types: ball valve and plunger valve. After the ball valve seat wears, place a steel ball on the valve seat, then gently tap the steel ball with a metal rod, until the ball valve seats tightly against the valve seat. If the valve seat is severely worn, ream to remove the wear marks, and then use the above method to achieve a tight seal. After the plunger-type valve seat wears, a small amount of valve grinding compound can be added for lapping, lapping until a tight seal is achieved. The above describes some of the most basic maintenance procedures for components of gear pumps. During application, other different problems may also be encountered. These different problems must be carefully analyzed to identify their causes.

Weidou Intelligent Technology specializes in selling German SKF gear pumps, SKF gear pumps, SKF diaphragm pumps, SKF centrifugal pumps, SKF piston pumps, SKF vacuum pumps, SKF screw pumps, SKF submersible pumps, SKF peristaltic pumps, SKF lubrication pumps, SKF vane pumps, SKF metering pumps, SKF hand pumps, SKF barrel pumps, SKF cam pumps, SKF booster pumps, SKF liquid pumps, and SKF air pumps. All products are original imports from Germany. Customers are welcome to inquire and place orders.