Classification of fuel injection pumps

Some most commonly used diesel engine fuel injection pumps in China are: A-type pump, B-type pump, P-type pump, VE type pump, etc. The first three types belong to plunger pumps; VE pump is a kind of distributor style pump. Below are the two main features of B-type and P-type pump. 

B-type

1. Use spiral groove plunger and hole type plunger sleeve; 

2. The fuel adjustment mechanism uses toothed rod system, with an adjustable maximum oil quantity rigid limiter (or spring limiters) installed at the front end of the toothed rod; 

3. Adjust the screw type roller body transmission components; 

4. The camshaft is a tangent cam, supported on the housing by a conical roller bearing; 

4. The pump body is integral and uses independent lubrication method. 

P-type

1. Suspended pump assembly. The plug, plunger sleeve, oil outlet valve and other parts are fixed together with a steel sleeve with a flange plate, forming an assembly component. Then it is fixed directly on the shell with compression studs to form a suspended structure. The steel sleeve can rotate at a certain angle; 

2. Adjustment of the fuel supply of each sub pump. There is an arc groove on the flange plate of the steel sleeve of the sub pump. When the clamping screw is loosened and the steel sleeve is turned, the plunger sleeve of the sub pump rotates at a certain angle, changing the position of the inlet and return oil holes relative to the inclined groove on the plunger, and the return oil time changes accordingly; 

3. Adjustment of the starting point of the fuel supply for the sub pump. Adding or removing shims under the flange plate sleeve causes a slight upward and downward movement of the inlet and return oil holes of the plunger sleeve, thereby changing the position relative to the upper end of the plunger and adjusting the oil supply starting point of the sub pump; 

4. Oil quantity adjustment mechanism using ball pin angle plate. There are 1-2 steel balls welded on the end face of the transmission sleeve, and the cross section of the oil supply rod is in the shape of an angle steel. There is a small square groove on its horizontal right angle edge, which meshes with the steel balls on the transmission sleeve during operation. Non adjustable roller body transmission components; 

5. Fully enclosed box pump body. It adopts an integral sealed pump body without opening side windows but only the upper and lower covers. The pump body has high stiffness and can withstand high fuel injection pressure without deformation, resulting in a longer lifespan of the plunger components; 

6. It also adopts pressure lubrication method; 

7. There is a specially designed pre-stroke inspection hole with a screw plug above the roller body, which can be used to check whether the pre-stroke of each sub pump is consistent (measured with a specialized instrument).