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| No. | Name | Material | QTY | Remark | No. | Name | Material | QTY | Remark |
| 1 | Blower Case | HT250 | 1 | | 20 | End cover | Q325A | 1 | |
| 2 | Impeller | QT500 | 2 | | 21 | Flat key | 45 | 1 | |
| 3 | Driving shaft | 40cr | 1 | | 22 | Drain plug | 35 | 1 | |
| 4 | Driven shaft | 40cr | 1 | | 23 | Oil Level | | 1 | |
| 5 | Driving side plate | HT250 | 1 | | 24 | Exhaust gas | | 1 | |
| 6 | Gearing side plate | HT250 | 1 | | 25 | Grease cup | | 2 | |
| 7 | Bearing | GCr15 | 2 | | 26 | Gear case washer | Highland barley paper | 1 | |
| 8 | Bearing | GCr15 | 2 | | 27 | T type discharge connection pipe | HT200 | 1 | |
| 9 | Gearing seal ring | NBR | 2 | | 28 | Outlet washer | Asbestos | 1 | |
| 10 | Driving seal ring | NBR | 2 | | 29 | Washer | Q235A | 1 | |
| 11 | Bearing sleeve | 45 | 2 | | 30 | Blower pulley | | 1 | |
| 12 | Driving bearing cover | HT200 | 1 | | 31 | O type seal ring | | | GB1235-86 |
| 13 | Driven bearing cover | HT200 | 1 | | 32 | Taper bolt | 45 | 1 | |
| 14 | Z type seal ring | NBR | 1 | | 33 | Hexagon headed bolt | | | |
| 15 | Gear | 20CrMnTi | 2 | | 34 | Hexagon headed bolt | | | |
| 16 | Flat washer | | 2 | | 35 | Hexagon headed bolt | | | |
| 17 | U type nut washer | | 2 | | 36 | Hexagon headed bolt | | 6 | |
| 18 | Gear box | HT250 | 1 | | 37 | Hexagon headed bolt | | 4 | |
| 19 | Shaft sleeve | 45 | 1 | | 38 | Hexagon headed bolt | | 2 | |
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HDSR series roots blower is a positive displacement, constant volume machine which operates against varying pressure. The two impellers (involute design) which are mounted on parallel shafts, rotate in opposite direction and with every movement of the impeller across the blower inlet, a definite volume of air is trapped and carried across the casing to the blower outlet where the air is discharged. With a constant speed operation, the displaced volume is essentially the same at a constant pressure, temperature or barometric pressure. Increasing the speed of the blower against a constant pressure increase the volume of air delivery. The timing gear fitted in a blower control the relative position of the impellers to one another and maintain small but definite clearances. This allows operation without the need for lubrication inside the air casing.
