Tumanski R-25
The Tumanski R-25 is a twin-shaft jet engine that was mass-produced in the USSR .
history
The R-25 was developed from the Tumansky R-13 by Sergei Alexejewitsch Gawrilow from the late 1960s to 1971 and is also a twin-shaft turbojet. For this purpose, the engine was equipped with a new three-stage low-pressure compressor with 21 wide titanium blades and a revised afterburner with two fuel pumps and improved cooling. It was installed in the MiG-21bis and the Su-15bis ; a total of about 3200 pieces were produced.
Versions
- R-25-300 / R-25F-300 - version for the MiG-21bis and the Su-15bis
- R-25-300-94 - Version for the MiG-21-93
construction
stator
The stator consists of seven stages. In the first stage, the stator contains a total of 36 guide vanes. Five of these blades are designed as hollow blades. One of them has an axial bore through which the axial shaft for driving the lubricant suction pump of the front bearing is guided. The other four hollow blades are used
- the lubricant supply to the front bearing
- the lubricant drain from the cavity of the front bearing
- the air supply from the compressor to heat the inlet cap and
- for venting the lubricant chamber of the front bearing.
The high pressure stator is used to hold the diffuser of the 4th, 5th, 6th and 7th stage, it is divided into two parts for assembly reasons and connected to one another with bolts. The casing of the first compressor stage and the guide vanes of the 1st to 7th stage are made of titanium, the casings of stages 2 to 7 are made of steel.
Low pressure rotor
The low-pressure rotor consists of the inseparably connected discs of the second and third compressor stage and the removable disc of the first compressor stage. It is stored on two camps.
High pressure rotor
The high pressure rotor consists of five disks made from a titanium alloy.
Two-stage turbine
The first turbine stage has 55 blades and is mounted on two bearings. It is made from a forged piece made of a heat-resistant alloy. The blades that sit on the disc are hollow for cooling and precision cast from a heat-resistant alloy. The second turbine stage has 64 blades, which are also seated on a disk guided through two bearings and are attached with a Christmas tree toothing with five teeth. The turbine is cooled with air that is taken from various points in the airway of the engine.
Aggregate drive
The units of the engine are driven either by the shaft of the low-pressure or the high-pressure rotor. The lubricant suction pump of the front bearing and the speed sensor of the low-pressure rotor are flanged onto the low-pressure rotor via a pair of spur gears. The units that are connected to the shaft of the high pressure rotor are listed in the table.
| Unit designation | Type | Gear ratio | Direction of rotation |
|---|---|---|---|
| Starter generator | GSR-ST-12000 WT | 1,3408 as a generator | Left |
| Starter generator | GSR-ST-12000 WT | 2.2580 as a starter | Left |
| Alternator | GO4Ptsch4 or SGO-8 | 1.3408 | Left |
| Fuel pressure pump | DZN44-DT1 | 1.3408 | Left |
| Main fuel pump | NR-54F2 | 2.5470 | right |
| Fuel afterburner pump | NR-22F2M2 | 2.5470 | right |
| Auxiliary fuel afterburner pump | NR44 | 2.5358 | right |
| Hydraulic pumps (2 pieces) | NP-34M-1T or NP-26M2-3 | 2.9639 | right |
| Lubricant unit | Gear pump | 2.8732 | right |
| Air separator | Centrifugal separator | 2.8732 | right |
| Lubricant separator | Centrifugal separator | 0.8570 | right |
| High pressure rotor speed sensor | DTÄ-1 | 4.5446 | right |
Technical specifications
| Parameter | Data R-25-300 |
|---|---|
| power | 69.6 kN / 40.2 kN |
| Air flow | 67.9 kg / s |
| Total pressure ratio | 9.55: 1 |
| length | 4.61 m |
| Inlet diameter | 0.91 m |
| Dry matter | 989 kg |
| Compressor stages (LP / HP) | 3/5 |
| Turbine stages (LP / HP) | 1/1 |
Individual evidence
- ↑ Jefim Gordon , Keith Dexter, Dmitri Komissarow; MiG-21; P. 426ff; ISBN 978-1-85780-257-3
- ↑ a b R-25-300 (warrior horse)
- ↑ Aircraft Engines ( Memento of the original from March 16, 2012 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF)
- ↑ a b c d e service instruction "A 107/1/159 engine R-25"
