# 577518

(Parte 1 de 5)

Project and Engineering Department

Student: Maxim Tsankov Vasilev Tutors: Dr. Pedro Villanueva Roldan Dk.

 I. Radial Engine 5 I. History of the Radial Engine 7 I. Radial engines nowadays 15 I. Kinematical and Dynamical Calculations 18 1. Ratio 18 2. Angular velocity 18 3. Current Piston Stroke 18 4. Area of the piston head: 21 5. Different forces acting on the master-rod: 21 I. Strength calculations of some of the major parts of the engine 29 1. Cylinders 29 2. Piston 31 3. Piston Bolt 39 4. Piston Rings 47 5. Master rod 50 6. Auxiliary Rod 52 7. Crank-Shaft 54 - Crank Cheeks 54 - Main Journal 56 - Crank Shaft (rear) 57 - Crank Shaft (front) 59 8. Cylinder Head 60 9. Bearings 62 - Rear Bearing 62 - Front Bearing 63 10. Gear Box 64 1. Gear drives mechanism: 65

Contents - Calculation of the Gear Drive Mechanism................................................................................. 67

 12. Valves 69 13. Cam Mechanism 70 - Pushing Rod 70 - Arm of the Cam mechanism 71 - Sockets 72  Socket connecting the Pushing rod and the Arm 72  Socket connecting the Arm with the Valve 73 14. Crank Case 75 15. Front Cover 7 16. Propeller 78 17. Materials used in the parts of the Radial Engine 79 18. Parts specifications table 82 I. Conclusion 83

4 Chapter 1

The Radial Engine is a reciprocating type internal combustion engine configuration in which the cylinders point outward from a central crankshaft like the spokes on a wheel.

This type of engine was commonly used in most of the aircrafts before they started using turbine engines.

In a Radial Engine, the pistons are connected to the crankshaft with a master-and-articulating-rod assembly. One of the pistons has a master rod with a direct attachment to the crankshaft. The remaining pistons pin their connecting rods attachments to rings around the edge of the master rod. Four-stroke radials always have an odd number of cylinders per row, so that a consistent every-other-piston firing order can be maintained, providing smooth operation. This is achieved by the engine taking two revolutions of the crankshaft to complete the four strokes. Which means the firing order for a 9-cylinder radial engine is 1,3,5,7,9,2,4,6,8 and then again back to cylinder number 1.This means that there is always a two-piston gap between the piston on its power stroke and the next piston on fire(the piston on compression). If an even number of cylinders was used the firing order would be something similar to 1,3,5,7,9,2,4,6,8,10 which leaves a three-piston gap between firing pistons on the first crank shaft revolution, and only onepiston gap on the second crankshaft revolution. This leads to an uneven firing order within the engine, and is not ideal.

The Four-stroke consequence of every engine is:

a) Intake b) Compression c) Power d) Exhaust

Most radial engines use overhead poppet valves driven by pushrods and lifters on a cam plate which is concentric with the crankshaft, with a few smaller radials. A few engines utilize sleeve valves instead.

I. History of the Radial Engine

At least five companies build radials today. Vedeneyev engines produces the M-14P model, 360 Hp (270kW)(up to 450 Hp (340kW) radial used on Yakovlevs and Sukhoi, Su-26 and Su-29 aerobic aircraft. The M-14P has also found great favor among builders of experimental aircrafts, such as the Culps Special and Culps Sopwith Pup, Pitts S12 “Monster” and the Murphy “Moose”. Engines with 110 Hp (82kW) 7-cylinders and 150 Hp (110 kW) 9- cylinders are available from Australia’s Rotec Engineering. HCI Aviation offers the R180 5-cylinders (75 Hp (56kW)) and R220 7- cylinders (110 Hp (82kW)), available “ready to fly” and as a “build it yourself” kit. Verner Motor from the Czech Republic now builds several radial engines. Models range in power form 71 Hp (53 kW) to 172 Hp (128 kW). Miniature radial engines for model airplane use are also available from Seidel in Germany, OS and Saito Seisakusho of Japan, and Technopower in the USA. The Saito firm is known for making 3 different sizes of 3-cylinder engines, as well as a 5-cylinder example, as the Saito firm is the specialist in making a large line of miniature four-stroke engines for model use in both methanol-burning glow plug and gasoline-fueled spark plug ignition engine formats.

16 Chapter 2

Rpm =6000

Piston diameter Dp= 70 m. Master-rod length Lmr=120 m.

Crank Length Rcr=30mm.

I. Kinematical and Dynamical Calculations 1. Ratio

Between the crank of the crankshaft and the master-rod length:

2. Angular velocity

Specifies the angular velocity of the object and the axes about which the object is rotating.

3. Current Piston Stroke

Reciprocating motion, used in reciprocating engines and other mechanisms is back-and-forth motion. Each cycle of reciprocation consists of two opposite motions, there is a motion in one direction and then a motion back in the opposite direction. Each of them is called a stroke.

In the table below I will show you the behavior of the master rod.

Table N.1

Graph N.1

The following tables show the behavior of the linear velocity of the master-rod and its acceleration.

Graph N.2

Graph N.3

Vp m/s Vp m/s

Jp m/s2 Jp m/s2

4. Area of the piston head:

p DF

5. Different forces acting on the master-rod:

- Gas Forces, Pg, N - Analytical calculation of the gas forces as a function of the angle of rotation of the crankshaft

Is done according to the next formula:

nhc g b opp p

S P p p F

() nhc cx

Sh- Working stroke;

Sc- The stroke according to the height of the combustion chamber

Popp.=0,1MPa- The pressure acting on the opposite side of the piston. It is equal to this in 4-stroke engines.

Pb.- That is the pressure in the beginning

n-indicator that is changing in the following borders:

- Inertia Forces:

(Parte 1 de 5)