JPH0644799Y2 - Counter-rotating propeller type propulsion device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a contra-rotating propeller type propulsion device for ships and underwater vehicles.

[Conventional technology]

Although the idea of a double-reversal propeller type propulsion device for improving the propulsion performance of a ship is old, its application to general ships has not been realized due to anxiety about the investment effect.

However, according to the recent model test results, it has become clear that the propulsion performance and energy saving effect of the contra-rotating propeller type propulsion device are great and the investment effect is promising.

Then, various counter-rotating propeller type propulsion devices have been devised, such as those in which the front and rear propellers reverse at a constant speed, those in which the propellers reverse at different speeds, those in which the front and rear propellers have the same number of blades, and different propellers.

Among these, in the double-reversal propeller type propulsion device, the front and rear propellers reverse at different speeds, or the front and rear propeller blades have different numbers of propellers. Therefore, there are many electromotive frequencies that should avoid resonance.

[Problems to be solved by the invention] With respect to the vibration force of a propeller, there are many components having various frequencies, and it is necessary to be careful in anti-vibration measures.

That is, the main component of the vibration force of the contra-rotating propeller is not a problem when the number of blades of the front and rear propellers is the same as the number of revolutions, but the number of blades of the front and rear propellers and The frequencies of the main components of the motive force of the counter-rotating propeller with different rotational speeds are Z _F and N _{F, respectively,} and the number of blades and the rotational speed of the forward propeller are Z _A and N, respectively. When _a, components of the front _{propeller; f1 = nZ F n F (} n = 1,2,3) component of the rear _{propeller; f2 = nZ a n a (} n = 1,2,3) , and the forward wing occurrence However, there are many frequencies to avoid resonance, and there is a drawback that it is difficult to avoid resonance.

SUMMARY OF THE INVENTION The present invention is intended to solve the above drawbacks, and an object of the present invention is to provide a contra-rotating propeller type propulsion device in which there are few frequencies to avoid resonance and resonance can be easily avoided.

[Means for solving problems]

For this reason, the counter-rotating propeller type propulsion device of the present invention includes a counter-rotating gear device driven by a main engine of a ship, a counter-rotating shaft system having different rotational speeds, which are mutually reversed by the gear device, and a coaxial shaft. It is characterized in that it comprises a counter-rotating propeller with different numbers of blades which are coupled to the system and reverse each other, and the ratio of the rotational speeds of the two propellers is set to the inverse ratio of the respective different numbers of blades of the propellers. There is.

[Action]

With the above configuration, the product of the number of blades of the front propeller and the number of rotations matches the product of the number of blades of the rear propeller and the number of rotations. If expressed by the formula, Z _A N _A = Z _F N _{F and} resonance can be avoided.

〔Example〕

FIG. 1 is an embodiment of the contra-rotating propeller type propulsion device of the present invention, and is an overall layout showing the layout of components.

As shown in FIG. 1, a counter-rotating gear device 3 is provided so as to be connected to a main shaft 2 driven by a main engine 1 of a ship. The counter-rotating gear device 3 includes a counter-rotating shaft system 4 including an outer shaft 4a and an inner shaft 4b that rotate in opposite directions.
Is set to drive. At the rear end of the counter-rotating shaft system, a counter-rotating propeller 5 including a front propeller 5a connected to the outer shaft 4a and a rear propeller 5b connected to the inner shaft 4b is provided.

Furthermore, in the gear system (not shown) in the counter rotating gear device,
The rotation speed ratio of the outer shaft 4a and the inner shaft 4b is set to be the reverse ratio of the different blade numbers of the front propeller 5a and the rear propeller 5b.

[Effect of device]

Above, the number of wings Z _F and the rotational speed N _F of the front propeller as described, the number of wings Z _A and the rotational speed N _A of the rear propeller of the propeller vibratory force so satisfying Z _A N _A = Z _F N _F The number of main orders is halved, which makes it easier to avoid resonance. Also, by adjusting the relative mounting phases of the front and rear propellers, it is possible to cancel the vibration forces of the same order.

[Brief description of drawings]

FIG. 1 is an embodiment of the present invention and is an overall layout view showing components and layout of a contra-rotating propeller type propulsion device. DESCRIPTION OF SYMBOLS 1 ... Main engine, 2 ... Drive shaft of main engine, 3 ... Double inversion gear device, 4 ... Double inversion shaft system, 4a ... Outer shaft of double inversion shaft system, 4b ...
Inner shaft of counter-rotating shaft system, 5 ... counter-rotating propeller, 5a ... front propeller as above, 5b ... rear propeller as above.

Claims (1)

[Scope of utility model registration request] 1. A counter-rotating gear device driven by a main engine of a ship, a counter-rotating shaft system having different rotational speeds that are mutually reversed by the gear device, and a blade that is coupled to a coaxial system and mutually reverses. Comprised of a number of contra-rotating propellers, the above 2
A counter-rotating propeller-type propulsion device, wherein the ratio of the number of revolutions of each propeller is set to the inverse ratio of the number of different blades of the propeller.