RU2334316C1 - Antenna device - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention consists in that the antenna device incorporates a fixed dish aerial, a reflector arranged at an angle to the said dish aerial, a reflector azimuth scanning and rotation drive, an azimuth rotation output hollow shaft housing coaxially arranged second shaft with a cam located on its end face to interact with the slot of a carriage fitted on the first shaft to reciprocate in the plane perpendicular to the shaft common axis and furnished with a rack interacting with a ratchet latch rigidly linked to the reflector fitted on the first shaft to swing relative to the axis perpendicular to the shafts common axis. Invention novelty consists in that the device incorporates an angle transducer linked to both shafts and outputting the data on the reflector azimuth rotation and inclination defined from the proposed formulae.

EFFECT: smaller weight and sizes and lower manufacturing costs.

2 dwg

Description

The invention relates to the field of radio engineering and can be used for installation on aircraft, in particular helicopters.

A known antenna device for a helicopter radar [1], consisting of a stationary parabolic antenna, a reflector mounted at an angle to it, and azimuthal rotation drives and scanning the reflector, each of which is driven by its own electric motor and has its own angle sensors in azimuth and angle tilt reflector. However, this technical solution is large in size, and the presence of two drives causes significant difficulties in ensuring synchronization of sensor readings both under conditions of changing loads on electric motors, voltage fluctuations in their supply network, and when the ambient temperature changes.

A known antenna device [2], adopted for the prototype, consisting of a stationary parabolic antenna, a reflector mounted at an angle to it, an azimuthal rotation drive and scanning the reflector, the azimuthal rotation output shaft of which is hollow, a second shaft with an eccentric mounted coaxially at the end and interacting with the groove of the carriage mounted on the first shaft with the possibility of reciprocating movement in a plane perpendicular to the common axis of the shafts and having a gear rack, in interacting with a gear sector rigidly connected to the reflector mounted on the first shaft with the possibility of swinging about an axis perpendicular to the common axis of the shafts. This device is small in size, in it the azimuthal rotation and scanning of the reflector is provided by one drive, but it does not solve the problem of obtaining information on the azimuth and angle of inclination of the reflector.

The technical result of the invention is to obtain information on the angle of rotation of the reflector in azimuth and on the angle of its inclination from one sensor.

The technical result is achieved by the fact that in the known device [2] an angle sensor is introduced, kinematically connected with both shafts and giving information about the angles of azimuthal rotation and inclination of the reflector, determined by the formulas:

where φ is the angle of rotation of the reflector in azimuth,

α is the angle of inclination of the reflector,

φ _∂ is the angle of rotation of the angle sensor,

i is the gear ratio between the sensor and the azimuthal rotation shaft,

r is the eccentricity of the eccentric,

d is the diameter of the pitch circle of the gear sector,

Δi is the difference in the gear ratios between the sensor and the shafts.

Figure 1 presents a diagram of the proposed antenna device, figure 2 shows a diagram of the interface of the shaft with the eccentric and the gear sector with the carriage.

The antenna device consists of a stationary parabolic antenna 1, a reflector 2, mounted at an angle to it, an azimuthal rotation drive 3 and a reflector tilt 2. A second shaft 5 is installed in the hollow output shaft 4 of the azimuthal rotation of the reflector 2, at the end of which there is an eccentric 6 included in the groove of the carriage 7 mounted on the shaft 4. A gear rack is made on the carriage 7, with which the gear sector 8 is engaged, rigidly connected to the reflector 2, mounted in bearings on the shaft 4. The shafts 4 and 5 receive rotation from the electric motor 9 through gears 10, 11 and 12, 13. An angle sensor 15 is connected to the shaft 14.

The transmission is designed so that the frequency difference between the relative rotation of the shaft 4 (n ₄ ) and the shaft 5 (n ₅ ) is equal to the required speed of the eccentrics (n _ex ), corresponding to the swing frequency of the reflector 2; those. n _ex = n ₄ -n ₅ , whence the angle of rotation of the eccentric φ _ex in the relative rotation of the shafts 4 and 5 will be equal to φ _ex = φ ₄ -φ ₅ (1), where φ ₄ , φ ₅ are the angles of rotation of the shafts 4 and 5, respectively .

The device operates as follows. The rotation from the electric motor 9 is transmitted to the shaft 14, to which the angle sensor 15 is connected, and through the gears 10, 11 and 12, 13 to the shafts 4 and 5. Since the shafts 4 and 5 rotate in the same direction with different frequencies, the cam 6 of the shaft 5 rotating with a frequency corresponding to the oscillation frequency of the reflector 2, it rolls along the groove of the carriage 7 and moves it back and forth. In this case, the gear rack of the carriage 7 through the gear sector 8 leads the reflector 2 into oscillatory motion with a frequency of n _ex .

Determine the dependence of the angle of rotation of the reflector 2 in azimuth and the angle of its inclination from the angle of rotation of the angle sensor 15.

We take for the initial (initial) average position of the carriage 7 and the gear sector 8, in which the eccentric 6 of the shaft 5 occupies one of the extreme positions in the groove of the carriage 7. Then the movement S of the carriage 7, corresponding to the angle of rotation of the eccentric φ _ex in the relative rotation of the shafts 4, 5 equal to r · sinφ _ex , where r is the eccentricity value. This movement will be converted into a swinging movement with an angle α of sector 8 and a reflector 2 rigidly connected to it, by dependence,

where d is the diameter of the pitch circle of sector 8.

The rotation angles of the shafts 4 and 5, depending on the rotation angle φ _∂ of the angle sensor 15 are determined by the following formulas:

where z ₁₀ , z ₁₁ , z ₁₂ , z ₁₃ - the number of teeth of the gears 10, 11, 12, 13, respectively.

Then it follows from (1)

where i, i ₁ - gear ratio between the sensor and shafts 4 and 5, and Δi their difference.

Then

The rotation angle φ _{4 of the} shaft 4 is the rotation angle φ of the reflector in azimuth: φ ₄ = φ. From (2)

Thus, the introduction into the known device [2] of the angle sensor kinematically connected with both shafts, provides information on both the azimuthal angle and the angle of inclination of the reflector. This ensures the uniqueness and stability of the relationship of information on the azimuthal angle and angle of inclination of the reflector, regardless of changes in the loads on the electric motor, voltage fluctuations in its supply, changes in ambient temperature and other disturbing factors. In addition, information on the angle of inclination of the reflector can be obtained with high accuracy, because the full cycle of the tilt of the reflector takes place over several revolutions of the angle sensor, and the possibility of obtaining information on the azimuthal angle and the angle of inclination of the reflector from one sensor can reduce the overall dimensions of the drive of the antenna device and the cost of its manufacture.

Bibliography.

1. Annual review of the achievements and prospects of electronic technology. Electronics, 1982, No. 21, t.55, p.15, 16.

2. RF patent No. 1810941 by application No. 4931694 of April 29, 1991 for the invention of the "Antenna device".

Claims (1)

Antenna device designed for installation on aircraft, consisting of a stationary parabolic antenna, a reflector mounted at an angle to it, an azimuthal rotation drive and scanning the reflector, the azimuthal rotation output shaft of which is hollow, a second shaft with an eccentric mounted coaxially on it the end and interacting with the groove of the carriage mounted on the first shaft with the possibility of reciprocating movement in a plane perpendicular to the common axis of the shafts, and a gear rack interacting with a gear sector rigidly connected to the reflector mounted on the first shaft with the possibility of swinging about an axis perpendicular to the common axis of the shafts, characterized in that an angle sensor is introduced into it kinematically connected to both shafts and giving information about the angles azimuthal rotation and inclination of the reflector, determined by the formulas:

where φ is the angle of rotation of the reflector in azimuth; α is the angle of inclination of the reflector; φ _∂ is the angle of rotation of the angle sensor; i is the gear ratio between the sensor and the azimuthal rotation shaft; r is the eccentricity of the eccentric; d is the diameter of the pitch circle of the gear sector; Δi is the difference in the gear ratios between the sensor and the shafts.

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