US2896173A

US2896173A - Rotary joint

Info

Publication number: US2896173A
Application number: US384363A
Authority: US
Inventors: George R Cooney
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-10-05
Filing date: 1953-10-05
Publication date: 1959-07-21
Anticipated expiration: 1976-07-21

Description

July 21, 1959 COQNEY 2,896,173

ROTARY JOINT Filed Oct. 5; 195a HIGH FREQUENCY I l/ SOURCE INVENTOR. I GEORGE R. CooNsY ROTARY .1 GENT George R. Cooney, Lawrence, Mass, assign'or, by mesne assignments, to the United States of America as rep resented by the Secretary of the Navy Application flctober 5, 1953, Serial No. 384,363

3 t'llaims. (Cl. 333-7) The present invention concerns a waveguide joint and selector valve for coupling a stationary rectangular waveguide to a selected one only of a plurality of separate and distinct stationary rectangular waveguides for passage of electromagnetic energy through the first-mentioned rectangular waveguide and the selected one of the plurality of rectangular waveguides.

A further object is to provide a rotary joint for rectangular waveguides which separates the rectangular waveguides by a shorter distance than does any of the heretofore known devices of this type.

A further object is to provide a rotary joint in combination with a selector valve for rectangular waveguides.

A further object is to provide a rotary joint for rectangular waveguides wherein one of the waveguides that is connected thereto is rotatable therewith and is coaxial with the axis of rotation of the joint and wherein the joint separates the rectangular waveguides by shorter distances than does any of the heretofore known devices of this type.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. 1 is the diagrammatic view showing a relationship of this invention with associated elements in a radar transmitter and Fig. 2 is an exploded view showing an embodiment of this invention.

There is shown in Fig. 1 a high frequency source 11 connected by a rectangular waveguide 13 with a rotary joint 15 that is in turn connected through a center waveguide 17 to a selector valve 19. Selector valve 19 is preferably of the type disclosed in U.S. Patent 2,798,208. Selector valve 19 is connected by rectangular zenith waveguide 25 or rectangular surface waveguide 27 to zenith reflector 29 or surface reflector 31 respectively. Zenith waveguide 25 and zenith reflector 29 together form zenith antenna 33; surface waveguide 27 and surface reflector 31 together form surface antenna 35.

Rotary joint 15 and selector valve 19 is illustrated in Fig. 2. Rotary joint 15 includes a lower rotary joint 41 and an upper rotary joint 43. Lower rotary joint 41 resembles an elbow and transforms high frequency energy from rectangular to circular waveguide. This is shown at the bottom of Fig. 2 wherein adaptor 45, which is adapted for connection to rectangular waveguide 13' (Fig. 1), is sealed by neoprene gasket 47 to input flange 49. Thus the elbow that forms lower rotary joint 41 transforms the rectangular waveguide of input flange 49 to a circular waveguide at its outlet end 51. An example of a waveguide structure for transforming rectangular to circular waveguide is shown in U.S. Patent 2,584,399. Fixedly mounted in sealed relation on top of lower rotary joint 41 is a lower housing 53 that is sealed from lower rotary joint 41 by oil seal 55 and adjusted into proper clearance by laminated shim 57. Bolts 59 fasten lower Patent "ice housing 53 to lower rotary joint 41. Secured on top of lower housing 53 by means of screws 61 is an upper housing 63. Lower rotary joint 41, lower housing 53 and upper housing 63 form a fixed unit of the radar transmitter.

Inside the space defined by lower housing 53 and upper housing 63 is a rotatable waveguide element 65 that at its lower end is supported for rotation in a lower roller bearing 67 seating in lower housing 53 and shielded by shield 69 and that at its upper end is supported for rotation in an upper roller bearing 71 seating in upper housing 63 and sealed by a felt oil seal 73. Upper roller bearing 71 is retained against axial displacement upward in upper housing 63 by means of retainer ring 75 that is fitted against upper housing 63 by laminated shim 77 and secured in place by screws 79.

Waveguide element 65 comprises a lower inlet stub 81 that has a circular waveguide (not shown) adapted for communication with the circular waveguide outlet 51 of lower rotary joint 41. The upper extremity of waveguide element 65 forms an upper outlet stub 83 having a rectangular waveguide 85 that is adapted for communication with rectangular center waveguide 17 (Fig. 1). Lower inlet stub 81 is adapted to seat for rotation in lower roller bearing 67 and upper outlet stub 83 is adapted to seat for rotation in upper roller bearing 71. Between lower inlet stub 81 and upper outlet stub 83 is disposed a U-shaped waveguide element 87 that is rectangular in cross-section. The U-shaped element is strengthened by a brace 88. The purpose of the U-shaped waveguide element 87 is to get the rectangular waveguide 17 in line with the axis of rotation of the joint for easy connection to the selector valve 19; the construction of waveguide element 87 is shown in detail in Fig. 2.

Both the lower rotary joint 41 and the upper rotary joint 43 contain irises and transformers for proper int-- pedance matching and the assembly is designed to minimize the standing-wave ratio and to provide sufiicient clearance so as not to arc with a line voltage about 10% above nominal to the modulator associated with the high frequency source 11.

Upper outlet stub 83 of the impedance matcher 65 is mechanically coupled with the lower extremity of center waveguide 17 (Fig. 1). The upper extremity of center waveguide 17 is mechanically coupled to the lower extremity of selector valve 19. Selector valve 19, center waveguide 17 and upper rotary joint 15 rotate together in train.

In operation, assuming that selector valve 19 as seen in Fig. 1 is in position to feed high frequency energy through zenith waveguide 25 to zenith reflector 29 and assuming that it is desired to operate the radar transmitter on surface search, selector valve 19 is moved from the solid-line position to the dotted-line position in Fig. l to feed high frequency energy through surface waveguide 27 to surface reflector 31. Conversely, selector valve 19 may be moved from the dotted line position to the solid line position in Fig. 1. Rotation of selector valve 19 causes center waveguide 17 and rotary joint 15 that is mechanically coupled'thereto to rotate together through the angular displacement of selector valve 19.

At all times during operation high frequency energy fed into rotary joint 15 (Fig. 1) through input flange 49 (Fig. 2) is transformed in lower rotary joint 41 to circular waveguide at outlet 51. Energy is fed from outlet 51 through the circular waveguide of lower inlet stub 81 of waveguide element 65 where the energy is transformed to rectangular waveguide. The energy is fed outwardly through rectangular waveguide 85 to waveguide element 65 to zenith antenna 33 or surface antenna 35.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwith than as specifically described.

I claim:

1. In combination, a selector valve including a rectangular waveguide portion rotatable to any one of a plurality of angularly spaced operative positions for communication with any one of a corresponding plurality of antennas; a rotary joint including support means, a waveguide member secured to said support means, said member being formed with a rectangular waveguide termination at one end, a circular waveguide termination at its opposite end and a transition portion therebetween, a generally U-shaped rectangular waveguide member, a brace secured between the ends of said U-shaped member, means secured to the outside end of one of the legs of said U-shaped member to provide a circular waveguide termination to said U-shaped member; the other leg of said U-shaped member being arcuately bent substantially ninety degrees to terminate coaxial with the circular waveguide termination on the one leg of said U-shaped member, said U-shaped member and said last-mentioned means secured thereto being mounted for rotation on said support means with the circular waveguide terminations of said last-mentioned means and said first-mentioned waveguide member in registration; and a length of straight rectangular waveguide connected between the rectangular waveguide portion of said selector valve and the termination of the ninety degree bend of said .U- shaped member.

2. A waveguide joint for coupling a stationary rectangular waveguide to a selected one of a plurality of separate and distinct stationary rectangular waveguides for passage of electromagnetic energy through said firstmentioned rectangular waveguide and the selected one of said plurality of rectangular waveguides, comprising: a waveguide member having a rectangular waveguide termination at one end for connection to said first-mentioned rectangular waveguide and having a circular waveguide termination at its other end, a rectangular waveguide member having a circular waveguide termination adjacent one end thereof in registration with the circular Waveguide termination of said first waveguide member and supported for rotation about the axis of the circular waveguide termination thereof, said rectangular waveguide member being shaped along the length thereof so that its other end is transverse to the axis of rotation whereby said other end is positionable along a circular path, a plurality of rectangular waveguide terminations for connection to said plurality of separate and distinct stationary rectangular waveguides, respectively, and mounted in arcuate spaced relation along said path whereby said waveguide joint may be selectively positioned to establish a passage for electromagnetic energy from the rectangular waveguide termination of said first waveguide member and the selected one only of said plurality of rectangular Waveguide terminations in said circular path.

3. A waveguide joint as defined in claim 2 wherein said rectangular waveguide member having said circular waveguide termination adjacent one end thereof is generally U-shaped for a portion of its length extending from its circular waveguide termination and for a succeeding portion of its length is coaxial with its circular waveguide termination and terminates in a portion that is transverse to the portion coaxial with the circular waveguide termination.

References Cited in the file of this patent UNITED STATES PATENTS 2,531,455 Barrow et a1. Nov. 28, 1950 2,556,869 Charles June 12, 1951 2,584,399 Preston Feb. 5, 1952 2,596,398 Habich May 13, 1952 2,654,868 Zaleski Oct. 6, 1953 FOREIGN PATENTS 667,290 Great Britain Feb. 27, 1952