Vane guides for rotary vane gas cycle apparatus

A rotary vane gas cycle apparatus having radial vane guide slots in the rotor for receiving vane guides on the rotor vanes which slide in the slots. One or more radial guides are provided for each vane. In one embodiment a vane guide is provided on one side of the vane. The rotor guide slots restrict movement of the vane toward or away from the guide slot.

BACKGROUND OF THE INVENTION 
This invention relates to a rotary vane gas cycle apparatus. 
In rotary vane gas cycle apparatus, such as a reverse Brayton cycle cooling 
system described in the U.S. Pat. Nos. to Edward, 3,967,466 and 3,977,852, 
compression and expansion is obtained by the radial movement of vanes in 
slots in a rotor. Various means have been used, such as bearings and cams, 
to control the movement of the vanes in the slots to reduce end wear on 
the vanes. Conventional means used however, permit axial and radial 
twisting of the vanes in the slots thus requiring greater end clearance to 
eliminate uneven wear on the vane ends. The added clearance results in 
greater thrust loading of the bearings. Movement of the vanes in the slots 
also add to the frictional loading of the apparatus. 
BRIEF SUMMARY OF THE INVENTION 
According to this invention vane guides are provided to control movement of 
the vanes in the rotor slots to substantially eliminate axial and radial 
skewing of the vanes. With the use of the vane guides, the vane faces can 
be spaced a greater distance from the sides of the rotor slots thus 
reducing the frictional loads. Also the end clearance between the vanes 
and the end walls can be reduced to decrease blowby. Thrust loading of the 
bearings is also susbtantially reduced.

DETAILED DESCRIPTION OF THE INVENTION 
Reference is now made to FIG. 1 of the drawing which shows a conventional 
rotary vane air cycle apparatus 10 such as used in a reverse Brayton cycle 
cooling system. The rotary vane air cycle apparatus 10 includes a rotor 12 
within a chamber 14. The rotor includes a plurality of radial slots 16 
with movable vanes 18. The rotor 12 is driven through shaft 20 by a drive 
indicated at 22. Compression and expansion is obtained by the change in 
volume between adjacent vanes as the shaft 20 rotates. With rotation as 
indicated at 23 the compressor 24 has an inlet port at 26 and an outlet 
port at 28. The expander 30 has an inlet port at 32 and an outlet port at 
34. 
According to this invention the rotor 12 is constructed as shown in FIG. 2. 
The rotor slots 16' are provided with radial vane guide tracks 40 with the 
shape of cylindrical segments and the vanes 18' are provided with vane 
guides 42 with the shape of cylindrical segments. The vane guides 42 act 
to space the vanes from the sides of the slots 16' as indicated 
schematically at 44 to reduce the frictional load. While only two vane 
guides are shown on each side of the blade more than two may be required, 
in some applications, to overcome the problem of localized heating. 
The vane guides would be lubicated in a conventional manner, for example 
lubricant could be supplied to the vane guide tracks 40 or the vane guides 
42 could be made to include materials with self lubricating properties. 
While vane guides have been shown on opposite sides of the vanes in FIG. 2, 
vane guides could be provided on only one side of the vanes as shown in 
FIG. 3 wherein vane guide tracks 48 are provided with guide surfaces 50 
and 52 for engaging surfaces 54 and 56 on vane guides 58. A space 60 is 
provided between the vane guide surfaces 54 to reduce friction. If a 
plurality of smaller guide tracks such as 48 were used the space 60 could 
be omitted. The showing in FIG. 2 is the preferred embodiment since it is 
easier to manufacture. Vane guide configurations other than those shown 
could be used. The vane guides can be made integral with the vanes, such 
as when the vanes are made as composite structures, or the vane guides can 
be made as separate elements and can then be secured to the vanes with 
bolts or other well known means. 
In the operation of the device the rotary air cycle apparatus operates in a 
conventional manner with conventional vane actuation apparatus, not shown, 
controlling the movement of the vanes 18' in slots 16'. The vane guides 42 
move in guide tracks 40 and space the vanes 18' from the sides of slots 
16'. The vane guides also keep the vanes from skewing in the slots and 
reduce end wear on the vanes. The vane guides act to reduce thrust loading 
on cam bearings in devices using cam actuated vanes. 
There is thus provided apparatus for use in a rotary gas cycle device for 
reducing frictional loading and for reducing vane wear.