The pressure cover has a plurality of radially outwardly directed teeth while the housing has a corresponding plurality of inwardly directed teeth. The cover can be inserted past the housing teeth and then rotated to bring the teeth into alignment for closing off the housing. In addition, a flange ring is provided to seal a gap between the cover and housing and the sealing means are disposed between the flange ring and the cover and housing, respectively. The sealing means can be replaced without having to detach the cover.

This invention relates to a turbomachine housing. 
As is known, various types of housings have been provided for 
turbomachines, such as pumps, compressors or turbines. In many cases, the 
housings have been constructed with an open end which is closed by a 
pressure cover with the interposition of elastic sealing elements such as 
elastomer O-rings, metallic C-rings, flat or spiral seals for example in 
the dividing gap between the housing and cover in order to seal the 
interior of the machine from the surrounding environment. In one type of 
construction, the pressure cover which closes off the housing on the end 
face, usually from the driving end, is provided with a driving flange and 
is secured to the housing by means of large expansion bolts and, possibly 
nuts. In this case, the sealing elements for sealing the pressure against 
the outside environment are in the form of elastic flat seals or O-rings 
disposed between the cover and the housing. Such a construction is 
described in Swiss Pat. No. 562,405. However, these constructions require 
salient flanges on the housing cover to receive the expansion bolts and, 
therefore, a relatively large housing. Further, the entire cover must be 
removed for replacement of the seals. 
In other constructions, such as described in Hitachi Review vol. 30, 1981, 
No. 6, page 6, FIG. 2, a housing cover is equipped with radial O-rings and 
is inserted into the housing in an axial direction. In this case, the 
cover is held by shear rings which are split in the circumferential 
direction. These shear rings, in turn, are fixed by a retention means 
fastened on the housing, which retention is also screwed to the housing 
cover. This construction is, however, very complicated and requires 
considerable effort for disassembly and re-assembly, for example, to 
replace the O-rings. Moreover, the radial O-rings are exposed to 
considerable danger of damage during insertion of the cover into the 
housing. 
Accordingly, it is an object of the invention to provide a simple, easy and 
space-saving construction for the cover and housing of a turbomachine, for 
example a pump in which seals can be replaced without disassembly of the 
cover. 
It is another object of the invention to provide a relatively simple 
construction of machine or pump housing and cover which can be readily 
assembled and disassembled. 
It is another object of the invention to be able to replace the sealing 
means between the housing and cover without need to remove the cover. 
It is another object of the invention to provide a relatively simple 
technique for mounting a cover in a centrifugal pump housing. 
Briefly, the invention provides a turbomachine housing having an open end 
which defines a cavity for receiving machine components with a plurality 
of radially inwardly directed teeth circumferentially spaced at the open 
end and a cover which is disposed within the open end of the housing to 
close the cavity with a plurality of radially outwardly directed teeth 
coaxially abutting the teeth of the housing. 
In addition, a flange ring is mounted circumferentially on the cover and is 
secured to the end of the housing. Further, a sealing means is disposed 
between the ring and the housing while another sealing means is disposed 
between the ring and the cover. 
The cover is sized to correspond to the clearance of the teeth on the 
housing so that the cover can be moved into and out of the housing with 
the teeth of the cover interposed between the teeth of the housing, i.e. 
with the teeth of the housing and cover in non-aligned relation. 
In this construction, the teeth of the housing and the teeth of the cover 
are brought into coincidence or abutment by a rotation of the cover. In 
this way, the pressure developed during operation of the machine is 
absorbed by the tooth connection. The sealing of the pressure is effected 
by the two elastic sealing means which are mounted and held by the flange 
ring. In this respect, the sealing means may each be formed by an 
elastomer packing such as an O-ring. 
A rather simple slide-in unit can also be formed, in part, by the cover for 
assembly of the machine or pump. To this end, the slide-in unit is 
comprised of a rotor assembly, a stator assembly having means defining 
threaded bores therein, and the cover. In this case, at least some of the 
teeth on the cover have an axially disposed bore therethrough and bolts 
are passed through these bores into threaded engagement with the threaded 
bores in the stator assembly. Such a slide-in unit can be readily slid 
into place in the housing. Once in place, the bolts can be unthreaded so 
as to permit the cover to be rotated relative to the teeth of the housing 
in order to bring the respective sets of teeth into alignment and coaxial 
abutment. 
The construction does not require salient flanges or large expansion bolts. 
Hence, the cover and the housing can be made smaller than previously known 
constructions. In addition, the risk of damage to the sealing means can be 
reduced or practically precluded. Moreover, replacement of the sealing 
means should leaks occur over time does not require disassembly of the 
housing cover. Instead, only the flange ring need be removed in order to 
replace the sealing means. 
In addition, at least some of the teeth on the housing may include an 
axially disposed bore. Thus, should the teeth of the cover and housing 
become firmly connected together, for example by sticking, a hydraulic 
pressure medium may be delivered through these bores in order to separate 
the abutting pressure cover and housing teeth for disassembly of the cover 
from the housing prior to rotation of the cover relative to the housing.

Referring to FIG. 1, the centrifugal pump housing 1 houses a rotor assembly 
which is composed of a shaft 2, a plurality of rotors 3 which are secured 
to the shaft 2 and a relief piston 4 which is mounted on the shaft 2. In 
addition, the housing 1 receives a stator assembly composed of a stepped 
housing 5, a stator 6 for each rotor stage and a bushing 9 rotatably 
receiving the relief piston 4 which, as is known, functions as a pressure 
equalization piston for receiving possible axial shifting. 
The housing 1 has an open end defining a cavity 11 for receiving the 
centrifugal pump components, i.e. the rotor assembly and stator assembly 
and is closed off by a pressure cover 7 at that end. As indicated, a 
pressure compensation line 8 opens into the cover 7 to communicate with 
the cavity 11. In addition, a slide ring packing 10 (shown schematically) 
is disposed within the cover 7 about the shaft 2. 
Referring to FIGS. 1 and 2 a serration in the form of a plurality of 
radially inwardly directed and circumferentially spaced teeth 12 is 
disposed at the open end of the housing 1 at the edge of the inner cavity 
11. As indicated in FIG. 2, the teeth 12 are evenly distributed about the 
circumference of the housing 1. In addition, every other tooth 12 is 
provided with an axially disposed bore 13 which is situated eccentrically 
therein. 
Referring to FIGS. 1 and 3 a serration in the form of a plurality of 
radially outwardly directed and circumferentially spaced teeth 14 is 
disposed on the cover 7 at the innermost end relative to the housing 1. As 
shown in FIG. 1, the cover 7 is of a diameter which corresponds to the 
clearance of the housing serration, i.e. the outwardly directed teeth 14 
of the cover are disposed in coaxial abutting relation with the teeth 12 
on the housing 1. 
As indicated in FIGS. 2 and 3, the form and position of the teeth 12, 14 
are matched so that the teeth 14 of the pressure cover 7 can be introduced 
between the teeth 12 into the housing 1. 
The teeth 14 of the cover 7 are each provided with an axially disposed bore 
15 through which bolts 16 may pass when the rotor assembly, stator 
assembly and cover 7 are to form a slide-in unit for mounting within the 
housing 1. To this end, the stator assembly is provided with means, such 
as fishplates 17 having threaded bores 18 therein to receive the bolts 16. 
In this way, the cover 7 is secured to the stator 6 of the last stage. 
After mounting of the slide-in unit, the bolts 16 are unscrewed and removed 
before the teeth 12,14 are brought into abutment with one another by the 
rotation of the cover 7 relative to the housing 1. In this regard, the 
pressure cover 7 is rotated, for example, by .pi./8 radians. 
Referring to FIG. 1, a flange ring 21 circumferentially surrounds the cover 
7 and is secured to the end of the housing 1 in order to close the radial 
gap between the housing 1 and the pressure cover 7. As indicated, the 
flange ring 21 is provided with bores through which bolts 22 may pass into 
threaded engagement with threaded bores 23 in the end of the housing 1. 
In addition, an annular groove 19 is cut into the end face of the housing 1 
to receive a radial sealing means in the form of an O-ring 20 in order to 
seal the flange ring 21 relative to the housing 1. In like manner, the 
cover 7 is provided with a circumferential groove 19' into which an axial 
sealing means, such as an O-ring 20', is disposed to seal the flange ring 
21 relative to the cover 7. 
The correct and always equal positioning of the cover 7 relative to the 
housing 1 after each disassembly and re-assembly is ensured by a 
positioning pin 25 which engages in a bore 24 (see FIG. 2) in the end face 
of the housing 1 and makes sure that the flange ring 21 assumes the 
correct position relative to the housing. Adjustment of the cover 7 and 
the flange ring 21 relative to each other is then effected by an adjusting 
wedge 26 which is placed into corresponding cutouts in the cover 7 and 
ring 21, respectively (see FIG. 1). 
During disassembly, after the flange ring 21 has been removed, one or more 
pressure lines of a hydraulic system (not shown) may be connected to the 
bores 13 in the teeth 12 of the housing 1 in order to inject a pressure 
medium between the teeth 12, 14 so as to separate the teeth 12, 14 from 
each other. Use of the hydraulic system is particularly useful where the 
teeth 12, 14 have been fixed together by sticking. Further, an axial 
clearance between the cover 7 and the stator 6 of the last stage allows 
rotation of the cover 7 without need for any axial movement during the 
mounting and disassembling rotations. 
The invention thus provides a turbo machine housing and cover arrangement 
of relatively small size and of relatively simple construction. 
Further, the invention provides an arrangement wherein the sealing means 
for the cover and housing arrangement can be readily replaced without need 
to disassemble the cover and/or housing.