[0001] The present invention relates to Lysholm compressors which are used, for example,
for superchargers in automotive engines and more particularly to casing structures
for such compressors. More specifically, the invention relates to a Lysholm compressor
casing structure which is adapted to accommodate intermeshing male and female rotors
and which comprises two part-cylindrical walls which constitute a casing and merge
together at two cusps which project inwardly towards one another, a suction port at
one axial end of the casing and a discharge port at the other axial end of the casing.
[0002] JP 07 217563 A which is considered as the closest state of the art discloses the
features described in the preamble of claims 1 and 2.
[0003] Fig. 1 is a schematic perspective view of a known Lysholm compressor of the type
referred to above, which comprises parallel intermeshing male and female rotors 1
and 2 rotatably accommodated in an accommodation space 7 within a casing 3. The rotors
1 and 2 are counter-rotated in the directions of the arrows to suck air 5 into the
space 7 through a suction or inlet port 4 at one axial end of the casing 3. The air
5 is compressed by the rotors 1 and 2 and is discharged through a discharge port 6
at the other axial end of the casing 3 adjacent to the intermeshing portions 8 of
the rotors 1 and 2.
[0004] As best shown in Fig. 2, which is a schematic vertical sectional view of the compressor
in Fig. 1, and Fig 3, which is a view in the direction of the arrows III in Fig. 2,
the casing 3 comprises part-cylindrical walls 9a and 9b which are of substantially
uniform thickness and which surround the majority of the peripheries of the rotors
1 and 2 except for the intermeshing portions 8. The casing 3 further comprises a pair
of opposed cusps 10 and 11 which project inwardly from the walls 9a and 9b towards
the intermeshing portions 8 of the rotors 1 and 2.
[0005] In the Lysholm compressor shown in Figs. 1 to 3, rotation of the rotors 1 and 2 in
the directions of the arrows shown in Fig. 1 causes the air 5 induced through the
port 4 to pass through the space 7 whilst being compressed by the rotors 1 and 2,
the compressed air 5 then being discharged out of the casing 3 through the port 6.
[0006] This construction is disadvantageous in that it generates much noise during operation.
It is conventionally proposed for the purpose of suppressing the noise that specially
designed suction and discharge ports 4 and 6 be used or that the piping connected
to the ports 4 and 6 be provided with noise suppressor means, such as a silencer or
resonator (not shown).
[0007] However, the designed ports are not very effective at suppressing the noise. More
specifically, the cusps 10 and 11 of the casing 3 have low stiffness and tend to cause
vibration of the walls, thereby generating noise; such noise due to vibration of the
walls may not be easily suppressed merely by specially designed ports.
[0008] Even if noise were satisfactorily suppressed by specially designed ports, the latter
would increase the resistance to the air 5 flowing into and out of the space 7, resulting
in impairment of the performance of the compressor.
[0009] On the other hand, when the compressor described above is used, for example, as a
supercharger for an integral combustion engine of a vehicle and noise suppressor means,
such as a silencer or resonator, are provided in the piping connected to the suction
and discharge ports 4 and 6, it is difficult to arrange this piping with the noise
suppressor means in association with other equipment and machinery in the vehicle.
Moreover, the arrangement of the noise suppressor means remote from the compressor
impairs the noise-suppressing effect.
[0010] Accordingly it is the object of the present invention to provide a Lysholm compressor
and particularly a Lysholm compressor casing structure therefor which generates less
noise and may be readily mounted in a vehicle.
[0011] According to one aspect of the present invention a Lysholm compressor casing structure
of the type referred to above is characterised in that a silencer chamber is defined
between one of the cusps and an outer wall portion, which is situated outside the
said one cusp and is integral with the casing, and has an opening in communication
with the suction port.
[0012] According to a further aspect of the present invention the Lysholm compressor casing
structure is characterised in that a silencer chamber is defined between one of the
cusps and an outer wall portion which is situated outside the said one cusp and is
integral with the casing and has an opening in communication with the discharge port.
[0013] Thus a Lysholm compressor casing structure in accordance with the present invention
may have a silencer chamber defined between a respective one of the cusps and an associated
outer wall portion situated outside the cusp and integral with the casing and having
an opening in communication with either the suction port or the discharge port. Accordingly
to a further aspect of the present invention the noise suppression is further enhanced
if two such silencer chambers are provided communicating with the suction port and
the discharge, respectively.
[0014] The invention relates also to a Lysholm compressor comprising male and female rotors
which intermesh at a region and/or are rotatably accommodated within a casing structure
of the type defined above.
[0015] Further features of the invention will be apparent from the following description
of three preferred embodiments of the invention which is given by way of example with
reference to Figures 4 to 9 of the accompanying drawings, in which:
Fig. 4 is a schematic vertical sectional view of a first embodiment of the present
invention;
Fig. 5 is a view in the direction of the arrows V in Fig. 4;
Fig. 6 is a view similar to Fig. 4 of a second embodiment of the invention;
Fig. 7 is a view in the direction of the arrows VII in Fig. 6;
Fig. 8 is a further view similar to Fig. 4 of a third embodiment of the invention;
and
Fig. 9 is a view in the direction of arrows IX in Fig. 8.
[0016] Those components which are essentially the same as those described in conjunction
with Fig. 1 to 3 are referred to by the same reference numerals.
[0017] The Lysholm compressor shown in Figs. 4 and 5 comprises male and female rotors 1
and 2 and a casing 3 for rotatably accommodating the rotors 1 and 2. The casing 3
comprises two part-cylindrical walls 9a and 9b which are of substantially uniform
thickness and surround the majority of the rotors 1 and 2 except for their intermeshing
portions 8. The part-cylindrical walls 9a and 9b merge at a pair of opposed cusps
10 and 11 which extend inwardly towards the intermeshing portions 8 of the rotors
1 and 2. The casing 3 is provided at one axial end with a suction port 4 and at the
other axial end with a discharge port 6 adjacent the intermeshing portions 8 of the
rotors 1 and 2.
[0018] A stagnation space constituting a suction-side silencer chamber 13 is defined by
the cusp 10 and the adjacent portions of the part-cylindrical walls and an outer wall
portion 12 outside the cusp 10 and integral with the casing 3. The silencer chamber
13 has a suction-side opening 14 in communication with the suction port 4.
[0019] The shape, size and other details of the silencer chamber 13 and also of the opening
14 may be freely selected.
[0020] In use, rotation of the rotors 1 and 2 causes the air 5 induced through the suction
port 4 to pass through the accommodation space 7 in the casing 3 whilst being compressed
by the rotors 1 and 2, and the compressed air is discharged through the discharge
port 6 at the other end of the casing 3 adjacent to the intermeshing portions 8 of
the rotors.
[0021] Any noise due to pressure fluctuations of the air 5 sucked through the port 4 can
be effectively suppressed due to the presence of the silencer chamber 13. The noise-suppressing
effect is maximised since the silencer chamber 13 is adjacent to the source of noise
generation by the compressor.
[0022] The cusp 10 is reinforced and thus stiffened by the presence of the outer wall portion
12, so that any vibration of the cusp 10 is suppressed, thereby suppressing the generation
of noise by vibration.
[0023] Figs. 6 and 7 illustrate a further embodiment of the present invention in which a
stagnation space constituting a discharge-side silencer chamber 16 is defined by the
other cusp 11 and adjacent portions of the part-cylindrical walls and an outer wall
portion 15 outside the cusp 11 and integral with the casing 3. The silencer chamber
16 has a discharge-side opening 17 in communication with the discharge port 6.
[0024] The shape, size and other details of the silencer chamber 16 and opening 17 may be
freely selected.
[0025] Operation of the second embodiment is similar to that of the first embodiment and
any noise due to pressure fluctuations of the air 5 discharged through the port 6
can be effectively suppressed due to the presence of the silencer chamber. The noise-suppressing
effect is maximised since the silencer chamber 16 is adjacent to the source of noise
generation by the compressor.
[0026] The cusp 11 is reinforced and thus stiffened by the presence of the outer wall portion
15, so that any vibration of the cusp 11 is suppressed, thereby suppressing the generation
of noise due to vibration.
[0027] Figs. 8 and 9 illustrate a still further embodiment of the invention in which both
suction- and discharge-side silencer chambers 13 and 16 like those in Figs. 4 and
5 and in Figs. 6 and 7 are defined by the cusps 10 and 11 and the adjacent portions
of the part-cylindrical walls and the silencer outer wall portions 12 and 15, respectively.
The silencer chambers 13 and 16 have suction- and discharge-side openings 14 and 17
in communication with the suction and discharge ports 4 and 6, respectively.
[0028] In all three embodiments the noise suppression is attained with no substantial change
in size of the casing 3 since, as mentioned above, the silencer chambers are defined
between a respective cusp 10,11 and the associated outer wall portion 12,15 integral
with the casing 3. Therefore, the compressor may be readily mounted in a vehicle or
the like without difficulty in contrast to conventional compressors with silencers
or the like connected to the piping leading to the suction and discharge ports.
[0029] In the compressor shown in Figs. 8 and 9, the provision of both suction- and discharge-side
silencer chambers 13 and 16 fulfils the effects of both the first and second embodiments
and suppresses noise at both the suction- and discharge-sides. Moreover, it makes
the outer shape of the whole of the casing 3 substantially cylindrical, so that the
overall strength and rigidity is further increased. As a result, any vibration of
the cusps 10 and 11 is further suppressed thereby further suppressing the generation
of noise due to vibration.
1. A Lysholm compressor casing structure adapted to accommodate intermeshing male and
female rotors (1,2) and comprising two part-cylindrical walls (9a,9b) which constitute
a casing (3) and merge together at two cusps (10,11) which project inwardly towards
one another, a suction port (4) at one axial end of the casing (3) and a discharge
port (6) at the other axial end of the casing, characterised in that a silencer chamber (13) is defined between one of the cusps (10) and an outer wall
portion (12) which is situated outside the said one cusp (10) and is integrally contiguous
with the two part-cylindrical walls (9a, 9b) of the casing (3) and has an opening
(14) in communication with the suction port (4) at the said one axial end.
2. A Lysholm compressor casing structure adapted to accommodate intermeshing male and
female rotors (1, 2) and comprising two part-cylindrical walls (9a, 9b) which constitute
a casing (3) and merge together at two cusps (10, 11) which project inwardly towards
one another, a suction port (4) at one axial end of the casing (3) and a discharge
port (6) at the other axial end of the casing, characterised in that a silencer chamber (16) is defined between one of the cusps (11) and an outer wall
portion (15) which is situated outside the said one cusp (11) and is integrally contiguous
with the two part-cylindrical walls (9a, 9b) of the casing (3) and has an opening
(17) in communication with the discharge port (6) at the said other axial end.
3. A Lysholm compressor casing structure as claimed in Claim 2, characterised in that a silencer chamber (13) is defined between the other of the cusps (10) and a further
outer wall portion (12) which is situated outside the said other cusp (10) and is
integrally contiguous with the two part-cylindrical walls (9a, 9b) of the casing (3)
and has an opening (14) in connection with the suction port (4) at the said one axial
end.
4. A Lysholm compressor which comprises male and female rotors (1,2) which intermesh
at a region (8) and are rotatably accommodated in a casing structure as claimed in
any one of claims 1 to 3.
1. Gehäuseaufbau für einen Lysholm Verdichter zur Unterbringung von ineinandergreifender
Rotoren (1, 2), nämlich einem eingreifenden Rotor und einem aufnehmenden Rotor, mit
zwei teilzylindrischen Wänden (9a, 9b), die ein Gehäuse (3) bilden und ineinander
an zwei Kuppen (10, 11) übergehen, die nach innen zueinander vorstehen, einer Saugöffnung
(4) an einem axialen Ende des Gehäuses (3) und einer Abgabeöffnung (6) an dem anderen
axialen Ende des Gehäuses,
dadurch gekennzeichnet,
daß eine Kammer (13) für die Schalldämpfung zwischen einer der Kuppen (10) und einem
äußeren Wandabschnitt (12) ausgebildet ist, der außerhalb der einen Kuppe (10) liegt
und einstückig an die zwei teilzylindrischen Wände (9a, 9b) des Gehäuses (3) angrenzt
und eine in Verbindung mit der Saugöffnung (4) an dem einen axialen Ende stehende
Öffnung (14) hat.
2. Gehäuseaufbau für einen Lysholm Verdichter zur Unterbringung von ineinandergreifender
Rotoren (1, 2), nämlich einem eingreifenden Rotor und einem aufnehmenden Rotor, mit
zwei teilzylindrischen Wänden (9a, 9b), die ein Gehäuse (3) bilden und ineinander
an zwei Kuppen (10, 11) übergehen, die nach innen zueinander vorstehen, einer Saugöffnung
(4) an einem axialen Ende des Gehäuses (3) und einer Abgabeöffnung (6) an dem anderen
axialen Ende des Gehäuses,
dadurch gekennzeichnet,
daß eine Kammer (16) für die Schalldämpfung zwischen einer der Kuppen (11) und einem
äußeren Wandabschnitt (15) ausgebildet ist, der außerhalb der einen Kuppe (11) liegt
und einstückig an die zwei teilzylindrischen Wände (9a, 9b) des Gehäuses (3) angrenzt
und eine in Verbindung mit der Abgabeöffnung (6) an dem einen axialen Ende stehende
Öffnung (17) hat.
3. Gehäuseaufbau für einen Lysholm Verdichter nach Anspruch 2,
dadurch gekennzeichnet,
daß eine Kammer (13) für die Schalldämpfung zwischen der anderen der Kuppen (10) und
einem weiteren äußeren Wandabschnitt (12) ausgebildet ist, der außerhalb der anderen
Kuppe (10) liegt und einstückig an die zwei teilzylindrischen Wände (9a, 9b) des Gehäuses
(3) angrenzt und eine in Verbindung mit der Saugöffnung (4) an dem einen axialen Ende
stehende Öffnung (14) hat.
4. Lysholm Verdichter mit Rotoren (1, 2), nämlich einem eingreifenden Rotor und einem
aufnehmenden Rotor, die in einem Bereich (8) ineinandergreifen und drehbar in einem
Gehäuseaufbau nach einem der Ansprüche 1 bis 3 untergebracht sind.
1. Structure de carter de compresseur Lysholm conçue pour loger des rotors mâle et femelle
s'engrenant (1, 2) et comprenant deux parois en partie cylindriques (9a, 9b) qui constituent
un carter (3) et qui se rejoignent au niveau de deux points de rebroussement (10,
11) qui font saillie vers l'intérieur l'un vers l'autre, un orifice d'aspiration (4)
à une extrémité axiale du carter (3) et un orifice de refoulement (6) à l'autre extrémité
axiale du carter, caractérisée en ce qu'une chambre de silencieux (13) est définie entre l'un des points de rebroussement
(10) et une partie de paroi extérieure (12) qui est située à l'extérieur dudit un
point de rebroussement (10) et qui est contiguë de manière intégrée aux deux parois
en partie cylindriques (9a, 9b) du carter (3), et comporte une ouverture (14) en communication
avec l'orifice d'aspiration (4) au niveau de ladite une extrémité axiale.
2. Structure de carter de compresseur Lysholm conçue pour loger des rotors mâle et femelle
qui s'engrènent (1, 2) et comprenant deux parois en partie cylindriques (9a, 9b) qui
constituent un carter (3) et qui se rejoignent au niveau de deux points de rebroussement
(10, 11) qui font saillie vers l'intérieur l'un vers l'autre, un orifice d'aspiration
(4) à une extrémité axiale du carter (3) et un orifice de refoulement (6) à l'autre
extrémité axiale du carter, caractérisée en ce qu'une chambre de silencieux (16) est définie entre l'un des points de rebroussement
(11) et une partie de paroi extérieure (15) qui est située à l'extérieur dudit un
point de rebroussement (11) et qui est contiguë de manière intégrée aux deux parois
en partie cylindriques (9a, 9b) du carter (3), et comporte une ouverture (17) en communication
avec l'orifice de refoulement (6) au niveau de ladite autre extrémité axiale.
3. Structure de carter de compresseur Lysholm selon la revendication 2, caractérisée en ce qu'une chambre de silencieux (13) est définie entre l'autre des points de rebroussement
(10) et une autre partie de paroi extérieure (12) qui est située à l'extérieur dudit
autre point de rebroussement (10) et qui est contiguë de manière intégrée aux deux
parois en partie cylindriques (9a, 9b) du carter (3), et comporte une ouverture (14)
en liaison avec l'orifice d'aspiration (4) au niveau de ladite une extrémité axiale.
4. Compresseur Lysholm qui comprend des rotors mâle et femelle (1, 2) qui s'engrènent
au niveau d'une région (8) et qui sont logés avec possibilité de rotation dans une
structure de carter selon l'une quelconque des revendications 1 à 3.