US2022136504A1PendingUtilityA1
Rotor pair for a compression block of a screw machine
Est. expiryApr 25, 2034(~7.8 yrs left)· nominal 20-yr term from priority
Inventors:Gerald Weih
F04C 2240/20F04C 18/16F04C 18/084F01C 1/084F01C 1/16F04C 18/20F04C 2240/30F04C 2240/60
73
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Claims
Abstract
The invention relates to a rotor pair for a compressor block of a screw machine, wherein the rotor pair comprises a secondary rotor that rotates about a first axis and a main rotor that rotates about a second axis, wherein the number of teeth of the main rotor is 3 and the number of teeth of the secondary rotor is 4. The relative profile depth of the secondary rotor is at least 0.5, preferably at least 0.515, and at most 0.65, preferably at most 0.595. rk1 is an addendum circle radius drawn around the outer circumference of the secondary rotor and rf1 is a dedendum circle radius starting at the profile base of the secondary rotor, wherein the ratio of the axis distance of the first axis from the second axis and the addendum circle radius rk1 is at least 1.636, and at most 1.8, preferably at most 1.733.
Claims
exact text as granted — not AI-modified1 . A rotor pair for a compressor block of a screw machine, wherein the rotor pair comprises:
a secondary rotor that rotates about a first axis and a main rotor that rotates about a second axis, wherein a number of teeth of the main rotor is 3 and a number of teeth of the secondary rotor is 4, wherein a relative profile depth of the secondary rotor
P
T
rel
=
r
k
1
-
r
f
1
r
k
1
is between 0.50 and 0.65, wherein rk 1 is an addendum circle radius drawn around the outer circumference of the secondary rotor and rf 1 is a dedendum circle radius starting at the profile base of the secondary rotor, wherein a ratio of an axis distance a of the first axis from the second axis and the addendum circle radius rk 1
a
rk
1
is between 1.636 and 1.8, wherein optionally the main rotor is configured with a wrap-around angle ϕ HR for which it holds that 240°≤ϕ HR ≤360°, and wherein preferably for a rotor length ratio L HR /a:
1.4≤ L HR /a≤ 3.4,
wherein optionally the rotor length ratio is formed from a ratio of the rotor length L HR of the main rotor and an axis distance a, and the rotor length L HR of the main rotor is formed by a distance of a suction-side main-rotor rotor end face to an opposite pressure-side main-rotor rotor end face.
2 - 14 . (canceled)
15 . A rotor pair for a compressor block of a screw machine, wherein the rotor pair comprises a secondary rotor that rotates about a first axis and a main rotor that rotates about a second axis, wherein a number of teeth of the main rotor is 4 and the number of teeth of the secondary rotor is 5, wherein a relative profile depth of the secondary rotor
P
T
rel
=
r
k
1
-
r
f
1
r
k
1
is at least 0.5, optionally at least 0.515, and at most 0.58 wherein rk 1 is an addendum circle radius drawn around an outer circumference of the secondary rotor and rf 1 is a dedendum circle radius starting at a profile base of the secondary rotor, wherein a ratio of an axis distance a of a first axis from a second axis and the addendum circle radius rk 1
a
rk
1
is between 1.683 to 1.836, wherein optionally the main rotor is configured with a wrap-around angle ϕ HR for which it holds that 240°≤ϕ HR ≤360°, and wherein optionally for a rotor length ratio L HR /a:
1.4≤ L HR /a≤ 3.3,
wherein a rotor length ratio is formed from a ratio of the rotor length L HR of the main rotor and the axis distance a and the rotor length L HR of the main rotor is formed by a distance of a suction-side main-rotor rotor end face to an opposite pressure-side main-rotor rotor end face.
16 - 28 . (canceled)
29 . A rotor pair for a compressor block of a screw machine, comprising a secondary rotor that rotates about a first axis and a main rotor that rotates about a second axis, wherein a number of teeth of the main rotor is 5 and a number of teeth of the secondary rotor is 6, wherein a relative profile depth of the secondary rotor
P
T
rel
=
r
k
1
-
r
f
1
r
k
1
is between 0.44 and 0.495 wherein rk 1 is an addendum circle radius drawn around an outer circumference of the secondary rotor and rf 1 is a dedendum circle radius starting at a profile base of the secondary rotor, wherein a ratio of the axis distance a of the first axis from the second axis and an addendum circle radius rk 1
a
rk
1
is between 1.74 and 1.8, wherein optionally the main rotor is configured with a wrap-around angle ϕ HR for which 240°≤ϕ HR ≤360°, and wherein optionally for a rotor length ratio L HR /a
1.4≤ L HR /a≤ 3.2,
wherein a rotor length ratio is formed from a ratio of a rotor length Lim of the main rotor and the axis distance a and a rotor length Lim of the main rotor is formed by a distance of a suction-side main-rotor rotor end face to an opposite pressure-side main-rotor rotor end face.
30 . The rotor pair according to claim 29 , wherein in a transverse sectional view, circular arcs B 25 , B 50 , B 75 running within a secondary rotor tooth are defined, the common centre point of which is given by the first axis, wherein a radius r 25 of B 25 has a value r 25 =rf 1 +0.25*(rk 1 −rf 1 ), a radius r 50 of B 50 has a value r 50 =rf 1 +0.5*(rk 1 −rf 1 ), and a radius r 75 of B 75 has a value r 75 =rf 1 +0.75*(rk 1 −rf 1 ), and wherein the circular arcs B 25 , B 50 , B 75 are each delimited by a leading tooth flank F V and a trailing tooth flank F N , wherein tooth thickness ratios are defined as ratios of the arc lengths b 25 , b 50 , b 75 of the circular arcs B 25 , B 50 , B 75 with ε 1 =b 50 /b 25 and ε 2 =b 75 /b 25 and at least one of 0.76<ε 1 ≤0.86 and/or 0.62≤ε 2 ≤0.72.
31 . The rotor pair according to claim 29 , wherein in a transverse sectional view, foot points F 1 and F 2 are defined between an observed tooth of a secondary rotor and the respectively adjacent tooth of the secondary rotor and an apex point F 5 is defined at a radially outermost point of the observed tooth, wherein a triangle D z is defined by foot points F 1 , F 2 and apex point F 5 and wherein in a radially outer region, the observed tooth projects beyond the triangle D z with its leading tooth flank F V formed between apex point F 5 and F 2 with an area A 1 and with its trailing tooth flank F N formed between foot point F 1 and apex point F 5 with an area A 2 and wherein 4≤A 2 /A 1 ≤7.
32 . The rotor pair according to claim 29 , wherein in a transverse sectional view, foot points F 1 and F 2 are defined between an observed tooth of the secondary rotor and a respectively adjacent tooth of the secondary rotor and an apex point F 5 is defined at a radially outermost point of the observed tooth, wherein a triangle D z is defined by foot points F 1 , F 2 and apex point F 5 and wherein in a radially outer region of the observed tooth, a leading tooth flank F V formed between apex point F 5 and foot point F 2 projects with an area A 1 beyond the triangle D z and in a radially inner region is set back with respect to the triangle D z with an area A 3 and wherein 8≤A 3 /A 1 ≤14.
33 . The rotor pair according to claim 29 , wherein in a transverse sectional view, foot points F 1 and F 2 are defined between an observed tooth of the secondary rotor and a respectively adjacent tooth of the secondary rotor and an apex point F 5 is defined at a radially outermost point of the observed tooth, wherein a triangle D z is defined by foot points F 1 , F 2 and apex point F 5 and wherein in a radially outer region of the observed tooth, a leading tooth flank F V formed between apex point F 5 and foot point F 2 projects with an area A 1 beyond the triangle D z , wherein the tooth itself has a cross-sectional area A 0 delimited by a circular arc B running between foot points F 1 and F 2 about a centre point defined by the first axis and wherein 1.9%≤A 1 /A 0 ≤3.2%.
34 . The rotor pair according to claim 29 , wherein in a transverse sectional view, foot points F 1 and F 2 are defined between an observed tooth of the secondary rotor and a respectively adjacent tooth of a secondary rotor and an apex point F 5 is defined at a radially outermost point of the observed tooth, wherein the circular arc B running between foot points F 1 and F 2 defines a tooth partition angle γ corresponding to 360°/number of teeth of the secondary rotor about a centre point defined by the first axis, wherein a point F 1 t is defined on the half circular arc B between foot points F 1 and F 2 , wherein a radial half-line R drawn from a centre point of the secondary rotor defined by the first axis through the apex point F 5 intersects a circular arc B at a point F 12 , wherein an offset angle ( 3 is defined by an offset of points F 11 to F 12 viewed in a direction of rotation of the secondary rotor and wherein
13.5%≤δ≤18%
where
δ
=
β
γ
*
100
[
%
]
.
35 . The rotor pair according to claim 29 , wherein the main rotor is formed with a wrap-around angle ϕ HR for which 320°≤ϕ HR ≤360°.
36 . The rotor pair according claim 29 , wherein a blow hole factor μ B1 is between 0.03% and 0.25%,
wherein
μ
Bl
=
A
Bl
A
6
+
A
7
*
100
[
%
]
and
wherein A B1 designates an absolute pressure-side blow hole area and A 6 and A 7 designate tooth gap areas of the secondary rotor or the main rotor, wherein an area A 6 in a transverse sectional view is an area enclosed between a profile course of the secondary rotor between two adjacent apex points F 5 and an addendum circle KK 1 and an area A 7 in a transverse sectional view is an area enclosed between a profile course of the main rotor between two adjacent apex points H 5 and an addendum circle KK 2 .
37 . The rotor pair according to claim 29 , wherein for a blow hole/profile gap length factor μ 1 *μ B1
0.1%≤μ 1 *μ B1 ≤1.26%
where
μ
l
=
l
sp
PT
1
,
where l sp designates a length of a profile engagement gap of a tooth gap of the secondary rotor and PT 1 designates a profile depth of the secondary rotor where PT 1 =rk 1 rf 1
and
μ
Bl
=
A
Bl
A
6
+
A
7
*
100
[
%
]
where A B1 designates an absolute blow hole area and A 6 and A 7 designate a profile areas of the secondary rotor or the main rotor, wherein an area A 6 in a transverse sectional view designates a area enclosed between a profile course of the secondary rotor between two adjacent apex points F 5 and an addendum circle KK 1 , and an area A 7 in a transverse sectional view designates an area enclosed between a profile course of the main rotor between two adjacent apex points H 5 and an addendum circle KK 2 .
38 . The rotor pair according to claim 29 , wherein the main rotor and the secondary rotor are configured and tuned to one another in such a manner that a dry compression with a pressure ratio Π of up to 5 is achieved, or alternatively a fluid-injected compression with a pressure ratio Π of up to 20 where a pressure ratio is a ratio of compression end pressure to suction pressure.
39 . The rotor pair according to claim 29 , wherein dry compression the main rotor is configured to be operated relative to an addendum circle KK 2 at a circumferential speed in a range from 20 to 100 m/s and a fluid-injected compression the main rotor is configured to be operated relative to an addendum circle KK 2 at a circumferential speed in a range from 5 to 50 m/s.
40 . The rotor pair according claim 29 , wherein for a diameter ratio defined by a ratio of an addendum circle radii of the main rotor and the secondary rotor
D
v
=
D
k
2
D
k
1
=
r
k
2
r
k
1
1
.
1
9
≤
D
v
≤
1.26
where Dk 1 designates a diameter of an addendum circle KK 1 of the secondary rotor and Dk 2 designates a diameter of an addendum circle KK 2 of the main rotor.
42 . The rotor pair according to claim 29 , wherein a transverse sectional view arc lengths b(r), running inside a tooth of the secondary rotor, of a respectively appurtenant concentric circular arcs having a radius rf 1 <r<rk 1 and a common central point defined by the first axis are each delimited by a leading tooth flank F V and a trailing tooth flank F N and the arc lengths b(r) decrease monotonically with increasing radius r.
43 . The rotor pair according to claim 29 , wherein a transverse sectional configuration of the secondary rotor is executed in such a manner that a direction of action of torque which results from a reference pressure on a partial surface of the secondary rotor delimiting a working chamber is directed contrary to the direction of rotation of the secondary rotor.
44 . The rotor pair according to claim 29 , wherein the main rotor and secondary rotor are configured and tuned to one another for conveying air or inert gases.
45 . The rotor pair according to claim 29 , wherein in a transverse sectional view, the profile of a tooth of the secondary rotor relative to the radial half-line R drawn from the centre point defined by the first axis C 1 through the apex point F 5 is configured to be asymmetrical.
46 . The rotor pair according to claim 29 , wherein in a transverse sectional view a point C is defined on a connecting section between the first axis and the second axis where a pitch circles WK 1 of the secondary rotor and WK 2 of the main rotor contact, that K 5 defines a point of intersection of a dedendum circle FK 1 of the secondary rotor with the connecting section where r 1 determines the distance between K 5 and C and that K 4 designates a point of the suction-side part of a line of engagement which lies at a greatest distance from the connecting section between the first and second axis, where r 2 determines a distance between K 4 and C and where:
0
.
9
≤
r
1
r
2
≤
0
.
8
7
5
×
z
1
z
2
+
0
.
2
2
where z 1 is a number of teeth of the secondary rotor and z 2 is a number of teeth of the main rotor.
47 . The rotor pair according claim 29 , wherein for a rotor length ratio L HR /a it holds: 0.85*(z 1 /z 2 )+0.67≤L HR /a≤1.26*(z 1 /z 2 )+1.18 where z 1 is a number of teeth of the secondary rotor and z 2 is a number of teeth of the main rotor, wherein a rotor length ratio L HR /a denotes a ratio of a rotor length L HR to the axial distance a and the rotor length L HR is the distance of a suction-side main-rotor rotor end face to the pressure-side main-rotor rotor end face.
48 . A compressor block comprising a compressor housing and a rotor pair according to claim 29 , wherein the rotor pair comprises the main rotor and the secondary rotor, which are each mounted rotatably in the compressor housing.Cited by (0)
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