WO1991010846A1 - Centrifuge gearboxes - Google Patents

Centrifuge gearboxes Download PDF

Info

Publication number
WO1991010846A1
WO1991010846A1 PCT/GB1991/000012 GB9100012W WO9110846A1 WO 1991010846 A1 WO1991010846 A1 WO 1991010846A1 GB 9100012 W GB9100012 W GB 9100012W WO 9110846 A1 WO9110846 A1 WO 9110846A1
Authority
WO
WIPO (PCT)
Prior art keywords
stage
gear
bowl
carrier
sun gear
Prior art date
Application number
PCT/GB1991/000012
Other languages
French (fr)
Inventor
Colin Reynolds
Original Assignee
Alfa-Laval Separation, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Alfa-Laval Separation, Inc. filed Critical Alfa-Laval Separation, Inc.
Publication of WO1991010846A1 publication Critical patent/WO1991010846A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
    • B04B—CENTRIFUGES
    • B04B1/00—Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles
    • B04B1/20—Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles discharging solid particles from the bowl by a conveying screw coaxial with the bowl axis and rotating relatively to the bowl
    • B04B1/2016—Driving control or mechanisms; Arrangement of transmission gearing
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H1/00—Toothed gearings for conveying rotary motion
    • F16H1/28—Toothed gearings for conveying rotary motion with gears having orbital motion
    • F16H1/46—Systems consisting of a plurality of gear trains each with orbital gears, i.e. systems having three or more central gears
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H3/00—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion
    • F16H3/44—Toothed gearings for conveying rotary motion with variable gear ratio or for reversing rotary motion using gears having orbital motion
    • F16H3/46—Gearings having only two central gears, connected by orbital gears
    • F16H3/58—Gearings having only two central gears, connected by orbital gears with sets of orbital gears, each consisting of two or more intermeshing orbital gears
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
    • B04B—CENTRIFUGES
    • B04B1/00—Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles
    • B04B1/20—Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles discharging solid particles from the bowl by a conveying screw coaxial with the bowl axis and rotating relatively to the bowl
    • B04B1/2016—Driving control or mechanisms; Arrangement of transmission gearing
    • B04B2001/2025—Driving control or mechanisms; Arrangement of transmission gearing with drive comprising a planetary gear

Definitions

  • This invention relates to gearboxes for centrifuges and in particular, but not exclusively decanter centrifuges.
  • Decanter centrifuges are centrifugal machines employed for separating large quantities of particu- late solids from liquids. They comprise a bowl which is rotated at high speed to effect separation, forming an outer layer of solids against the inner surface of the bowl, and a screw conveyor which is rotated relative to the bowl to displace the solids axially towards an outlet at one end of the bowl.
  • the present invention is concerned with gear ⁇ boxes for coupling the screw conveyor of a decanter centrifuge to the bowl to provide the desired relative rotation between the bowl and the conveyor.
  • a gearbox for a decanter centrifuge comprising a double epicyclic gear train having a first stage comprising a sun gear, a ring gear coupled to the bowl for rotation therewith and planet gears mounted on a carrier, the second stage comprising a sun gear fast with the first stage carrier, a ring gear coupled to the bowl for rotation therewith, and planet gears mounted on a carrier which is coupled to the screw conveyor, and wherein one of the said stages comprises idler gears which couple the sun gear of that stage to the corresponding planet gears.
  • the idler gears are incorporated in the first stage.
  • Fig. 1 is a diagrammatic axial cross-section of the gearbox; and Fig. 2 is an end view illustrating the gearing in the first stage of the gearbox.
  • the gearbox shown in the drawings comprises a housing 1 having a tubular extension 1A fast with the bowl of a decanter centrifuge.
  • the transmission gearing takes the form of a two-stage epicyclic gear train.
  • the first stage comprises a sun gear SI which is held stationary by virtue of its spindle 3 being fixed by a torque arm (not shown) external of the housing 1.
  • Two (or more) idler gears G1 mounted on a carrier 4 mesh, on the one hand with the sun gear S1 and on the other hand with two (or more) respective planet gears P1 , also mounted on the carrier 4.
  • the planet gears mesh with a ring gear R1 fixed to the housing 1.
  • the housing 1 constitutes the drive input member and the output member of the first stage train is the carrier 4.
  • the second stage comprises a sun gear S2 fast with the carrier and co-axial therewith, planet gears P2 mounted on a carrier 6 and a ring gear R2 fast with the gear box housing.
  • the final drive or output is a driven shaft 7 fast with the carrier 6, fast with the screw conveyor (not shown) of the decanter centri ⁇ fuge.
  • the screw conveyor is coupled to the bowl for rotation in the same direction as the bowl but at a higher speed.
  • the difference in speed between the bowl and the conveyor screw might typically be in the range of about 1 r.p.m to 80 r.p.m, although higher differ ⁇ ential speeds may be provided for in some applications.
  • the gearing in the illustrated gear box may be as follows, where "t" indicates the number of teeth in the indicated gears: First stage : S1-9t; G1-45t; P1-50t; R1-135t Second stage: S2-10t; P2-28t; R2-68t.
  • the speed of rotation of the conveyor relative to that of the bowl will be 1.009:1 (more exactly 110.2:109.2).
  • the conveyor will rotate at 3027 r.p.m. in the same direction.
  • the sun gear S1 of the first stage is held stationary which is usual. but it is also possible for the sun gear S1 to be rotated, which has the affect of altering the speed ratio of the conveyor relative to the bowl. Rotating the sun gear in the same direction as the bowl will cause the speed of the conveyor relative to the bowl to decrease, while rotating the sun gear in the opposite direction will cause the speed of the conveyor relative to the bowl to increase. Usually the speed of the sun gear in any direction will not exceed the speed of the bowl, but when operating in a reverse direction to the bowl, higher sun gear speeds are possible to further increase the speed of the conveyor relative to the bowl.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Centrifugal Separators (AREA)
  • Liquid Crystal Display Device Control (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)
  • Compression Or Coding Systems Of Tv Signals (AREA)
  • Two-Way Televisions, Distribution Of Moving Picture Or The Like (AREA)

Abstract

A gearbox for transmitting drive from the bowl of a decanter centrifuge to its screw conveyor comprises a double epicyclic gear train in which idler gears (G1) are inserted in the first stage between the sun (S1) and planet gears (P1) thereof to reverse the sense of rotation of the carrier (4) which is fast with the sun gear (S2) of the second stage, in order that the second stage carrier is rotatable in the same direction as the ring gear and at a higher speed.

Description

Centrifuge Gearboxes
This invention relates to gearboxes for centrifuges and in particular, but not exclusively decanter centrifuges.
Decanter centrifuges are centrifugal machines employed for separating large quantities of particu- late solids from liquids. They comprise a bowl which is rotated at high speed to effect separation, forming an outer layer of solids against the inner surface of the bowl, and a screw conveyor which is rotated relative to the bowl to displace the solids axially towards an outlet at one end of the bowl.
The present invention is concerned with gear¬ boxes for coupling the screw conveyor of a decanter centrifuge to the bowl to provide the desired relative rotation between the bowl and the conveyor.
It has long been known to employ double epicyclic gear boxes for this purpose, but it has been accepted that this imposes the limitation that the screw conveyors will rotate slower than the bowl when the first stage sun gear is stationary or is rotated at less than the bowl speed.
In accordance with a feature of the invention, there is provided a gearbox for a decanter centrifuge, comprising a double epicyclic gear train having a first stage comprising a sun gear, a ring gear coupled to the bowl for rotation therewith and planet gears mounted on a carrier, the second stage comprising a sun gear fast with the first stage carrier, a ring gear coupled to the bowl for rotation therewith, and planet gears mounted on a carrier which is coupled to the screw conveyor, and wherein one of the said stages comprises idler gears which couple the sun gear of that stage to the corresponding planet gears.
In the embodiment described below, the idler gears are incorporated in the first stage.
With this arrangement, it is possible to drive the screw conveyor at a faster speed than the bowl. In terms of separating efficiency it is often advantageous to drive the conveyor faster than the bowl, primarily to reduce slippage of the solids and liquids when the conveyor rotates slower than the bowl. However, it has not hitherto been possible to achieve this desirable characteristic using an epicyclic gearbox. One form of the decanter centrifuge gearbox will now be described, by way of example only, with reference to the accompanying drawings, in which:
Fig. 1 is a diagrammatic axial cross-section of the gearbox; and Fig. 2 is an end view illustrating the gearing in the first stage of the gearbox.
The gearbox shown in the drawings comprises a housing 1 having a tubular extension 1A fast with the bowl of a decanter centrifuge. The transmission gearing takes the form of a two-stage epicyclic gear train. The first stage comprises a sun gear SI which is held stationary by virtue of its spindle 3 being fixed by a torque arm (not shown) external of the housing 1. Two (or more) idler gears G1 mounted on a carrier 4 mesh, on the one hand with the sun gear S1 and on the other hand with two (or more) respective planet gears P1 , also mounted on the carrier 4. The planet gears mesh with a ring gear R1 fixed to the housing 1. The housing 1 constitutes the drive input member and the output member of the first stage train is the carrier 4.
The second stage comprises a sun gear S2 fast with the carrier and co-axial therewith, planet gears P2 mounted on a carrier 6 and a ring gear R2 fast with the gear box housing. The final drive or output is a driven shaft 7 fast with the carrier 6, fast with the screw conveyor (not shown) of the decanter centri¬ fuge.
With this arrangement, the screw conveyor is coupled to the bowl for rotation in the same direction as the bowl but at a higher speed.
According to the operating requirements of the centrifuge, the difference in speed between the bowl and the conveyor screw might typically be in the range of about 1 r.p.m to 80 r.p.m, although higher differ¬ ential speeds may be provided for in some applications.
Purely by way of example, the gearing in the illustrated gear box may be as follows, where "t" indicates the number of teeth in the indicated gears: First stage : S1-9t; G1-45t; P1-50t; R1-135t Second stage: S2-10t; P2-28t; R2-68t. In this case the speed of rotation of the conveyor relative to that of the bowl will be 1.009:1 (more exactly 110.2:109.2). In absolute terms, if the bowl rotates at a typical operating speed of 3000 r.p.m, the conveyor will rotate at 3027 r.p.m. in the same direction.
As described in the foregoing the sun gear S1 of the first stage is held stationary which is usual. but it is also possible for the sun gear S1 to be rotated, which has the affect of altering the speed ratio of the conveyor relative to the bowl. Rotating the sun gear in the same direction as the bowl will cause the speed of the conveyor relative to the bowl to decrease, while rotating the sun gear in the opposite direction will cause the speed of the conveyor relative to the bowl to increase. Usually the speed of the sun gear in any direction will not exceed the speed of the bowl, but when operating in a reverse direction to the bowl, higher sun gear speeds are possible to further increase the speed of the conveyor relative to the bowl.

Claims

Claims :
1. A gearbox for a centrifuge, comprising a double epicyclic gear train having a first stage comprising a sun gear, a ring gear coupled to the bowl for rotation therewith and planet gears mounted on a carrier, the second stage comprising a sun gear fast with the first stage carrier, a ring gear coupled to the bowl for rotation therewith, and planet gears mounted on a carrier which is coupled to a screw conveyor, and wherein one of the said stages includes idler gears which couple the sun gear of that stage to the corresponding planet gears.
2. A gearbox according to claim 1 , wherein the said idler gears are incorporated in the first stage of the epicyclic train.
3. A gear box according to claim 1 or 2, wherein said first stage idler gear is rotatable with respect to ground.
4. A gear box according to claim 1 , 2 or 3 where¬ in the speed of the first stage idler gear is controlled to alter the relative speed of the second stage carrier to that of the ring gear.
PCT/GB1991/000012 1990-01-08 1991-01-04 Centrifuge gearboxes WO1991010846A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB9000343A GB2239924B (en) 1990-01-08 1990-01-08 Centrifuge gearboxes
GB9000343.5 1990-01-08
CA002072043A CA2072043A1 (en) 1990-01-08 1992-06-23 Centrifuge gearboxes

Publications (1)

Publication Number Publication Date
WO1991010846A1 true WO1991010846A1 (en) 1991-07-25

Family

ID=25675258

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1991/000012 WO1991010846A1 (en) 1990-01-08 1991-01-04 Centrifuge gearboxes

Country Status (5)

Country Link
EP (1) EP0510053A1 (en)
JP (1) JPH05502928A (en)
CA (1) CA2072043A1 (en)
GB (1) GB2239924B (en)
WO (1) WO1991010846A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1994023223A1 (en) * 1993-03-29 1994-10-13 Cyclo Getriebebau Lorenz Braren Gmbh Planetary gear with two driven shafts
WO2002081094A1 (en) 2001-04-04 2002-10-17 Centriquip Limited A gearbox for a centrifuge, such as a decanter centrifuge
WO2008078396A1 (en) 2006-12-26 2008-07-03 Tomoe Engineering Co., Ltd. Gear box for centrifugal separator

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102006028804A1 (en) * 2006-06-23 2007-12-27 Westfalia Separator Ag Slug centrifuge with drive device
CN100453847C (en) * 2006-12-01 2009-01-21 洛阳聚翔机械科技有限公司 Countershaft planetary transmission backing device for tractor
CN103438162B (en) * 2013-08-13 2017-02-08 柳州博泽科技有限公司 Double-planetary gearbox
JP2017088091A (en) * 2015-11-16 2017-05-25 株式会社シマノ Drive unit for bicycle
WO2020182163A1 (en) * 2019-03-12 2020-09-17 熊建文 Bidirectional overrunning clutch and two-speed transmission
EP4040015A1 (en) * 2021-02-09 2022-08-10 Alfredo Tampieri Compact epicyclic gearing

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3187997A (en) * 1962-02-12 1965-06-08 Ametek Inc Horizontal type centrifugal separator
US3359833A (en) * 1964-11-25 1967-12-26 Borg Warner Transmission controls
FR2610058A1 (en) * 1987-01-26 1988-07-29 Maag France Power transmission device with speed reduction between a rotating assembly and a shaft mounted coaxially inside the latter
WO1989002041A1 (en) * 1987-09-04 1989-03-09 Allied-Signal Inc. Compound planetary gear assembly

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3187997A (en) * 1962-02-12 1965-06-08 Ametek Inc Horizontal type centrifugal separator
US3359833A (en) * 1964-11-25 1967-12-26 Borg Warner Transmission controls
FR2610058A1 (en) * 1987-01-26 1988-07-29 Maag France Power transmission device with speed reduction between a rotating assembly and a shaft mounted coaxially inside the latter
WO1989002041A1 (en) * 1987-09-04 1989-03-09 Allied-Signal Inc. Compound planetary gear assembly

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1994023223A1 (en) * 1993-03-29 1994-10-13 Cyclo Getriebebau Lorenz Braren Gmbh Planetary gear with two driven shafts
WO2002081094A1 (en) 2001-04-04 2002-10-17 Centriquip Limited A gearbox for a centrifuge, such as a decanter centrifuge
WO2008078396A1 (en) 2006-12-26 2008-07-03 Tomoe Engineering Co., Ltd. Gear box for centrifugal separator

Also Published As

Publication number Publication date
EP0510053A1 (en) 1992-10-28
GB2239924B (en) 1993-06-30
GB2239924A (en) 1991-07-17
GB9000343D0 (en) 1990-03-07
JPH05502928A (en) 1993-05-20
CA2072043A1 (en) 1993-12-24

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