GB2114701A - Toothed gear wheels and displacement rollers - Google Patents

Toothed gear wheels and displacement rollers Download PDF

Info

Publication number
GB2114701A
GB2114701A GB08203246A GB8203246A GB2114701A GB 2114701 A GB2114701 A GB 2114701A GB 08203246 A GB08203246 A GB 08203246A GB 8203246 A GB8203246 A GB 8203246A GB 2114701 A GB2114701 A GB 2114701A
Authority
GB
United Kingdom
Prior art keywords
toothed
former
displacement
preformed
flexible member
Prior art date
Legal status (The legal status 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 status listed.)
Withdrawn
Application number
GB08203246A
Inventor
Alan Lawrence Beresford
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
DAVALL MOULDED GEARS
Original Assignee
DAVALL MOULDED GEARS
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 DAVALL MOULDED GEARS filed Critical DAVALL MOULDED GEARS
Priority to GB08203246A priority Critical patent/GB2114701A/en
Publication of GB2114701A publication Critical patent/GB2114701A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C2/00—Rotary-piston machines or pumps
    • F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
    • F04C2/082—Details specially related to intermeshing engagement type machines or pumps
    • F04C2/084—Toothed wheels
    • 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
    • F16H55/00—Elements with teeth or friction surfaces for conveying motion; Worms, pulleys or sheaves for gearing mechanisms
    • F16H55/02—Toothed members; Worms
    • F16H55/17—Toothed wheels
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C2/00—Rotary-piston machines or pumps
    • F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
    • F04C2/12—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
    • F04C2/14—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons
    • F04C2/18—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons with similar tooth forms
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C2230/00—Manufacture
    • F04C2230/20—Manufacture essentially without removing material
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
    • F05C2225/00—Synthetic polymers, e.g. plastics; Rubber

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Rotary Pumps (AREA)

Abstract

A gear wheel or toothed displacement roller (3), and method of manufacturing the same, comprising a central former (7) of a predetermined cross-section with respect to its rotational axis (4) and a preformed, flexible member (8) secured thereto and having radially outwardly extending teeth (9) of a desired pitch. The preformed, flexible member (8) may be keyed (10) to or heat shrunk on to the central former (7). Alternatively, the flexible member (8) can be elastomeric, in which case, it is retained on the former (7) by means of its inherent elasticity. Toothed displacement rollers in accordance with the invention are particularly useful in displacement pumps and the inventive method may be used to manufacture basic and high order gear constructions of many different types, for instance, involute, cycloidal and circular arc, as well as worm, spur and helical configurations. <IMAGE>

Description

SPECIFICATION Toothed gear wheels and displacement rollers This invention relates to gear wheels, toothed displacement rollers and the like and is especially, but not exclusively, related to non-circular gear wheels or toothed displacement rollers.
In the manufacture of non-circular gear wheels the most difficult and expensive operation is the cutting of the gear teeth in accordance with a predetermined configuration for providing a desired output.
This is particularly so where the gear wheels are made of a metallic material which is comparatively hard and requires additional machining and finishing.
An alternative method of manufacturing gear wheels of any desired shape is to mould them from a plastics material which has the desired rigidity and durability.
In accordance with one aspect of the invention, there is provided a method of manufacturing a gear wheel or toothed displacement roller, which method comprises providing a former of a predetermined cross-section with respect to its rotational axis and applying radially with respect thereto a preformed, flexible member having radially extending teeth thereon of a desired pitch.
In accordance with a second aspect of the invention, there is provided a gear wheel or toothed displacement roller comprising a central former of a predetermined cross-section with respect to its rotational axis and a flexible member secured thereto and having radially outwardly extending teeth of a desired pitch.
Preferably, the flexible, toothed member is keyed to the central former, although any other form of securement, such as, adhesive, heat shrinking or the inherent elasticity of the flexible member, may be used.
The flexible toothed member can be made of any suitable flexible material but is preferably formed from a synthetic plastics material which may be elastomeric whereby its inherent elasticity assists in its securement to the central former, as mentioned briefly above.
The teeth of the flexible member are also preferably flexible, in which case, the inventive article is particuiarly suited to use as a displacement roller, in which case, its crosssection can be of any predetermined shape, as will be discussed below with reference to the preferred embodiment which will now be described by way of example and with reference to the accompanying drawing in which: Fig. 1 is a partial sectional, plan view of a displacement pump, and Fig. 2 is a partiai elevational view of the pump shown in Fig. 1.
Referring to the drawing, a displacement pump comprises a housing 1 provided with an inner, cavity 2 of a predetermined shape, in this case, having a substantially double-circular crosssection. Within each half of the cavity 2 is located an elliptically cross-sectioned displacement roller 3 rotatable about a respective axis 4.
Respective inlet and outlet fucts 5, 6 are provided for a pumped fluid.
Each displacement roller 3 comprises a central former 7 of eliptical cross-section and an outer, toothed band 8 which has been preformed from an elastomeric material. Each band 8 is provided with flexible, integral teeth 9 which mesh generally centrally of the cavity 2 between the inlet and outlet ducts 5, 6. Also, these flexible teeth 9 perform a wiping action in engagement with the surface of the cavity 2, to provide fluid sealing therebetween.
As a displacement pump, at least one of the displacement rollers is driven, although the arrangement may also be used as a fluid meter, wherein fluid flowing from the inlet duct 5 to the outlet duct 6 rotates the rollers 3 of which one is connected to any suitable measuring, indicating and/or monitoring apparatus.
As indicated above, each elastomeric, toothed band 8 is keyed to its respective central former 7 at 10, although any other suitable form of securement may be used, for instance, heat shrinking of the band on to the former, the inherent elasticity of the preformed band and/or an adhesive.
The preformed, toothed elastomeric band 8 can be manufactured by any suitable moulding method and is preferably moulded initially in circular form, whereby its natural flexibility and elasticity permits it to be located around any desired shape of central former 7. Thus, it will be appreciated that the invention provides a comparatively simple method of manufacturing basic and high order gear constructions of many different types, for instance, involute, cycloidal and circular arc (Novikor), as well as worm gears.
Spur and helical gear configurations also fall within the scope of the invention, together with gear wheels for harmonic drive systems.
A further application of the present invention is the manufacture of a master mould for electromed reversals, whereby a gear wheel in accordance with the invention and of any predetermined cross-section can have built-up thereon an electric coating, by the usual electromed method, to provide a mould for subsequently forming gear wheels of that particualr shape.
Claims (Filed on 29th Nov 1982).
1. A method of manufacturing a gear wheel or toothed displacement roller, comprising providing a former of a predetermined cross-section with respect to its rotational axis and applying radially with respect thereto a preformed, flexible member having radially extending teeth thereon of a desired pitch.
2. A method according to claim 1, wherein the preformed, flexible member is keyed to the former.
3. A method according to claim 1, wherein the preformed, flexible member is heat shrunk on to the former.
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (14)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Toothed gear wheels and displacement rollers This invention relates to gear wheels, toothed displacement rollers and the like and is especially, but not exclusively, related to non-circular gear wheels or toothed displacement rollers. In the manufacture of non-circular gear wheels the most difficult and expensive operation is the cutting of the gear teeth in accordance with a predetermined configuration for providing a desired output. This is particularly so where the gear wheels are made of a metallic material which is comparatively hard and requires additional machining and finishing. An alternative method of manufacturing gear wheels of any desired shape is to mould them from a plastics material which has the desired rigidity and durability. In accordance with one aspect of the invention, there is provided a method of manufacturing a gear wheel or toothed displacement roller, which method comprises providing a former of a predetermined cross-section with respect to its rotational axis and applying radially with respect thereto a preformed, flexible member having radially extending teeth thereon of a desired pitch. In accordance with a second aspect of the invention, there is provided a gear wheel or toothed displacement roller comprising a central former of a predetermined cross-section with respect to its rotational axis and a flexible member secured thereto and having radially outwardly extending teeth of a desired pitch. Preferably, the flexible, toothed member is keyed to the central former, although any other form of securement, such as, adhesive, heat shrinking or the inherent elasticity of the flexible member, may be used. The flexible toothed member can be made of any suitable flexible material but is preferably formed from a synthetic plastics material which may be elastomeric whereby its inherent elasticity assists in its securement to the central former, as mentioned briefly above. The teeth of the flexible member are also preferably flexible, in which case, the inventive article is particuiarly suited to use as a displacement roller, in which case, its crosssection can be of any predetermined shape, as will be discussed below with reference to the preferred embodiment which will now be described by way of example and with reference to the accompanying drawing in which: Fig. 1 is a partial sectional, plan view of a displacement pump, and Fig. 2 is a partiai elevational view of the pump shown in Fig. 1. Referring to the drawing, a displacement pump comprises a housing 1 provided with an inner, cavity 2 of a predetermined shape, in this case, having a substantially double-circular crosssection. Within each half of the cavity 2 is located an elliptically cross-sectioned displacement roller 3 rotatable about a respective axis 4. Respective inlet and outlet fucts 5, 6 are provided for a pumped fluid. Each displacement roller 3 comprises a central former 7 of eliptical cross-section and an outer, toothed band 8 which has been preformed from an elastomeric material. Each band 8 is provided with flexible, integral teeth 9 which mesh generally centrally of the cavity 2 between the inlet and outlet ducts 5, 6. Also, these flexible teeth 9 perform a wiping action in engagement with the surface of the cavity 2, to provide fluid sealing therebetween. As a displacement pump, at least one of the displacement rollers is driven, although the arrangement may also be used as a fluid meter, wherein fluid flowing from the inlet duct 5 to the outlet duct 6 rotates the rollers 3 of which one is connected to any suitable measuring, indicating and/or monitoring apparatus. As indicated above, each elastomeric, toothed band 8 is keyed to its respective central former 7 at 10, although any other suitable form of securement may be used, for instance, heat shrinking of the band on to the former, the inherent elasticity of the preformed band and/or an adhesive. The preformed, toothed elastomeric band 8 can be manufactured by any suitable moulding method and is preferably moulded initially in circular form, whereby its natural flexibility and elasticity permits it to be located around any desired shape of central former 7. Thus, it will be appreciated that the invention provides a comparatively simple method of manufacturing basic and high order gear constructions of many different types, for instance, involute, cycloidal and circular arc (Novikor), as well as worm gears. Spur and helical gear configurations also fall within the scope of the invention, together with gear wheels for harmonic drive systems. A further application of the present invention is the manufacture of a master mould for electromed reversals, whereby a gear wheel in accordance with the invention and of any predetermined cross-section can have built-up thereon an electric coating, by the usual electromed method, to provide a mould for subsequently forming gear wheels of that particualr shape. Claims (Filed on 29th Nov 1982).
1. A method of manufacturing a gear wheel or toothed displacement roller, comprising providing a former of a predetermined cross-section with respect to its rotational axis and applying radially with respect thereto a preformed, flexible member having radially extending teeth thereon of a desired pitch.
2. A method according to claim 1, wherein the preformed, flexible member is keyed to the former.
3. A method according to claim 1, wherein the preformed, flexible member is heat shrunk on to the former.
4. A method according to claim 1 or 2, wherein the preformed"flexible member is elastomeric and is retained on the former by means of its inherent elasticity.
5. A method of manufacturing a gear wheel or toothed displacement roller substantially as hereinbefore described.
6. A gear wheel or toothed displacement roller when made by a method according to any of claims 1 to 5.
7. A gear wheel of toothed displacement roller comprising a central former of a predetermined cross-section with respect to its rotational axis and a preformed, flexible member secured thereto and having radially outwardly extending teeth of a desired pitch.
8. A wheel or roller according to claim 8, wherein the preformed, flexible member is keyed to the central former.
9. A wheel or roller according to claim 7, wherein the preformed, flexible member is heat shrunk on to the central former.
10. A wheel or roller according to claim 7 or 8, wherein the preformed, flexible member is elastomeric and is retained on the former by means of its inherent elasticity.
11. A gear wheel or toothed displacement roller substantially as hereinbefore described with reference to the accompanying drawing.
12. A gear assembly or displacement pump incorporating at least one gear wheel or toothed displacement roller according to any of claims 7 to 11.
13. A displacement pump according to claim 12 comprising two toothed displacement rollers rotatably mounted on parallel axes in meshing relationship with each other and in sealing engagement with respective portions of the inner surface of a cavity in the pump housing, the crosssection of each roller being elliptical and the rollers having their major axes perpendicular to each other.
14. A method of manufacturing a master mould for electromed reversals comprising providing on the exterior surface of a gear wheel or toothed displacement roller, according to any of claims 6 to 11, an electromed coating and subsequently casting mould from the coated wheel or roller.
GB08203246A 1982-02-04 1982-02-04 Toothed gear wheels and displacement rollers Withdrawn GB2114701A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB08203246A GB2114701A (en) 1982-02-04 1982-02-04 Toothed gear wheels and displacement rollers

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB08203246A GB2114701A (en) 1982-02-04 1982-02-04 Toothed gear wheels and displacement rollers

Publications (1)

Publication Number Publication Date
GB2114701A true GB2114701A (en) 1983-08-24

Family

ID=10528114

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08203246A Withdrawn GB2114701A (en) 1982-02-04 1982-02-04 Toothed gear wheels and displacement rollers

Country Status (1)

Country Link
GB (1) GB2114701A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6644947B2 (en) * 2002-03-14 2003-11-11 Tuthill Corporation Wave tooth gears using identical non-circular conjugating pitch curves
US10954939B2 (en) 2015-10-30 2021-03-23 Cytiva Sweden Ab Gear pumps

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6644947B2 (en) * 2002-03-14 2003-11-11 Tuthill Corporation Wave tooth gears using identical non-circular conjugating pitch curves
US10954939B2 (en) 2015-10-30 2021-03-23 Cytiva Sweden Ab Gear pumps

Similar Documents

Publication Publication Date Title
US5163826A (en) Crescent gear pump with hypo cycloidal and epi cycloidal tooth shapes
US2362106A (en) Laminated gear pump
US5120204A (en) Helical gear pump with progressive interference between rotor and stator
HU186334B (en) Volumetric displacement screw compressor
GB1597011A (en) Rotary positive displacement flow meter
GB1580241A (en) Hydrostatic gear machine
US2897765A (en) Driving apparatus comprising modified elliptic gear wheels
US4552030A (en) Gear drive
GB2114701A (en) Toothed gear wheels and displacement rollers
JP6434914B2 (en) Geared hydraulic machine and related gears
US20100021332A1 (en) Screw pump
US2530173A (en) Helical interengaging impellers blower
GB2139313A (en) Toothed gearwheels and displacement rollers
US2336479A (en) Pump construction
US2952216A (en) Rotary screw unit for displacing fluid
CN110748626A (en) Gear capable of reducing meshing noise
US2498848A (en) Gear unit
US5135373A (en) Spur gear with epi-cycloidal and hypo-cycloidal tooth shapes
CN106224237B (en) Gear pump flank profil molded line determines method and crescent gear pump
EP0381413A2 (en) Helical gear pump
ATE34029T1 (en) GEARBOX WITH HYPOCYCLOIDAL DRIVE.
ATE139305T1 (en) SHAFTLESS INTERNAL GEAR PUMP WITH SEALING ELEMENTS INSERTED INTO THE GEAR HEADS
GB2037372A (en) Rotary Positive-displacement Fluid-machines
GB2170863A (en) Rotary positive displacement pump or motor
CN220416153U (en) Worm wheel

Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)