CA1128782A - Friction drive wheels - Google Patents
Friction drive wheelsInfo
- Publication number
- CA1128782A CA1128782A CA343,571A CA343571A CA1128782A CA 1128782 A CA1128782 A CA 1128782A CA 343571 A CA343571 A CA 343571A CA 1128782 A CA1128782 A CA 1128782A
- Authority
- CA
- Canada
- Prior art keywords
- friction drive
- drive wheel
- spokes
- spoke
- central hub
- 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.)
- Expired
Links
Classifications
-
- 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
- F16H55/32—Friction members
- F16H55/34—Non-adjustable friction discs
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Tires In General (AREA)
Abstract
ABSTRACT
A friction drive wheel suitable for high impressed loads has a central hub in which are mounted a plurality of resilient spokes.
The spokes over at least a portion of their length exhibit curvature in a plane normal to the axis of the wheel and may be tapered towards their free end to modify the stress/strain relationship.
A suitable tyre for the wheel has stepped projections which engage the ends of the spokes.
A friction drive wheel suitable for high impressed loads has a central hub in which are mounted a plurality of resilient spokes.
The spokes over at least a portion of their length exhibit curvature in a plane normal to the axis of the wheel and may be tapered towards their free end to modify the stress/strain relationship.
A suitable tyre for the wheel has stepped projections which engage the ends of the spokes.
Description
87~2 Description ~ his invention relates to friction drive wheels and, In particular, to wheels suitable for deriving motive powex from tranælational movement to drive high pressure hydraulic pumps, electrical generators and like potential energy sources.
~riction drive wheels are known in many applications for the conversion of translational movement into other fo~ms of energy and vice versa. ~or example, a knurled wheel which ~ esses against the pneumatic t~re is employed to drive the lighting dynamo of a pedal cycls. In our co-pending Canadian ~pplication ~o. 308,407 we describe a hydraulic braking system for a pipeline in~pection pig which employs a friction wheel bearing against the wall of a pipeline. The wheel rotateæ as the pig traverses the pipeline ~nd drives a high pres6uxe hydraulic pump which, in turn, actuate~ a ~ervo-controlled braking system to limit the speed at ~hibh ~he pig t.ravels.
p rticularly in applications such as the latter~ it i~
necessary to apply a large force to urge the friction wheel ~o ~ rds the pipeline wall to prevent the occurrence of slipping. lf a conventional solid wheel with an elastomeric tyre were employed, there would be a subst~ntial deformation of the tyre and he~c~ high .~
7E~2 losses due to hysteris. This would create high heat dissipation and would result in rapid degradation of the elastomeric wheel.
In order ~o overcome this difficulty, a wheel structure has been devised in which a relatively thin elastom-eric tyre is mounted on spokes having a curved section so that radial deformation causes flexure of the spoke. The inherent elasticity of the spokes gives rise to a force normal to the driven surface of the wheel.
- Accordingly, the present invention provides a friction drive wheel which comprises, a central hub, a plurality of fexible spokes extending from their inner ends outwardly from said central hub to their outer ends, at least a portion of each spoke being curved in a plane extending normally to the central hub, and a rim mounted around and in direct abutting contact with the outer ends of said flexible spokes, said rim being made of a resilient material.
An embodiment of the invention will now be described by way of example with reference to the acco~panying drawings in which:
Figure 1 shows in partial section a side ~iew of a friction drive wheel and tyre, Figure 2 shows a cross-section along the line X-X of Figure 1, and ~- : . .: . . - :: . :
, : : : . .: ' :~ : , Figure 3 ~hows an enlarged side view of a spoke taken from the wheel shown m ~igure 1.
Referring now to the drawings, a friction drive wheel has a central hub 1. Mounted in slots 2 in the hub are twenty four spokes 3. ~he ends of the spokes have a groove 4 in each of the outer edges.
Mounted on the hub by means of bolts 5 are two flanges 6 which have inward facing projections 7 which engage -the complementary grooves on the spokes and act as retaining members.
~he spoked wheel is provided with an elastomeric tyre 8 which is fabricated from a resilient polymeric material ~uch as polyurethane or nitrile rubberO It may be moulded using a split outer molll d with a solid inner core, and needs no fabric reinforcement) although this may be provided to enhance the strength and durability. ~he tread of the tyre has sipes 9 to improve the grip on the surface of the pipeline.
On`the inner surface of the tyre cArcase is a se~ies of inward projecting step~ 10 which co-operate with the ends 11 of the spokee to impro~re traction.
~he design of the spokes is shown in elevation in grea~er detai1 in Figure ~. Indicated on the drawing are the dimen~ion~ in millimetres of a spoke suitable for a friction drive wheel for use with an hydraulic pump to be mounted on an inspection pig for gas pipelines.
.,, ~ :, ~
- 5 ~ 1 2 ~ 8 ~
The spoke has a straight, relatively thick root end section 12, which locates in the grooves of the hub. ~his straigh~ ~ectiorl, when mounted, projects in a radial direction for a short distance and then bends at an angle of approximately sixty degrees (58.7 in the embodiment). Over the remainder of its length, the spoke exhibits a curvature in a plane normal to the ~'s of the wheel. ~he radius of cu~vature i6 approximately two-thirds of the radius of the wheel.
Over the curved portionl the æpoke section tapers gradually, the free end being approximately 0.4 times the thickness of the root end. ~he free end is rounded to reduce wear on the inner surface of the tyre.
In operation the load is carried on three of the twenty four spokes.
~he spokes carry a tangential load as well as the normal load. ~n important factor of the shape is that, since the spokes are interleaved in a spiral arrangement, a large proportion of the volume of the wheel i8 occupied, thus improving the performance.
A friction wheel such as has been described is particularly suitable for dri~ing a high-pres~ure pump for a servo-controlled braking system for an inspection pig used in gas pipelines. ~he form of construction is, however, of more general application and may be used in other situations where a high stress is to be applied normal to the bearing surface. It may also be used where some form of springing is to be a~plied to the impressed load and even for simple traction applications. ~
~riction drive wheels are known in many applications for the conversion of translational movement into other fo~ms of energy and vice versa. ~or example, a knurled wheel which ~ esses against the pneumatic t~re is employed to drive the lighting dynamo of a pedal cycls. In our co-pending Canadian ~pplication ~o. 308,407 we describe a hydraulic braking system for a pipeline in~pection pig which employs a friction wheel bearing against the wall of a pipeline. The wheel rotateæ as the pig traverses the pipeline ~nd drives a high pres6uxe hydraulic pump which, in turn, actuate~ a ~ervo-controlled braking system to limit the speed at ~hibh ~he pig t.ravels.
p rticularly in applications such as the latter~ it i~
necessary to apply a large force to urge the friction wheel ~o ~ rds the pipeline wall to prevent the occurrence of slipping. lf a conventional solid wheel with an elastomeric tyre were employed, there would be a subst~ntial deformation of the tyre and he~c~ high .~
7E~2 losses due to hysteris. This would create high heat dissipation and would result in rapid degradation of the elastomeric wheel.
In order ~o overcome this difficulty, a wheel structure has been devised in which a relatively thin elastom-eric tyre is mounted on spokes having a curved section so that radial deformation causes flexure of the spoke. The inherent elasticity of the spokes gives rise to a force normal to the driven surface of the wheel.
- Accordingly, the present invention provides a friction drive wheel which comprises, a central hub, a plurality of fexible spokes extending from their inner ends outwardly from said central hub to their outer ends, at least a portion of each spoke being curved in a plane extending normally to the central hub, and a rim mounted around and in direct abutting contact with the outer ends of said flexible spokes, said rim being made of a resilient material.
An embodiment of the invention will now be described by way of example with reference to the acco~panying drawings in which:
Figure 1 shows in partial section a side ~iew of a friction drive wheel and tyre, Figure 2 shows a cross-section along the line X-X of Figure 1, and ~- : . .: . . - :: . :
, : : : . .: ' :~ : , Figure 3 ~hows an enlarged side view of a spoke taken from the wheel shown m ~igure 1.
Referring now to the drawings, a friction drive wheel has a central hub 1. Mounted in slots 2 in the hub are twenty four spokes 3. ~he ends of the spokes have a groove 4 in each of the outer edges.
Mounted on the hub by means of bolts 5 are two flanges 6 which have inward facing projections 7 which engage -the complementary grooves on the spokes and act as retaining members.
~he spoked wheel is provided with an elastomeric tyre 8 which is fabricated from a resilient polymeric material ~uch as polyurethane or nitrile rubberO It may be moulded using a split outer molll d with a solid inner core, and needs no fabric reinforcement) although this may be provided to enhance the strength and durability. ~he tread of the tyre has sipes 9 to improve the grip on the surface of the pipeline.
On`the inner surface of the tyre cArcase is a se~ies of inward projecting step~ 10 which co-operate with the ends 11 of the spokee to impro~re traction.
~he design of the spokes is shown in elevation in grea~er detai1 in Figure ~. Indicated on the drawing are the dimen~ion~ in millimetres of a spoke suitable for a friction drive wheel for use with an hydraulic pump to be mounted on an inspection pig for gas pipelines.
.,, ~ :, ~
- 5 ~ 1 2 ~ 8 ~
The spoke has a straight, relatively thick root end section 12, which locates in the grooves of the hub. ~his straigh~ ~ectiorl, when mounted, projects in a radial direction for a short distance and then bends at an angle of approximately sixty degrees (58.7 in the embodiment). Over the remainder of its length, the spoke exhibits a curvature in a plane normal to the ~'s of the wheel. ~he radius of cu~vature i6 approximately two-thirds of the radius of the wheel.
Over the curved portionl the æpoke section tapers gradually, the free end being approximately 0.4 times the thickness of the root end. ~he free end is rounded to reduce wear on the inner surface of the tyre.
In operation the load is carried on three of the twenty four spokes.
~he spokes carry a tangential load as well as the normal load. ~n important factor of the shape is that, since the spokes are interleaved in a spiral arrangement, a large proportion of the volume of the wheel i8 occupied, thus improving the performance.
A friction wheel such as has been described is particularly suitable for dri~ing a high-pres~ure pump for a servo-controlled braking system for an inspection pig used in gas pipelines. ~he form of construction is, however, of more general application and may be used in other situations where a high stress is to be applied normal to the bearing surface. It may also be used where some form of springing is to be a~plied to the impressed load and even for simple traction applications. ~
Claims (13)
1. A friction drive wheel which comprises, a central hub, a plurality of flexible spokes extending from their inner ends outwardly from said central hub to their outer ends, at least a portion of each spoke being curved in a plane extending normally to the central hub, and a rim mounted around and in direct abutting contact with the outer ends of said flexible spokes, said rim being made of a resilient material.
2. A friction drive wheel as claimed in Claim 1, wherein said central hub includes slots around its outer periphery, the inner ends of said spokes being substantially straight and dimensioned to fit within a respective slot.
3. A friction drive wheel as claimed in Claim 2, wherein the curved portion of each spoke is bent at an angle to the substantially straight inner end.
4. A friction drive wheel as claimed in Claim 3 wherein the curved portion of each spoke is bent at an angle of approximately 60° to the substantially straight inner end.
5. A friction drive wheel as claimed in Claim 2, wherein the inner ends of each spoke includes a groove therein and wherein flanges are connected to the central hub which include inwardly facing projections which are engageable with the grooves of the spokes to retain the inner end of the spokes in the slots of the central hub.
6. A friction drive wheel as claimed in Claim 1, wherein the curved portion of each spoke decreases in thickness as it extends away from the substantially straight inner end.
7. A friction drive wheel as claimed in Claim 6, wherein the curved portion of each spoke extends outwardly to its outer end.
8. A friction drive wheel as claimed in Claim 7, wherein the radius of ourvature of the curved portion of each spoke is about 2/3 the radius of the friction drive wheel.
9. A friction drive wheel as claimed in Claim 1, wherein said resilient rim has an inner surface and an outer surface, and wherein the inner surface includes step-like projections against which the outer ends of the spokes abut.
10. A friction drive wheel as claimed in Claim 9 wherein said resilient rim includes sipes in its outer surface to improve traction.
11. A friction drive wheel as claimed in Claim 1, wherein said resilient material forming said rim is a resilient polymeric material.
12. A friction drive wheel as claimed in Claim 11, wherein said resilient polymeric material is selected from the group consisting of polyurethane and nitrile rubber.
13. A friction drive wheel as claimed in Claim 1, wherein the spokes occupy at least one half of the total volume of the annular space between the central hub and the resilient rim.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7905774 | 1979-02-19 | ||
| GB7905774A GB2042674B (en) | 1979-02-19 | 1979-02-19 | Friction drive wheel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1128782A true CA1128782A (en) | 1982-08-03 |
Family
ID=10503277
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA343,571A Expired CA1128782A (en) | 1979-02-19 | 1980-01-14 | Friction drive wheels |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA1128782A (en) |
| GB (1) | GB2042674B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4603839A (en) * | 1983-05-27 | 1986-08-05 | Igelfors Bruks Ab | Device for transport or displacement of elongated objects in particular, as well as a pulling or traction wheel comprised in said device |
| JP5930941B2 (en) | 2012-10-31 | 2016-06-08 | 株式会社ブリヂストン | Non pneumatic tire |
-
1979
- 1979-02-19 GB GB7905774A patent/GB2042674B/en not_active Expired
-
1980
- 1980-01-14 CA CA343,571A patent/CA1128782A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| GB2042674B (en) | 1983-02-16 |
| GB2042674A (en) | 1980-09-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10703140B2 (en) | Wheel assemblies with non-pneumatic tires | |
| US3907370A (en) | Plastic wheel construction for utility vehicles | |
| US3836201A (en) | Wheel assemblies | |
| CA2532099A1 (en) | Compliant wheel | |
| IE790716L (en) | Radial tyres. | |
| CA1128782A (en) | Friction drive wheels | |
| FI64913C (en) | KOMBINATION AV DAECK OCH HJUL | |
| US4046182A (en) | Safety tire and wheel assemblies | |
| US20050067079A1 (en) | Demountable tire rim with a spare inner wheel and tire for said tire rim | |
| JP2021037944A (en) | Non-pneumatic tire and wheel assembly with integrated spoke structure | |
| GB1491005A (en) | Assembly of a pneumatic tyre and wheel rim | |
| US4370895A (en) | Friction drive wheels | |
| JPS5965667A (en) | Low friction composite pulley made of plastic with thin typehub | |
| FR2265555A1 (en) | Reinforced light alloy wheel rim - with high tensile fibres or cords moulded radially inside rim | |
| GB2187685A (en) | Bead retaining rims for vehicle tyres | |
| ES2008981A6 (en) | Cable drum which can be dismantled | |
| CA1309881C (en) | Pulley tyre rim configuration | |
| CN221090388U (en) | Tire structure | |
| US4122881A (en) | Gripping shoes for vehicle wheels | |
| CN217726958U (en) | Straightening wheel for steel cord straightener | |
| CN216268494U (en) | Tire capable of improving abrasion and braking performance | |
| CN218986254U (en) | Heavy-duty mechanical tire tread structure | |
| US20210009090A1 (en) | Magnetic Brake Assist,Traction Control and Forward Assist | |
| US20070187298A1 (en) | Vehicle wheel, in particular for cycles | |
| EP0452083A2 (en) | Linear cable engines |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |