Track wheel and elastic body for such a track wheel

Abstract

The present invention relates to a multi-part track wheel with a wheel tyre, with a wheel rim and with at least two elastic bodies arranged between the wheel tyre and the wheel rim, via which the wheel tyre is supported spring elastically on the wheel rim and which are arranged distributed in the circumferential direction around the rotary axis of the track wheel, wherein the elastic bodies are clamped between an inner circumferential surface of the wheel tyre and an outer circumferential surface of the wheel rim and in this case abut with their outer side assigned to the wheel tyre on the inner circumferential surface of the wheel tyre and with their inner side assigned to the wheel rim on the outer circumferential surface of the wheel rim and an elastic body for use in a track wheel. The track wheel according to the invention designed according to the one-ring concept provides an optimised low spring constant and the elastic body as an essential component for the spring properties allows the manufacture of a one-ring track wheel with optimised usage properties. This is achieved in that the elastic bodies are locked against a movement in the circumferential direction by forming elements provided in each case on the inner circumferential surface of the wheel tyre and/or on the outer circumferential surface of the wheel rim.

Claims

1. A multi-part track wheel with a wheel tyre, with a wheel rim and with at least two elastic bodies arranged between the wheel tyre and the wheel rim, through which the wheel tyre is supported elastically on the wheel rim and which are arranged in the circumferential direction around the rotary axis of the track wheel, wherein the elastic bodies are clamped between an inner circumferential surface of the wheel tyre and an outer circumferential surface of the wheel rim and abut with outer sides of the elastic bodies assigned to the wheel tyre on the inner circumferential surface of the wheel tyre and with inner sides of the elastic bodies assigned to the wheel rim on the outer circumferential surface of the wheel rim, wherein the elastic bodies are locked against a movement in the circumferential direction by forming elements provided on the inner circumferential surface of the wheel tyre and/or on the outer circumferential surface of the wheel rim, wherein a number of the elastic bodies have, on the outer side or inner side of the elastic bodies, at least one forming element, which interacts at least in the circumferential direction in a positive-locking manner with one of the forming elements present on the inner circumferential surface of the wheel tyre or the outer circumferential surface of the wheel rim; wherein each of the at least two elastic bodies has one end section on the ends of the elastic body viewed in opposition to the axial direction aligned axially-parallel to the rotary axis of the track wheel and in that a trough is formed between the end sections into the outer side of each of the at least two elastic bodies on whose base a projection forming the forming element of each of the at least two elastic bodies is established.

2. The track wheel according to claim 1, wherein at least 20% of the elastic bodies are provided on the outer sides of the elastic bodies with the forming element.

3. The track wheel according to claim 1, wherein the forming elements provided on the inner circumferential surface of the wheel tyre are recesses formed into the inner circumferential surface and at least one projection interacting in a positive-locking manner with one of these recesses is present as the forming element on the outer side of the elastic bodies provided with such a forming element.

4. The track wheel according to claim 1, wherein seat surfaces for the elastic bodies are formed on the outer circumferential surface of the wheel rim.

5. The track wheel according to claim 4, wherein the seat surfaces are delimited by webs which are aligned axially-parallel to the rotary axis of the track wheel.

6. The track wheel according to claim 5, wherein the webs are formed by boundary elements held on the wheel rim.

7. The track wheel according to claim 4, wherein the seat surfaces are arranged in depressions formed into the outer circumferential surface of the wheel rim.

8. The track wheel according to claim 7, wherein the depressions are delimited by side surfaces, which form a spatial polygon and together form the respective seat surface.

9. The track wheel according to claim 7, wherein the side surfaces delimiting the depressions are vaulted.

10. The track wheel according to claim 1, wherein the height of the elastic bodies is lower by 7-29% in the state clamped between the wheel tyre and wheel rim than the height of the elastic bodies in the fully unloaded new state.

11. The track wheel according to claim 1, wherein the elastic bodies consist of an elastomer material with a shore hardness of 65 to 89 ShA.

12. Elastic bodies for use in a track wheel comprising a wheel tyre and a wheel rim and at least two elastic bodies, through which the wheel tyre is elastically supported by a spring on the wheel rim, wherein the elastic body has a block-shaped base form with end side front sides of which one is assigned to one of the front sides of the track wheel, longitudinal sides extending laterally between the front sides, an outer side assigned to the wheel tyre, also extending between the front sides and meeting at longitudinal edges of the outer side with the longitudinal sides and an inner side opposed to the outer side, which is assigned to the wheel rim of the track wheel, wherein the elastic body is provided, on the outer side of the elastic body assigned to the wheel tyre, with a forming element, which is provided to interact with a correspondingly shaped forming part on the inner circumferential surface of the wheel tyre in a positive-locking manner; wherein each of the at least two elastic bodies has one end section on the ends of the elastic body viewed in opposition to the axial direction aligned axially-parallel to the rotary axis of the track wheel and in that a trough is formed between the end sections into the outer side of each of the at least two elastic bodies on whose base a projection forming the forming element of each of the at least two elastic bodies is established.

13. The elastic body according to claim 12, wherein the projection extends in the axial direction between the end sections of the respective elastic body.

14. The elastic body according to claim 12, wherein the projection is formed in a semi-circular shape viewed in a section transverse to the axial direction.

15. The elastic body according to claim 12, wherein the slopes, with which the end sections merge into the trough delimited between the slopes, are curved continuously without cracks.

16. The elastic body according to claim 14, wherein the longitudinal sides of the elastic body are vaulted.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained in greater detail below based on a drawing representing exemplary embodiments. They show in each case schematically in:

(2) FIG. 1 a track wheel in frontal view;

(3) FIG. 2 a first elastic body in perspective view from above;

(4) FIG. 3 a second elastic body in perspective view from above;

(5) FIG. 4a the elastic body according to FIG. 3 in a section along the section line A-A drawn into FIG. 3;

(6) FIG. 4b the elastic body according to FIG. 3 in a side view;

(7) FIG. 4c the elastic body according to FIG. 3 in a plan view from above;

(8) FIG. 5 a wheel tyre of the track wheel represented in FIG. 1 in a perspective view;

(9) FIG. 6 the elastic body according to FIG. 2 in a section along the section line B-B drawn into FIG. 2;

(10) FIG. 7 a partially interrupted cut-out C of the wheel tyre represented in FIG. 5 in a frontal view;

(11) FIG. 8 the elastic body according to FIG. 2 in the uncompressed new state (solid lines) and in the compressed installation state (dashed lines) in each case in side view;

(12) FIG. 9a-9c variants of wheel rims of the track wheel represented in FIG. 1 in each case in perspective view;

(13) FIG. 10a-10d cut-outs of different track wheels in conventional constructions in each case in a longitudinal section;

(14) FIG. 11 a cut-out of a wheel rim in a longitudinal section;

(15) FIG. 12 cross-sectional shapes of boundary elements.

DESCRIPTION OF THE INVENTION

(16) The track wheel 1 represented in FIG. 1 comprises a wheel rim 2 and a wheel tyre 3, which is supported via elastic bodies 4 arranged between the wheel rim 2 and the wheel tyre 3. The elastic bodies 4 are also arranged distributed at even angular distances around the central rotary axis X of the track wheel 1 in the gap present between the wheel rim 2 and the wheel tyre 3.

(17) The base structure of the track wheel 1 corresponds to the “two-part” structure of a track wheel known under the designation “BO54” and offered by the applicant, whose longitudinal section is represented in sections in FIG. 10a. The elastic bodies EK are pressed there between the wheel tyre RR and the wheel rim RF such that the wheel tyre RR is fixed in the circumferential direction UR by the pressure forces acting in the radial direction RR in a force-fitting manner on the wheel rim RF. At the same time, the elastic bodies EK are secured against displacement in the axial AR direction by a shoulder 30, 31 circulating in each case around the respective front side-edge of the wheel rim RF. The three other known track wheels “BO84”, “BO2000” and BO06” shown in FIGS. 10b, 10c and 10d and also offered by the applicant are variants of three-part track wheels in the case of which, in addition to the wheel tyre and the wheel rim, a tension ring for pre-tensioning the elastic bodies supporting the wheel tyre on the wheel rim is provided as a third element consisting of metal. The radial spring stiffness is in the case of the track wheel BO54 roughly 80 kN/mm, in the case of the track wheel BO84 roughly 100 kN/mm, in the case of the track wheel BO2000 roughly 200 kN/mm and in the case of the track wheel BO06 roughly 240 kN/mm.

(18) The elastic bodies 4 consist of an elastomer material that has proven reliable for this purpose in practice, e.g. made of natural rubber (NR) with a shore hardness of 65-88 ShA and are shaped in each case in one piece.

(19) As represented for their two variants 4′ and 4″ shown in FIGS. 2 and 3, the elastic bodies 4 in each case have a square-shaped base form with two end side front sides 5, 6 opposite one another of which in each case one is assigned to one of the front sides of the track wheel 1, with two longitudinal sides 7, 8 extending laterally between the front sides 5, 6, with an outer side 9 assigned to the wheel tyre 3, also extending between the front sides 5, 6 and meeting at its longitudinal edges with the longitudinal sides 7, 8 and an inner side 10 opposed to the outer side 9, which is assigned to the wheel rim 2 of the track wheel 1.

(20) An end section 11, 12 is in each case formed adjoining the front sides 5, 6 on the outer side 9 of the elastic bodies 4′, 4″, which in each case merges in a continuously crack-free curved slope 13, 14 into a trough 15 delimited by the end sections 11, 12.

(21) Proceeding from the base of the trough 15, a forming element 16 is formed in the shape of a projection extending in the longitudinal direction L of the respective elastic body 4′, 4″. The forming element 16 in this case has the shape of a half cylinder with a semi-circular shaped cross-sectional shape (FIG. 4) and takes in the width BR of the elastic body 4′, 4″ in the region of the deepest point of the trough 15 up to a small undersize.

(22) In the case of the installation, the elastic bodies 4 are compressed in the vertical direction HR such that their height HvK in the completely mounted state is shorter by a height value Hv than their height HgK in the uncompressed new state (FIG. 8). Irrespective of which variant 4′, 4″ is installed, the height HvK of the completely mounted elastic body 4 is roughly 71-93% of the height HgK (Hv=0.07 . . . 0.29 HgK).

(23) In order to receive material displaced during this compression and to ensure a substantially block-shaped design in the case of the completely mounted elastic bodies 4, the longitudinal sides 7, 8 and the front sides 5, 6 are slightly vaulted in each case in the new state in the case of variant 4″. As a result of the tensioning, the elastic bodies 4 designed according to variant 4″ are deformed such that their longitudinal sides 7, 8 and front sides 5, 6 are shaped substantially straight and flat and optimal spring properties are ensured.

(24) The wheel tyre 3 is shaped from a steel material proven for this purpose in practice and has an inner circumferential surface 17 which is subdivided into two circulating edge regions 17′, 17″. The edge regions 17′, 17″ run in each case starting from the front side of the wheel tyre 3 assigned to them in each case in a pitched roof manner towards one another and meet in the centre of the length LI of the inner circumferential surface 17 measured in the axial direction AR. Channel-shaped recesses 19 shaped in the manner of a cylinder half shell are formed at regular angular distances into the protrusion formed on the inner circumference of the opening 18 enclosed by the wheel tyre 3 and circulating around the opening 18, said recesses extending in the axial direction AR over the length LI of the inner circumferential surface 17 and whose depth is selected such that the channel-shaped recesses 19 run out close to the respective front side of the wheel tyre 3 with their front side ends.

(25) The cross-sectional radius rH of the forming element 16 (FIG. 6) provided in each case on the elastic bodies 4 and the cross-sectional radius rA of the recess 19 are matched to one another such that they meet the condition 0.75 rA≤rH≤0.98 rA. In this manner, in the case of the uncompressed elastic bodies 4, there is lateral clearance between their forming elements 16 and the recesses 19, said lateral clearance being filled by the material of the forming element when the elastic bodies 4 are compressed between the wheel tyre 3 and the wheel rim 2.

(26) Seat surfaces 21 are formed on the outer circumferential surface 20 of the wheel rim 2 at angular distances corresponding to the arrangement of the recesses 19.

(27) In the case of the variant 2′ of the wheel rim 2 shown in FIG. 9a, the seat surfaces 21′ are formed as flat surfaces which abut on one another in each case in a border such that the outer circumferential surface 20 has a polygonal design in this variant 2′. In this case, the outer circumferential surfaces 20′ and with them the seat surfaces 21′ are in each case divided into two edge regions 22′, 22″ which run towards one another in a V shape in the direction of the rotary axis X of the track wheel 1.

(28) In the case of the variant 2″ of the wheel rim 2 shown in FIG. 9b, the seat surfaces 21″ are formed, in contrast, as flat surfaces aligned axially-parallel to the rotary axis X, which are in each case separated from one another by an border region 23. The inner circumferential surface 17 also consequently has a polygonal design here.

(29) In the case of the variant 2″′ of the wheel rim 2 shown in FIG. 9c, the seat surfaces 21″′ are formed by the side surfaces 24 of recesses 25 formed into the material of the wheel rim 2. The four side surfaces 24 are shaped and aligned such that they form a spatial polygon directed into the material of the wheel rim 2 and together form the respective seat surface 21″′. In this case, the side surfaces 24 aligned opposite one another in the axial direction AR are vaulted in order to achieve the most secure and centred seat of the respective elastic body 4 on the seat surface 2″′.

(30) In the case of the variant 2″′ of the wheel rim 2, webs 26 are in each case provided between the recesses 25, which extend axially-parallel to the rotary axis X and delimit the recesses 25 in the manner of compartments. The webs 26, in this manner, form stops by means of which the elastic bodies 4 in each case sitting in the recesses 25 are fixed in the axial direction AR and circumferential direction UR.

(31) Alternatively, the webs can also be formed by locking pins serving as boundary elements 27, which are inserted through recesses 28, 29 formed as through openings in order to be inserted into shoulders 30, 31 circulating the front side edges of the outer circumferential surface 20. The boundary elements 27 are optimally shaped such that they have a minimised notch effect in the region of their contact surface with the elastic bodies 4 supported thereon in each case. To this end, they can have a rounded, circular or ellipsoid cross-sectional shape (FIG. 12).

(32) If the wheel rims, the wheel tyres and the elastic bodies are reconstructed in the case of the known track wheel constructions BO54, BO84, BO2000 and BO06 (see FIGS. 10a-10d) in the manner according to the invention explained above, a reduction of the spring stiffness by up to 60% can be achieved with unchanged high protection against rotation of the wheel tyre relative to the wheel rim taking place in the circumferential direction.

REFERENCE NUMERALS

(33) 1 track wheel 2 wheel rim 2′,2″,2″′ variants of the wheel rim 2 3 wheel tyre 4 elastic body 4′,4″ variants of the elastic body 4 5,6 front sides of the elastic body 4 7,8 longitudinal sides of the elastic body 4 9 outer side of the elastic body 4 10 inner side of the elastic body 4 11,12 end sections of the elastic body 4 13,14 slopes of the elastic body 4 15 trough 16 forming element (projection) 17 inner circumferential surface 17′,17″ circulating edge regions of the inner circumferential surface 17 18 opening enclosed by the wheel tyre 3 19 recesses 20 outer circumferential surface of the wheel rim 2 21 seat surfaces 21′,21″,21″′ variants of the seat surface 21 22′,22″ edge regions 23 border region 24 side surfaces 25 recesses (depressions) 26 webs 27 boundary elements 28,29 recesses 30,31 shoulders AR axial direction BR width of the elastic body 4 EK elastic body RR wheel tyre RF wheel rim HR vertical direction HvK height of the elastic body 4 in the completely mounted state Hv height value HgK height of the elastic body 4 in the uncompressed new state L longitudinal direction of the elastic body 4 LI length of the inner circumferential surface 17 rA cross-sectional radius of the recess 19 rH cross-sectional radius of the forming element 16 UR circumferential direction X central rotary axis of the track wheel 1