ITUA20163929A1 - ASSEMBLY ASSEMBLY FOR THE PAIRING OF A TREE AND A PINION - Google Patents

Description

DESCRIPTION

Field of application

[0001] The present invention is generally applicable to the technical sector of mechanical coupling systems for the transmission of motion and particularly has as its object a locking assembly for coupling a shaft and a pinion.

State of the art

[0002] It has been known for some time in the sector of systems for coupling mechanical components to use shrink disc assemblies for coupling a motorized solid shaft with another motion transmission element, for example a further hollow shaft, a pinion or pulley.

[0003] These known assemblies include shrink disks which allow the solid shaft to be coupled in rotation with the motion transmission element, exerting a radial compression capable of preventing the relative rotation of one with respect to the other .

[0004] In particular, the aforementioned locking assemblies comprise at least a pair of rings that can be removably anchored to the shaft and to the motion transmission element and can be coupled together by means of suitable connecting members, for example screws and / or bolts.

[0005] These shrink discs ensure the coupling of the solid shaft with the motion transmission element within a certain range of driving torque applied to one of the two elements.

[0006] A first drawback of these locking assemblies is represented by the fact that they allow a stable and efficient coupling between the shaft and the motion transmission element only for substantially constant and particularly reduced driving torques.

[0007] Furthermore, a further drawback is represented by the fact that the driving torque is also transmitted through the connecting members, which therefore tend to wear out in particularly short times and require continuous maintenance.

[0008] To overcome these drawbacks, locking assemblies have been developed in which the components of the locking device are coupled to each other or to the motion transmission elements by means of respective toothings.

[0009] From DE102012012012 a shrink disc assembly is known for coupling a hollow shaft with a solid motor shaft comprising an inner ring coupled to the solid shaft and an outer ring coupled to the hollow shaft.

[0010] The two rings have respective portions facing each other in which a plurality of mutually interacting teeth are obtained and adapted to transfer the rotary motion associated with the solid shaft from the inner ring to the outer ring.

[0011] In addition, the inner ring is mounted fixed on the solid shaft by means of an axial keying while the outer ring is rotatably mounted on a bearing whose internal flange is inserted on the end of the solid shaft.

[0012] A first drawback of this solution is represented by the fact that this locking assembly allows to increase the tolerated driving torque only to a limited extent before this affects the stability of the coupling between the two shafts.

[0013] Furthermore, a further drawback is represented by the fact that the centering of the shrink disc rings on the shafts is particularly complex at the time of assembly and assembly of the same.

[0014] Another drawback is represented by the fact that the internal components of the shrink disc are difficult to access by the operator following its installation on the shafts, and this makes the assembly disassembly and / or maintenance operations particularly complex.

[0015] Taken together, these drawbacks lead to an increase in the overall disassembly / disassembly times of the assembly by the operator and require particular skill and attention from the latter during the aforementioned phases.

Technical problem

[0016] In light of the known state of the art, the technical problem that the present invention aims to solve is that of providing a locking assembly which allows coupling a shaft to a pinion even in the presence of particularly high driving torques and is easily assembled and removable by an operator.

Presentation of the invention

[0017] The purpose of the present invention is to overcome the drawbacks encountered above, by providing a locking assembly for the coupling of a shaft with a pinion that has characteristics of high efficiency and relative cheapness.

[0018] A particular purpose of the present invention is to provide a locking assembly that promotes the stable and long-lasting coupling of a shaft with a pinion, even in the presence of high rotating torques.

[0019] A further object of the present invention is to provide a locking assembly for coupling a shaft with a pinion that can be easily assembled and disassembled by a user.

[0020] Another object of the present invention is to provide a locking assembly of the type described above which allows a quick and precise centering of its components during the installation steps.

[0021] A further object of the present invention is to provide a locking assembly of the type described above which facilitates access to all its components by an operator after its installation.

[0022] Another object of the present invention is to provide a locking assembly of the type described above which requires reduced maintenance.

[0023] The aforementioned purposes, as well as others which will appear more clearly in the following, are achieved by a locking assembly for coupling a shaft with a pinion in accordance with claim 1 and comprising a first ring that can be removably inserted on one end of the shaft and having an outer frusto-conical surface and a flat front surface and a second ring which can be positioned externally to the first and having an inner frusto-conical surface designed to couple with the frusto-conical surface of the first ring in order to fit it onto the end of the shaft.

[0024] In addition, the assembly includes a pinion with a pair of opposite flat and parallel faces, first members for connecting the first ring with the second ring and second members for connecting the pinion with one of the two rings.

[0025] The first ring has on the front surface a series of first protrusions which can be engaged in a corresponding series of first recesses formed on a flat face of the pinion and of a shape complementary to the protrusions.

Furthermore, the second connecting members are adapted to force the pinion against the first ring along an axial direction to lock the first protrusions in the first recesses.

[0027] Advantageous embodiments of the invention are obtained in accordance with the dependent claims.

Brief description of the drawings

[0028] Further characteristics and advantages of the invention will become more evident in the light of the detailed description of a preferred but not exclusive embodiment of a locking assembly for coupling a shaft with a pinion according to the invention, illustrated by way of example not limiting with the help of the following drawing tables in which:

FIG. 1 is a perspective view of a locking assembly for the coupling of a shaft and a pinion according to the invention;

FIG. 2 is a sectional side view of the shrink disc of Fig. 1;

FIG. 3 is an exploded front and rear perspective view of the shrink disc of Fig. 1;

FIG. 4 is an exploded sectional side view of the shrink disc of Fig. 1;

FIGS. 5 is a front view of a first detail of the shrink disc of Fig. 1;

FIG. 6 is a front view of a second detail of the shrink disc of Fig. 1.

Detailed description of a preferred embodiment [0029] With particular reference to the figures, a shrink disc assembly is shown, generally indicated with the reference number 1, used to rigidly couple a shaft A with a pinion 2 in a coaxial position with respect to a common longitudinal axis L.

[0030] In the embodiment illustrated in the figures, the shaft A is solid and can be connected to a mechanical member, not shown in the figures, capable of exerting a driving or resisting torque on the shaft A, and the pinion 2 in its Once it can be associated with a gearmotor or a similar device, also not shown in the figures and capable of exerting a resisting or driving torque on the pinion 2.

[0031] The locking assembly 1 according to the invention allows the shaft A to be coupled with the pinion 2 so that high mechanical torques are transmitted between them.

[0032] In its most essential configuration illustrated in the figures, the locking assembly 1 comprises a first ring 3 that can be removably positioned around an end portion of the shaft A and a second ring 4 that can be positioned externally to the first ring 3.

[0033] The first ring 3 has a substantially cylindrical internal surface 5 with a diameter d corresponding to the diameter of the solid shaft A, an external frusto-conical surface 6 and a substantially flat front surface 7.

[0034] The second ring 4 comprises a substantially frusto-conical internal surface 8 intended to interact axially with the frusto-conical external surface 6 of the first ring 3 so as to narrow it radially and perform its keying on the end portion of the shaft A.

[0035] In particular, the keying of the assembly 1 on the shaft A is achieved by means of the reciprocal axial approach of the first 3 and the second ring 4 promoted by appropriate first members 9 for the connection of the two rings 3, 4.

[0036] These first connecting members 9 may comprise a plurality of first screws 10 which can be inserted in a series of corresponding first through holes 11 distributed on the first ring 3 in angularly equidistant positions and screwable in a series of first threaded holes 12 angularly distributed on the second ring 4 and aligned with the first through holes 11.

[0037] As best illustrated in FIGS. 2 and 4, the first ring 3 has a substantially tubular portion 13 whose external surface defines the frusto-conical surface 6 and is joined to a substantially annular flange 14 by means of an intermediate portion 15 having an external stepped edge 15 '.

[0038] The flat front surface 7 of the first ring 3 is formed on the annular flange 14 while the second ring 4 may have an internal stepped seat 16 adapted to house the stepped edge 15 'of the intermediate portion 15 to guide the first ring 3 in a substantially axial direction during their mutual approach promoted by the first connecting members 9.

[0039] In an embodiment not shown in the figures, the tubular portion 13 of the first ring 3 may comprise at least one substantially longitudinal notch adapted to allow its radial deformation to facilitate locking on the external surface S of the solid shaft A.

[0040] Preferably, the first through holes 11 can be formed on the first ring 3 passing through the flange 14 and the intermediate portion 15 while the first threaded holes 12 can be formed on the second ring 4 in correspondence with the bottom wall 17 of the internal seat step 16.

[0041] The pinion 2 comprises an annular body 18 with an internal peripheral portion 19 having opposite faces 20, 21 which are substantially flat and parallel and is removably connected to one of the two rings, preferably to the first 3, by means of second connecting members 22.

[0042] The second connecting members 22 may comprise a plurality of second screws 23 which can be inserted in a series of second through holes 24 angularly distributed on the pinion 2 and screwable in a series of second threaded holes 25 formed and angularly distributed on the first ring 3.

[0043] The second threaded holes 25 can be formed on the first ring 3 in correspondence with its annular flange 14 along a first circumference Ci and can be radially and angularly offset with respect to the first through holes 11 to avoid encumbrance when inserting the first 10 and the second screws 23.

[0044] As best illustrated in FIG. 5, the pinion 2 may comprise at least three angularly offset radial notches 26 suitable to allow its radial deformation and to delimit respective angular portions 27 thereof.

[0045] Thus, when a portion of the external toothing 28 of the pinion 2 is worn, the operator can only replace the angular portion 27 comprising the worn portion by removing the second screws 23 inserted in the corresponding second through holes 24 and without having to replace the whole pinion 2.

[0046] Conveniently, along the radial development of each notch 26 respective holes 26 'can be formed for the insertion of rigid pins designed to keep the angular portions 27 of the pinion 2 apart following its assembly on shaft A.

[0047] The locking assembly 1 may comprise a locking ring 29 removably coupled to the pinion 2 on the opposite side with respect to the first ring 3 and having an internal face 30 facing the pinion 2 and a substantially flat external face 31.

[0048] The locking ring 29 can be connected to the pinion 2 by means of third connecting members 32, better illustrated in FIGS. 3 to 4, acting axially so as to force the locking ring 29 along a substantially axial direction.

[0049] The third connecting members 32 may comprise a plurality of third screws 33 which can be inserted in respective series of third through holes 34, 34 'formed and uniformly angularly distributed in the pinion 2 and in the locking ring 29 and screwable in a series of third threaded holes 35 also angularly uniformly distributed on the first ring 3.

[0050] As best illustrated in FIGS. 5 and 6, the third threaded holes 35 will be formed on the flange 14 of the first ring 3 along a second circumference C2 that is concentric and radially offset with respect to the first C1.

[0051] A series of first access holes 36 can be made on the locking ring 29 which can be aligned with the second through holes 24 of the pinion 2 for the insertion of a tool for screwing the second screws 23 without removing the locking ring 29.

[0052] According to a peculiar aspect of the invention, the first ring 3 has on its front surface 7 a series of first protrusions 37 which can be engaged in a corresponding series of first recesses 38 formed on a flat face 20 of the pinion 2.

[0053] By screwing the second connecting members 22 it will be possible to force the pinion 2 against the first ring 3 in a coaxial position so as to mutually couple the first protrusions 37 to the first recesses 38.

[0054] Thanks to this arrangement, it will be possible to keep the pinion 2 and the shaft A stably coupled even in the presence of high driving or resistant torques associated with the shaft A and reduces the load associated with the second 22 and the third connecting members 32 .

[0055] As best illustrated in FIGS. 5 and 6, the first protrusions 37 and the first recesses 38 may be substantially identical to each other and angularly offset with the same angular pitch and substantially truncated cone shape in plan, preferably with a "U" -shaped cross section with slightly flared sides.

[0056] Furthermore, the locking ring 29 has, on its internal face 30, a series of second front protrusions 39 which can be engaged in a series of second recesses 40 present on the other flat face 21 of the pinion 2 and adapted to be locked to the internally through third connecting bodies 32.

[0057] In the embodiment illustrated in the figures, the second protrusions 39 and the second recesses 40 may also be angularly offset and have a shape substantially identical to that of the first protrusions 37 and the first recesses 38.

[0058] Conveniently, the first recesses 38 formed on a flat face 20 of the pinion 2 may be radially offset with respect to the second recesses 40 formed on the other flat face 21 of the pinion 2.

[0059] This device helps to make the centering operations of the components of the shrink disc assembly 1 particularly simple and therefore their assembly on the solid shaft A.

[0060] As best illustrated in FIGS. 3 and 6, each of the second threaded holes 25 can be formed on the first ring 3 at a corresponding first protrusion 37 while each of the first through holes 11 and each of the third threaded holes 35 can be formed in a respective gap 41 between a first projection 37 and the subsequent one 37 'in a radially offset position with respect to the first through holes 11.

Furthermore, as illustrated in FIG. 3, the third through holes 34 of the locking ring 29 may be formed at the second protrusions 39 which can be inserted in the second recesses 40 of the pinion 2.

[0062] The locking ring 29 and the pinion 2 may comprise respective series of second access holes 42, 42 'adapted to allow the screwing of respective release screws, not shown in the figures, to promote the uncoupling of the first ring 3 from the pinion 2 and of the latter from the locking ring 29.

[0063] Operationally, the assembly of the locking assembly 1 initially involves the insertion of the first 3 and the second ring 4 on the end of the solid shaft A and their mutual coupling by means of the first connecting members 9.

[0064] Subsequently, the pinion 2 is coupled to the first ring 3 by inserting the first protrusions 37 in the first recesses 38, inserting the second screws 23 in the second through holes 24 and screwing them into the second threaded holes 25.

[0065] Finally, the locking ring 29 is coupled with the pinion 2 by means of the second protrusions 39 and the third connecting members 32, so as to keep all the components of the assembly stably coupled.

[0066] From the foregoing, it is evident that the locking assembly according to the invention achieves the intended purposes and in particular allows high driving or resistant torques to be transmitted safely and without failures.

[0067] The assembly according to the invention is susceptible of numerous modifications and variations, all of which fall within the inventive concept expressed in the attached claims.

[0068] All the details can be replaced by other technically equivalent elements, and the materials can be different according to the requirements, without departing from the scope of the invention.

[0069] Although the assembly has been described with particular reference to the attached figures, the reference numbers used in the description and in the claims are used to improve the intelligence of the invention and do not constitute any limitation to the scope of protection

Claims (12)

R I V E N D I C AZ I O N I 1. A locking assembly (1) for coupling a shaft (A) with a pinion (2) in a substantially coaxial position with respect to a longitudinal axis (L), which assembly (1) includes: - a first ring (3) removably positioned around one end of the shaft (A), said first ring (3) having a frusto-conical outer surface (6) and a substantially flat front surface (7); - a second ring (4) that can be positioned externally to said first ring (3) and having a substantially frusto-conical internal surface (8) intended to interact with said external frusto-conical surface (6) of said first ring (3) to key it on the end portion of the shaft (A); - a pinion (2) comprising an annular body (18) with an internal peripheral portion (19) with flat and parallel opposite faces (20, 21); in which said first ring (3) and said second ring (4) are connected to each other by means of first connecting members (9) and in which said pinion (2) is connected to at least one of said rings (3, 4) by means of second connecting members (22); characterized in that said first ring (3) has on its front surface (7) a series of first protrusions (37) which can be engaged in a corresponding series of first recesses (38) obtained on a flat face (20) of said pinion (2 ) and substantially complementary in shape to said protrusions (37), said second connecting members (22) being able to force said pinion (2) against said first ring (3) in a substantially coaxial position so as to mutually couple said first protrusions ( 37) to said first recesses (38). 2. Assembly according to claim 1, characterized in that said first protrusions (37) and said first recesses (38) are substantially identical and angularly offset with the same angular pitch and have a substantially truncated conical plan shape with a substantially U-shaped cross section ". 3. Assembly according to claim 1, characterized in that said first connecting members (9) comprise a plurality of first screws (10) which can be inserted in a series of first through holes (11) angularly distributed on said first ring (3), said first screws (10) being screwable in a series of first threaded holes (12) angularly distributed on said second ring (4). 4. Assembly according to claim 3, characterized in that said second connecting members (22) comprise a plurality of second screws (23) which can be inserted in a series of second through holes (24) angularly distributed on said pinion (2), called second screws (23) being screwable in a series of second threaded holes (25) angularly distributed on said first ring (3). 5. Assembly according to claim 4, characterized in that it comprises a locking ring (29) removably coupled to said pinion (2) on the opposite side with respect to said first ring (3), said locking ring (29) having a face internal (30) facing said pinion (2) and a substantially flat external face (31). 6. Assembly according to claim 5, characterized in that said locking ring (29) has on said internal face (30) a series of second front protrusions (39) which can be engaged in a series of second recesses (40) formed on the other of said flat faces (21) of said pinion (2), third connecting members (32) being provided for forcing said pinion (2) against said locking ring (29) along a substantially axial direction so as to lock said second projections (39) in said second recesses (40). 7. Assembly according to claim 6, characterized in that said third connecting members (32) comprise a plurality of third screws (33) which can be inserted in a series of third through holes (34, 34 ') angularly distributed in said pinion (2 ) and screwable in a series of third threaded holes (35) angularly distributed on said first ring (3) and can be aligned with said third through holes (34, 34 '). 8. Assembly according to claim 5, characterized in that said locking ring (29) comprises a series of first access holes (36) which can be aligned with said second through holes (24) of said pinion (2) for the insertion of a tool for screwing said second screws (23) without removing said locking ring (29). 9. Assembly according to claim 8, characterized in that said first ring (3) comprises a substantially tubular end portion (13) joined to a substantially annular flange (14) by means of an intermediate portion (15) with an external stepped edge (15 '), said second ring (4) having an internal stepped seat (16) adapted to house said stepped edge (15') of said intermediate portion (15). 10. Assembly according to claim 9, characterized in that said first through holes (11) are formed on said first ring (3) passing through said flange (14) and said intermediate portion (15), said second (25) and said third threaded holes (35) being formed on said flange (14) of said first ring (3) along concentric and radially offset circumferences (Ci, C2). 11. Assembly according to claim 8, characterized in that said locking ring (29) comprises a series of second threaded access holes (42) for screwing in respective release screws intended to act against said face (21) to promote the uncoupling of said locking ring (29) from said pinion (2), the latter comprising a respective series of second threaded access holes (42 ') for the screwing of corresponding release screws to promote the uncoupling of said first ring (3) from said pinion (2). 12. Assembly according to claim 1, characterized in that said pinion (2) comprises at least three notches (26) radially staggered and adapted to allow its radial deformation.