RU208043U1 - Assembly for fixing the part on the shaft - Google Patents

Abstract

The utility model relates to mechanical engineering, in particular, to shaft-hub connections and is designed for simple and reliable fastening of various parts on the shaft with the possibility of mobile adjustment of their axial and angular positions. The unit for fixing the part on the shaft contains two bushings made of elastic material with a conical outer and connected to the shaft by means of a rigid connection for transmitting torque (for example, splined), the inner surface. Each of the bushings has grooves at both of its ends alternately between an even number of evenly spaced smooth holes for the screw rods in one of the bushings and the same number of respectively located threaded holes for the screw threads in the second bushing. Both bushings are placed in two conical counter-directional holes of the inner surface of the hub, fixed on the shaft of the part, and are pulled together by screwing the screws placed in the smooth holes of the first bushing with the heads from the outer side of the hub into the threaded holes of the second bushing. At the same time, on the outer conical surfaces of the bushings, friction forces proportional to the tightening force of the screws are formed, which are necessary to transfer the specified torque from the shaft through the bushings to the hub of the part fixed on the shaft (or vice versa). 4 ill.

Description

The utility model relates to mechanical engineering, in particular, to shaft-hub connections and is intended for simple and reliable fastening of gear wheels, pulleys, sprockets, levers and similar parts on shafts with the possibility of mobile adjustment of their axial and angular positions.

From the prior art, it is known to connect the shaft to the hub with biconical outer and inner rings, which are expanded by bringing together with screws two intermediate rings installed on both sides in the annular gaps between the biconical rings (Orlov P.I. book 2, p. 304, fig. 638).

The disadvantages of this connection are the need to center the part relative to the shaft on four surfaces and the uneven distribution of contact pressures along the length of the contacting surfaces.

The closest in technical essence to the proposed utility model is a unit selected as a prototype for fastening a part on a shaft, containing two bushings made of elastic material with an outer conical and inner cylindrical seating surfaces, placed towards each other in the gap between the shaft and the hub, which has internal seating surface in the form of two oppositely directed tapered ends of the tapered sections. The bushings are equipped with a means for their axial movement, made in the form of an even number of screws placed in the corresponding holes, which are made evenly around the circumference in one of the bushings with a clearance for the screw shaft, and screwed into the threaded holes in the second bushing, which are equal in number and corresponding the location of the smooth holes in the first sleeve. Between these holes, alternately from both ends of each of the bushings, grooves are made, spaced from the adjacent holes for the screws at the same distance. The shaft, on which both bushings are located, is made with a cylindrical seating surface. (Patent No. 1999090 Assembly for fastening a part on a shaft from 13.02.2020).

The disadvantages of the known, described above unit for fastening the part on the shaft, as shown by the experience of the practical use of an identical design, including a technical problem, is the low load capacity of the unit for fastening the part on the shaft, associated with the frictional method of transferring torque from the shaft to the hub of the part ( or vice versa) both along the inner and outer seating surfaces of the bushings, and with an increase in the value of the transmitted torque, slip in the assembly begins along the inner cylindrical seating surfaces of both bushings in contact with the shaft, and not along the outer tapered seating surfaces of the bushings in contact with the two inner multidirectional conical surfaces of the hub of the part fixed to the shaft. This circumstance underestimates the initially rated design value of the torque transmitted by the unit for fastening the part on the shaft, i.e. reduces the load capacity of the unit as a whole.

The claimed model was based on the technical result - an increase in the efficiency of the unit for attaching the part to the shaft by increasing the load capacity of the unit by performing a rigid connection of the bushings with the shaft to transmit torque using, for example, spline, keyway or profile connections.

The technical result is achieved in that the unit for fixing the part on the shaft, containing two bushings made of elastic material with an outer conical seating surface, placed towards each other in the gap between the shaft and the hub having an inner seating surface in the form of two oppositely directed tapering ends of the conical sections, and equipped with a means for their axial movement, made in the form of an even number of screws placed in the corresponding holes, which are made evenly around the circumference in one of the bushings with a gap for the screw shaft, and screwed into the threaded holes in the second bushing, which are equal in number and corresponding the arrangement of smooth holes in the first bushing, and between these holes, alternately from both ends of each of the bushings, grooves are made, spaced from the nearby holes for the screws at the same distance, and the inner seating surfaces of both bushings are connected to the shaft for transferring torque his moment between them through a rigid connection.

The utility model is illustrated by graphic images.

FIG. 1 shows a section along the axis of the unit for fixing the part on the shaft with one of the possible rigid (here spline) execution of the connection of the bushings with the shaft.

FIG. 2 shows a section a-a in Fig. one.

FIG. 3 shows in diameter one of the two sleeves with smooth holes for the rods of the screws.

FIG. 4 shows in diameter another sleeve with threaded holes for screwing screws into them.

The unit for fixing the part on the shaft contains two bushings 1 and 2 made of elastic material (see Fig. 1) with a tapered outer seating surface 3, placed towards each other in the gap between the shaft 4 and the hub 5, which has an inner seating surface in the form of two opposite directed conical sections 6 and a cylindrical technological section 7 in the middle between them, and provided with means for their axial movement, made in the form of an even number of screws 8, placed in the corresponding holes 9, made evenly in the sleeve 1 with a gap for the rod 10 of the screws 8 and, for example, with a possible socket 11 for the head 12 of the screws 8 from the side of the end 13 of the bushing 1, facing the outside of the hub 5, and screwed into the threaded holes 14 of the bushing 2, made equal in number and corresponding to the arrangement of smooth holes 9 in the bushing 1, between which alternately from both ends 13 and 15 of the sleeve 1 and from both ends 16 and 17 of the sleeve 2 grooves are made (see Fig. 2, 3 and 4), from standing from the nearby holes 9 and 14 for screws 8 at the same distance. The internal seating surfaces 19 of the bushings 1 and 2 (see Fig. 1) are connected to the shaft 4 by means of a rigid connection for transmitting torque between the bushings 1 and 2 and the shaft 4 using, for example, a splined (see Fig. 1, 2, 3 , 4), keyway or profile (not shown in the figures) connections.

The assembly of the unit for fixing the part on the shaft is carried out as follows.

Bushing 1 is installed in the inner cavity of the hub 5 of the part, on the side from which the part will be fixed on the shaft 4 by means of the described assembly, and on the other side of the hub 5, bushing 2 is installed in the same cavity, after which all smooth holes 9 of the sleeve 1 insert screws 8 with heads 12 from the side of the end 13 of the sleeve 1 and screw them in advance, without tightening, into the threaded holes 14 of the sleeve 2, aligning the axes of the two types of holes by rotating one of the sleeves 1 or 2 around its axis. After that, the assembled set of several parts, by means of its axial movement, is pushed onto the shaft 4, placing it in the desired axial position, and, if necessary, by turning around the axis of the shaft 4, and in the desired angular position, and proceeding to fix the part on the shaft 4 through the described fixing unit. To do this, finally screw all the screws 8 into the threaded holes 14 of the bushing 2 until the heads 12 of the screws 8 completely enter the slots for them 11 in the bushing 1, and in the case of the bushing 1 without sockets 11 for the screw heads 8 - until the heads 12 do not press against the outer end 13 of the sleeve 1, and tighten all the screws 8, pulling together both sleeves 1 and 2 with an axial force of such magnitude that is necessary to create friction forces on the outer seating surfaces 3 of the sleeves 1 and 2, which will be sufficient to ensure transmission by the fixing unit of the part on the shaft from the bushings 1 and 2 to the hub 5 (or vice versa) of the torque of a given value.

Disassembly of the assembly for fixing the part on the shaft is carried out in the following order.

All screws 8 are unscrewed and removed from the bushing 1, the set is removed from the shaft, which includes a part fixed to the shaft 4 together with two bushings 1 and 2 in its hub 5, with the subsequent disassembly of this set.

The claimed technical solution, namely, the implementation of the inner seating surfaces of the bushings are not smooth cylindrical, connected to the shaft by a friction method for transferring torque between the bushings and the shaft, as in the prototype, but by means of a rigid connection for transferring torque between the bushings and the shaft by using, for example , spline, keyway or profile connections, increases the nominal value of the torque transmitted by the unit from the shaft to the hub of the part (or vice versa) and, thereby, increases the load capacity of the unit (as a whole). Or, arguing differently, an increase in the load capacity of the unit for fixing the part on the shaft, in comparison with the prototype, by replacing the frictional method of transferring torque between the bushings and the shaft to a rigid connection, makes it possible to reduce the dimensions of the unit when implementing the claimed utility model of the unit for securing the part on the shaft.

Thus, the claimed set of essential features, reflected in the utility model formula, ensures, when implementing the utility model, the claimed technical result - an increase in the efficiency of the unit for securing the part on the shaft by increasing the load capacity of the unit by performing a rigid connection of the bushings with the shaft to transmit torque using , for example, spline, keyway or profiled connections.

An analysis of the claimed technical solution for compliance with the conditions of patentability showed that the features indicated in the utility model formula are essential and interconnected with the formation of a stable set of necessary features, unknown at the priority date from the prior art and sufficient to obtain the claimed technical result.

Thus, the above information indicates the fulfillment of the following set of conditions when using the claimed technical solution:

- an object embodying the claimed technical solution, in its implementation, relates to mechanical engineering, in particular, to shaft-hub connections, and can be used to fix gears, pulleys, sprockets, levers and similar parts on shafts;

- for the declared object in the form as it is characterized in the formula of the utility model, the possibility of its implementation has been confirmed using the means and methods described above in the application and known from the prior art as of the priority date;

- an object that embodies the claimed technical solution, in its implementation, is able to ensure the achievement of the technical result perceived by the applicant.

Consequently, the declared object meets the criteria of patentability "novelty" and "industrial applicability" under the current legislation.

Claims (1)

A unit for fixing a part on a shaft, containing two bushings made of elastic material with an outer tapered seating surface, placed towards each other in the gap between the shaft and a hub having an inner seating surface in the form of two oppositely directed tapering ends of the tapered sections, and equipped with a means of their axial movement made in the form of an even number of screws located in the corresponding holes, which are made evenly around the circumference in one of the bushings with a gap for the screw shaft, and screwed into threaded holes in the second bushing, which are made equal in number and corresponding to the arrangement of smooth holes in the first bushing , and between these holes, alternately from both ends of each of the bushings, grooves are made, spaced from the nearby holes for the screws at the same distance, and characterized in that the inner seating surfaces of both bushings are connected to the shaft to transfer torque between them. by means of a rigid connection.

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