RU2173800C2 - Key joint - Google Patents

Abstract

FIELD: mechanical engineering; connection of parts with split over plane. SUBSTANCE: key joint has parts to be connected with opposite slots to receive key provided with cylindrical rod. Ends of rod are sheared in direction of key length and are arranged at both sides of key in corresponding holes of parts to be connected with guaranteed fitting clearance. Sheared ends of rod can be made V-shaped. V-shaped ends of rod can be made to suit width of key. Ends of rod can be made also in the form of concentrically arranged ring sectors to be fitted in holes of connected parts. Said holes are to be made in the form of ring grooves. Maximum outer diameter of ring sectors will be equal to length of key. EFFECT: enlarged operating capabilities, simplified design, provision of high load capacity of key joint. 4 cl, 16 dwg

Description

 The invention relates to mechanical engineering and can be used in the connection of parts with a connector on a plane.

 It is well known to connect parts with two cylindrical mounting pins (see PI Orlov, "Fundamentals of Design", Moscow, "Mechanical Engineering", 1988, vol. 2, p. 104, Fig. 227). This connection, along with such advantages as simplicity of design, has several disadvantages. These include the lack of interchangeability of the connected parts, since the processing of the pin holes is carried out, as a rule, assembled. In addition, before machining the holes for the pins, the parts to be joined must be precisely positioned and secured with fasteners, and then joint processing of these holes should be performed. All this in general makes assembly difficult, which makes it unacceptable to use this compound in equipment assembled under conditions of mass production.

 It is also known to connect parts with a connector in a plane (see AS N 1320544, MKI F 16 B 19/02), in which parts are connected using two installation step pins and two bushings, in one of which a groove is made with a width equal to pin diameter, and symmetrical to the outer diameter of the sleeve. According to the author, the groove in the sleeve makes it possible to fully compensate for the error in processing the center-to-center distance between the holes. This statement is true only if, firstly, the groove is made symmetrical with respect to the outer diameter of the sleeve, and secondly, if there are no gaps between the outer diameter of the sleeve and the mating hole in the part, as well as between the outer diameter of the pin and the mating groove in the sleeve , and thirdly, if the groove is oriented during assembly strictly parallel to the line connecting the axis of the holes in the parts, and is fixed in this position. Failure to comply with these conditions leads to additional errors during assembly. In particular, if the groove in the sleeve is not aligned parallel to the axis of the connected holes, then from an error in the distance between the latter there is an additional inaccuracy in the mutual position of the connected parts. In addition, the pin in contact with the groove of the sleeve is in contact with the cylindrical surface (along the line of contact) and cannot absorb significant shear forces. However, the presence of intermediate sleeves complicates the design and reduces the accuracy of the connection. Additional means are required for installation and fixing in the angular position of the sleeve with the groove.

 A key connection is known (see A.S. N 1460442, MKI F 16 B 3/00), in which the prismatic elements are located on both sides of a cylindrical rod located in the hole of one of the parts to be joined, and in the latter there are opposed grooves which are installed prismatic key elements.

 The advantage of this compound is the increased load capacity due to the increase in the length of the prismatic key elements. However, in this connection it is necessary to maintain high accuracy of centering of the axis of the cylindrical rod relative to the axis of the prismatic elements of the dowel, since the cylindrical rod is not cut in the direction of the length of the dowel. Hence the complication of processing and assembly and, as a result, the cost of construction. In addition, using this connection, it is impossible to fix the parts to be connected with the connector in a plane, and moreover, additional means are required for fastening the key itself.

 The task of the invention is to expand technological capabilities, simplify the design and obtain a technical result, which consists in providing a high load capacity of the keyed joints in the necessary directions while reducing the requirements for manufacturing accuracy at a given joint accuracy.

 To solve the above problems and obtain the specified technical result in a known key connection containing connected parts with opposed grooves, in which a key is provided, equipped with a cylindrical rod, the ends of the shaft are cut off in the direction of the length of the key and are located on both sides in the corresponding holes of the parts to be joined with guaranteed landing clearance. In this case, the cut ends of the rod can be made prismatic and the width of the keys. In addition, the ends of the rod can be made in the form of concentric annular sectors located in the holes of the parts to be joined, while these holes are made in the form of annular grooves, and the largest outer diameter of the annular sectors is equal to the length of the dowel.

 The presence of a permissible displacement of the cut ends of the cylindrical rod in the holes of the parts to be joined in the direction perpendicular to the length of the dowel, which is usually many times greater than the guaranteed landing clearance of the cylindrical part of the rod, can reduce the manufacturing accuracy of the components of the keyed connection and, accordingly, the accuracy of the assembly itself. At the same time, the above guaranteed landing clearance provides the specified accuracy of the keyway connection. In addition, the latter has a high load capacity in mutually perpendicular directions, and the increase in the number of concentrically arranged annular sectors can significantly increase the transmitted force in the direction of the key length.

 In FIG. 1 shows a frontal section of a key with the rhombic ends of a cylindrical rod.

 In FIG. 2 is a view A in FIG. 1.

 In FIG. 3 shows a frontal section of a key with the prismatic ends of a cylindrical rod.

 In FIG. 4 is a view B in FIG. 3.

 In FIG. 5 shows a key with the prismatic ends of the cylindrical rod equal to the width of the key.

 In FIG. 6 is a view B in FIG. 5.

 In FIG. 7 shows a key with two concentric annular sectors, the outer diameter of the latter being equal to the length of the key.

 In FIG. 8 is a view D in FIG. 7.

 In FIG. 9 shows a key with 6 concentrically arranged ring sectors, the largest outer diameter of the ring sectors located on the periphery of the key being equal to its length.

 In FIG. 10 is a view D in FIG. 9.

 In FIG. 11 shows a key connection to the key shown in FIG. 5, 6.

 In FIG. 12 is a view E of FIG. eleven.

 In FIG. 13 shows the keyed connection with the key shown in FIG. 7, 8.

 In FIG. 14 is a view G in FIG. thirteen.

 In FIG. 15 shows the keyed connection with the key shown in FIG. 9, 10.

 In FIG. 16 is a view 3 in FIG. fifteen.

 The key connection consists of parts 1 and 2 connected along the plane with opposed grooves 3 and 4, in which the key 5 is placed. The key is equipped with a cylindrical rod 6, the ends of which are located on both sides of it and enter the corresponding holes 7 and 8 connected parts 1 and 2, while the ends of the rod 6 are cut in the direction of the length of the key 5 and are made, in the case under consideration, of a keyed connection (see Figs. 11, 12), prismatic in width of the latter. In addition, the ends of the rod 6 can be made in the form of concentrically arranged annular sectors 9 included in the holes made in the form of annular grooves 10, the reception of the largest outer diameter of the annular sectors is equal to the length of the keys (see Fig. 13, 14, 15, 16) . Fasteners 11 are provided for the final connection.

 Assembly keyway (see Fig. 1-6, 11, 12) is as follows.

 First, the key 5 is installed in the groove 4 of the part 2 with the simultaneous placement of the lower cut end of the cylindrical rod 6 in the hole 8 of the same part. Then, in the same way, the response part 1 is mounted on the protruding part of the key 5 and the upper cut-off end of the cylindrical rod 6 until the mounting planes of the parts to be connected come into contact. For ease of assembly, the chamfers are made on the cylindrical parts of the cut ends of the rod 6. After combining the planes, parts 1 and 2 are connected using fasteners 11 (bolts). Thus, one part is completely balanced relative to another with the help of one key, which also does not require separate fasteners. In one coordinate (perpendicular to the keyway) in the plane of the connector, the force is transmitted due to the prismatic key. In another coordinate (perpendicular to the first) in the plane of the connector, the force is transmitted due to the cylindrical part of the rod.

 The assembly of the keyed connection (see Figs. 7-10, 13-16) is carried out similarly to the previous one, with the only difference being that concentricly located annular sectors 9 are combined with the corresponding annular grooves 10. In this case, as mentioned above, the increase in this case the number of bearing cylindrical surfaces allows to increase the force perceived by the key in the direction of its length.

Claims (4)

 1. A keyed connection comprising connected parts with opposed grooves, in which a key is provided, provided with a cylindrical rod, characterized in that the ends of the rod are cut off in the direction of the length of the key and are located on both sides in the corresponding holes of the connected parts with a guaranteed landing clearance.  2. The key connection according to claim 1, characterized in that the cut ends of the rod are made prismatic.  3. The key connection according to claim 2, characterized in that the prismatic ends of the rod are made across the width of the keys.  4. The key connection according to claim 1, characterized in that the ends of the rod are made in the form of concentrically arranged annular sectors located in the holes of the parts to be joined, while these holes are made in the form of annular grooves, and the largest outer diameter of the annular sectors is equal to the length of the key.

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