RU2499918C1 - Cardan mechanism - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: cardan mechanism includes a stiff coupling attaching the forks. The coupling is made in the form of a coupling-sprocket, and forks are connected to the coupling along annular slots through lead-in planes perpendicular to each other.

EFFECT: simplifying both the cardan mechanism structure and its assembly/disassembly process.

6 dwg

Description

The invention relates to the field of mechanical engineering and automotive industry and can be used to connect shafts that transmit torque at various, possibly varying angles.

A device is known as an articulated coupling [GOST 5147-97], which has found wide application in various machines: aircraft, instruments, machine tools, automobiles, agricultural machines, etc., when, under operating conditions, the relative position of the shafts transmitting rotation is necessary. The hinged coupling consists of two identical half-couplings and in the form of a hub with a fork (the half-couplings forks are turned 90 °) and a cross connecting the half-couplings. The crosspiece is connected to the forks of the coupling halves by hinges.

However, the drawbacks of the articulated clutch are the complexity of the design and the assembly-disassembly process, as well as the unevenness of the rotation speed of the driven shaft at a constant drive speed.

Closest to the proposed invention is the Hooke joint - a mechanism connecting with a rigid coupling - crosses, forks that are the ends of the connecting shafts. The kinematics of the cardan mechanism is similar to the kinematics of the Hook joint, as a simple rigid cardan joint, a member of the family of cardan mechanisms [Tarasov V.K. The course of theoretical mechanics for mathematicians. - TulSU, 2008. - S.264-266].

The disadvantages of this device are the complexity of the design, as well as the assembly-disassembly process.

The objective of the present invention is to simplify both the design of the cardan mechanism (cardan joint, Hooke joint, cardan joint, articulated coupling, cardan) and its assembly-disassembly process.

The problem is achieved in that the coupling is made in the form of a sprocket coupling, and the forks are connected to the coupling in annular grooves through the lead-in planes perpendicular to each other. The device has a new way of engaging parts of the cardan mechanism (cardan joint, Hooke joint, cardan joint, articulated clutch, cardan), its design is simplified (two forks and sprocket coupling), dimensions are reduced, assembly-disassembly time is reduced, and fasteners are eliminated.

The invention is illustrated by drawings: in Fig. 1, the simplest universal joint mechanism is shown in general form; in Fig. 2, an asterisk coupling with two ring grooves is shown; Fig. 3 is an engagement of a fork with an asterisk coupling before turning in an annular groove; 4 shows the structure after turning the fork in the annular groove of the sprocket coupling, FIG. 5 shows the installation of the second fork in the free ring groove of the sprocket coupling through the reference planes, FIG. 6 shows the assembled structure,

Where:

1 - sprocket coupling

2 - fork

3 - ring groove

4 - axis of intersection of the annular grooves

5 - reference plane

6 - fork distance equal to the distance between the reference planes of the sprocket coupling

The cardan mechanism comprises a sprocket coupling 1 and two forks 2 [Fig. 1]. Figure 2 shows the sprocket coupling 1 with two annular grooves 3, the axes of which 4 intersect at an angle of 90 °. Two parallel reference planes 5, are located at the intersections of the annular grooves 3 and are symmetrical to each other relative to the plane built through the intersecting axis 4 of the annular grooves 3. In Fig.3. the distance 6 of the yoke 2 is equal to the distance between the reference planes 5 of the sprocket coupling 1. The diameters of the annular grooves 3 and the cylindrical hole of the yoke 2 are equal, but greater than the distance 6. To engage the yoke 2 with the sprocket coupling 1, these parts must be mutually correctly positioned. The parts can only be connected at the position indicated in Fig. 3 and, through two reference planes 5 of the sprocket coupling 1, insert the parts one into the other along the annular groove 3. Figure 4 shows the design after turning the plug 2 in the annular groove 3 of the sprocket coupling 1 by 90 °, while the possibility of disengaging the already connected parts disappears, but it becomes possible to insert the second fork 2 into the sprocket coupling 1. Figure 5 shows the institution the second fork 2 along the free annular groove 3 of the sprocket coupling 1 through the reference planes 5. And since the cardan joint cannot work at an angle between the axes of the shafts equal to 90 °, it must be significantly reduced by rotating the fork 2 along the annular groove of the 3 coupling sprockets 1. Moreover, the item th automatically lost the opportunity to disengage. The mechanism is assembled in Fig.6.

The device is a cardan mechanism for connecting shafts transmitting torque at various, possibly changing angles, works as follows. When transmitting rotation between the main shafts, the gear ratio turns out to be unstable: during one revolution it varies from cos α to 1 / cos α, where α is the angle between the shaft axes. At α = 90 °, transmission is not possible; at α close to 90 °, the non-uniformity of rotation is very significant, therefore, the cardan mechanism in its pure form can be used only at small angles between the main shafts.

The advantages of the invention are its compactness, ease of manufacture, lack of fasteners and special tools for assembly-disassembly, which are provided by a new way of engaging parts of this gimbal mechanism.

Claims (1)

A cardan mechanism containing a rigid coupling connecting the forks, characterized in that the coupling is made in the form of a sprocket coupling, and the forks are connected to the coupling in annular grooves through the lead-in planes perpendicular to each other.

Images