RU2458269C1 - Harmonic rack-and-gear drive with intermediate links in form of wedges - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: harmonic rack-and-gear drive with intermediate links in the form of wedges includes housing (1), rack (2), wedge movement device (4) orthogonal to the rack, which consists of shaft (6) and flat cams (8) installed on it along its axis through screw line. Diaphragm (11) is installed between housing and wedges. Rack has the possibility of being moved in guides of housing parallel to shaft axis. Brolling bearings (9) are installed in wedges with possibility of direct interaction of their inner rings with working surfaces of flat cams (8). Rollers (10) are installed in the rack with constant pitch and with possibility of being rotated about their axes. Rollers interact with wedges subsequently displaced in phase relative to each other only in straight-line sections of their back-and-forth movements.

EFFECT: uniform tractive force on rack, and rigid drive.

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Description

The invention relates to the field of engineering and can be used to create transport and technological modules, autonomous devices for translational movement of the working bodies of machines and devices.

Known wave rack and pinion transmission with intermediate links in the form of wedges (USSR author's certificate No. 10433392, IPC F16H 19/04, 1983), designed for unlimited travel of the rack by converting rotational motion into translational, containing a gear rack and a device for moving the wedges orthogonally to rail made in the form of a shaft and flat cams placed along the axis of the latter along the helix, the profiles of which are turned at an angle φ = 360 ° / z, where φ is the number of wedges. The step of installing wedges t _k in the grooves of the transmission housing is greater than the pitch of the teeth of the rack t _p by Δt = t _k -t _p = t _p / z, and the number of wedges z is taken so that some of them interact with the teeth of the rack at the same time. To ensure the linearity of the rail movement in the corresponding sections of the wedge diagram, the cam sections interacting with the wedges are outlined in a spiral of Archimedes. The force closure of the wedges with the cams is carried out using springs.

The disadvantages of this transmission are the variable contact area of the teeth of the rail and wedges, which leads to uneven traction on the rail and the rigidity of the transmission, and the inability to enter translational motion into an isolated space.

Also known is a wave transmission with intermediate links in the form of wedges (RF patent No. 2309310, IPC F16H 21/16, 2007), designed to transmit movement from one medium to another, containing a gear rack and a device consisting of a shaft and designed for orthogonal the movement of the wedges to the rail, made with the possibility of their movement in the guides and associated with the sealing membrane. On the shaft along its axis along the helix there are bushings with an eccentricity relative to the axis of the shaft. The working parts of the wedges interacting with the rail are made in the form of multi-tooth combs. The rolling bearings are mounted on bushings with an eccentricity with respect to the axis of the shaft with the possibility of their direct interaction with the supporting surface of the wedges and the surface of the spring-loaded slats mounted on the wedges with the possibility of providing power closure of the contact of the rolling bearings with the wedges.

The disadvantages of this transmission are uneven traction on the rail and the rigidity of the transmission caused by the variable area of the interacting contact surfaces of the teeth of the wedges and the rack.

The technical result of the invention is the uniformity of traction on the rail and the stiffness of the transmission.

The problem for solving the technical result is achieved in that in a wave rack and pinion with intermediate links in the form of wedges containing a housing, a rail, a device for moving the wedges orthogonal to the rail, consisting of a shaft and cams mounted on it along its axis along the helix, rolling bearings and a membrane installed between the wedges and the housing, the rail is made to move in the guides of the housing parallel to the axis of the shaft, according to the invention, the cams are made flat, the bearings are mounted in the wedges and rolling with the possibility of direct interaction of their inner rings with the working surfaces of the flat cams, and in the rail mounted with a constant step with the possibility of rotation around their axes, the rollers and with the possibility of their interaction with wedges that are sequentially phase-shifted relative to each other only in rectilinear sections of them back translational movements.

The proposed wave rack and pinion transmission provides constant linear contact of several wedges with rollers on the rail during its movement, forming kinematic rolling pairs. All this provides uniform traction on the rail and transmission stiffness.

Figure 1 shows the wave rack and pinion transmission (General view); figure 2 is a section aa in figure 1; figure 3 is a diagram of the movement of the wedge relative to the rollers of the rail.

The wave rack and pinion transmission with intermediate links in the form of wedges contains (see FIGS. 1, 2) a housing 1, a rail 2 installed in the guides 3, and a device for moving the wedges 4 in the guides 5 of the housing 1 orthogonal to the rail 2, consisting of a shaft 6 installed in the thrust bearings 7, and placed on it along its axis along the helical line of the flat cams 8. In the wedges 4, rolling bearings 9 are installed with the possibility of direct interaction of their inner rings with the working surfaces of the flat cams 8. In the rail 2 are installed with a constant With the first step and with the possibility of rotation around their axes, the rollers 10 interacting with the wedges 4, between which a membrane 11 is mounted 11. The force closure of each of the cams 8 with the bearing 9 of the wedge 4 is carried out using a spring 12 installed in the hole of the wedge 4 and housing grooves 1.

Working profiles of the surfaces of the flat cams 8, interacting with the bearings 9, are made with the possibility of moving the wedges 4 in accordance with the diagram of figure 3.

Wave rack and pinion with intermediate links in the form of wedges works as follows.

When the shaft 6 is rotated, the cams 8, interacting with the bearings 9, move the wedges 4 in accordance with the diagram of FIG. 3. In sections I-II and VIII-0 of the diagram (Fig. 3), the wedges 4 remain motionless. In section II-III, diagrams of wedges 4 with bearings 9 installed in them move in guides 5 orthogonally to rail 2, accelerating to a set speed. On a straight section III-IV of the diagram, the wedges 4 interact with the rollers 10, move the rail 2 in the guides 3 with a set speed. With further rotation of the shaft 6, the wedges 4, without interacting with the rollers 10, slow down their movement in the guides 5 of the housing 1 to a complete stop at point V of the diagram. With the continuation of the rotation of the shaft 6 on the plot of the diagram V-VI, the wedge 4 is accelerated to the set speed during the reverse movement from the rail. Then the wedge 4 moves further, interacting on a straight section of the VI-VII diagram with the roller, choosing a clearance in the transmission, and then on the plot of the diagram VII-VIII it slows down to a complete stop at point VIII. The movements of the wedges 4 in accordance with the diagram of FIG. 3 are phase shifted relative to each other. For one complete rotation of the shaft 6, all the wedges will make one cycle of reciprocating movement in the guides 5 and move the rack 2 in the guides 3 by one step of installing the rollers 10.

Claims (1)

A wave rack and pinion transmission with intermediate links in the form of wedges, comprising a housing, a rail, a device for moving the wedges orthogonally to the rail, consisting of a shaft and cams mounted on it along its axis along the helix, rolling bearings and a membrane installed between the wedges and the housing, the rail made with the possibility of movement in the guides of the housing parallel to the axis of the shaft, characterized in that the cams are made flat, wedges have rolling bearings with the possibility of direct interaction with them inside nal rings with flat bearing surfaces of cams, and a rail mounted at a constant pitch rotatably around their axes, with the rollers and their interaction with the wedges successively shifted in phase relative to each other only at straight portions of their reciprocating movement.

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