RU2049283C1 - Cam mechanism - Google Patents

Abstract

FIELD: mechanical engineering. SUBSTANCE: cam mechanism has housing and driving cam and pusher with a roller mounted inside the housing. The pusher can reciprocate in guides of the housing. The cam and roller are made as eccentrics. Gears are rigidly secured to each eccentric. EFFECT: improved design. 6 dwg

Description

 The invention relates to mechanical engineering and is intended to convert rotational motion to translational.

Known three-link cam mechanism with a progressively moving flat pusher, comprising a housing with a drive cam and a flat pusher located therein, with the possibility of translational movement in the guide of the housing [1]
This mechanism does not allow changing the magnitude of the stroke and speed parameters of the pusher. To change these values, it is necessary to manufacture a new cam.

Closest to the proposed is a three-link cam mechanism comprising a housing with a drive cam placed therein and a pusher with a roller having the possibility of translational movement in the housing guide [2]
However, the known mechanism does not allow changing the magnitude of the stroke of the pusher, which significantly narrows its kinematic capabilities. To change the stroke of a known mechanism, it is necessary to manufacture a new cam.

 The aim of the invention is to expand the kinematic capabilities of the mechanism due to readjustment.

 The goal is achieved by the fact that in the known cam mechanism, comprising a housing with a drive cam and a pusher with a roller that can translate in the guides of the housing, the cam and roller are made in the form of eccentrics, on each of which gear gears are fixed rigidly to the circles of the eccentrics. and the diameters of the pitch circles of the gears are equal to the diameters of the circles of the corresponding eccentrics.

 Due to this embodiment of the mechanism, the eccentrics slip against each other is eliminated, which ensures the constancy of the phase angle and, therefore, the invariance of the cycle for a given phase angle.

 Such a constructive solution allows for the changeover to change the stroke of the pusher by changing the phase angle of rotation of one of the eccentrics, which expands the kinematic capabilities of the mechanism.

 Thus, by providing readjustment of the mechanism, it becomes possible to change the stroke and speed parameters of the pusher, which expands the kinematic capabilities of the mechanism.

1(φ₀= 0,45,90^°);
на фиг. 5 то же при

0,5(φ₀= 0,45,90^°); на фиг. 6 то же при

0,25(φ₀= 0,45^°).In FIG. 1 schematically shows a mechanism; in FIG. 2, section AA in FIG. 1; in FIG. 3 design scheme; in FIG. 4 graph of the movement of the pusher at

1 (φ ₀ = 0.45.90 ^° );
in FIG. 5 the same for

0.5 (φ ₀ = 0.45.90 ^° ); in FIG. 6 the same for

0.25 (φ ₀ = 0.45 ^° ).

 The cam mechanism comprises a housing 1, in which a drive cam 2 is mounted on the bearings, made in the form of an eccentric with a gear 3 fixed to an equidistant circumference of the cam 2, the diameter of the pitch circumference of the gear 3 being equal to the diameter of the cam 2 circumference. the pusher 4, in which the roller 5 is mounted on the bearings, made in the form of an eccentric, on which the gear 6 is fixed equidistant to the circumference of the roller 5, the diameter being The circumferential circumference of the gear 6 is equal to the diameter of the circumference of the roller 5. The roller 5 is pressed against the cam 2 by a clamping device made in the form of a spring, a pneumatic cylinder, etc. (not shown in FIGS. 1 and 2).

 The cam mechanism operates as follows.

 When the cam 2 rotates, the roller 5 rises and rotates simultaneously in the bearings of the pusher 4, and as a result of the interaction of the cam 2 and the roller 5 (eccentrics), the pusher 4 moves.

 It should be noted that the gearing of gears 3 and 6 relative to the instantaneous centers of rotation of the gears is constant both in terms of the center-to-center distance and the angle of engagement, and the axial loads of the gearing are compensated by the surfaces of the eccentrics (ie, the teeth are not “pressed” into each other).

The kinematic parameters of the mechanism are varied by separating gears 3 and 6 and rotating the roller 5 by a certain phase angle φ ₀ (in the initial state of the mechanism φ = 0).

-l₂·cos(Ψ+φ₀)-l₁cosφ где Ψ

U+arcsin

d₁ диаметр кулачка 2, он же диаметр делительной окружности шестерни 3;
d₂ диаметр ролика 5 (эксцентрика), он же диаметр делительной окружности шестерни 6;
l₂ эксцентриситет ролика 5;
φ₀ фазовый угол сдвига ролика 5 в исходном положении;
l₁ эксцентриситет кулачка (эксцентрика);
φ текущий угол поворота кулачка 2.The stroke x of the pusher 4 is generally determined by the formula
x

-l ₂ cos (Ψ + φ ₀ ) -l ₁ cosφ where Ψ

U + arcsin

d _{1 the} diameter of the cam 2, it is the diameter of the pitch circle of the gear 3;
d _{2 the} diameter of the roller 5 (eccentric), it is the diameter of the pitch circle of the gear 6;
l _{2 the} eccentricity of the roller 5;
φ _{0 the} phase angle of the shift of the roller 5 in the initial position;
l ₁ cam eccentricity (cam);
φ current angle of rotation of cam 2.

KTo simplify the calculations, the assumption was used

K

Claims (1)

 A CAM MECHANISM comprising a housing with a drive cam and a pusher with a roller that can translate in the guides of the housing, characterized in that the cam and roller are made in the form of eccentrics, on each of which gear wheels are rigidly fixed to the circles of the eccentrics, with diameters pitch circles of gears are equal to the diameters of the circles of the corresponding eccentrics.

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