CN2346983Y

CN2346983Y - Disk-shape cam mechanism of concave arc bottom slave piece

Info

Publication number: CN2346983Y
Application number: CN 98221530
Authority: CN
Inventors: 贾延龄; 昃向博; 张尚盈
Original assignee: SHANDONG BUILDING MATERIALS INDUSTRIAL COLLEGE
Current assignee: SHANDONG BUILDING MATERIALS INDUSTRIAL COLLEGE
Priority date: 1998-06-17
Filing date: 1998-06-17
Publication date: 1999-11-03
Anticipated expiration: 2008-06-17

Abstract

The utility model relates to a disk-shaped cam mechanism of concave arc bottom slave piece, which is mainly composed of a cam 1, a driven piece 2 and a machine frame 3. The cam rotating at an angular velocity of omega [1] is a drive part. The driven piece moves or swings. The bottom surface of the cam connected with the driven piece is a concave circle arc shape. By hertz stress theory, the structure of the driven piece with the concave arc shape can obviously reduce the contact stress of the cam higher-pair, and the structure easily forms a lubricant film, so the abrasion is reduced and the mechanical life is improved. Therefore, the utility model can adapt the demands of the modern high-speed and heavy-duty machinery better and can also be conveniently used in the common machinery.

Description

Driven member disk cam mechanism at the bottom of the concave circular arc

The utility model is a kind of high-performance cam mechanism, is adapted to the requirement of modern mechanical high-speed overload especially.

Present general disk cam mechanism, its driven member bottom is roller or flat shape often, cam is driving link and rotates that driven member then moves back and forth or swings.The area of contact of driven member and cam was very little when this structural type made work, so contact stress is very big, was difficult for forming lubricant film, therefore was easy to wearing and tearing.And the roller follower complex structure, weight is bigger, and inertial force and noise are also bigger when therefore moving.So the cam mechanism of these two kinds of forms has been difficult to adapt to the requirement of modern mechanical high-speed overload.

The purpose of this utility model provides a kind of new type of cam mechanism of function admirable, and it is simple in structure, and is in light weight, and inertial force and noise are little during work; Can increase area of contact, reduce contact stress, form lubricant film easily, thereby alleviate wearing and tearing, improve mechanical life, can either adapt to the requirement of modern mechanical high-speed overload better, also can be advantageously used among the conventional machinery.

Accompanying drawing 1 is that one of structural type of the present utility model is the structure principle chart of reciprocating follower cam mechanism.

Accompanying drawing 2 is structure principle charts that another kind of structural type of the present utility model is cam with oscillating follower.

As shown in Figure 1, the utility model mainly is comprised of cam 1, driven member 2 and frame 3. Cam is driving link, with angular velocity omega₁Rotate around the O point, driven member moves back and forth. E is offset distance, is when e=0 core type is installed. The shape of driven member is different from common flat-face follower, and its bottom is not the plane, but radius is r_rConcaved circular cambered surface. Can prove that according to the hertz stress theory this planform can increase the composite curve radius of the secondary contact point of cam, strengthens the contact area between two members, significantly reduce contact stress, and be easier to form lubricating oil film, so can alleviate wearing and tearing, improve mechanical life; It is simple in structure, and is lightweight, and inertia force and noise are little during work, therefore can adapt to better the requirement of modern mechanical high-speed overload, also can be advantageously used in the common mechanical.

In the utility model cam mechanism, the concave circular arc radius r of driven member bottom surface _rSize system according to radius of cam base-circle r _o, offset distance e and driven member stroke h size and decide.

Need to prove that the utility model only allows the cam profile evagination, can not indent, must guarantee the maximum curvature radius ρ of cam profile curve _Max≤ r _rThe concave circular arc radius r of driven member bottom surface _r=1.2 (r _o+ e+h) or r _r=1.5 (r _o+ h).

The utility model is described in further detail below by accompanying drawing and example.

Offset roller-follower cam mechanism as shown in Figure 1, its Base radius r _o=25mm, offset distance e=5mm, driven member stroke h=30mm, the minimum profile curvature radius ρ of cam profile _Min=25mm, maximum curvature radius ρ _Max=40mm, radius r at the bottom of the driven member concave circular arc _r=72mm.If use roller follower, establish radius of roller r _T=5mm.Under the situation of all parameter constants, at the bottom of adopting roller follower, flatface follower and concave circular arc respectively during driven member, the contact stress that the cam by-product is given birth to such as shown in the following table:

The contact stress ratio	Cam ρ _minThe place	Cam ρ _maxThe place
The contact stress ratio	Cam ρ _minThe place	Cam ρ _maxThe place	σ _{H rolls}/σ _{H is recessed}	3	4.5
σ _{H is flat}/σ _{H is recessed}	1.24	1.5	σ _{H rolls}/σ _{H is recessed}	3	4.5

This shows that under the same conditions, the utility model has reduced the contact stress in the cam pair significantly, thereby reduce wearing and tearing, the life-span of having improved cam mechanism.According to lubrication theory, lubricating status of the present utility model also can be better.

Claims

1. driven member disk cam mechanism at the bottom of the concave circular arc is made up of cam, driven member and frame, and cam is driving link and rotates that driven member moves back and forth or swings, and of the present utility modelly is characterised in that the bottom shape of driven member is a concaved circular cambered surface.

2. driven member disk cam mechanism at the bottom of the concave circular arc according to claim 1 is characterized in that the concave circular arc radius r of driven member bottom surface _rSize system according to radius of cam base-circle r _o, offset distance e and driven member stroke h size and decide r _rShould be more than or equal to radius of curvature maximum on the cam profile.

3. driven member disk cam mechanism at the bottom of the concave circular arc according to claim 2 is characterized in that driven member bottom surface concave circular arc radius r _r=1.2 (r _o+ e+h) or r _r=1.5 (r _o+ h).