Classifications

• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
  • D03D49/00—Details or constructional features not specially adapted for looms of a particular type
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
  • F16F15/00—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion
  • F16F15/02—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems
  • F16F15/04—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems using elastic means
  • F16F15/06—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems using elastic means with metal springs
  • F16F15/063—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems using elastic means with metal springs with bars or tubes used as torsional elements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
  • F16F15/00—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion
  • F16F15/22—Compensation of inertia forces

Definitions

• the invention relates to a method of balancing the dynamic effects of a material body with a periodic reversing motion by means of a balancing material body.
• the invention also proposes a device for carrying out the method
• the inertial effects of each body or the specific components of such effects or the resulting inertial effects of a plurality of bodies have been balanced by inertial effects of each balancing body or by inertial effects of a plurality of balancing bodies.
• the balancing body/bodies is/are attached to a suitable section of the mechanism to be balanced or of an auxiliary mechanism by means of a mechanism comprising rigid members such as gear wheels or articulation mechanisms.
• the motion of the balancing body is periodic and opposite in direction to the motion of the component to be balanced.
• the aim to be achieved by such balancing consists in reducing the effects acting in the mechanism and spreading to its surroundings, i.e., in most cases, to the machine frame.
• Relevant for the function of such balancing bodies is the motion that would be effected by an absolutely rigid mechanism. Both the compliance and the oscillations of the mechanism have no influence on the function of the balancing body Consequently, the effect of the balancing of the mechanism in this way does not depend on its operating frequency
• Its drawback consists in high stress imposed on some parts of the mechanism, in particular of the drive mechanism balancing the periodic motions both of the component to be balanced and of the balancing body
• Another well-known method of balancing the dynamic effects of a material body carrying out a periodic reversing motion consists in the application of a dynamic absorber This method is used in order to reduce the machine frame oscillations
• the balancing body is attached by means of an elastic member to the section of the machine where the oscillations shall be suppressed, and represents a system of the balancing body with elastic coupling
• said balancing body can rotate or slide only in the direction in which the oscillations shall be suppressed
• the mass of the balancing body and the compliance of the elastic member attaching it to the frame are selected so as to ensure, at the operation speed, such oscillations of the balancing body as are required to suppress said oscillations of the frame This is achieved by the resonance tumng of the system of the balancing body with elastic coupling
• the aim of the proposed method of balancing is the balancing or reduction of dynamic effects of a material body carrying out a pe ⁇ odic reversing motion, and the creation of a device for carrying out this method of balancing
• the principle of the device for carrying out the method of balancing according to the invention consists in that the material balancing body is connected with the material body to be balanced by means of a coupling comprising an elastic member.
• the balancing material body is mounted movable with respect both to the machine frame and to the material body to be balanced, due to the elastic member inserted between said bodies. Then, the balancing material body carries out a periodic reversing motion in the direction opposite to the component to be balanced of the inertial effects of the material body and thus creates balancing inertial effects reducing the inertial effects to be balanced.
• the advantage of the proposed method of, and device for, balancing the dynamic effects of the material body with periodic reversing motion consists in the reduction of the stress the drive mechanism is exposed to in a stabilized state under the force action of the compensation system consisting of the balancing material body and the elastic member, on the material body to be balanced
• Another advantage of the proposed solution consists in the elimination of the need to tune the compensation system exactly to the exciting frequency as is the case in dynamic absorbers requiring great intensification.
• the amplitudes of the periodic reversing motion are comparable or inferior to the amplitudes of the harmonic components of the periodic reversing motion of the material body to be balanced.
• a device which principle consists in that one end of the material body to be balanced has attached thereto, in the rotation axis of the body, one end of a torsion spring mounted for rotation in the machine frame and having fastened thereto the balancing material body.
• the material balancing body is preferably mounted on the free end of the torsion spring from the outer side of the machine frame.
• FIG. 1 An example of embodiment of the device for carrying out the method of balancing according to the invention is schematically shown in Fig. 1 relating to the balancing of the batten of a weaving machine.
• FIG. 2 a schematic representation of the beat-up mechanism of the weaving machine
• Fig. 3 the dependance of the rotation angle of the batten on the rotation angle of the crank of a four-linked mechanism
• Fig. 4 the dependance of the angular acceleration of the batten on the rotation angle of the crank of the four-linked mechanism
• Fig. 5 the dependance of the moment acting into the machine frame on the rotation angle of the crank of the four-linked mechanism.
• a batten I is in a well-known way rotatably mounted in a frame 2 of a weaving machine and is in a well-known way coupled with a well-known four-linked mechanism 3 coupled with a wellknown not represented drive of the weaving machine
• the batten i is the driven member of the four-linked mechanism 3 receiving from it its swinging motion, i e , its reversing rotary motion around the rotation axis U . of the batten I
• the well-known four-linked mechanism 3 consists of the frame 2 having housed therein a crank 3 _ coupled with a well-known not represented drive and adapted to turn around the rotation axis 311 of the crank 3_1
• a crank arm 32 Rotatably mounted on the crank 3_1 there is a crank arm 32 rotatably connected with the batten 1, the latter being at the same time mounted in the frame 2 of the weaving machine rotatably around the axis JJ . of rotation of the batten I
• a torsion spring 4 mounted near its other end rotatably in the frame 2 of the weaving machine, for instance by means of a bearing 5, the other end of the torsion spring 4 having fixed thereto a balancing material body 6
• the balancing material body 6 and the torsion spring 4 form together a compensation system whose natural frequency, determined by the mass of the balancing material body 6 and the elasticity of the torsion spring 4, is inferior to the frequency of the to-be-balanced harmonic component of the dynamic effects of the batten i so that the compensation system is excited in an over-resonance way, thus achieving the above effect
• the motion of the balancing material body 6 is opposite in direction to the motion of the material body to be balanced In case of an ideally rigid coupling without the elastic member or in case of a sub-resonance excitation, the balancing material body 6 would move concurrently with the material body to be balanced
• the dynamic effects of the moving balancing body 6 are in the described example of embodiment opposite and compensate the dynamic effects of the to-be-balanced harmonic component of the dynamic effects generated by the reversing rotary motion of the batten 1 At the same time, the energy produced by the moving balancing material body 6 and by the torsion spring 4 being twisted is accumulated and transmitted to the batten 1 thus reducing the stress imposed on the drive four-linked mechanism 3
• Fig 2 shows schematically a four-linked mechanism 3 acting as the beat-up mechanism of a weaving machine 1 ⁇ represents the distance between the batten rotation axis 11 . and the axis 311 of the drive crank 3J_, ____, the length of the crank 31; J , the length of the crank arm 32, and j, the distance between the rotation axis 11 of the batten 1 and the axis of connection with the crank arm 32.
• the other symbols mean, ⁇ the angular velocity of the crank 31; J ⁇ , the axial moment of inertia of the batten i, i.e , of the material body to be balanced; J, the axial moment of inertia of the balancing material body 6; ⁇ , the angle of revolution of the crank 3J . from the beat-up position; and ⁇ , the angle of rotation of the batten 1 from the beat-up position.
• the natural frequency ⁇ of the compensation system consisting of the torsion spring 4 and the balancing material body 6 can be calculated as follows:
• k stands for the order of the harmonic component
• g ⁇ for the phase offset
• m ⁇ for the moment related to the k-th harmonic component
• a ⁇ for the mean value of the batten 1 rotation angle, representing the nullth harmonic component.
• FIGs. 3 to 5 show the course of development of the angle ⁇ &_ of the batten rotation, of the angular acceleration of the batten 1, and of the moment acting into the frame 2 of the machine depending on the angle ⁇ of rotation of the crank 31 of the four-linked mechanism 3 of a given mechanism
• the comparison of the moment M ⁇ of an unbalanced mechanism with the moment M of the mechanism balanced by the method according to this invention shows clearly the reduction of the moment M acting into the frame 2 with the balanced mechanism

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Acoustics & Sound (AREA)
• Aviation & Aerospace Engineering (AREA)
• Mechanical Engineering (AREA)
• Textile Engineering (AREA)
• Manipulator (AREA)
• Registering, Tensioning, Guiding Webs, And Rollers Therefor (AREA)
• Looms (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=5464966

Family Applications (1)

Country Status (2)

Cited By (2)

Families Citing this family (1)

Family Cites Families (6)

• 1996
  • 1996-08-19 CZ CZ962440A patent/CZ284099B6/cs not_active IP Right Cessation
• 1997
  • 1997-07-24 WO PCT/CZ1997/000026 patent/WO1998008002A2/en active Application Filing

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