Machine element or mechanism – Mechanical movements – Reciprocating or oscillating to or from alternating rotary
Patent
1997-12-04
2000-07-11
Bucci, David A.
Machine element or mechanism
Mechanical movements
Reciprocating or oscillating to or from alternating rotary
334 20, H03J 300, F16H 2702
Patent
active
06085605&
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to an actuator for linear movement comprising a motor provided with a rotatable motor axle, a movement axle, a thread transmission between the motor axle and the movement axle, a supporting frame, a controlling support between the supporting frame and the movement axle for changing the rotating movement of the motor axle into a linear movement of the movement axle, and further, a clearance removing means for removing clearance in the axial direction, the actuator for linear movement being such that the thread transmission between the motor axle and the movement axle comprises an internal thread in the motor axle and an external thread in the movement axle.
The present actuator for linear movement can be used for moving a frequency control element especially in a filter, such as a combiner filter, used in a base station of a cellular radio network. Actuators for linear movement use an electrically driven stepping motor whose rotating movement is changed into a linear movement. The changing of the rotating movement into a linear movement is a result of the movement axle being supported on a supporting frame, that is, in practice, on a mounting flange of the motor, whereupon the rotating movement of the motor axle changes into a linear movement of the movement axle because the movement axle is not able to rotate.
In prior art solutions there is an external thread in the motor axle and an internal thread in the movement axle. A so-called square axle is used as a movement axle in prior art solutions, the axle being quadrangular at its external surfaces and supported on the square-shaped opening in the supporting frame. The square axle comprises an internal thread inside it against which the external thread of the motor axle is settled. This construction is poor for the support of the movement axle as the supporting surfaces of the movement axle, that is, the overlapping portion of the threads and, on the other hand, the supporting point of the movement axle are more or less on top of each other, whereby there is no distance between the supporting surfaces when viewed in the axial direction. In this construction the support of the movement axle will be inadequate and it causes clearance which impairs the properties of the construction. One disadvantage is also that the construction will be long in the axial direction, that is, great in size. In prior art solutions clearance is removed by using only an axial spring which, when stressed in the axial direction, removes clearance only in the axial direction.
In other solutions, that is, mainly in heavy transfer operations, it is known to use such actuators for linear movement that have a different thread transmission, that is, a thread transmission in which there is an internal thread in the motor axle and an external thread in the movement axle. Such solutions are disclosed e.g. in U.S. Pat. Nos. 2,476,584, 3,008,340, 3,377,878, 2,471,129, 4,497,215 and CH-649,357. The references cited and also other prior art solutions have a problem in that the removal of clearance of the movement axle remains inadequate. This problem is emphasized in one special application of the invention, that is, in transfer of a light frequency control element, because clearance causes a control error.
The object of the present invention is to introduce a new kind of actuator for linear movement that will obviate the problems associated with prior art solutions.
The object is attained with a solution according to the invention that is characterized in that the actuator for linear movement comprises a means for removing vertical, horizontal and rotary clearances.
Several advantages are attained with the actuator for linear movement according to the invention. The actuator for linear movement according to the invention is such that a very accurate operation is achieved with it because the vertical, horizontal and rotary clearances of the movement axle are also removed in addition to ordinary removal of clearance, that is, removal of clearance in the axial directi
REFERENCES:
patent: 2476584 (1949-07-01), Clark
patent: 2481129 (1949-09-01), Tourneau
patent: 2690682 (1954-10-01), Passman
patent: 3008340 (1961-11-01), Chillson
patent: 3377878 (1968-04-01), Maroth
patent: 3715690 (1973-02-01), Young et al.
patent: 4179944 (1979-12-01), Conner
patent: 4246991 (1981-01-01), Oldakowshi
patent: 4497215 (1985-02-01), Gronbech et al.
patent: 4772849 (1988-09-01), Tedder
Bucci David A.
Hansen Colby
Nokia Telecommunications Oy
LandOfFree
Actuator for linear movement does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Actuator for linear movement, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Actuator for linear movement will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-530772