EP0093715A1 - Combined linear motor and carriage - Google Patents

Combined linear motor and carriage

Info

Publication number
EP0093715A1
EP0093715A1 EP82901338A EP82901338A EP0093715A1 EP 0093715 A1 EP0093715 A1 EP 0093715A1 EP 82901338 A EP82901338 A EP 82901338A EP 82901338 A EP82901338 A EP 82901338A EP 0093715 A1 EP0093715 A1 EP 0093715A1
Authority
EP
European Patent Office
Prior art keywords
carriage
core
linear motor
combination according
armature
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
EP82901338A
Other languages
German (de)
French (fr)
Other versions
EP0093715A4 (en
Inventor
David A. Sutton
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
DMA Systems Corp
Original Assignee
DMA Systems Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by DMA Systems Corp filed Critical DMA Systems Corp
Publication of EP0093715A1 publication Critical patent/EP0093715A1/en
Publication of EP0093715A4 publication Critical patent/EP0093715A4/en
Ceased legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02KDYNAMO-ELECTRIC MACHINES
    • H02K41/00Propulsion systems in which a rigid body is moved along a path due to dynamo-electric interaction between the body and a magnetic field travelling along the path
    • H02K41/02Linear motors; Sectional motors
    • H02K41/035DC motors; Unipolar motors
    • H02K41/0352Unipolar motors
    • H02K41/0354Lorentz force motors, e.g. voice coil motors
    • H02K41/0356Lorentz force motors, e.g. voice coil motors moving along a straight path
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/48Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
    • G11B5/54Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head into or out of its operative position or across tracks

Definitions

  • the present invention relates to a linear motor and side mounted outboard carriage combination and, more particularly, to such a linear motor and carriage in which the center of gravity of the carriage and motor armature is aligned with the center of force of the linear motor.
  • a typical disc storage device includes a number of discs coated with a suitable magnetic material mounted for rotation on a common spindle and a set of transducer heads carried in pairs on elongate supports for insertion between adjacent discs, the heads of each pair facing in opposite directions to engage opposite faces of adjacent discs.
  • the support structure is coupled to the linear motor, the linear motor typically including a coil mounted within a magnetic field for linear movement and oriented relative to the discs to move the heads radially over the disc surfaces to thereby enable the heads to be positioned over any annular track on the surfaces.
  • the linear motor in response to control signals from the computer, positions the transducer heads radially for recording data signals on or retrieving data signals from a preselected one of a set of concentric recording tracks on the discs.
  • a widely used computer motor is open at one end and a helical armature coil supported by a matching cylindrical tube projects into the open end of the motor.
  • the coil is adhered to the end of the tube and the tube is mounted on a carriage that moves back and forth under influence of the motor coil.
  • the equipment to be moved is mounted on the carriage.
  • the carriage moves on accurately ground ways so that the equipment (read-write transducers) secured to the carriage is moved with great accuracy.
  • the present invention solves the length problem necessary to accomodate heads, armature and magnetic structure in a series arrangement by providing a side mounted outboard carriage. Still further, the present invention overcomes the structural resonance and offset force problems of the Gillum design by arranging the carriage and the carriage ways so that there is an equal mass on each side of the center of force so that the center of gravity and the center of force are coaxial. As a result, there are no offset torquing forces and structural resonance problems are eliminated. This also permits the location of a crash stop very close to the center of gravity so that as the carriage assembly decelerates, it is not rotated.
  • the object of the present invention is to solve the problems associated with linear motors with side mounted outboard carriages. It is a feature of the present invention to solve these problems by arranging the center of gravity of the carriage and armature so that it is aligned with the center of force of the core- and armature.
  • An advantage to be derived is the elimination of forces attempting to rotate the carriage assembly.
  • a further advantage is the elimination of structural resonance problems.
  • a still further advantage is the elimination of the likelihood of the carriage bearings being knocked off its ways.
  • Another advantage is making the voice coil a structural member.
  • Another advantage is a side mounted carriage having a compact size.
  • Another advantage is a bearing guidance system which is symmetrical about the center line of force and motion.
  • Figure 1 is a perspective view of a linear motor and side mounted outboard carriage combination constructed in accordance with the teachings of the present invention, shown in operative relationship to a fixed support and a rotating magnetic disc;
  • Figure 2 is a top plan view thereof
  • FIGs 3, 4 and 5 are sectional views taken along the lines 3-3, 4-4 and 5-5, respectively, in Figure 2;
  • Figure 6 is a partial sectional view taken along the line 6-6 in Figure 5.
  • a combined linear motor and side mounted outboard carriage generally designated 10, which is shown in its preferred embodiment as being used in a magnetic data storage system for moving read-write transducers 12 over the surfaces 11 of moving data media, such as discs 13.
  • Discs 13 typically have a mangetic material coated on both surfaces 11 thereof to enable data to be magnetically recorded thereon.”
  • Discs 13 would be mounted coaxially on a spindle (not shown) which is driven by a spindle motor (not shown) which rotates discs 13 about an axis defined by the spindle.
  • Heads 12 are connected by gimbal assemblies 12a to the free ends of rigid cantilevered arms 14. As shown in Figures 1, 3 and 4, multiple arms 14/heads 12 can be mounted in facing relationship to transcribe data on the opposite surfaces 11 of discs
  • carriage 15 is physically coupled to the moving coil (armature) of a linear positioner motor, generally designated 16, which, in response to the application of positioning signals thereto, is capable of linearly moving carriage 15 so as to linearly move heads 12 radially over surfaces 11. This permits heads 12 to be selectively positioned over any one of a plurality of annular recording tracks defined on disc recording surfaces 11.
  • heads 12 In normal operation, that is, when heads 12 are writing data onto or reading data from surfaces 11 of discs 13, heads 12 will be loaded. When a head is loaded, it simply means that a spring force is acting upon the head to urge it toward surface 11 of disc 13. This force is counteracted by an air cushion caused by the rapid rotation of disc 13 so that head 12 actually flies immediately above surface 11. In magnetic disc drives, heads 12 may fly at distances of less than 20 microinches above surfaces 11.
  • Motor 16 includes a magnetic structure constructed preferably of high permeability iron. This structure consists of a central core 21, two end plates 22 and 23, a top plate 26 and a bottom plate 28. Fastening screws 24 are used to attach end plates 22 and 23 to core 21 and plates 26 and 28. Screws 27 are used to hold the entire magnetic structure to a base support 25. The result is a very rigid support structure for motor 16.
  • a pair of permanent magnet slabs 31 and 32 are fastened to a top plate 26 and bottom plate 28, respectively. Epoxy is the preferred means for fastening. Magnetization of slabs 31 and 32 is in the vertical direction, as shown by arrows "A" ( Figure 5) . As shown most clearly in Figure 5, magnets 31 and 32 are positioned in spaced relationship on opposite sides of core 21 to provide a working air gap between the interior surfaces of magnets 31 and 32 and core 21. Disposed within these working air gaps is a helically-wound coil 33 of conductor material, such a copper or aluminum, coil 33 having a rectangular cross-section and being wound on a suitable tube (not shown) and having end flanges 34.
  • Motor/carriage 10 includes a plurality of carriage ways, specifically rods 35 and 36, secured on opposite sides of motor 16. More specifically, rods 35 and 36 may be bolted by means of bolts 37 to the sides of supports 38 and 39, respectively, connected to base support 25.
  • the longitudinal axis of rods 35 and 36 are parallel, parallel to the longitudinal axis of core 21, and the axes of rods 35 and 36 and core 21 are preferably coplanar.
  • Opposed support arms 14 can be bolted together by means of bolts 17 with a spacer 18 therebetween.
  • the ends of arms 14 adjacent bolts 17 and spacer 18 are connected to first portion 19 of carriage 15 positioned on one side of motor 16.
  • Carriage portion 19 is a structural member having any desired configurations suitable for its function, to be described.
  • One end of carriage portion 19 is connected to arms 14 and spacers 18 by bolts 17, as described previously.
  • One side of carriage portion 19 is connected to flanges 34 and coil 33, such as by being epoxied thereto, as shown at 40.
  • the opposite side of carriage portion 19 supports, by means of a plurality of axles 41, a plurality of roller bearings 42 which engage rod 35 at approximately 90 degree intervals.
  • Four spaced roller bearings, two above and two below, provide sufficient support for carriage portion 19 to ensure accurate linear movement thereof along rod 35.
  • Carriage 15 incudes an additional carriage portion 43 mounted on the side of coil 33 opposite to carriage portion 19.
  • carriage portion 43 has any shape suitable for its function and operation.
  • carriage portion 43 is an elongate member, one side of which is connected to flanges 34 and coil 33, such as by being epoxied thereto, as shown at 44.
  • the opposite side of carriage portion 43 supports, by means of an axle 45, a roller bearing 46 which engages the upper portion of rod 36.
  • carriage portion 43 also has connected thereto, by means of screws 47, one end of a spring member 48, the other end of which supports an axle 49 on which a roller bearing 50 is mounted.
  • Roller bearing 50 engages the lower portion of rod 36.
  • the combination of roller bearings 46 and 50 provides sufficient support for carriage portion 43 to ensure accurate linear movement thereof along rod 36.
  • carriage 15 is self-adjusting, i.e., it aligns itself with rods 35 and 36, whereby the entire movable carriage assembly remains aligned to the magnet structure.
  • coil 33 is, in essence, used as a structural member to interconnect carriage portions 19 and 43 which are mounted on opposite sides thereof.
  • the mass of carriage portion 43 is adjusted to be equal to the combined mass of carriage portion 19, arms 14 and the structure supported thereby so that the center of mass of the entire moving structure is aligned with the center of force of motor 16.
  • motor 16 drives coil 33 and carriage 15, there is no resulting torque so that any resonance or structural deflection does not result in physical deflection of the line of travel of heads 12.
  • stops 51A, 51B and 52A, 52B are mounted at opposite ends of motor 16, internally of the magnetic structure.
  • stops 51a, 51b, 52A and 52B are made from a suitable resilient material and are connected to the facing sides of supports 22 and 23, respectively.
  • stops 51a and 52a extend between core 21 and top plate 26 whereas stops 51b and 52b extend between core 21 and bottom plate 28.
  • stops 51a, 51b and 52a, 52b can be positioned very close to the center of gravity and symmetrically thereabout so that if flanges 34, which form the ends of coil 33, strike same, carriage 15 is decelerated without simultaneously applying a torque thereto.
  • Carriage 15 is side mounted relative to motor 16 to decrease the overall length of motor/carriage 10.
  • the bearing guidance system consisting of rods 35 and 36 is symmetrical about the center line of force and the plane of guidance. Stops 51 and 52 are located internally to the magnetic structure on the center line of the mass. The result is a highly efficient linear motor and side mounted outboard carriage combination.

Abstract

Une combinaison d'un moteur linéaire et d'un chariot extérieur monté latéralement comprend un noyau magnétique allongé (21) ayant un axe longitudinal, un induit (33) associé au noyau et mobile le long de l'axe, plusieurs chemins de chariotage (35, 36) fixés sur les côtés opposés du noyau, et un assemblage de chariots (15) monté sur les chemins et relié à l'induit pour se déplacer avec celui-ci le long de l'axe, des parties de l'assemblage de chariot étant montées sur les côtés opposés du noyau et agencées de sorte que le centre de gravité de l'assemblage du chariot et de tous les éléments connectés à celui-ci se trouve approximativement aligné avec le centre de force du noyau.A combination of a linear motor and a laterally mounted external carriage comprises an elongated magnetic core (21) having a longitudinal axis, an armature (33) associated with the core and movable along the axis, several carriage paths ( 35, 36) fixed on opposite sides of the core, and an assembly of carriages (15) mounted on the tracks and connected to the armature to move therewith along the axis, parts of the assembly carriage being mounted on opposite sides of the core and arranged so that the center of gravity of the carriage assembly and of all elements connected thereto is approximately aligned with the center of force of the core.

Description

COMBINED LINEAR MOTOR AND CARRIAGE
BACKGROUND OF THE INVENTION
!• Field of the Invention The present invention relates to a linear motor and side mounted outboard carriage combination and, more particularly, to such a linear motor and carriage in which the center of gravity of the carriage and motor armature is aligned with the center of force of the linear motor.
2. Description of the Prior Art While linear electric motors have many uses in industry, the present invention will be described with reference to a linear motor and carriage for use in a magnetic disc storage system for moving read-write transducers over the surface of moving data media discs. Such use of a linear motor calls for extremely high precision of movement. Magnetic disc storage systems of the type in which the present linear motor may be used are widely used to provide large volumes of relatively low-cost computer-accessible memory or storage. A typical disc storage device includes a number of discs coated with a suitable magnetic material mounted for rotation on a common spindle and a set of transducer heads carried in pairs on elongate supports for insertion between adjacent discs, the heads of each pair facing in opposite directions to engage opposite faces of adjacent discs. The support structure is coupled to the linear motor, the linear motor typically including a coil mounted within a magnetic field for linear movement and oriented relative to the discs to move the heads radially over the disc surfaces to thereby enable the heads to be positioned over any annular track on the surfaces. In normal operation, the linear motor, in response to control signals from the computer, positions the transducer heads radially for recording data signals on or retrieving data signals from a preselected one of a set of concentric recording tracks on the discs.
A widely used computer motor is open at one end and a helical armature coil supported by a matching cylindrical tube projects into the open end of the motor. The coil is adhered to the end of the tube and the tube is mounted on a carriage that moves back and forth under influence of the motor coil. The equipment to be moved is mounted on the carriage. The carriage moves on accurately ground ways so that the equipment (read-write transducers) secured to the carriage is moved with great accuracy.
It has been generally believed that the dynamic accuracy necessary for movement of read-write transducers along an exact axis requires that the carriage be coaxial with the linear motor and that the mounting for the transducers also be coaxial. It has been generally believed that the non-coaxial transfer of motion from the armature coil would result in torques and moments that would so distort the carriage and its components that the required accuracy could not be achieved.
Unfortunately, when mounting the carriage coaxially with the linear motor, considerable length is required to accommodate the heads, coil and magnetic structure. With the present emphasis on providing magnetic storage systems in as small a package as possible, too much longitudinal space is required for a motor/carriage coaxial arrangement.
As a space saving innovation, it has been proposed to provide a carriage mounted on the side of a linear electric motor for motion parallel to the armature axis. A typical such combined linear motor and side mounted carriage combination is disclosed and claimed in U.S. Patent No. 3,656,015 to Donald E. Gillum and entitled "Combined Linear Motor and Carriage". By mounting the carriage off to one side, the magnetic structure need not be in series with the heads and the carriage.
Experience has shown that serious problems do indeed arise from this type of structure because the center of gravity of the moving mass does not line up with the center of force provided by the motor. Structural resonance has proved to be a serious problem with this configuration since the offset force excites lateral vibration modes not seen in a coaxial structure. The only thing that resists the laterial force is the bearing preload and, under certain circumstances, this can be overcome, knocking the carriage bearings off their ways. This often occurs in a runaway situation. That is, one problem with linear motors and servo loops in general is that they can get lost. In other words, the computer could signal the linear motor to move the transducer head in one direction, searching for a track which the head has in fact already passed. Often, the head continues accelerating until it reaches a mechanical stop at the end of its travel. The impact of hitting the mechanical stop with the center of gravity of the moving mass misaligned with the center of force can and does knock a bearing off its track because the force overcomes the bearing preload. SUMMARY OF THE INVENTION
In accordance with the present invention, these problems are solved in a manner unknown heretofore. The present invention solves the length problem necessary to accomodate heads, armature and magnetic structure in a series arrangement by providing a side mounted outboard carriage. Still further, the present invention overcomes the structural resonance and offset force problems of the Gillum design by arranging the carriage and the carriage ways so that there is an equal mass on each side of the center of force so that the center of gravity and the center of force are coaxial. As a result, there are no offset torquing forces and structural resonance problems are eliminated. This also permits the location of a crash stop very close to the center of gravity so that as the carriage assembly decelerates, it is not rotated.
Briefly, a linear motor and side mounted outboard carriage combination constructed in accordance with the teachings of the present invention comprises an elongate magnetic core having a longitudinal motion axis, an armature associated with the core and being movable along the axis, plural carriage ways secured on opposite sides of the core, and a carriage assembly mounted on the ways and connected to the armature for movement therewith along the axis, portions of the carriage assembly being mounted on the opposite sides of the core and being so arranged that the center of gravity of the carriage assembly and all elements connected thereto is aligned approximately with the center of force of the core.
Therefore, the object of the present invention is to solve the problems associated with linear motors with side mounted outboard carriages. It is a feature of the present invention to solve these problems by arranging the center of gravity of the carriage and armature so that it is aligned with the center of force of the core- and armature. An advantage to be derived is the elimination of forces attempting to rotate the carriage assembly. A further advantage is the elimination of structural resonance problems. A still further advantage is the elimination of the likelihood of the carriage bearings being knocked off its ways. Another advantage is making the voice coil a structural member. Another advantage is a side mounted carriage having a compact size. Another advantage is a bearing guidance system which is symmetrical about the center line of force and motion. Another advantage is the ability to provide crash stop bumpers located internal to the magnetic structure on the center line of the- moving mass. Still other objects, features, and attendant advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed description of the preferred embodiment constructed in accordance therewith, taken in conjunction with the accompanying drawings wherein like numerals designate like parts in the several figures and wherein:
- UR BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of a linear motor and side mounted outboard carriage combination constructed in accordance with the teachings of the present invention, shown in operative relationship to a fixed support and a rotating magnetic disc;
Figure 2 is a top plan view thereof;
Figures 3, 4 and 5 are sectional views taken along the lines 3-3, 4-4 and 5-5, respectively, in Figure 2; and
Figure 6 is a partial sectional view taken along the line 6-6 in Figure 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, there is shown a combined linear motor and side mounted outboard carriage, generally designated 10, which is shown in its preferred embodiment as being used in a magnetic data storage system for moving read-write transducers 12 over the surfaces 11 of moving data media, such as discs 13. Discs 13 typically have a mangetic material coated on both surfaces 11 thereof to enable data to be magnetically recorded thereon." Discs 13 would be mounted coaxially on a spindle (not shown) which is driven by a spindle motor (not shown) which rotates discs 13 about an axis defined by the spindle.
Data is recorded on disc surfaces 11 by signals applied to transducer assemblies 12, typically referred to as "heads" . Heads 12 are connected by gimbal assemblies 12a to the free ends of rigid cantilevered arms 14. As shown in Figures 1, 3 and 4, multiple arms 14/heads 12 can be mounted in facing relationship to transcribe data on the opposite surfaces 11 of discs
13, all of arms 14 being connected to a common portion 19 of a carriage, generally designated 15. As will be described more fully hereinafter, carriage 15 is physically coupled to the moving coil (armature) of a linear positioner motor, generally designated 16, which, in response to the application of positioning signals thereto, is capable of linearly moving carriage 15 so as to linearly move heads 12 radially over surfaces 11. This permits heads 12 to be selectively positioned over any one of a plurality of annular recording tracks defined on disc recording surfaces 11.
In normal operation, that is, when heads 12 are writing data onto or reading data from surfaces 11 of discs 13, heads 12 will be loaded. When a head is loaded, it simply means that a spring force is acting upon the head to urge it toward surface 11 of disc 13. This force is counteracted by an air cushion caused by the rapid rotation of disc 13 so that head 12 actually flies immediately above surface 11. In magnetic disc drives, heads 12 may fly at distances of less than 20 microinches above surfaces 11. For a more complete description of the means for supporting heads 12 above surfaces 11, for applying the force thereto, and for withdrawing heads 12 for surfaces 11, reference should be had to copending application serial number , filed and entitled "Head Loading and Retraction Apparatus for Magnetic Disc Storage Systems" and assigned to DMA Systems Corporation, the assignee of the present application.
Motor 16 includes a magnetic structure constructed preferably of high permeability iron. This structure consists of a central core 21, two end plates 22 and 23, a top plate 26 and a bottom plate 28. Fastening screws 24 are used to attach end plates 22 and 23 to core 21 and plates 26 and 28. Screws 27 are used to hold the entire magnetic structure to a base support 25. The result is a very rigid support structure for motor 16.
A pair of permanent magnet slabs 31 and 32 are fastened to a top plate 26 and bottom plate 28, respectively. Epoxy is the preferred means for fastening. Magnetization of slabs 31 and 32 is in the vertical direction, as shown by arrows "A" (Figure 5) . As shown most clearly in Figure 5, magnets 31 and 32 are positioned in spaced relationship on opposite sides of core 21 to provide a working air gap between the interior surfaces of magnets 31 and 32 and core 21. Disposed within these working air gaps is a helically-wound coil 33 of conductor material, such a copper or aluminum, coil 33 having a rectangular cross-section and being wound on a suitable tube (not shown) and having end flanges 34. The result is that coil 33, its support tube, and flanges 34 surround core 21 and reciprocate back and forth along the length of core 21, depending upon the current passed through coil 33. The operation of such a linear motor is well known to those skilled in the art. Motor/carriage 10 includes a plurality of carriage ways, specifically rods 35 and 36, secured on opposite sides of motor 16. More specifically, rods 35 and 36 may be bolted by means of bolts 37 to the sides of supports 38 and 39, respectively, connected to base support 25. The longitudinal axis of rods 35 and 36 are parallel, parallel to the longitudinal axis of core 21, and the axes of rods 35 and 36 and core 21 are preferably coplanar.
Opposed support arms 14 can be bolted together by means of bolts 17 with a spacer 18 therebetween. The ends of arms 14 adjacent bolts 17 and spacer 18 are connected to first portion 19 of carriage 15 positioned on one side of motor 16. Carriage portion 19 is a structural member having any desired configurations suitable for its function, to be described. One end of carriage portion 19 is connected to arms 14 and spacers 18 by bolts 17, as described previously. One side of carriage portion 19 is connected to flanges 34 and coil 33, such as by being epoxied thereto, as shown at 40. The opposite side of carriage portion 19 supports, by means of a plurality of axles 41, a plurality of roller bearings 42 which engage rod 35 at approximately 90 degree intervals. Four spaced roller bearings, two above and two below, provide sufficient support for carriage portion 19 to ensure accurate linear movement thereof along rod 35.
Carriage 15 incudes an additional carriage portion 43 mounted on the side of coil 33 opposite to carriage portion 19. As was the case with carriage portion 19, carriage portion 43 has any shape suitable for its function and operation. As shown most clearly in Figures 2, 4, 5 and 6, carriage portion 43 is an elongate member, one side of which is connected to flanges 34 and coil 33, such as by being epoxied thereto, as shown at 44. The opposite side of carriage portion 43 supports, by means of an axle 45, a roller bearing 46 which engages the upper portion of rod 36.
The same side of carriage portion 43 also has connected thereto, by means of screws 47, one end of a spring member 48, the other end of which supports an axle 49 on which a roller bearing 50 is mounted. Roller bearing 50 engages the lower portion of rod 36. The combination of roller bearings 46 and 50 provides sufficient support for carriage portion 43 to ensure accurate linear movement thereof along rod 36. Furthermore, by spring mounting roller bearing 50, carriage 15 is self-adjusting, i.e., it aligns itself with rods 35 and 36, whereby the entire movable carriage assembly remains aligned to the magnet structure.
It can be seen that coil 33 is, in essence, used as a structural member to interconnect carriage portions 19 and 43 which are mounted on opposite sides thereof. According to the techings of the present invention, the mass of carriage portion 43 is adjusted to be equal to the combined mass of carriage portion 19, arms 14 and the structure supported thereby so that the center of mass of the entire moving structure is aligned with the center of force of motor 16. As a result, as motor 16 drives coil 33 and carriage 15, there is no resulting torque so that any resonance or structural deflection does not result in physical deflection of the line of travel of heads 12.
Also in accordance with the present invention, four stops 51A, 51B and 52A, 52B, are mounted at opposite ends of motor 16, internally of the magnetic structure. Specifically, stops 51a, 51b, 52A and 52B are made from a suitable resilient material and are connected to the facing sides of supports 22 and 23, respectively. As seen most clearly in Figure 4, stops 51a and 52a extend between core 21 and top plate 26 whereas stops 51b and 52b extend between core 21 and bottom plate 28. What should be apparent is that stops 51a, 51b and 52a, 52b can be positioned very close to the center of gravity and symmetrically thereabout so that if flanges 34, which form the ends of coil 33, strike same, carriage 15 is decelerated without simultaneously applying a torque thereto. The features and advantages of the present invention should now be apparent. Carriage 15 is side mounted relative to motor 16 to decrease the overall length of motor/carriage 10. The bearing guidance system consisting of rods 35 and 36 is symmetrical about the center line of force and the plane of guidance. Stops 51 and 52 are located internally to the magnetic structure on the center line of the mass. The result is a highly efficient linear motor and side mounted outboard carriage combination. While the invention has been described with respect to the preferred physical embodiment constructed in accordance therewith, it will be apparent to those skilled in the art that various modifications and improvements may be made without departing from the scope and spirit of the invention. Accordingly, it is to be understood that the invention is not to be limited by the specific illustrative embodiment, but only by the scope of the appended claims.

Claims

I CLAIM;
1. A linear motor and side mounted outboard carriage combination comprising: an elongate magnetic core having a longitudinal motion axis; an armature associated with said core and being movable along said axis; plural carriage ways secured on opposite sides of said core; and a carriage assembly mounted on said ways and connected to said armature for movement therewith along said axis, portions of said carriage assembly being mounted on said opposite sides of said core and being so arranged that the center of gravity of said carriage assembly and all elements connected thereto is approximately aligned with the center of force of said core.
2. A linear motor and side mounted outboard carriage combination according to claim 1, wherein said magnetic core is supported at the opposite ends thereof and wherein said armature surrounds said core for reciprocation relative thereto.
3. A linear motor and side mounted outboard carriage combination according to claim 2, wherein said armature comprises: a tube surrounding said core and having end flanges; and a helical coil of conductor material wound on said tube, between said flanges.
4. A linear motor and side mounted outboard carriage combination according to claim 3, wherein said carriage assembly comprises: a first carriage portion positioned on one side of said core and connected to said tube flanges; and a second carriage portion positioned on an opposite side of said core and connected to said tube flanges.
5. A linear motor and side mounted outboard carriage combination according to claim 4, wherein each of said carriage portions supports at least a pair of roller bearings for engaging said carriage ways.
6. A linear motor and side mounted outboard carriage combination according to claims 1 or 2, wherein said carriage ways comprises: first and second elongate rods positioned on opposite sides of said core, the longitudinal axes of said rods being parallel to each other and parallel to the longitudinal axis of said core.
7. A linear motor and side mounted outboard carriage combination according to claim 6, wherein the axes of said rods and said core are coplanar.
8. A linear motor and side mounted outboard carriage combination according to claim 6, wherein said carriage assembly comprises: a first carriage portion positioned on one side of said core, one side of said first carriage portion being structurally connected to said armature, the opposite side of said first carriage portion supporting a plurality of roller bearings which engage said first rod.
9. A linear motor and side mounted outboard carriage combination according to claim 8, wherein different ones of said roller bearings supported by said first carriage portion engage different portions of said first rod.
10. A linear motor and side mounted outboard carriage combination according to claim 8, wherein said carriage assembly further comprises: a second carriage portion positioned on a side of said core opposite to said first carriage portion, one side of said second carriage portion being structurally connected to said armature, the opposite side of said second carriage portion supporting a plurality of roller bearings which engage said second rod.
11. A linear motor and side mounted outboard carriage combination according to claim 10, wherein different ones of said roller bearings supported by said second carriage portion engage different portions of said second rod.
12. A linear motor and side mounted outboard carriage combination according to claims 1, 2, 3, 4 or 5, further comprising: a pair of mechanical stops made from a resilient material positioned in the path of said armature.
13. A linear motor and side mounted outboard carriage combination according to claim 12, wherein said stops are positioned approximately on the center line of said carriage assembly.
EP19820901338 1981-11-16 1982-04-01 Combined linear motor and carriage. Ceased EP0093715A4 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US32138881A 1981-11-16 1981-11-16
US321388 1981-11-16

Publications (2)

Publication Number Publication Date
EP0093715A1 true EP0093715A1 (en) 1983-11-16
EP0093715A4 EP0093715A4 (en) 1984-04-17

Family

ID=23250409

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19820901338 Ceased EP0093715A4 (en) 1981-11-16 1982-04-01 Combined linear motor and carriage.

Country Status (7)

Country Link
EP (1) EP0093715A4 (en)
JP (1) JPS58501892A (en)
BR (1) BR8207980A (en)
CA (1) CA1185307A (en)
DE (1) DE8237132U1 (en)
GB (1) GB2120019B (en)
WO (1) WO1983001872A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0113008A1 (en) * 1982-12-29 1984-07-11 International Business Machines Corporation Magnetic actuator

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0222362B1 (en) * 1985-11-13 1990-05-09 Sharp Kabushiki Kaisha Linear motor
GB2187031B (en) * 1986-01-21 1990-10-17 Raymond Engineering Magnetic disc memory unit

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3149254A (en) * 1961-08-07 1964-09-15 Thomas A Carter Linear motor or generator
US3588767A (en) * 1969-02-13 1971-06-28 Esterline Corp Servomotor shuttle guide assembly
FR2421501A1 (en) * 1978-03-27 1979-10-26 Ibm ELECTROMAGNETIC LINEAR MOTOR AND ITS APPLICATION TO MOVING MAGNETIC HEADS IN A DISC MEMORY
DE2912531A1 (en) * 1979-03-29 1980-10-09 Papst Motoren Kg LINEAR MOTOR

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3521092A (en) * 1968-07-10 1970-07-21 Ibm Data storage extended stroke actuator
US3666977A (en) * 1970-09-10 1972-05-30 Sperry Rand Corp Linear positioner
NL7106185A (en) * 1971-05-06 1972-11-08
US3723780A (en) * 1971-07-06 1973-03-27 Information Magnetics Corp Self shielding linear motor
US3743870A (en) * 1972-06-28 1973-07-03 Ltv Ling Altec Inc Moving coil linear actuator
US3899699A (en) * 1972-12-19 1975-08-12 Ibm Brushless linear DC motor actuator
US4006372A (en) * 1975-03-10 1977-02-01 Wangco Incorporated Transducer positioner
US4287445A (en) * 1980-04-21 1981-09-01 Sperry Corporation High performance disk drive actuator

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3149254A (en) * 1961-08-07 1964-09-15 Thomas A Carter Linear motor or generator
US3588767A (en) * 1969-02-13 1971-06-28 Esterline Corp Servomotor shuttle guide assembly
FR2421501A1 (en) * 1978-03-27 1979-10-26 Ibm ELECTROMAGNETIC LINEAR MOTOR AND ITS APPLICATION TO MOVING MAGNETIC HEADS IN A DISC MEMORY
DE2912531A1 (en) * 1979-03-29 1980-10-09 Papst Motoren Kg LINEAR MOTOR

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO8301872A1 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0113008A1 (en) * 1982-12-29 1984-07-11 International Business Machines Corporation Magnetic actuator

Also Published As

Publication number Publication date
GB2120019A (en) 1983-11-23
EP0093715A4 (en) 1984-04-17
JPS58501892A (en) 1983-11-04
GB2120019B (en) 1985-11-06
DE8237132U1 (en) 1984-10-18
BR8207980A (en) 1983-10-04
CA1185307A (en) 1985-04-09
GB8317982D0 (en) 1983-08-03
WO1983001872A1 (en) 1983-05-26

Similar Documents

Publication Publication Date Title
US4427905A (en) Combined linear motor and side mounted outboard carriage
US4544972A (en) Swinging actuators for use in magnetic disc type memory devices
US4890176A (en) Crash stop and magnetic latch for a voice coil actuator
US4692999A (en) Method of making a multi-coil/multi-magnet actuator
US5224000A (en) Crash stop and magnetic latch for a voice coil actuator
JPS58161176A (en) Linear actuator for memory device
US4947274A (en) Resiliently mounted crash stop and magnetic latch for a voice coil actuator
US4908816A (en) Voice coil motor with linearized force constant
US3521092A (en) Data storage extended stroke actuator
US3886595A (en) Actuator for a disc drive apparatus
EP0550220B1 (en) Disk drive
US5023861A (en) Single stage tracking actuator apparatus for optical beam information storage drive system
US6538853B1 (en) E-block having improved resonance characteristics and improved fragility
US4573094A (en) Moving magnet disc drive actuator
US4612592A (en) Dual coil/dual magnet actuator
US4868432A (en) Multi-coil actuator with end cap flux carrier
US5016238A (en) Linear actuator for radial access in disk recorder/player
US3576454A (en) Data storage accessing mechanism with moving coil motor
US6330828B1 (en) Method and apparatus for subjecting a device to rotational vibration
US3769467A (en) Vibration damped transducer head assembly
US4006372A (en) Transducer positioner
US4166284A (en) Read/write head-positioning apparatus
KR0150438B1 (en) Linear actuator for disc drive
CA1185307A (en) Combined linear motor and side mounted outboard carriage
US7016157B1 (en) E-block having improved resonance characteristics and improved fragility

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): CH DE FR GB LI SE

17P Request for examination filed

Effective date: 19831105

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN REFUSED

18R Application refused

Effective date: 19860715

RIN1 Information on inventor provided before grant (corrected)

Inventor name: SUTTON, DAVID A.