The disclosure herein relates to a linear actuator assembly for a data storage devices including rotating recording mediums.
An illustrative apparatus may include an actuator arm extending along an actuator axis between a proximal end and a distal end. The apparatus may also include one or more rails extending along a rail axis between a first end and a second end. The rail axis may be at an angle to the actuator axis. The actuator arm may be movably attached to the one or more rails such that the actuator arm may be restricted to linear motion along the one or more rails. The apparatus may also include a linear motor positioned adjacent to the actuator arm and adapted to move the actuator arm.
An illustrative system may include a drive base, a spindle attached to the drive base, and a recording medium rotatably coupled to the spindle. The system may also include an actuator arm extending along an actuator axis between a proximal end and a distal end. The actuator arm may include at least one head for reading and writing data from and to the recording medium. Further, the system may include one or more rails extending along a rail axis between a first end and a second end. The rail axis may be at an angle to the actuator axis. The actuator arm may be movably attached to the one or more rails such that the actuator arm may be restricted to linear motion along the one or more rails. The system may also include a linear motor positioned adjacent to the actuator arm and adapted to move the actuator arm.
An illustrative apparatus may include a first actuator arm extending along a first actuator axis between a proximal end and a distal end. The apparatus may also include a second actuator arm extending along a second actuator axis between a proximal end and a distal end. The distal end of the first actuator arm may be connected to the distal end of the second actuator arm. Further, the apparatus may include at least one head located proximate the distal ends of each of the first and second actuator. The at least one head may be adapted to read and write data from and to a recording medium. The apparatus may include a linear motor associated with each of the first and second actuator arms and positioned adjacent to the proximal end of the respective actuator arm and adapted to move the respective actuator arm. Each of the first and second actuator arms may include a base located proximate the proximal end and adapted to interact with the respective linear motor. Each of the first and second actuator arms may also include a suspension extending between the base and the at least one head. The suspension may define a thickness of less than 1 millimeter
The above summary is not intended to describe each embodiment or every implementation of the present disclosure. A more complete understanding will become apparent and appreciated by referring to the following detailed description and claims taken in conjunction with the accompanying drawings. In other words, these and various other features and advantages will be apparent from a reading of the following detailed description.
The disclosure may be more completely understood in consideration of the following detailed description of various embodiments of the disclosure in connection with the accompanying drawings.
Exemplary systems, apparatus, and methods shall be described with reference to
The present disclosure relates to a linear actuator for a data storage device. One way to improve areal density of a data storage device is to have a slider or head assembly with zero skew (or fixed skew) throughout the entire stroke of the slider or head assembly. For example, by configuring the slider to have zero skew throughout the entire stroke of the slider, the slider may be able to read data immediately after writing the data. In a skewed configuration, the angle of the slider relative to the data track (e.g., the stroke extending along an arc) may not allow for this immediate reading after writing. A slider using a linear actuator to move the slider linearly through the stroke may help to accomplish this task. For example, in a zero skew configuration, the read and/or write pole may be nominally normal to a centerline of the track and, in a fixed skew configuration, the read and/or write pole may be at a fixed angle that is nominally non-normal to the centerline of the track.
However, the linear actuator may also present some undesirable characteristics. For example, the linear actuator may encounter inertia issues, lower speed, and/or increased noise (e.g., relative to a pivoting actuator). Previously, these characteristics were undesirable because the trade-off of increased reliability and areal density (e.g., due to the zero skew) was not worth the potential decrease in performance (e.g., due to inertia, lower speed, and increased noise). As other types of storage become faster at reading and writing (e.g., solid state drives), data storage devices including rotating recording mediums have started to focus on improving areal density, even if it comes as a trade-off to higher performance. In other words, performance or speed may be reduced in an attempt to further improve areal density through increased reliability (e.g., by having zero skew throughout the entire stroke). As such, the data storage device having a linear actuator may act as an archival type of storage by providing an increase in dollar per terabyte as compared to a traditional pivoting actuator (i.e., these data storage devices may be used in a storage server for the cloud).
Additionally, by providing linear movement of the actuator, two actuators may be used in combination. For example, the head assemblies of the two actuators may be connected at each of the distal ends and the read/write heads may be located at the intersection (e.g., which is different than a drive having multiple independent actuators not connected at the distal ends). As a result, the thickness of the actuator (e.g., suspension of the actuator) may be reduced significantly. For example, with a typical actuator, a read/write head may be located on a cantilevered end of the head assembly and, therefore, the suspension of the actuator may need to be thick enough to support the weight of the actuator and the read/write head. However, because the read/write head may be supported by two separate actuators in this embodiment, the suspension of each actuator may be thinner. In other words, the read/write head may be supported at two points (e.g., a base end of each actuator). By providing a thinner suspension (e.g., relative to typical actuators that are cantilevered), the spacing between recording disks may be reduced and the resistance (e.g., air resistance) encountered by the actuators during operation may be reduced. Further, the two actuator configuration may also provide increased stiffness such that the suspension may be more robust to shock events. In one or more embodiments, the actuators may be different or the same (e.g., type, size, etc.) due to the actuators working together. For example, one of the actuators may be smaller than the other but still provide similar performance. Further yet, active control of head media spacing may be achieved at the suspension due to the two actuators combined at the distal ends.
Reference will now be made to the drawings, which depict one or more aspects described in this disclosure. However, it will be understood that other aspects not depicted in the drawings fall within the scope and spirit of this disclosure. Like numbers used in the figures refer to like components, elements, portions, regions, openings, apertures, and the like. However, it will be understood that the use of a reference character to refer to an element in a given figure is not intended to limit the element in another figure labeled with the same reference character.
The data storage device 100 may include a drive base 110, a spindle 102 attached to the drive base 110, and a recording medium 104 rotatably coupled to the spindle 102. The spindle 102 and the recording medium 104 may be any suitable spindle and medium as is known in the art. The drive base 110 may define a first side 111 and a second side 112 opposite the first side 111 (e.g., such that drive components of the data storage device 100 are located between the first and second sides 111, 112). Further, the drive base 110 may define a third side 113 and a fourth side 114 extending between the first and second sides 111, 112. In other words, the four sides may combine to define a rectangular box that may form the physical boundaries of the data storage device 100.
The linear actuator assembly 120 of the data storage device 100 may include one or more rails 130. For example, the one or more rails 130 may extend along a rail axis 135 between a first end 131 and a second end 132. As shown in
In one or more embodiments, the one or more rails 130 may include a first rail 136 and a second rail 138 (e.g., as shown in
The linear actuator assembly 120 may also include an actuator arm 140 extending along an actuator axis 145 between a proximal end 141 and a distal end 142. The actuator arm 140 may include at least one head 122 for reading and writing data from and to the recording medium 104. The at least one head 122 may be located proximate the distal end 142 of the actuator arm 140. Further, the actuator arm 140 may be movably attached to the one or more rails 130 proximate the proximal end 141 of the actuator arm 140. The actuator arm 140 may be movably attached to the one or more rails 130 such that the actuator arm 140 may be restricted to linear motion along the one or more rails 130. In other words, the actuator arm 140 may be movably attached to the one or more rails 130 so that the actuator arm 140 moves linearly and, therefore, the at least one head 122 also moves linearly relative to the recording medium 104.
The actuator arm 140 may be movably coupled to the one or more rails 130 in any suitable way. For example, the actuator arm 140 may include one or more sliding brackets (e.g., corresponding to the one or more rails 130) proximate the proximal end 141 of the actuator arm 140 to movably attach the actuator arm 140 to the one or more rails 130. Specifically, as shown in
Further, the actuator arm 140 may be movably coupled to the one or more rails 130 in such a way as to stabilize the actuator arm 140 as it moves linearly along the one or more rails 130. In other words, the actuator arm 140 is prevented from moving in other rotational or directional ways (e.g., other than linearly along the one or more rails 130). Also, the actuator axis 145 may be oriented at an angle relative to the rail axis 135. For example, as shown in
The linear actuator assembly 120 of the data storage device 100 may also include a linear motor 150 adapted to move the actuator arm 140 relative to the one or more rails 130. The linear motor 150 may include any suitable type of motor that moves the actuator arm 140 linearly along the one or more rails 130. For example, the linear motor 150 may include a linear stepper motor, an inchworm motor, a linear voice coil motor, ball screw and gear motor, etc.
For example, as shown in
As shown in
In one or more embodiments, the linear motor 150 may include an inchworm motor 170, e.g., as shown in
The inchworm motor 170 may move relative to the shaft 176 in response to movement of actuators of the inchworm motor 170. For example, the inchworm motor 170 may include a variety of different types of actuators (e.g., actuation technologies) including, e.g., piezos, shape memory alloys (SMA), electrostatics, bi-metallics, etc. In one or more embodiments, the inchworm motor 170 may include one or more lateral actuators 174 that extend and retract in a direction along the longitudinal axis 171 and clutch actuators that extend and retract in a direction perpendicular to the longitudinal axis 171. Specifically, the inchworm motor 170 may include a first grip 180 corresponding to a first clutch actuator 172 and a second grip 184 corresponding to a second clutch actuator (not shown, but operates on the respective grip similar to the first clutch actuator 172).
When the first clutch actuator 172 extends (e.g., along axis 173), fingers 181, 182 of the first grip 180 move closer together to contact the shaft 176 and restrict movement of the shaft 176. When the first clutch actuator 172 retracts (e.g., along axis 173), the fingers 181, 182 of the first grip 180 move farther apart to space away from the shaft 176 such that the shaft 176 may move relative thereto. Similarly, when the second clutch actuator extends, fingers 185, 186 of the second grip 184 move closer together to contact the shaft 176 and restrict movement of the shaft 176, and when the second clutch actuator retracts, the fingers 185, 186 of the second grip 184 move farther apart to space away from the shaft 176 such that the shaft 176 may move relative thereto. Further, the one or more lateral actuator 174 may expand to move the first and second grips 180, 184 apart from one another and retract to move the first and second grips 180, 184 closer to one another.
For the inchworm motor 170 to move relative to the shaft 176, the actuators may act in a specific sequence to create linear movement along the shaft 176. The process starts by actuating the clutch actuator farthest from the desired movement direction. For example, first clutch actuator 172 may extend such that the first grip 180 contacts and restricts movement of the shaft 176. Next, the lateral actuator 174 extends to move the first grip 180 relative to the second grip 184 to increase the distance therebetween. The second clutch actuator may then extend such that the second grip 184 contacts and restricts movement of the shaft 176, and the first clutch actuator 172 may retract to release contact of the first grip 180 with the shaft 176. Then, the lateral actuator 174 retracts to move the first grip 180 relative to the second grip 184 to decrease the distance therebetween. Thereafter, the first clutch actuator 172 may extend such that the first grip 180 contacts and restricts movement of the shaft 176, and the second clutch actuator may retract to release contact of the second grip 184 with the shaft 176. This process is repeated multiple times to move the inchworm motor 170 (and the actuator arm attached thereto) relative to the shaft 176 in a direction from the first grip 180 to the second grip 184. In order to move in the opposite direction, the first and second clutch actuators may be swapped in the process above.
In one or more embodiments, the linear motor 150 may include a linear voice coil motor, e.g., as shown in
The linear voice coil motor may also include a voice coil 158 that interacts with the permanent alternating magnet 156. For example, the system 100 may send a signal to the voice coil 158 to change polarity such that the voice coil 158 moves along the permanent alternating magnet 156 (e.g., due to attraction/repellant forces formed therebetween). The voice coil 158 may be coupled to the proximal end 141 of the actuator arm 140 to move the actuator arm 140 relative to the permanent alternating magnet 156 and, e.g., along the one or more rails 130. As such, the at least one head 122 positioned on the distal end 142 of the actuator arm 140 moves in a straight line radially on the recording medium 104. Furthermore, the voice coil 158 may encircle the permanent alternating magnet 156 (e.g., the voice coil 158 defining an opening 159 through which the permanent alternating magnet 156 extends). It is noted that in one or more embodiments, the permanent alternating magnet 156 may be located on the actuator arm 140 (e.g., at the proximal end 141) and the voice coil 158 may be spaced apart from the proximal end 141 of the actuator arm 140 and defining an opening parallel to the one or more rails 130. For example, the moving part may be either the voice coil 158 or the permanent alternating magnet 156. In other words, the permanent alternating magnet 156 and the voice coil 158 may be in any suitable arrangement.
In one or more embodiments, the data storage device 100 may also include bellows 160 covering the one or more rails 130, e.g., as shown in
Furthermore, in one or more embodiments, the data storage device 100 may include contamination confining magnets 162 that also may serve to bias and load the bearings, e.g., as shown in
Additionally, in one or more embodiments, the linear actuator assembly 120 may include two linear actuators that operate in combination. For example, the distal ends 142 of each of the actuator 140 arms may be connected and adapted to operate together (e.g., each moves linearly at the same pace). The at least one head 122 may be positioned at the intersection of the two actuator arms (e.g., at the distal ends 142). By connecting two opposing actuator arms, the suspensions of the opposing actuator arms may define a thinner thickness relative to a typical cantilevered suspension. As such, the thinner suspension may produce less drag and/or reduce disk to disk spacing and, therefore, may make the data storage device more efficient. Additionally, this configuration may provide more stiffness for robustness to shock events and achieving active control of head media spacing at the suspension.
As shown in
The linear actuator assembly 220 may also include a linear motor 228 associated with each of the first and second actuator arms 250, 260. Each of the corresponding linear motors 228 may be positioned adjacent to the respective actuator arm 250, 260 (e.g., proximate the proximal end 252, 262) and adapted to move the respective actuator arm 250, 260. The linear motor 228 may include any suitable motor such as, e.g., the linear motors described herein as they relate to
Additionally, the linear actuator assembly 220 may include one or more rails 230 associated with each of the first and second actuator arms 250, 260. The one or more rails 230 may operate and be arranged similar to as described with respect to
Furthermore, each of the first and second actuator arms 250, 260 may include a base 208 and a suspension 206. The base 208 may be located proximate the proximal end 251, 261 of the actuator arm 250, 260 and may be adapted to interact with the respective linear motor 228. The at least one head 222 may be located proximate the distal ends 252, 262 of each of the actuator arms 250, 260 and may be adapted to read and write data from and to a recording medium 204. The suspension 206 may extend between the base 208 and the at least one head 222. Further, the suspension 206 may define a thickness of less than or equal to about 2 millimeters, less than or equal to about 1.5 millimeters, less than or equal to about 1 millimeter, less than or equal to about 0.5 millimeters, etc. As described herein, because the distal ends 252, 262 of the actuator arms 250, 260 are connected and supported at two locations, the suspension 206 may define a smaller thickness than a typical cantilevered actuator arm.
Specifically, as shown in
The linear actuator assembly 220 shown in
Further, another embodiment is shown in
In the preceding description, reference is made to the accompanying set of drawings that form a part hereof and in which are shown by way of illustration several specific embodiments. It is to be understood that other embodiments are contemplated and may be made without departing from (e.g., still falling within) the scope or spirit of the present disclosure. The preceding detailed description, therefore, is not to be taken in a limiting sense. The definitions provided herein are to facilitate understanding of certain terms used frequently herein and are not meant to limit the scope of the present disclosure.
Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein. The recitation of numerical ranges by endpoints includes all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range within that range.
As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” encompass embodiments having plural referents, unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise. As used herein, “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise. As used herein, “have,” “having,” “include,” “including,” “comprise,” “comprising,” or the like are used in their open-ended sense, and generally mean “including, but not limited to.”
Embodiments of the systems, apparatus, and methods associated therewith are disclosed. The implementations described above and other implementations are within the scope of the following claims. One skilled in the art will appreciate that the present disclosure can be practiced with embodiments other than those disclosed. The disclosed embodiments are presented for purposes of illustration and not limitation, and the present disclosure is limited only by the claims that follow.