GB2272792A - Disk drive carrier assembly - Google Patents

Abstract

To facilitate maintenance, a disk drive assembly 40 includes a disk-head assembly (HDA) 45 and an electronic card pack 47 both releasably mounted on a carrier frame 49 e.g. using quick-release shock mounts 44, 46. In use, a carrier assembly connector plug 59 mounted at the rear edge of a circuit hoard included within the electronic card pack engages a stationary connector plug 81 mounted within a host system receiving unit. The carrier frame has guide rails 42 which are received by guide grooves or tracks 87 within the receiving unit to allow the carrier assembly to be inserted in and extracted from the receiving unit. Alignment pins 77 protruding from the connector plug 81 engage and align the connector plug 59 as the carrier assembly is inserted into the receiving unit. A locking handle 53 may provide a force to maintain the carrier assembly in place during operation. <IMAGE>

Description

DISK DRIVE CARRIER ASSEMBLY The present invention relates generally to high capacity information storage systems and, more particularly, to a disk drive carrier assembly.

One of the principle components of a computer system is a place to store data. Typically computer systems employ a number of storage means to store data for use by a computer system. For example, a computer system can store data in a peripheral storage device referred to as a disk drive or direct access storage device (DASD). More commonly, especially in large computer systems, data will be stored in on-line DASD arrays utilizing multiple disk drive devices mounted in racks or drawers.

A disk drive or DASD includes one or more disks which appear similar to records utilized with a record player or compact disks (CD) which are utilized with a CD player. The disks are stacked on a spindle for rotary motion in parallel planes, much like records. In a disk drive, however, the disks are mounted to the spindle and spaced apart so that the separate disks do not touch each other.

Such data storage devices employing rotating magnetic or optical media disks are well-known for high capacity, low cost storage of data.

Such disks typically have a multiplicity of concentric data track locations formed on one or both surfaces, each capable of storing useful information. The information stored in each track is accessed by a transducer head which is moved among the tracks during track seeking operations and which is maintained in alignment with the track during read only and/or read/write track following operations of the device.

Typically one or more transducer heads are provided for each data storage surface. The electro-mechanical assembly for rotation of the disk relative to the head and for moving the head radially relative to the disk surface for track accessing purposes is referred to as the head and disk assembly (HDA). A control mechanism is provided in order to maintain the head within the boundaries of each data track, and may take the form of detents provided by a stepping motor, or by a continuously positionable actuator operating within a closed loop servo, or a timesampled servo. Additionally, an interface device is required for connection of the HDA to a controller and for communication between the disk drive and the computer system. Typically, a standardized interface is utilized, for example, the Small Computer Synchronous Interface (SCSI).

Today's technology relating to data storage is marked by continuing trends towards standardization and towards increased storage capacity, reduced data storage device weight and size, and reduced power consumption. Standardization in size, referred to as form factor, and in interface compatibility is being pursued by manufacturers of both desktop systems such as personal computer (PC) and workstation systems and larger computing systems. Thus, disk drives having differing capabilities and capacities provided in standard form factors and plug-in configurations by several different manufacturers may be used interchangeably in different PC's, for example, in standardized plug-in slots provided by the PC manufacturers.

Increasing system storage capacity while reducing disk drive size requires careful balancing of the reduction of the area of the storage medium, i.e., the area of the disk surface, against the corresponding reduction in storage capacity. Typically, the tradeoff is to increase the number of disks per spindle and/or increase the number of disk drives. On a large scale, large numbers of relatively small disk drives are mounted in drawers to provide high storage capacity while taking advantage of common power supplies and cooling facilities, for example, to achieve an overall reduction in power requirements.

In large rack and drawer mounted information storage systems increases in storage capacity is achieved by increasing the capacity of the individual disk drive devices or by increasing the number of devices in the system. More typically, increased capacity is achieved by a combination of both methods. It is also required that this increased capacity be achieved with the use of standard, accepted size components and without increasing the system footprint, i.e., without consuming additional floorspace for installation of the system. Additionally, large systems require on-line maintenance to repair or replace failed components as well as scheduled periodic maintenance on the system. On line maintenance can require removal and installation of disk drive units without securing electrical power to the system.In typical prior art systems, electronic circuitry essential to the operation of the disk drive unit is housed within the disk drive enclosure thus making it necessary to remove and replace the disk drive unit to repair failed electronics. The removable of a disk drive from the system can result in loss of the data stored in the memory device. This is a crucial consideration in the maintenance strategy for such a storage system, especially for non-redundant systems in which the data in the memory device cannot be reconstructed and is not readily transferable to another memory device in the field.

U.S. Patent No. 5,045,960 discloses a disk drive module mounted on a carrier frame which can be removably installed in a computer system.

The carrier frame includes guide means which cooperate with receiving tracks provided on the interior walls of a computer housing such that a connector on the forward end of the drive module aligns and engages a stationary connector in the housing as the disk drive module is inserted into the computer housing. Similarly, U.S. Patent No. 4,912,580 discloses a disk drive carrier module including a disk drive which is removably installed in a receiving unit of a computer system. The disk drive carrier module provides a connector and guide means arranged for automatically interconnecting the connector with a cooperating connector mounted in the receiving unit as the carrier module is inserted into the receiving unit. These and other patents show removable disk drive modules which can be installed and removed by system operators and moved between computer systems.However, while these prior art removable disk drive modules greatly ameliorate problems associated with manually removing disk drive units requiring unscrewing of nuts and bolts and disconnection of multiple cables, they do not provide for field replacement of components such as the disk-head assembly (HDA) or electronics required for future maintenance strategies for large information storage systems.

It is therefore an object of the present invention to provide a removable disk drive carrier assembly having quick-release removable components to provide a field replacement capability.

This object is achieved by the invention claimed in claim 1.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is an exploded view in perspective of a disk-head assembly in a disk drive carrier assembly of the present embodiment; Fig. 2 is a perspective view illustrating the disk drive carrier assembly according to the present embodiment; Fig. 3 is an exploded view in perspective illustrating the disk drive carrier assembly system of Fig. 2; Fig. 4 is an exploded view in perspective illustrating the electronic card pack for the disk drive carrier assembly system of Fig.

2; Figs. 5a and 5b is an exploded view in perspective illustrating the electronic cards of the electronic card pack shown in Fig. 4; Fig. 6 is a rear view of the disk drive carrier assembly shown in Fig. 2 illustrating the electronic card pack and the electrical connector; Figs. 7a and 7b are a plan view illustrating the pin arrangement and pin lengths for the electrical connector shown in Fig. 6; Fig. 7c is a side view in section of the electrical connector shown in Fig. 6; Fig. 8 is a view in perspective of the front end of the disk drive carrier assembly shown in Fig. 2 illustrating the locking handle; Fig. 9 is a side view in section of the alignment pins for the electrical connector of the disk drive carrier assembly of Fig. 2; ; Fig. 10 is a top view of the disk drive carrier assembly of Fig. 2 partially inserted into the receiving unit illustrating the electrical connector alignment pins; Fig. 11 is an exploded view in perspective of a second. embodiment of the disk drive carrier assembly according to the present invention; Fig. 12a is a cutaway view in perspective of a drawer utilized in a multiple-drive information storage system illustrating a number of the disk drive carrier assemblies of Fig. 1; and Fig. 12b is a front view of a cabinet for an information storage system which utilizes one or more of the drawers shown in Fig. 12a.

Fig. 1 is an exploded view of a disk drive 10. It should be noted that the invention described in this application is applicable to any suitable direct access storage devices (DASD). The disk drive 10, referred to as a disk-head assembly (HDA), includes a housing 11, and a housing cover 13 which, after assembly, is mounted within an HDA frame (such as frame 43 shown in Figs. 2 and 3). Rotatably mounted within the housing 11 on an actuator shaft 15 is an actuator arm assembly 17. One end of the actuator arm assembly 17 includes an E block or comb-like structure 19 having a plurality of arms 18. Attached to the separate arms 18 on the comb or E block 19, are load springs 21. Attached at the end of each load spring is a slider 23 which carries a magnetic transducer (not shown).On the other end of the actuator arm assembly 17 opposite the load springs 21 and the sliders 23 is a voice coil 25.

Attached within the housing 11 is a pair of magnets 27. The pair of magnets 27 and the voice coil 25 are the main components of a voice coil motor which applies a force to the actuator arm assembly 17 to rotate it about the actuator shaft 15. Also mounted within the housing 11 is a spindle shaft 29. Rotatably attached to the spindle shaft 29 are a number of disks 31. As shown in Fig. 1, eight disks are attached to the spindle shaft 29 in spaced apart relation. Flexible cable 33 carries electrical signals to and from actuator arm assembly 17 and provides power and control signals to a spindle motor (not shown) which provides rotary motion to the disks 31 attached to the spindle 29.

Fig. 2 is a perspective view of the disk drive carrier assembly.

The disk drive carrier assembly 40 comprises a carrier frame 41 having an HDA frame 43 permanently attached to one side on a forward portion and a circuit board pack or electronic card pack 47 removably attached to the same side on a rearward portion of the carrier frame 41. The electronic card pack 47 comprises a metal frame 49 supporting one or more electronic cards 51 mounted thereon and is attached to the carrier frame 41 and the HDA frame 43 by screws 48 or other suitable quick-release fasteners, such as quick-release hook fasteners, for example. An HDA 45, such as HDA 10 described with reference to Fig. 1 and having a 3 1/2 inch form factor, for example, is mounted within the HDA frame 43 on shock mounts 44 which are received in slots 52 formed in the HDA frame 43.The shock mounts are secured in the HDA frame slots by quick-release clips 46 or other suitable quick-release attachment devices. An electrical connector (electrical connector 59 shown in Fig. 4) mounted at the rear of the carrier frame, or, alternatively, at a rearward edge of one of the electronic cards 51, provides all electrical connections for the HDA 45 and associated electronics on the electronic cards 51. The carrier assembly electrical connector provides transmission to and from a host system of all control and data signals and all power connections for the HDA and associated electronic circuitry. A locking handle 53 is is provided at the front end of the carrier assembly and is pivotally attached to the carrier frame 11.The handle 53 provides a means for transporting of the carrier assembly 40 as well as a means for insertion and extraction of the carrier assembly into and from a host system receiving unit.

Figs. 4 and 5 are exploded views in perspective illustrating the electronic card pack 47 frame and circuit boards. The electronic card pack frame comprises a two-piece frame 49 and provides various mounting tabs 52b having apertures therethrough for mounting circuit boards 51a, 51b and Sic thereto with fasteners through corresponding holes 52a.

Suitable fasteners such as screws or rivets are suitable for this purpose. With the circuit boards secured to the frame pieces 49, the electronic card pack 47 is then attached to the carrier frame 41 (as shown in Fig. 3), utilizing quick-release fasteners such as screws or other suitable quick-release fasteners, through frame tabs 71 at the forward end of the card pack and through tabs 73 formed in the carrier frame 41 (as shown in Fig. 6) at the rearward end of the card pack 47.

The carrier assembly electrical connector plug 59 is mounted on the lower circuit board Sic of the card pack 47. The connector plug 59 is secured to the circuit board such as by rivets, for example, through corresponding holes 74a and 74b provided in the circuit board and connector, respectively. Alternatively, the electrical connector plug can be mounted directly on the carrier frame 41. The construction of the electronic card pack 47 and the releasable mounting thereof to the carrier frame 41 facilitates simple, quick and reliable field replacement of the carrier assembly electronics should a failure occur.

The electronic card pack 47 provides sufficient card area to contain all circuitry necessary for the operation or the HDA 45 including the data channel, the controller and system interfaces and all power distribution circuitry. Utilizing the field replaceable unit (FRU) concept, not only are in-field repairs easily accomplished, but device capabilities can be easily and quickly upgraded with exchangeable electronic card packs 47. Different controller configurations can be realized with different electronic card packs. For example, a disk drive carrier assembly can be manufactured with a device level interface, such as an IPI interface, and later be field upgraded to a more sophisticated intelligent and buffered host channel level interface, such as SCSI.

Preferably, the carrier assembly electronics includes a DC-DC converter which converts any supply voltage between +30V and +40V into regulated +5V and +12V outputs required by most available disk drive HDAs.

Alternatively, the electronics can accept a +5V and +12V power inputs directly.

The HDA 45 is coupled to the electronics by three cables 63, 64 and 57, via connector 66 on circuit board 55, which provides the necessary control, data and power signal to the HDA. The various circuit boards 51a, 51b and 51c are coupled each other as required by cables and connectors or other means. The carrier assembly 40 provides an onboard operator panel which includes LED system condition indicators 65 (Fig.

8), such as drive failure, and a number of operator switches 67 which provide operator control over write protection, port disabling and drive spin-up, for example. The onboard operator panel is mounted on circuit board 55 at the front end of the carrier assembly (as shown in Fig. 8) and is coupled to the remainder of the carrier assembly electronics via cable 57.

Fig. 6 is a rear view of the carrier assembly 40 illustrating the placement of the electrical connector 59. Fig. 7a is a plan view of the connector illustrating the connector pin arrangement. Figs. 7b and 7c provide a side view in section of the connector mounted on the circuit board 51c and the pin length. The electrical connector used with the carrier assembly 40 comprises a two-piece connector having the receptacle piece 59, (i.e., the female plug) mounted on the carrier assembly and the header piece (i.e., the male piece, connector 81 as shown in Figs. 9 and 10) mounted in a receiving unit which engages the carrier assembly connector 59 when the carrier assembly 40 is installed in the receiving unit. The connectors 59, 81 provide 128 electrical pins in a 4x32 pin array 71 with pin assignments as shown in Fig. 7a.The connectors 59, 81 are constructed with pins of three different physical lengths: the ground pins 1 are the longest, the power pins 3 are the shortest and the data and control signal pins 2 are of intermediate length. This pin arrangement ensures that the power connection is always the first to break while the ground connection is always the last to break when the connectors are disengaged, i.e., separated. Conversely, the ground connection is always the first to engage and the power connection is always the last to engage when the connector parts 59, 81 are engaged as the carrier assembly is inserted into the receiving unit. This pin arrangement allows the carrier assembly to be installed and removed without removing power from the receiving unit or the host system.The carrier assembly connector 59 includes apertures 75 formed at either end of the connector for receiving alignment pins 77 (as shown in Figs. 9 and 10) as the carrier assembly 40 is inserted into the receiving unit to ensure that the connectors 59, 81 are properly aligned prior to engagement.

Referring now also to Figs. 8, 9 and 10, a carrier assembly receiving unit 80 is defined by a pair of opposing walls or rails 85 or the like having an open front end for receiving the carrier assembly and a closed rear or inner end forming a backplane 83. The receiving unit includes guide tracks or grooves 87 formed on the inwardly facing sides of the rails 85 which receive and cooperate with guide rails 42 formed at the opposing longitudinal edges of the carrier frame 41 to guide and support the carrier assembly 40 as it is slidingly inserted in or extracted from the receiving unit 80. The carrier assembly connector 59 alignment apertures 75 receive the alignment pins 77 both of which have conical forward ends that enter and slide into the apertures 75 as the carrier assembly 40 is slidingly inserted into the receiving unit.The alignment pins 77 are positioned with respect to the connectors 59, 81 so as to ensure proper pin alignment just prior to and during engagement of the connectors 59, 81.

When the carrier assembly 40 is completely inserted into the receiving unit, the locking handling 53 (as illustrated in Fig. 8), is pivoted to a locked position with the handle end tabs 56 engaging cammed tabs 86 formed in the receiving unit side rails 85. With the locking handle 53 in the locked position, an inwardly biasing force is generated along the longitudinal axis of the carrier frame 41 retaining the carrier assembly in the receiving unit and ensuring a reliable electro-mechanical engagement of the connectors 59, 81.When the locking handle 53 is pivoted out of the locked position, an offset portion 54 of the handle bears against a retaining bracket 58 protruding from the front of the carrier frame 41 generating an ejecting force which separates the connector receptacle piece 59 from the connector header piece 81 and allows the carrier assembly to be extracted from the receiving unit. (A two-piece connector plug manufactured by AMP Incorporated, part number 646249-1 for the receptacle and part number 646247-1 for the header is suitable for this purpose.) Referring now to Fig. 11, a second preferred embodiment of a disk drive carrier assembly is shown.A multiple disk drive carrier assembly 110 comprises a carrier frame 111 having two HDAs 113 and 115 removably mounted on an upper side thereof and an electronic card pack 117 providing all of the necessary circuitry and components required for the operation and control of the two HDAs.

As described above with reference to Figs. 2 through 7, an electrical connector (not shown in Fig. 11) is mounted on the electronic card pack 117 or, alternatively, on the carrier frame 111 for engagement with a matching connector mounted within a receiving unit to couple all required data, control and power signals to and transfer data to and from the HDAs 113 and 115. As described above with reference to Figs. 8 through 10, the carrier frame includes guide rails 112 formed along both longitudinal edges of the carrier frame and a locking handle 121 to facilitate removably mounting the carrier assembly 110 in a receiving unit. A preferred embodiment of the disk drive carrier assembly 110 comprises two 2.5-inch form factor magnetic disk drive HDAs removably mounted on the carrier frame 111 utilizing quick-release shock mounts as described above.Alternatively, the disk drive carrier assembly comprises four 1.8-inch form factor magnetic disk drive HDAs removably mounted on the carrier frame 111. In embodiments implementing multiple disk drive HDAs on a single carrier frame, the electronics implemented in the electronic card pack can be designed to provide a centralized storage or array controller, or, alternatively, can provide the control and data requirements for multiple individually addressable disk drives mounted on a single common carrier.

In the preferred embodiment as described above with reference to Fig. 2, the disk drive module, HDA 45, is a 3.5 inch form factor magnetic disk drive having a capacity of 2.0 Gigabytes. All required electronics for the HDA operation are provided in the electronic card pack. The complete disk drive carrier assembly has an approximate overall length of 280.8 mm, an approximate overall width of 108.3 mm and an approximate overall height of 44.6 mm. The FRU cards are designed such that the high temperature components receive maximum air flow for cooling. Cooling apertures are provided throughout the carrier assembly to ensure efficient cooling of the HDA and electronic components with either longitudinal or vertical airflow generated by fans and cooling systems provided in the receiving unit. The HDA frame in combination with the electronic card pack frame and the carrier frame provide a structurally rigid assembly capable of withstanding handling forces and other forces imposed upon the carrier assembly during insertion and extraction. The use of 4 shock mounts for mounting of the HDA within the HDA frame ensures sufficient isolation for operating shock forces up to 10 g's and static shock forces up to 100 g's.

Referring now also to Figs. 12a and 12b, in one preferred embodiment, large numbers of the disk drive carrier assembly 40 are removably mounted in drawers 120 (as shown in Fig. 12a) to provide large amounts of directly accessible data storage in large information storage systems. A drawer 120 accessible from either end includes a chassis 122 on which various system components are mounted, and an access door at each end. The drawer 120 is divided into a number of side-by-Bide receiving units or cavities 124, each receiving unit defined by a pair of opposing carrier mounting rails 125 and the drawer backplane 127 at the rear end of the receiving unit 124. Each of the carrier mounting rails 125 include guide tracks formed on opposing inside walls which receive guide rails 42 formed by the longitudinal edges of the carrier frame 41.

The carrier mounting rails 125 form a mounting frame which supports and maintains the carrier assembly 40 in a fixed relationship with respect to the drawer 120 and the drawer backplane 127 when the carrier assembly 40 is installed in the receiving unit 124. Additionally, the guide tracks guide and align the carrier assembly 40 during insertion and extraction.

The engagement or mating end of the carrier assembly electrical connector 59 projects rearwardly for automatic interconnection with cooperating connector fittings of a stationary electrical connector mounted on the receiving unit backplane, as described in greater detail above with reference to Figs. 9 and 10. As shown in greater detail in Fig. 8, handle 53 incorporates a latching mechanism which ensures reliable electro-mechanical engagement of the carrier assembly connector with the receiving unit connector when the carrier assembly 40 is installed in the receiving unit. In the locked position, the handle 53 provides a positive force biasing the carrier assembly connector into engagement with the receiving unit connector.For extraction and removal of the carrier assembly 40, as the handle 53 is pivoted to the unlocked position, an ejecting force is applied longitudinally to the carrier assembly which separates and disengages the carrier assembly connector from the receiving unit electrical connector.

Figure 12b is a front view of a large capacity information storage system 130 and illustrates a system cabinet 132 for "rack" mounting of large numbers of individual disk drive memory devices to form an array of disk drive memory devices. Such an array may be a redundant system, sometimes referred to as a "RAID" system which provides one or more levels of data protection or may be an array of individually addressable disk drive devices providing a high capacity on-line memory for a computer system which includes a central processing unit with integrated floppy disk storage devices and further auxiliary devices such as a keyboard, monitor and printer.The information storage system cabinet 132 includes racks or drawers for mounting system power supplies 133, cooling system components 135 and system electronic components 131 such as disk drive controllers, system interfaces and microprocessors, for example. Such an information storage system will include one or more drawers 120 removably mounted on racks in a vertical stack to provide the desired amount of storage capacity. For example, a typical system may utilize nine drawers having sixteen individual disk drive storage modules having a capacity of 2.0 Gigabytes each mounted therein providing 144 disk drives and a total storage capacity of 288 Gigabytes.

While the invention has been particularly shown and described with reference to various preferred embodiments thereof, it is understood by those skilled in the art that the invention is not to be limited to the disclosed embodiments, but that various modifications in the form and details may be made therein without departing from the scope of the appended claims.

Claims (10)

1. A disk drive carrier assembly for use in an information storage system including at least one receiving unit having electrical connector means mounted therein and into which unit the carrier assembly may be inserted and removed, the carrier assembly comprising: a frame having means for slidably cooperating with guide means formed within the receiving unit for guiding the carrier assembly during insertion and removal; at least one disk drive unit removably mounted on the frame; a circuit board pack removably mounted on the frame, the circuit board pack including at least one circuit board having electronic circuitry mounted thereon which is connected to the disk drive unit; and electrical connector means connected to the electronic circuitry, the electrical connector means releasably engaging the electrical connector means of the receiving unit when the disk drive carrier assembly is inserted into the receiving unit, the electrical connection means providing electrical power and control and data signals to the disk drive unit.

2. A disk drive carrier assembly as claimed in Claim 1, further comprising an HDA frame attached to the carrier frame, the disk drive unit being releasably mounted in the HDA frame.

3. A disk drive carrier assembly as claimed in Claim 2, wherein the disk drive unit is supported within the HDA frame on shock absorbers.

4. A disk drive carrier assembly as claimed in Claim 1, further comprising a handle attached to the carrier at a forward end thereof for assisting insertion of the carrier assembly into and extraction of the carrier assembly from the receiving unit, and for releasably locking the carrier assembly in the receiving unit.

5. A disk drive carrier assembly as claimed in Claim 4, wherein the handle is pivotally attached to the carrier frame, the handle having a locked position for releasably locking the carrier assembly in the receiving unit and an unlocked position for insertion and extraction of the carrier assembly.

6. A disk drive carrier assembly as claimed in Claim 5, wherein the handle engages cam means formed on the receiving unit as the handle is pivoted from the unlocked to the locked position, the handle thereby generating a force biasing the carrier assembly inwardly therebyto assist electro-mechanical engagement between the carrier assembly electrical connector means and the receiving unit electrical connector means.

7. A disk drive carrier assembly as claimed in Claim 6, wherein the handle in cooperation with retaining brackets formed on the forward end of the carrier frame generates an ejecting force as the handle is pivoted from the locked to the unlocked position, the ejecting force biasing the carrier assembly outwardly and positively separating the carrier assembly electrical connector means from the receiving unit electrical connector means.

8. A disk drive carrier assembly as claimed in Claim 1, wherein the carrier assembly electrical connector means and the receiving unit electrical connector means form a plug and socket connector set, the carrier assembly electrical connector means being the socket and the receiving unit electrical connector means being the plug, the plug including a plurality of connector pins so arranged that the carrier assembly can be installed and removed without removing electrical power from the receiving unit.

9. A disk drive carrier assembly as claimed in Claim 8, wherein the connector pins are arranged so that electrically ground pins always make electrical contact first and break electrical contact last and electrically power pins always make electrical contact last and break electrical contact first when the carrier assembly is inserted into and extracted from the receiving unit, respectively.

10. A disk drive carrier substantially as described herein with reference to figures 1 to 10 or figure 11 of the accompanying drawings.