CN112846340A

CN112846340A - Extension milling head with unclamping cylinder

Info

Publication number: CN112846340A
Application number: CN202110248575.5A
Authority: CN
Inventors: 周道恒; 卢强; 卫继健; 蔡喜
Original assignee: Neway Cnc Equipment Suzhou Co ltd
Current assignee: Neway Cnc Equipment Suzhou Co ltd
Priority date: 2021-03-09
Filing date: 2021-03-09
Publication date: 2021-05-28

Abstract

The invention discloses an extended milling head with a unclamping cylinder, wherein a connecting assembly is arranged at the end part of a shell, a main shaft is rotatably arranged in the shell, a pull rod is arranged in the main shaft, a clamping jaw assembly is arranged at the tail end of the pull rod, the extended milling head with the unclamping cylinder also comprises a unclamping assembly, the unclamping assembly is arranged in the shell and is positioned between the connecting assembly and the pull rod, the unclamping assembly comprises a unclamping cylinder, a piston and a unclamping block, the piston is positioned in the unclamping cylinder, the unclamping block is connected with the pull rod, the extended milling head with the unclamping cylinder is also provided with an oil circuit communicated with the unclamping cylinder, the oil circuit supplies oil to the unclamping cylinder to enable the piston to move in the unclamping cylinder to abut against the unclamping block to enable the unclamping block to move, the unclamping block and the unclamping are driven by the pull rod and the clamping jaw, the cost is reduced; the bearing on the extension milling head bears small tension, so that the situation that the tension is insufficient when a user uses the extension milling head is avoided.

Description

Extension milling head with unclamping cylinder

Technical Field

The invention relates to a milling head, in particular to an extension milling head with a unclamping cylinder.

Background

The milling head is one of machine tool accessories which are arranged on the milling machine, connected with the main shaft and used for driving the milling cutter to rotate.

The existing extension milling machine has two main types, one is a disc spring with an extension head providing tension, and the power during tool loosening is provided by a main shaft of the machine tool. The unclamping cylinder of the machine tool spindle can simultaneously press down the disc spring of the spindle and the disc spring in the extension head to achieve the purpose of loosening the cutter on the extension milling head. The pressure required by the machine tool spindle when the spindle is subjected to self-tapping is 7-8MPa, and the hydraulic system is designed to be 10MPa so as to meet the requirement; the pressure required by two simultaneous cutters is about 15MPa, a hydraulic system needs to be designed to be more than 15MPa, and the cost is increased linearly. The tool loosening force directly acts on a bearing of a machine tool spindle, for example, a common BT50 spindle, and when only the spindle loosens the tool, the axial force borne by the spindle shaft is about 40-50 KN. If the cutter loosening force of the milling head is added, the stressed axial force of the main shaft bearing of the BT50 is about 80-100KN, and the service life and the rotation precision of the main shaft bearing of the machine tool are seriously influenced after the main shaft bearing is used for a long time.

The second extension milling machine has no disc spring, and the tool pulling force and the tool beating force are both provided by a main shaft of the machine tool. The stroke of a disc spring on a machine tool spindle is very small, the required broach force can be provided only by controlling the disc spring at a proper position, the service life of the disc spring is influenced by too tight control, and the too loose broach force is insufficient. If the broach force of the extension head is provided by the main shaft of the machine tool, the broach force needs to pass through the main shaft and then be transmitted to the pull rod of the extension head, the transmission chain is lengthened, one more link is needed, and the position control is not better controlled. This situation is very demanding both in the manufacture and in the mounting of the parts, and often the situation occurs where the tension is insufficient for use at the customer's site. The cutter on the main shaft of the extension milling head is tensioned by the main shaft of the machine tool, taking the main shaft of BT50 as an example, a bearing on the extension milling head always bears about 18KN of tension during machining, the bearing is not suitable for high-speed rotation, the bearing generates heat after long-term use, the rotation precision of the bearing is influenced, and the service life of the bearing is shortened.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide the extension milling head with the unclamping cylinder, wherein the power for unclamping is provided by the unclamping component of the extension milling head, so that the requirement on the pressure of a hydraulic system is not high, and the cost is reduced; the bearing on the extended milling head bears small tension, and the situation that the tension is insufficient when a user uses the extended milling head is avoided.

One of the purposes of the invention is realized by adopting the following technical scheme:

the utility model provides a from extension cutter head of taking unclamping cylinder, includes coupling assembling, casing, main shaft, pull rod and jack catch subassembly, coupling assembling install in the casing tip, the main shaft rotates install in inside the casing, the pull rod install in inside the main shaft, the jack catch subassembly install in the pull rod is terminal, from extension cutter head of taking unclamping cylinder still includes the unclamping subassembly, the unclamping subassembly install in inside the casing and be located between coupling assembling and the pull rod, the unclamping subassembly includes unclamping cylinder, piston and unclamping block, the piston is located the unclamping cylinder, the unclamping block is connected with the pull rod, from extension cutter head of taking unclamping cylinder still be equipped with the oil circuit that the unclamping cylinder communicates, the oil circuit to the unclamping cylinder fuel feeding makes the piston move in the unclamping cylinder and contradict the unclamping block makes the unclamping block remove, the unclamping block drives the pull rod and the jaw assembly to move in the spindle to realize unclamping and complete unclamping.

Further, the knife beating assembly further comprises a second elastic piece, the knife beating cylinder comprises a cylinder base, two ends of the second elastic piece are respectively abutted to the cylinder base and the piston, and the second elastic piece is convenient for the piston to reset.

Furthermore, the cutter beating assembly further comprises a guide sleeve, an upper spacing ring and a cushion block, the cutter beating block is fixed on the guide sleeve, the guide sleeve is fixed on the upper spacing ring, the guide sleeve is fixedly connected with the cushion block, and the upper spacing ring is inserted into the pull rod and clamped between the guide sleeve and the cushion block.

Further, the connecting assembly comprises a connecting disc, the connecting disc is mounted at the end of the shell, pipelines are arranged on the connecting disc and the shell, and the pipelines are communicated with each other to form the oil path.

Further, the extension cutter head with the unclamping cylinder further comprises a transmission assembly, the transmission assembly comprises a key seat and a transmission shaft, the key seat is rotatably installed on the connecting assembly, the key seat is in meshed transmission with the transmission shaft through a spline, and the transmission shaft is fixedly connected with the main shaft.

Further, the extension milling head with the unclamping cylinder further comprises a mounting assembly, the mounting assembly comprises a second pull nail, a taper shank and a screw, the taper shank is mounted on the key seat through the screw, and the pull nail is fixed at the end part of the taper shank.

Further, the installation component further comprises a first elastic piece, the first elastic piece is sleeved on the screw, and two ends of the first elastic piece are respectively abutted to the taper shank and the key seat, so that the taper shank can be relatively shaken by the key seat, and the blind rivet is prevented from interfering with a machine tool when the extension milling head with the unclamping cylinder is installed.

Further, the extension milling head with the unclamping cylinder further comprises a bearing assembly, the bearing assembly is located between the spindle and the housing, the bearing assembly comprises an upper bearing assembly, a spacer bush and a lower bearing assembly, two ends of the spacer bush respectively abut against the upper bearing assembly and the lower bearing assembly, the upper bearing assembly comprises a lock nut, a dust ring and two second bearings, the lock nut and the dust ring lock the second bearings, the lower bearing assembly comprises a plurality of third bearings, an outer spacer ring and an inner spacer ring, and two adjacent third bearings are spaced by the outer spacer ring and the inner spacer ring.

Further, the bearing assembly further comprises a second gland, a labyrinth structure and a baffle plate, wherein the second gland is installed at the tail end of the shell, the labyrinth structure is located between the second gland and the main shaft, and the baffle plate is installed on the second gland and covers the labyrinth structure.

Further, the bearing assembly further comprises a nozzle fixed to the gland.

Compared with the prior art, the extension milling head with the unclamping cylinder has the following beneficial effects:

(1) after the cutter beating assembly is added in the extension milling head, the broaching mechanism of the extension milling head and the broaching mechanism of the machine tool spindle are mutually independent and can be respectively controlled, the pressure of a hydraulic system can meet the requirement below 10MPa, the low-pressure hydraulic system can meet the requirement, and the cost is saved;

(2) the loose broach mechanism of the extended milling head and the loose broach mechanism of the machine tool spindle can be separately debugged, so that the special requirements on manufacturing and installation are reduced, the workload is saved, and the risk of errors is reduced;

(3) the problems of bearing heating, damage and precision influence caused by the fact that a main shaft bearing bears large axial force for a long time are solved, the bearing can bear forces except cutting force only when a cutter is cut, and the high-speed and high-precision operation can be continuously carried out;

(4) when the full-automatic extension milling head is configured, a user generally configures the full-automatic right-angle milling head, the added hydraulic action can directly use the full-automatic right-angle milling head, and the cost is not increased greatly.

Drawings

FIG. 1 is a schematic structural view of an extended milling head with a unclamping cylinder according to the present invention;

fig. 2 is an enlarged view of the extended cutter head a with the unclamping cylinder of fig. 1.

In the figure: 10. a connecting assembly; 11. a coupling disc; 110. a pipeline; 12. a positioning ring; 13. positioning pins; 14. a first blind rivet; 15. a quick connector; 16. an electrical connector; 20. mounting the component; 21. a second blind rivet; 22. a taper shank; 23. a screw; 24. a first elastic member; 30. a transmission assembly; 31. a key base; 32. a first bearing; 33. a first gland; 34. a drive shaft; 40. a main shaft; 50. a housing; 60. a pull rod; 70. a jaw assembly; 80. a unclamping assembly; 81. a knife striking cylinder; 810. a cylinder base; 811. a cylinder body; 82. a piston; 83. a second elastic member; 84. a seal ring; 85. a wear ring; 86. a cutter beating block; 87. a guide sleeve; 88. an upper space ring; 89. cushion blocks; 90. a bearing assembly; 91. an upper bearing assembly; 910. locking the nut; 911. a dust ring; 912. a second bearing; 92. a spacer sleeve; 93. a lower bearing assembly; 930. a third bearing; 931. an outer space ring; 932. an inner spacer ring; 94. a second gland; 95. a labyrinth structure; 96. a baffle plate; 97. and (4) a nozzle.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present, secured by intervening elements. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or intervening components may also be present. When an element is referred to as being "disposed on" another element, it can be directly disposed on the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Fig. 1 to 2 show an extended milling head with a unclamping cylinder according to the present invention, which includes a connecting assembly 10, a mounting assembly 20, a transmission assembly 30, a spindle 40, a housing 50, a pull rod 60, a jaw assembly 70, an unclamping assembly 80, and a bearing assembly 90.

The connection assembly 10 includes a coupling disc 11, a retaining ring 12, a locating pin 13, a first pull stud 14, a quick-connect coupling 15, and an electrical connector 16. The coupling plate 11 is provided with a duct 110. A positioning ring 12 is mounted on the coupling disc 11, the positioning ring 12 being adapted to cooperate with a spigot on a ram of a machine tool to ensure that the spindle of the machine tool and the spindle 40 of the extension milling head are coaxial. The positioning pin 13 is fixed on the positioning ring 12, and the positioning pin 13 is matched with a pin hole in the ram in a glue pouring mode to resist the force generated when the extension milling head cuts. The first rivet 14 is fixed on the coupling disc 11, and the first rivet 14 is used for tensioning the milling head to enable the end face of the coupling disc 11 to be attached to a ram of a machine tool. Specifically, the number of the first blind rivets 14 is four, and the four first blind rivets 14 are uniformly distributed on the end face of the coupling disc 11. The quick connector 15 is mounted to the coupling plate 11 and communicates with the conduit 110 of the coupling plate 11. The quick connector 15 is used for quick connection with a machine tool pipeline. The electric connector 16 is attached to the coupling plate 11, and when a plurality of milling heads are arranged, the electric connector 16 is used to identify the kind of the attachment head.

The mounting assembly 20 includes a second blind rivet 21, a shank 22, a screw 23, and a first resilient member 24. The second blind rivet 21 is fixed to the end of the shank 22. The taper shank 22 is mounted to the key seat 31 by a screw 23, and the first elastic member 24 is a spring. The first elastic element 24 is sleeved on the screw 23 and two ends of the first elastic element respectively abut against the taper shank 22 and the key seat 31. Because the mounting hole of the taper shank 22 is slightly larger than the diameter of the screw 23, the existence of the first elastic piece 24 enables the taper shank 22 to slightly shake in all directions, so that the interference with a taper hole of a main shaft of a machine tool when the milling head is mounted on the machine tool is prevented, the main shaft of the machine tool can pull the second blind rivet 21, and the milling head extending from the unclamping cylinder is prevented from falling off accidentally.

The transmission assembly 30 includes a key bed 31, a first bearing 32, a first gland 33, and a transmission shaft 34. The key pad 31 is fixed to the first bearing 32 and rotatably mounted in the coupling plate 11 by the first bearing 32. The first gland 33 is mounted between the first bearing 32 and the key seat 31, and the first gland 33 is engaged with the coupling disk 11 to restrict the axial movement of the first bearing 32. The internal splines on the key seat 31 are engaged with the external splines of the transmission shaft 34, so that the key seat 31 can drive the transmission shaft 34 to rotate.

The main shaft 40 is fixedly connected with the transmission shaft 34. The main shaft 40 is located within the housing 50. The connection assembly 10 is mounted to the end of the housing 50. The pull rod 60 is slidably mounted inside the main shaft 40. Jaw assembly 70 is mounted to the end of pull rod 60. The housing 50 is provided with a duct 110, the duct 110 of the coupling disc 11 and the duct 110 of the housing 50 together forming an oil path.

The unclamping assembly 80 comprises a unclamping cylinder 81, a piston 82, a second elastic piece 83, a sealing ring 84, a wear-resistant ring 85, a unclamping block 86, a guide sleeve 87, an upper spacer ring 88 and a cushion block 89. The unclamping cylinder 81 includes a cylinder block 810 and a cylinder block 811 fixed to the cylinder block 810. The piston 82 is installed in the unclamping cylinder 81, and the sealing ring 84 is located between the piston 82 and the unclamping cylinder 81 to perform a sealing function. The wear ring 85 is located between the piston 82 and the unclamping cylinder 81 to support them. The cutter beating block 86 is positioned inside the cutter beating cylinder 81, the cutter beating block 86 is fixed on the guide sleeve 87, the guide sleeve 87 is fixed on the upper spacing ring 88, the upper spacing ring 88 is split, and the upper spacing ring 88 is inserted into the pull rod 60. The upper spacer 88 is held by the guide sleeve 87 and the spacer 89, and the guide sleeve 87 and the spacer 89 are fixed, so that the upper spacer 88 is fixed.

The bearing assembly 90 includes an upper bearing assembly 91, a spacer 92, a lower bearing assembly 93, a second gland 94, a labyrinth structure 95, a baffle 96, and a nozzle 97. The upper bearing assembly 91, the spacer 92, and the lower bearing assembly 93 are installed between the main shaft 40 and the housing 50. Spacer 92 is located between upper bearing assembly 91 and lower bearing assembly 93. The upper bearing assembly 91 includes a lock nut 910, a dust ring 911, and a second bearing 912. The number of the second bearings 912 is two. The outer rings of the two second bearings 912 are supported by the shell 50, the inner rings are locked by the locking nut 910 through the dust ring 911, and the axial direction is not fixed and cannot bear axial force. The lower bearing assembly 93 includes a third bearing 930, an outer spacer 931, and an inner spacer 932. The number of the third bearings 930 is three. The outer ring of the third bearing 930 is mounted on the housing 50, and the step on the housing 50 restricts the outer ring of one end of the third bearing 930 from moving axially, and the other end is pressed by the second press cover 94, restricting the outer ring of the third bearing 930 from moving in the other direction. Three third bearings 930 are spaced apart, and two adjacent third bearings 930 are separated by an outer spacer 931 and an inner spacer 932, so that the third bearings 930 can bear bidirectional axial force. The second gland 94 is mounted to the housing 50 and bears against the third bearing 930. The labyrinth structure 95 is installed between the second gland 94 and the main shaft 40, and the baffle plate 96 is installed at the second gland 94 and shields the labyrinth structure 95, and the labyrinth structure 95 and the baffle plate 96 prevent foreign materials from entering the bearing assembly 90 to damage the lower bearing assembly 93 at the front end. A nozzle 97 is attached to the second cover 94 for supplying a cutting fluid during machining.

When assembled from an extended cutter head with a unclamping cylinder, the coupling assembly 10 is mounted to the end of the housing 50. The main shaft 40 is rotatably installed in the housing 50, the transmission assembly 30 is rotatably installed inside the connecting assembly 10, and the transmission shaft 34 is fixed to the main shaft 40, so that the transmission assembly 30 can drive the main shaft 40 to rotate. The mounting assembly 20 is mounted at the end of the transmission assembly 30, and the spindle of the machine tool can pull the second blind rivet 21 of the mounting assembly 20, so that the extension milling head is prevented from falling off accidentally. The striking assembly 80 is mounted inside the housing 50 and below the connecting assembly 10. The transmission shaft 34 penetrates through the unclamping assembly 80, and the unclamping assembly 80 is symmetrically arranged relative to the transmission shaft 34. The unclamping cylinder 81 of the unclamping assembly 80 is in communication with the oil passage of the extended cutter head. The pull rod 60 is slidably mounted inside the main shaft 40. Jaw assembly 70 is mounted to the end of pull rod 60. After the shank of the tool is attached to the tapered hole of the spindle 40, the tool is clamped by the jaw assembly 70 on the pull rod 60 with pre-tightening tension. The bearing assembly 90 is installed between the main shaft 40 and the housing 50.

When the extended milling head with the unclamping cylinder is used, hydraulic oil on a machine tool is introduced into the quick-connection connector 15, then introduced into the pipeline 110 of the connecting disc 11, enters an oil path and enters the unclamping cylinder 81 through the oil path. The piston 82 is pushed to move downward and the piston 82 moves downward to press against the beater block 86. The pull rod 60 drives the jaw assembly 70 to move downwards, the jaw assembly 70 can be opened along the hole on the main shaft 40, the purpose of loosening the cutter is achieved, meanwhile, the jaw assembly 70 can continue to move forwards, and the end face of the jaw assembly 70 can be pushed against the end face of a pull nail on a cutter, so that the whole action of cutting is completed. When the oil pressure pushing the piston 82 to move downwards is relieved, the eight second elastic members 83 on the cylinder seat 810 push the piston 82 upwards, so that the piston 82 is separated from the knife block 86, and the knife block 86 is prevented from being driven to rotate to rub the piston 82 when the main shaft 40 rotates.

Through the design, after the cutter beating assembly 80 is additionally arranged in the extension milling head, the broaching mechanism of the extension milling head and the broaching mechanism of the machine tool spindle are mutually independent and can be respectively controlled, the pressure of a hydraulic system can meet the requirement below 10MPa, the low-pressure hydraulic system can meet the requirement, and the cost is saved; the loose broach mechanism of the extended milling head and the loose broach mechanism of the machine tool spindle can be separately debugged, so that the special requirements on manufacturing and installation are reduced, the workload is saved, and the risk of errors is reduced; the problems of bearing heating, damage and precision influence caused by the fact that a main shaft 40 bearing bears large axial force for a long time are solved, the bearing can bear forces except cutting force only when the cutter is cut, and the high-speed and high-precision operation can be continuously carried out; when the full-automatic extension milling head is configured, a user generally configures the full-automatic right-angle milling head, the added hydraulic action can directly use the full-automatic right-angle milling head, and the cost is not increased greatly.

The above examples only show some embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for those skilled in the art, variations and modifications can be made without departing from the spirit of the invention, and all equivalent modifications and changes can be made to the above embodiments according to the essential technology of the invention, which falls into the protection scope of the invention.

Claims

1. The utility model provides a from extension cutter head of taking unclamping cylinder, includes coupling assembling, casing, main shaft, pull rod and jack catch subassembly, coupling assembling install in casing tip, the main shaft rotate install in inside the casing, the pull rod install in inside the main shaft, the jack catch subassembly install in the pull rod is terminal, its characterized in that: the extension milling head of taking the unclamping cylinder still includes the unclamping subassembly, the unclamping subassembly install in the casing is inside and be located coupling assembling with between the pull rod, the unclamping subassembly includes unclamping cylinder, piston and unclamping piece, the piston is located in the unclamping cylinder, the unclamping piece with the pull rod is connected, the extension milling head of taking the unclamping cylinder still be equipped with from the area with the oil circuit of unclamping cylinder intercommunication, the oil circuit to the unclamping cylinder fuel feeding makes the piston is in the unclamping cylinder removes the conflict the unclamping piece makes the unclamping piece removes, the unclamping piece drives the pull rod and the jack catch subassembly is in remove in the main shaft and realize the loose sword and accomplish the unclamping.

2. The extension milling head with the unclamping cylinder according to claim 1, wherein: the knife beating assembly further comprises a second elastic piece, the knife beating cylinder comprises a cylinder base, two ends of the second elastic piece are respectively abutted against the cylinder base and the piston, and the second elastic piece is convenient for the piston to reset.

3. The extension milling head with the unclamping cylinder according to claim 1, wherein: the cutter beating assembly further comprises a guide sleeve, an upper spacer ring and a cushion block, the cutter beating block is fixed on the guide sleeve, the guide sleeve is fixed on the upper spacer ring, the guide sleeve is fixedly connected with the cushion block, and the upper spacer ring is inserted into the pull rod and clamped between the guide sleeve and the cushion block.

4. The extension milling head with the unclamping cylinder according to claim 1, wherein: the connecting assembly comprises a connecting disc, the connecting disc is mounted at the end of the shell, pipelines are arranged on the connecting disc and the shell, and the pipelines are communicated with each other to form the oil circuit.

5. The extension milling head with the unclamping cylinder according to claim 1, wherein: the extension milling head with the unclamping cylinder further comprises a transmission assembly, the transmission assembly comprises a key seat and a transmission shaft, the key seat is rotatably installed on the connecting assembly, the key seat and the transmission shaft are in meshed transmission through splines, and the transmission shaft is fixedly connected with the main shaft.

6. The extension milling head with the unclamping cylinder according to claim 5, wherein: the extension milling head with the unclamping cylinder further comprises a mounting assembly, the mounting assembly comprises a second pull nail, a taper shank and a screw, the taper shank is mounted on the key seat through the screw, and the pull nail is fixed at the end part of the taper shank.

7. The extension milling head with the unclamping cylinder according to claim 6, wherein: the mounting assembly further comprises a first elastic piece, the first elastic piece is sleeved on the screw, two ends of the first elastic piece are respectively abutted to the taper shank and the key seat, the taper shank can be enabled to swing relative to the key seat, and the blind rivet is prevented from interfering with a machine tool when the extension milling head with the unclamping cylinder is mounted.

8. The extension milling head with the unclamping cylinder according to claim 1, wherein: the extension milling head with the unclamping cylinder further comprises a bearing assembly, the bearing assembly is located between the spindle and the shell and comprises an upper bearing assembly, a spacer bush and a lower bearing assembly, two ends of the spacer bush are respectively abutted against the upper bearing assembly and the lower bearing assembly, the upper bearing assembly comprises a locking nut, a dust ring and two second bearings, the locking nut and the dust ring lock the second bearings, the lower bearing assembly comprises a plurality of third bearings, an outer spacer ring and an inner spacer ring, and two adjacent third bearings are spaced by the outer spacer ring and the inner spacer ring.

9. The extension milling head with the unclamping cylinder according to claim 8, wherein: the bearing assembly further comprises a second gland, a labyrinth structure and a baffle plate, the second gland is mounted at the tail end of the shell, the labyrinth structure is located between the second gland and the main shaft, and the baffle plate is mounted on the second gland and covers the labyrinth structure.

10. The extension milling head with the unclamping cylinder according to claim 9, wherein: the bearing assembly further includes a nozzle secured to the gland.