CN108789090B

CN108789090B - Eccentric polishing machine

Info

Publication number: CN108789090B
Application number: CN201810823994.5A
Authority: CN
Inventors: 何林; 张伟; 黄祖生
Original assignee: Zhuhai Sbs Precision Technology Co ltd
Current assignee: Zhuhai Sbs Precision Technology Co ltd
Priority date: 2018-07-25
Filing date: 2018-07-25
Publication date: 2024-05-28
Anticipated expiration: 2038-07-25
Also published as: CN108789090A

Abstract

The invention provides a grinding machine for eccentric grinding, which comprises a bearing frame and a grinding assembly, wherein the bearing frame is used for placing a product, the grinding assembly comprises a grinding driving device, a shaft sleeve, an eccentric shaft, a connecting shaft and a grinding frame, the grinding driving device is provided with a driving shaft, the eccentric shaft is arranged in the shaft sleeve, the driving shaft is connected with the eccentric shaft and drives the eccentric shaft to rotate around the axis of the driving shaft, the eccentric shaft is deviated from the axis of the driving shaft and is provided with an eccentric hole, the axis of the eccentric hole is parallel to the axis of the driving shaft, the connecting shaft is arranged in the eccentric hole, the connecting shaft is connected with the grinding frame, the grinding frame rotates around the axis of the eccentric shaft under the driving of the eccentric shaft through the eccentric hole on the eccentric shaft, and meanwhile, the grinding frame also rotates automatically, and vibration can be generated during high-speed eccentric rotation, so that eccentric grinding and vibration grinding of the product can be effectively improved, grinding smoothness degree is not overlapped, and grinding quality is improved on the whole.

Description

Eccentric polishing machine

Technical Field

The invention relates to the field of polishing equipment, in particular to a full-automatic eccentric polishing polisher.

Background

In the preparation process of the product, the surface of the product is polished by a polishing process, namely, the surface of the product is mechanically polished by a tool for fixing sand grains such as a grinding wheel, sand paper and the like, and the purposes can be divided into the following categories: removing burrs of the finished product, treating rust on the surface, polishing and cleaning the surface of the finished product, polishing the surface of the finished product, removing oxidized films and the like. With the rapid development of production automation, robot sanders have been widely used because of their advantages of saving time, reducing labor costs, improving product quality, improving work environment, reducing product variation, and the like.

On an automatic polishing production line, a polishing machine drives a polishing piece to polish a product to be processed, and the flatness, polishing texture and smoothness of the product are especially focused nowadays, so that the polishing process is required to be improved.

Disclosure of Invention

The invention aims to provide a grinding machine for eccentric grinding with high grinding quality.

In order to achieve the purpose of the invention, the invention provides an eccentric polishing polisher which comprises a bearing frame and a polishing assembly, wherein the bearing frame is used for placing products, the polishing assembly comprises a polishing driving device, a shaft sleeve, an eccentric shaft, a connecting shaft and a polishing frame, the polishing driving device is provided with a driving shaft, the eccentric shaft is arranged in the shaft sleeve and connected with the eccentric shaft to drive the eccentric shaft to rotate around the axis of the driving shaft, an eccentric hole is formed in the eccentric shaft, deviating from the axis of the driving shaft, the axis of the eccentric hole is parallel to the axis of the driving shaft, the connecting shaft is arranged in the eccentric hole, the connecting shaft is connected with the polishing frame, and the polishing frame is used for placing polishing pieces.

According to the scheme, the eccentric hole on the eccentric shaft drives the polishing frame to rotate around the axis of the eccentric shaft, and meanwhile, the polishing frame also rotates automatically, and vibration can be generated when the eccentric shaft rotates at a high speed, so that eccentric polishing and vibration polishing of a product can be realized, the polishing smoothness is effectively improved, polishing textures are not overlapped, and the polishing quality is integrally improved.

Still further scheme is, the polisher still includes material loading subassembly, sideslip subassembly and shifts the subassembly, and the material loading subassembly is used for bearing the product, and the sideslip subassembly includes sideslip support and sideslip drive arrangement, bears the frame setting on the sideslip support, shifts the subassembly including shifting the support, shifting drive arrangement and holder, and the holder setting is on shifting the support, shifts the drive arrangement drive and shifts the support rotation and drive holder and rotate sideslip drive arrangement drive sideslip support along shifting the subassembly and remove towards shifting between material loading subassembly and the frame.

From the above, through the mode of rotation material loading, can optimize the material loading structure for the overall structure of polisher is compacter.

Further, a plurality of bearing frames are arranged on the transverse moving bracket side by side; the plurality of transfer units are arranged side by side, one transfer unit is arranged opposite to the ground with respect to one bearing frame, and the transfer unit further comprises a first lifting driving device for driving the transfer frame to move longitudinally.

In a further scheme, the two clamping pieces are respectively arranged on two end parts of the transfer support, and the distance between the two spaced transfer assemblies is larger than the distance between the two clamping pieces on the same transfer support.

From the above, in order to further improve the compact structure, more polishing stations can be placed under the same size condition, so that the upper and lower staggered rotation mode is adopted for loading and unloading.

Still further the scheme is, the material loading subassembly includes work or material rest, first translation support and first translation drive arrangement, and the work or material rest sets up on first translation support, and first translation drive arrangement drives first translation support along first lateral movement, and the work or material rest is provided with a plurality of product placing bits along first lateral direction.

Still further scheme is, the material loading subassembly still includes second translation support and second translation drive arrangement, and work or material rest, first translation support and first translation drive arrangement all set up on the second translation support, and second translation drive arrangement drive second translation support along second lateral movement, and first horizontal perpendicular and first horizontal, a plurality of product placement positions are arranged along the second horizontal.

From the above, utilize the material loading subassembly can carry out horizontal migration's characteristic, so can arrange more product and put the position on the work or material rest, it can provide work efficiency still further, reduces and changes the work or material rest frequency.

Still further, the polisher still includes rack assembly, and rack assembly includes frame, rotation drive arrangement, elevating platform and second elevating drive arrangement, and the subassembly of polishing sets up on the frame, rotates drive arrangement drive frame rotation, and frame and rotation drive arrangement all set up on the elevating platform, and second elevating drive arrangement drive elevating platform is along longitudinal movement.

From the above, rotatable rack and liftable elevating platform for the polishing machine of the present case can carry out polishing of a plurality of angles of a plurality of positions to the product, not only effectively improves the quality of polishing, and it can also adapt to the demand of polishing of a plurality of different products.

Still further scheme is, the polisher still includes grinds a frame and push rod, grinds a frame and push rod and all is located the top of frame, grinds a frame and is provided with logical groove along vertically, is provided with the spacing groove at the inner wall of logical groove, and the push rod can be followed longitudinal movement and stretched into to logical groove in, leads to the groove and is used for placing the piece of polishing.

From the above, through the setting of grinding piece frame and push rod, realize the automatic change of grinding piece.

The shaft sleeve, the eccentric shaft, the connecting shaft and the polishing frame are respectively and symmetrically connected to two axial ends of the polishing driving device.

From the above, the polishing frames on two sides can provide polishing with two polishing precision, namely, one side is roughly polished and the other side is finely polished, and switching can be realized only by rotating the bench.

Still further scheme is, the polisher still includes rack subassembly and recovery subassembly, and rack subassembly includes the frame, rotates drive arrangement, elevating platform and second elevating drive arrangement, and the subassembly that polishes sets up on the frame, rotates drive arrangement drive frame and rotates, and frame and rotation drive arrangement all set up on the elevating platform, and second elevating drive arrangement drive elevating platform is along longitudinal movement, and recovery subassembly includes scraper and recovery groove, and scraper and recovery groove all set up on the sideslip support, and the scraper is located the top of recovery groove.

From the above, the separation of the grinding member on the grinding frame can be achieved by the movable recovery assembly, i.e. by means of the relative movement of the scraper and the grinding frame.

Drawings

Fig. 1 is a block diagram of an embodiment of a sander of the present invention.

Fig. 2 is a block diagram of an embodiment of the sander of the present invention in another view.

Fig. 3 is a block diagram of a loading assembly and a transfer assembly in accordance with an embodiment of the sander of the present invention.

Fig. 4 is a block diagram of a transfer assembly in accordance with an embodiment of the sander of the present invention.

Fig. 5 is a block diagram of a sanding assembly and a table assembly in accordance with an embodiment of the present invention.

Fig. 6 is an overall block diagram of a sanding assembly in accordance with an embodiment of the present invention.

Fig. 7 is a block diagram of a single sanding assembly in accordance with an embodiment of the present invention.

Fig. 8 is an exploded view of a single sanding assembly in an embodiment of the sanding machine of the present invention.

Fig. 9 is an elevation view of a single sanding assembly in an embodiment of a sanding machine in accordance with the present invention.

Fig. 10 is a cross-sectional view of a single sanding assembly in an embodiment of a sanding machine in accordance with the present invention.

Fig. 11 is an enlarged view at a in fig. 10.

The invention is further described below with reference to the drawings and examples.

Detailed Description

Eccentric sanding sander embodiment:

referring to fig. 1 and 2, the sander includes a loading assembly 1, a plurality of transfer assemblies 2, a traversing assembly, a carrier 3, a gantry assembly 4, and a plurality of sanding assemblies 5.

Referring to fig. 3, the feeding assembly 1 includes a material rack 11, a first translation bracket 12, a first translation driving device 131, a rod portion 132, a second translation bracket 14, a rod portion 152 and a second translation driving device 151, a plurality of product placement positions 111 are disposed on the material rack 11, the product placement positions 111 are distributed in a rectangular shape and are respectively arranged along the x and y directions, in this embodiment, the product placement positions 111 are disposed in a short convex column, and the product 10 is sleeved on the convex column. The material rack 11 is arranged on the first translation bracket 12, and the first translation driving device 131 is connected with the first translation bracket 12 through a rod portion 132 and drives the first translation bracket 12 to move along the first transverse direction y.

The material frame 11, the first translation bracket 12 and the first translation driving device 131 are all arranged on the second translation bracket 14, the second translation driving device 151 is connected with the second translation bracket 14 through a rod 152 and drives the second translation bracket 14 to move along the second transverse direction x, and the first transverse direction y is perpendicular to the first transverse direction y. The feeding component 1 is located at the outermost side of the grinding machine, and a user can perform feeding and discharging operations on the material rack 11.

Referring to fig. 4 in combination with fig. 3, the plurality of transfer units 2 are distributed along the transverse direction x, the transfer units 2 comprise a transfer support 21, a transfer driving device 23, two clamping pieces 22 and a first lifting driving device 24, the transfer support 21 is transversely arranged, the middle part of the transfer support 21 is connected with the transfer driving device 23, the two clamping pieces 22 are respectively arranged on two end parts of the transfer support 21, the transfer driving device 23 drives the transfer support 21 to rotate and drives the clamping pieces 22 to rotate between the feeding unit 1 and the bearing frame 3, and the first lifting driving device 24 is connected with the transfer driving device 23 and is used for driving the transfer support 21 to move along the longitudinal direction z.

The distance between two transfer units 2 spaced apart is greater than the distance between two clamps 22 on the same transfer carriage 21. Thus, if the rotation is performed at the same height, interference occurs, so that the transfer brackets 21 can be staggered in the height direction through height adjustment, staggered rotation can be realized, and loading and unloading operations can be realized.

The clamping pieces 22 of the transferring support 21 can take or discharge materials on the material rack 11, and by utilizing the horizontally moving material rack, one clamping piece 22 can clamp products at different positions, so that one clamping piece 22 corresponds to a plurality of product placing positions, and the space utilization rate is improved.

Referring to fig. 2 in combination with fig. 1, a plurality of carriers 3 are used for placing products, the carriers 3 are provided with positioning columns 31 and rotating devices 32, the positioning columns 31 are arranged on the rotating devices 32, and the rotating devices 32 can drive the positioning columns 31 to rotate on a horizontal plane. The traversing assembly comprises a traversing carriage 33, a rail 36 and traversing driving means connected to the traversing carriage 33 and driving the traversing carriage 33 to move along the rail 36 such that the traversing carriage 33 is movable in a transverse direction x and a plurality of carriers 3 are disposed on the traversing carriage 33 in a transverse direction y, such that the carriers 3 are movable between the transfer assembly and the sanding assembly 5.

The recovery assembly comprises a scraper 35 and a recovery groove 34, the scraper 35 is horizontally arranged, the scraper 35 and the recovery groove 34 are both arranged on the transverse moving support 33, the scraper 35 is located above the recovery groove 34, and the transversely moving scraper is used for separating polishing pieces located on the polishing assembly. The scraper 35 may also be arranged vertically, and the polishing member may be separated by a polishing assembly that moves up and down, and then falls into the recovery tank after separation.

Referring to fig. 5 in combination with fig. 2, above the sanding assembly 5, the sander further comprises a plurality of sanding element holders 61, a longitudinal driving device 62, a push rod 63, a transverse driving device 64 and a bracket 65, wherein the plurality of sanding element holders 61 are arranged on the bracket 65 along the transverse direction y, and can be used for placing sanding elements with different thickness and precision, the sanding element holders 61 are provided with through grooves 611 along the longitudinal direction z, a plurality of limiting grooves 612 are arranged on the inner walls of the through grooves 611, the limiting grooves 612 can be used for limiting the sanding elements, and the push rod 63 is driven by the longitudinal driving device 62, so that the push rod 63 can move along the longitudinal direction z and extend into the through grooves 611 from top to bottom, and is mainly used for pushing the sanding elements, so that the sanding elements can be better connected with the sanding assembly. The transverse driving device 64 is used for driving the bracket 65 to move along the transverse direction y, so that the multiple grinding frames 61 respectively correspond to the grinding assemblies, and then the grinding assemblies take different grinding members from different grinding frames 61.

Referring to fig. 6 in combination with fig. 5, the stand assembly 4 includes a lifting table 41, a second lifting driving device, a frame 45, and a rotation driving device 43, the second lifting driving device is connected with the lifting table 41 and drives the lifting table 41 to move along a longitudinal direction z, connection brackets 421 are respectively provided at both sides of the lifting table 41, a protective case 42 is provided outside the connection brackets 421, the frame 45 is rotatably connected between the connection brackets 421, the rotation driving device 43 is connected with a driving shaft 44 through a belt, and the driving shaft 44 drives the frame 45 to rotate on a vertical plane. A plurality of sanding assemblies are arranged in the transverse direction y in the frame 45.

Referring to fig. 7 to 10, the grinding assembly 5 includes a grinding driving device 51, two shaft sleeves 52, two eccentric shafts 53, two connecting shafts 54, and two grinding frames 55, the grinding driving device 51 is provided with driving shafts 511 at both axial ends, respectively, and the shaft sleeves 52, the eccentric shafts 53, the connecting shafts 54, and the grinding frames 55 are symmetrically connected to both axial ends of the grinding driving device 51, respectively, so that a description will be made below with one side.

The eccentric shaft 53 is arranged in the shaft sleeve 52, the driving shaft 511 is connected with the eccentric shaft 53 and drives the eccentric shaft 53 to rotate around the axis L1 of the driving shaft 511, the eccentric shaft 53 is provided with an eccentric hole 531 deviating from the axis L1 of the driving shaft 511, the axis L2 of the eccentric hole 531 is parallel to the axis L1 of the driving shaft 511, the opening of the eccentric hole 531 is arranged outwards, the connecting shaft 54 is arranged in the eccentric hole 531, the connecting shaft 54 is connected with the polishing frame 55, and the polishing frame 55 is used for placing polishing pieces. Under the driving action of the driving shaft 511, the polishing frame 55 can rotate around the axis L2 and also can eccentrically and circumferentially rotate around the axis L1, so that the polishing piece can eccentrically polish a product.

The axes L2 of the eccentric shafts 53 on both sides are arranged in line, so that at a high rotation speed, the rotation of the grinding frame 55 will resonate, and the grinding member can vibrate and grind the product by utilizing the resonance vibration.

One transfer subassembly 2 sets up for ground with one carrier 3, and one carrier 3 sets up for setting up with one polishing subassembly 5, and during polishing, transfer subassembly shifts the product on the material loading subassembly to the carrier on, and polishing subassembly 5 can polish the product multi-angle multiposition later, after polishing, utilizes the removal of sideslip subassembly to and transfer the unloading of subassembly to the product, realizes the automation of product and polishes in succession, utilizes eccentric polishing and vibration to polish effectively to improve the quality of polishing.

High-efficiency waterproof performance of rotating equipment embodiment:

Referring to fig. 10 and 11 in combination with fig. 8, the rotating apparatus may be based on the polishing assembly of the above embodiment, that is, the polishing assembly may be the rotating apparatus of the present embodiment, the gas bearing design of the rotating apparatus of the present embodiment may be applied to other applications in the polishing field, so that there is a difference in name, and in addition, the rotating shaft 53 of the present embodiment may be the same device as the eccentric shaft 53 of the above embodiment, and in other applications of the present embodiment, the rotating shaft 53 may not be provided with an eccentric hole, so that there is a difference in name, and the nature is substantially the same. And the polishing driving device 51 adopts motor driving in driving mode, namely, adopts the driving motor 51.

The rotating device comprises a driving motor 51, a shaft sleeve 52 and a rotating shaft 53, wherein the shaft sleeve 52 is provided with a positioning hole 521 in a penetrating manner along the axial direction, the rotating shaft 53 is arranged in the positioning hole 521 and is connected with the driving motor 51, the inner wall of the positioning hole 521 is in conical arrangement, the diameter of the positioning hole 521 is gradually reduced from the first side of the driving motor 51 to the second side of the rotating shaft 53, and the included angle between the inner wall of the positioning hole 521 and the axial direction is 0.5-3 degrees. A first air passage 524 is provided on the sleeve 52, and the first air passage 524 communicates with the positioning hole 521 at a position of the first side. Of course, the section line of the inner wall can be arranged in a straight line, and the section line of the inner wall can also be arranged in an arc shape, so that the positioning hole is arranged in a conical shape with an arc surface.

The shaft sleeve 52 is further provided with a limit hole 523 on one side of the positioning hole 521 near the driving motor 51, the diameter of the limit hole 523 is smaller than that of the positioning hole 521 on the first side, the diameter of the limit hole 523 is approximately the same as that of the positioning hole 521 on the second side, the rotating shaft 53 is in clearance fit with the limit hole 523, and the positioning hole 521 is in clearance fit with the rotating shaft 53 on the second side.

The driving motor 51 includes a casing, the shaft sleeve 52 is disposed on the casing, the first axial end surface of the shaft sleeve 52 is abutted with the second axial end surface of the casing, the casing is provided with the second air passage 513, the first air passage 524 has an opening at the first axial end surface, the second air passage 513 has an opening at the first axial end surface, the first air passage 524 and the second air passage 513 are abutted at the positions of the first axial end surface and the second axial end surface, and a sealing ring 525 is disposed between the first air passage 524 and the second air passage 513 at the abutted position.

The rotating apparatus further includes a frame 45, the frame 45 being formed by closing a long frame body and a cover body, the frame 45 being provided with a housing cavity 451 and two openings 452, the two openings 452 being located on both end portions of the housing cavity 451, respectively, the driving motor 51 being disposed in the housing cavity 451, the sleeve 52 being hermetically disposed at the opening 452, a radial end face of the sleeve 52 being adjacent to an inner peripheral wall of the opening 452 at the hermetically sealed position, and a seal ring 522 being provided between the sleeve 52 and the frame 45.

Since the casing of the driving motor is located in the accommodating cavity, an air passage interface is provided on a radial end surface of the casing, and the air passage interface is communicated with the second air passage 513, and the air passage interface is located in the accommodating cavity 451. When the rotating shaft rotates to work, the second air passage and the first air passage are communicated, so that gas is discharged from the positioning hole and discharged from the rotating shaft, and then the gas bearing is realized, so that the entry of water vapor is prevented, the lubrication effect of the gas bearing is also realized, the friction between the bearing and the rotating shaft is reduced, and waste heat can be taken away. In addition, the above-mentioned problem about resonance, the vibration at the rotating shaft is larger than the vibration at the motor, so the gap between the rotating shaft and the bearing is uneven, the lubrication is performed by using the gas to reduce friction and avoid the entry of water vapor, which plays a great role.

Of course, the sander is also provided with a spray device (not shown) which is arranged outside the rotating equipment, the spray device spraying liquid towards the carrier 3.

In addition, for the driving device of the invention, motor driving, hydraulic driving, pneumatic driving and the like of the conventional technical means can be adopted, the polishing piece can be sand paper, the polishing piece and the polishing frame can be connected in a magic tape mode, and meanwhile, the embodiment adopts a polishing mode of two opposite sides, and the polishing can be performed by adopting a single polishing frame.

From the above, through the eccentric hole on the eccentric shaft, make the frame of polishing rotate around the axis of eccentric shaft under the eccentric shaft drives, the frame of polishing is also from rotating simultaneously to because when high-speed eccentric rotation, will take place the vibration, so can realize the eccentric polishing and the vibration polishing to the product, thereby effectively improve the smooth degree of polishing, and the texture of polishing does not overlap, improves the quality of polishing on the whole. And through conical locating hole, blow in the locating hole, the flow direction of gas is set up from driving motor towards the pivot, utilizes the flow direction of gas to realize waterproof then, prevents that steam from entering into motor department, utilizes gas as lubricating fluid simultaneously, reduces the friction between axle sleeve and the pivot, improves driving efficiency.

Claims

1. A sanding machine for eccentric sanding, comprising:

The bearing frame is used for placing products;

The polishing assembly comprises a polishing driving device, a shaft sleeve, an eccentric shaft, a connecting shaft and a polishing frame, wherein the polishing driving device is provided with a driving shaft, the eccentric shaft is arranged in the shaft sleeve, the driving shaft is connected with the eccentric shaft and drives the eccentric shaft to rotate around the axis of the driving shaft, the eccentric shaft deviates from the axis of the driving shaft and is provided with an eccentric hole, the axis of the eccentric hole is parallel to the axis of the driving shaft, the connecting shaft is arranged in the eccentric hole, the connecting shaft is connected with the polishing frame, and the polishing frame is used for placing polishing pieces;

the feeding assembly is used for bearing products;

The transverse moving assembly comprises a transverse moving bracket and a transverse moving driving device, and the bearing frame is arranged on the transverse moving bracket;

The transfer assembly comprises a transfer bracket, a transfer driving device and a clamping piece, wherein the clamping piece is arranged on the transfer bracket, and the transfer driving device drives the transfer bracket to rotate and drives the clamping piece to rotate between the feeding assembly and the bearing frame;

The transverse moving driving device drives the transverse moving support to move towards the transfer assembly;

The plurality of bearing frames are arranged on the transverse moving support side by side;

a plurality of said transfer units arranged side by side, one of said transfer units being disposed opposite to one of said carriers, said transfer units further comprising a first lift drive for driving said transfer carriers to move longitudinally;

The two clamping pieces are respectively arranged on the two end parts of the transfer support, and the distance between the two spaced transfer assemblies is larger than the distance between the two clamping pieces on the same transfer support;

The feeding assembly comprises a material rack, a first translation bracket and a first translation driving device, wherein the material rack is arranged on the first translation bracket, the first translation driving device drives the first translation bracket to move along a first transverse direction, and a plurality of product placement positions are arranged on the material rack along the first transverse direction;

The feeding assembly further comprises a second translation bracket and a second translation driving device, the material rest, the first translation bracket and the first translation driving device are all arranged on the second translation bracket, the second translation driving device drives the second translation bracket to move along a second transverse direction, the first transverse direction is perpendicular to the first transverse direction, and a plurality of product placement positions are arranged along the second transverse direction;

the sander further includes a stand assembly, the stand assembly including:

The polishing device comprises a frame and a rotation driving device, wherein the polishing assembly is arranged on the frame, and the rotation driving device drives the frame to rotate;

the lifting platform and the second lifting driving device are arranged on the lifting platform, and the second lifting driving device drives the lifting platform to longitudinally move;

the grinding machine comprises a frame, a push rod, a limiting groove, a grinding frame and a grinding groove, wherein the grinding frame and the push rod are both located above the frame, the grinding frame is longitudinally provided with the limiting groove is formed in the inner wall of the through groove, the push rod can longitudinally move and extend into the through groove, and the through groove is used for placing grinding pieces.

2.A sanding machine according to claim 1, characterized in that:

the shaft sleeve, the eccentric shaft, the connecting shaft and the polishing frame are two in number, and the shaft sleeve, the eccentric shaft, the connecting shaft and the polishing frame are respectively and symmetrically connected to two axial ends of the polishing driving device.

3. A sanding machine according to claim 1, characterized in that:

The sander further includes a stand assembly and a recovery assembly, the stand assembly including:

the lifting platform and the second lifting driving device are arranged on the lifting platform, the second lifting driving device drives the lifting platform to move longitudinally,

The recovery assembly comprises a scraper and a recovery groove, wherein the scraper and the recovery groove are both arranged on the transverse moving support, and the scraper is positioned above the recovery groove.