Oil seal sleeve and fan bearing box

Abstract

The present invention relates to an oil seal sleeve and a fan bearing box. The oil seal sleeve comprises a sleeve, which is a circular tubular structure, a circle of extended wings is arranged on the outer surface of one end of the sleeve, a comb tooth annular groove is arranged on the outer wall of the sleeve near the extended wings, an annular groove is arranged on the inner wall of the sleeve, an O-ring is arranged in the annular groove, a threaded hole is arranged on the outer wall of the sleeve, the threaded hole is arranged between the comb tooth annular groove and the annular groove, and a set screw is arranged in the threaded hole. The present invention can effectively play the role of oil blocking by arranging the extended wings on the sleeve, the comb tooth annular groove is arranged on the outer wall surface of the sleeve, and the lubricating oil can be effectively prevented from being retained from the gap between the end cover and the oil seal sleeve when the extended wings do not block the oil in time, the O-ring is arranged in the annular groove to prevent the lubricating oil from overflowing from the gap between the main shaft and the oil seal sleeve, and can play a better oil blocking effect, and the set screw in the threaded hole can ensure that the oil seal sleeve and the main shaft keep rotating synchronously.

Description

Technical Field

[0001] The invention relates to the technical field of fans, and in particular to an oil seal sleeve and a fan bearing box. Background Art

[0002] In the engineering application of fans, more bearings are lubricated with thin oil than with grease. However, the use of thin oil lubricated bearings will lead to the common problem of oil leakage in the bearing box. Oil leakage in the bearing box not only pollutes the environment, consumes more fuel, and increases the workload of operation and maintenance, but also if the oil is not replenished in time, the bearing box will lack oil, which will cause bearing wear and heat, causing bearing damage. In severe cases, it will affect the operation of the fan and the operation of the entire system.

[0003] An oil retaining ring is generally provided on the existing fan bearing box. The oil retaining ring rotates with the main shaft. The oil retaining ring and the side cover of the bearing box both extend protrusions toward each other, forming a maze. The side cover of the bearing box is sleeved on the shaft, and a labyrinth ring groove is machined at the joint between the side cover and the main shaft. A small hole is machined at the bottom of the labyrinth ring groove farthest from the bearing to prevent the bearing box from leaking oil due to the oil retaining ring not blocking the oil in time. However, sometimes the bearing box leaks oil because the oil level in the bearing box is too high, or impurities in the oil cause the oil return hole to be blocked, which brings trouble to the user.

[0004] In addition, each component of the fan rotor is manufactured very precisely and balanced during assembly, but the center of gravity of the fan rotor cannot completely match the center of the main shaft. Since there is an eccentricity between the center of the shaft and the center of the rotor, centrifugal force is generated when the main shaft rotates, which is the main cause of fan vibration and main shaft bending.

[0005] When the rotor rotates, the center of gravity rotates with the center line of the shaft, and the centrifugal force also rotates with it. When the shaft rotates once, a vibration is generated. This is the forced vibration of the rotor caused by the centrifugal force. The number of forced vibrations generated per second is called the frequency of the forced vibration. The critical speed of the rotor is related to the geometric dimensions of the shaft, the position of the turntable, the span of the fulcrum, the elasticity and other factors. Therefore, when the rotor is running at a speed far less than or far greater than its critical speed, it can work smoothly with very little deflection. When it is close to or equal to the critical speed, the deflection of the rotor is large. If measures are not taken to reduce or limit it, the rotor may vibrate greatly, causing damage to the blades or the sealing mechanism, or even damage to the bearings, resulting in serious machine accidents. Summary of the invention

[0006] In order to reduce the critical speed of the main shaft, reduce the vibration of the fan, and solve the above technical problems such as oil leakage of the bearing box, the present invention provides an oil seal sleeve and a fan bearing box.

[0007] In a first aspect, the present invention provides an oil seal sleeve, which adopts the following technical solution:

[0008] An oil seal sleeve comprises a sleeve, which is a circular tubular structure, a circle of extended wings is provided on the outer surface of one end of the sleeve, a comb tooth ring groove is provided on the outer wall of the sleeve near the extended wings, an annular groove is provided on the inner wall of the sleeve, an O-ring is provided in the annular groove, a threaded hole is provided on the outer wall of the sleeve, the threaded hole is arranged between the comb tooth ring groove and the annular groove, and a set screw is provided in the threaded hole.

[0009] By adopting the above technical scheme, by arranging the extended fan wing on the sleeve, it can effectively play the role of oil blocking, and there is a comb-tooth ring groove on the outer wall surface of the sleeve, which can effectively prevent the lubricating oil from leaking out from the gap between the end cover and the oil seal sleeve when the extended fan wing does not block the oil in time. The role of arranging the O-ring in the annular groove is to prevent the lubricating oil from overflowing from the gap between the main shaft and the oil seal sleeve, which can achieve a better oil blocking effect. By arranging the set screw in the threaded hole, it can be ensured that the oil seal sleeve and the main shaft keep rotating synchronously.

[0010] Preferably, the extended fan wing is arranged at an angle of 45 degrees in a direction away from the shaft sleeve.

[0011] Preferably, there are four annular grooves, which are divided into two groups, one group consists of two, one group is arranged on the inner wall of one end of the sleeve, and the other group is arranged on the inner wall of the other end of the sleeve.

[0012] In a second aspect, the present invention provides a fan bearing box, which adopts the following technical solution:

[0013] A fan bearing box, comprising a bearing box body, two bearing box side covers, a main shaft arranged in the bearing box body, a bearing and an oil seal sleeve as described in any one of the above, wherein the bearing sleeve is arranged on the main shaft, the two bearing box side covers are respectively arranged on the left and right sides of the bearing box body, and the oil seal sleeve is arranged at the connection between the main shaft and the bearing box side covers;

[0014] A groove is provided on the main shaft at the connection between the oil seal sleeve and the main shaft, and a shaft elastic retaining ring is provided in the groove. The oil seal sleeve and the shaft elastic retaining ring fix the inner ring of the bearing, which can shorten the distance from the center of gravity of the impeller to the supporting point, keep the critical speed of the fan away from the rated speed of the fan, and prevent the generation of resonance. At the same time, the shaft elastic retaining ring is used instead of the round nut to fix the inner ring of the bearing. The entire main shaft does not need to be processed with threads, the main shaft processing is more convenient, the main shaft processing time is shortened, and the production cost is reduced.

[0015] Preferably, a through hole is provided at the center position of the bearing box side cover, a circle of relatively outwardly bent raised fan wings is provided at the edge of the through hole, a circle of convex stoppers is provided on the outer side of the raised fan wings, the height of the convex stoppers is higher than the height of the raised fan wings, a wedge-shaped groove is provided on the upper surface of the lower end of the raised fan wings, and an oil return groove is provided between the lower end of the raised fan wings and the lower end of the convex stoppers.

[0016] By adopting the above technical scheme, the bearing box side cover is used in conjunction with the oil seal sleeve to ensure the oil sealing effect, and the raised fan wings of the bearing box side cover cooperate with the extended fan wings of the oil seal sleeve to form a very small gap to prevent the lubricating oil from being thrown out of the bearing box; the through hole of the bearing box side cover is used in conjunction with the comb ring groove of the oil seal sleeve to form a maze to prevent oil leakage from the bearing box due to the oil seal sleeve not blocking the oil in time; the wedge-shaped groove and the oil return groove are used together to ensure that the lubricating oil at the through hole of the bearing box side cover flows back to the bearing box in time.

[0017] Preferably, a filling groove is provided on the inner wall of the end of the bearing box side cover away from the raised fan wing, a silicone sealing ring is provided in the filling groove, and a silicone sealing ring is provided in the filling groove of the bearing box side cover to prevent external impurities from entering the bearing box.

[0018] Preferably, an oil drain hole is provided on the right side cover of the bearing box, and the oil drain hole is connected to the oil return groove.

[0019] Preferably, the height of the oil drain hole is consistent with the height of the oil level line of the bearing box. If the user accidentally adds too much lubricating oil, it will cause oil leakage accidents in the bearing box. The oil drain hole is provided on the side cover of the bearing box. When lubricating oil is added to the bearing box, the lubricating oil will be discharged from the oil drain hole when it reaches the oil level line, thereby preventing oil leakage of the bearing box caused by the user adding too much lubricating oil.

[0020] Preferably, the bearing and the main shaft are fixed by a shoulder, and a bearing isolation ring is provided at the shoulder. The bearing isolation ring adopts a stepped shaft style, and the outer diameter of the bearing isolation ring is sufficient for a three-jaw chuck to grasp. Where the bearing isolation ring contacts the bearing, the outer diameter of the bearing isolation ring is consistent with the outer diameter of the bearing inner ring, which does not affect the lubrication of the bearing, and the bearing isolation ring ensures that it is more convenient to disassemble the bearing, and prevents bearing damage caused by disassembly during fault diagnosis.

[0021] In summary, the present invention has the following beneficial technical effects:

[0022] 1. The oil seal sleeve of the present invention can effectively block the oil by arranging the extended fan wings on the sleeve. The outer wall surface of the sleeve is provided with a comb-toothed annular groove, which can effectively prevent the lubricating oil from leaking out from the gap between the end cover and the oil seal sleeve when the extended fan wings fail to block the oil in time. The O-ring is arranged in the annular groove to prevent the lubricating oil from overflowing from the gap between the main shaft and the oil seal sleeve, which can achieve a better oil blocking effect. The set screw in the threaded hole can ensure that the oil seal sleeve and the main shaft keep rotating synchronously.

[0023] 2. The fan bearing box of the present invention, the oil seal sleeve and the shaft elastic retaining ring fix the inner ring of the bearing, can shorten the distance from the center of gravity of the impeller to the supporting point, keep the critical speed of the fan away from the rated speed of the fan, and prevent the generation of resonance. At the same time, the shaft elastic retaining ring is used instead of the round nut to fix the inner ring of the bearing, and the entire main shaft does not need to be processed with threads, the main shaft processing is more convenient, the main shaft processing time is shortened, and the production cost is reduced;

[0024] 3. The fan bearing box described in the present invention, the bearing box side cover is used in conjunction with the oil seal sleeve to ensure the oil sealing effect, the raised fan wings of the bearing box side cover are matched with the extended fan wings of the oil seal sleeve, and the two form a very small gap to prevent the lubricating oil from being thrown out of the bearing box; the through hole of the bearing box side cover is used in conjunction with the comb tooth ring groove of the oil seal sleeve to form a maze to prevent oil leakage from the bearing box due to the oil seal sleeve failing to block the oil in time; the wedge-shaped groove and the oil return groove are used together to ensure that the lubricating oil at the through hole of the bearing box side cover flows back to the bearing box in time. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the cross-sectional structure of the oil seal sleeve in the present invention.

[0026] Figure 2 It is a structural schematic diagram of the bearing box side cover in the present invention.

[0027] Figure 3 It is a structural schematic diagram of the fan bearing box in the present invention.

[0028] Figure 4 yes Figure 3 Schematic diagram of the enlarged structure of A.

[0029] Figure 5 yes Figure 3 Schematic diagram of the enlarged structure of B.

[0030] Figure 6 yes Figure 3 Schematic diagram of the enlarged structure of C in the figure.

[0031] Figure 7 It is a schematic diagram of the shaft deflection of a cantilever structure fan.

[0032] Figure 8It is a schematic diagram of the improved front fan transmission group structure.

[0033] Description of reference numerals: 1, shaft sleeve; 2, extended fan wing; 3, comb tooth ring groove; 4, annular groove; 5, threaded hole;

[0034] 11. Bearing box body;

[0035] 12. Bearing box side cover; 121. Raised wing; 122. Raised stopper; 123. Wedge-shaped groove; 124. Oil return groove; 125. Filling groove; 126. Oil drain hole; 127. Through hole;

[0036] 13. Spindle; 14. Bearing; 141. Bearing isolation ring; 15. Oil seal sleeve; 16. Shaft elastic retaining ring;

[0037] 6. Main shaft one; 7. Moving end bearing; 8. Locking washer; 9. Fixed end bearing; 10. Round nut one; 20. Round nut two; 30. Round nut three. DETAILED DESCRIPTION

[0038] The following is combined with Figure 1-8 The present invention is described in further detail.

[0039] Example 1

[0040] This embodiment discloses an oil seal sleeve. Figure 1 An oil seal sleeve comprises a sleeve 1, which is a circular tubular structure. A circle of extended wings 2 is arranged on the outer surface of one end of the sleeve 1, a comb tooth ring groove 3 is arranged on the outer wall of the sleeve 1 near the extended wings 2, an annular groove 4 is arranged on the inner wall of the sleeve 1, an O-ring is arranged in the annular groove 4, a threaded hole 5 is arranged on the outer wall of the sleeve 1, the threaded hole is arranged between the comb tooth ring groove 3 and the annular groove 4, and a set screw is arranged in the threaded hole 5.

[0041] Specifically, the extended wing 2 is arranged to be inclined at an angle of 45 degrees in a direction away from the shaft sleeve 1 .

[0042] Specifically, there are four annular grooves 4 , which are divided into two groups, one group consists of two, one group is arranged on the inner wall of one end of the sleeve 1 , and the other group is arranged on the inner wall of the other end of the sleeve 1 .

[0043] By arranging the extended wing 2 on the shaft sleeve 1, it can effectively play the role of oil blocking. The comb-toothed annular groove 3 is provided on the outer wall surface of the shaft sleeve 1, which can effectively prevent the lubricating oil from leaking out from the gap between the end cover and the oil seal sleeve when the extended wing 2 fails to block the oil in time. The O-ring is arranged in the annular groove 4 to prevent the lubricating oil from overflowing from the gap between the main shaft and the oil seal sleeve, which can achieve a better oil blocking effect. By arranging the set screw in the threaded hole 5, it can be ensured that the oil seal sleeve and the main shaft keep rotating synchronously.

[0044] Example 2

[0045] This embodiment discloses a fan bearing box. Figure 3-6 A fan bearing box includes a bearing box body 11, two bearing box side covers 12, a main shaft 13 arranged in the bearing box body 11, a bearing 14 and an oil seal sleeve 15 in the above embodiment, the bearing 14 is sleeved on the main shaft 13, the two bearing box side covers 12 are respectively arranged on the left and right sides of the bearing box body 11, and the oil seal sleeve 15 is arranged at the connection between the main shaft 13 and the bearing box side cover 12;

[0046] Reference Figure 7 In the figure, point C is the center of gravity of the impeller, A and B are the support positions of the two bearings, and the calculation formula for the critical speed of the cantilever structure fan is: , where nc: critical speed of the main shaft, d2: average diameter of the shaft between the two supports, d1: average diameter of the cantilever end shaft, m: impeller mass, g: acceleration of gravity, a: distance from the impeller center of gravity to support point A, l: span of the shaft between the two supports. It can be seen from the formula that reducing the distance a from the impeller center of gravity to support point A can increase the critical speed nc of the fan, keep the critical speed of the fan away from the rated speed of the fan, and prevent the occurrence of resonance. In addition, reducing the distance a from the impeller center of gravity to support point A can also increase the life of the bearing. For fans with the same parameters, if the critical speed of the fan is guaranteed to remain unchanged and the distance from the impeller center of gravity to support point A is shortened, the bearing model can sometimes be reduced, thereby reducing the size of the bearing box, greatly reducing the cost of the fan.

[0047] Reference Figure 8 Before the improvement, the fan transmission group consists of a main shaft 6, a bearing 1, and a bearing box 1. The impeller is fixed to the shaft head of the main shaft 6 with a round nut 10 and a locking washer 8. There are two bearings in the bearing box 1. When the fan rotates at high speed, the main shaft 6 will produce thermal expansion. In order to prevent the fan from malfunctioning due to the thermal expansion of the main shaft 6, the bearing box 1 has a floating end and a fixed end. The side close to the impeller is called the floating end bearing 7, and the side close to the motor is called the fixed end bearing 9. The inner ring of the floating end bearing 7 is fixed with a round nut 20 and a shaft shoulder. The interior of the bearing box accommodating the floating end bearing 7 is a through hole. The outer ring of the floating end bearing 7 is in a floating state. There is a boss inside the bearing box accommodating the fixed end bearing 9. The boss and the bearing box side cover fix the outer ring of the fixed end bearing, and the main shaft 6 and the round nut 30 fix the inner ring of the fixed end bearing.

[0048] Therefore, a groove is provided on the main shaft 13 at the connection between the oil seal sleeve 15 and the main shaft 13, and a shaft elastic retaining ring 16 is provided in the groove. A groove is machined on the main shaft 13, and a shaft elastic retaining ring 16 is provided in the groove. The groove structure on the main shaft 13, the shaft elastic retaining ring 16 and the oil seal sleeve 15 are combined to fix the inner ring of the bearing 14, replacing the structure of fixing the inner ring of the bearing 14 with a round nut, and the structure of the traditional oil retaining ring is also integrated into it. In this way, it is not necessary to process the external thread of the main shaft 13, the processing of the main shaft 13 is more convenient, the processing time of the main shaft 13 is shortened, and the cost is reduced. More importantly, compared with the traditional transmission group, this structure saves the space of the round nut, the structure is more compact, and the distance from the center of gravity of the impeller to the supporting point A can be shortened, the critical speed of the fan is increased, and resonance is prevented, making the fan operation safer.

[0049] Reference Figure 2 A through hole 127 is provided at the center position of the bearing box side cover 12, and a circle of raised fan wings 121 that are relatively bent outward are provided at the edge of the through hole 127. A circle of raised stoppers 122 are provided on the outer sides of the raised fan wings 121. The height of the raised stoppers 122 is higher than the height of the raised fan wings 121. A wedge-shaped groove 123 is provided on the upper surface of the lower end of the raised fan wings 121, and an oil return groove 124 is provided between the lower end of the raised fan wings 121 and the lower end of the raised stoppers 122.

[0050] The bearing box side cover 12 is used in conjunction with the oil seal sleeve 15 to ensure the oil sealing effect. The raised fan wing 121 of the bearing box side cover 12 cooperates with the extended fan wing 2 of the oil seal sleeve to form a very small gap to prevent the lubricating oil from being thrown out of the bearing box; the through hole 127 of the bearing box side cover 12 is used in conjunction with the comb ring groove 3 of the oil seal sleeve 15 to form a maze to prevent oil leakage from the bearing box due to the oil seal sleeve 12 not blocking the oil in time; the wedge-shaped groove 123 and the oil return groove 124 jointly ensure that the lubricating oil at the through hole 127 of the bearing box side cover 14 flows back to the bearing box in time.

[0051] Specifically, a filling groove 125 is provided on the inner wall of the end of the bearing box side cover 12 away from the raised wing 121, and a silicone sealing ring is provided in the filling groove 125. The silicone sealing ring can effectively prevent foreign matter from entering the bearing box.

[0052] Specifically, an oil drain hole 126 is provided on the right side cover 12 of the bearing box, and the oil drain hole 126 is connected to the oil return groove 124. The height of the oil drain hole 126 is consistent with the height of the oil level line of the bearing box. When the user adds lubricating oil to the bearing box, too much lubricating oil will be added, resulting in frequent oil leakage accidents in the bearing box. The oil drain hole 126 is provided on the side cover 12 of the bearing box, and pipes, valves, hoses, etc. are provided on the oil drain hole 126. When adding lubricating oil to the bearing box, the valve is opened. As long as the lubricating oil is added enough, the lubricating oil will flow back to the trash can from the hose. After the bearing box is filled with lubricating oil, the valve is closed to prevent the bearing box from leaking oil due to the user adding too much lubricating oil.

[0053] Specifically, the bearing 14 is fixed to the main shaft 13 through a shoulder, and a bearing isolation ring 141 is provided at the shoulder. The bearing isolation ring 141 adopts a stepped shaft style. Vibration, abnormal noise and other problems often occur at the operation site of the fan, and it is necessary to open the bearing box for fault diagnosis. In order to detect whether it is a problem with the bearing 14, it is sometimes necessary to replace the bearing 14 for verification. The outer edge of the inner ring of the bearing 14 is too close to the main shaft 13, and the diameter will cause the ball to fall off when the bearing 14 is removed with a three-jaw chuck. If there is no problem with the bearing 14 itself, but other problems, the bearing 14 is damaged. In the present invention, a bearing isolation ring is provided at the shoulder of the bearing 14 and the main shaft 13. The outer diameter of the bearing isolation ring is sufficient for the three-jaw chuck to grab. Where the bearing isolation ring contacts the bearing 14, the outer diameter of the bearing isolation ring 141 is consistent with the outer diameter of the inner ring of the bearing, which does not affect the lubrication of the bearing, and the bearing isolation ring 141 ensures that it is more convenient to remove the bearing 14. During fault diagnosis, the problem of damage to the bearing 14 caused by the removal of the bearing 14 is prevented.

[0054] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention; the terms "first", "second", and "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance. In addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0055] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A fan bearing box, characterized in that: The bearing box comprises a bearing box body (11), two bearing box side covers (12), a main shaft (13) arranged in the bearing box body (11), two bearings (14) and an oil seal sleeve (15), wherein the two bearings (14) are respectively sleeved on both ends of the main shaft (13), the two bearing box side covers (12) are respectively arranged on the left and right sides of the bearing box body (11), and the oil seal sleeve (15) is arranged at the connection between the main shaft (13) and the bearing box side covers (12); The oil seal sleeve (15) comprises a sleeve (1), the sleeve (1) being a circular tubular structure, a circle of extended wings (2) being provided on the outer surface of one end of the sleeve (1), a comb tooth annular groove (3) being provided on the outer wall of the sleeve (1) on a side close to the extended wings (2), an annular groove (4) being provided on the inner wall of the sleeve (1), an O-ring being provided in the annular groove (4), a threaded hole (5) being provided on the outer wall of the sleeve (1), the threaded hole (5) being provided between the comb tooth annular groove (3) and the annular groove (4), and a set screw being provided in the threaded hole (5); The extended fan wing (2) is arranged at an angle of 45 degrees in a direction away from the shaft sleeve (1); There are four annular grooves (4), which are divided into two groups, one group consisting of two, one group being arranged on the inner wall of one end of the shaft sleeve (1), and the other group being arranged on the inner wall of the other end of the shaft sleeve (1); A groove is provided on the main shaft (13) at the connection between the oil seal sleeve (15) and the main shaft (13), and a shaft elastic retaining ring (16) is provided in the groove. The groove structure on the main shaft (13), the shaft elastic retaining ring (16) and the oil seal sleeve (15) are combined to fix the inner ring of the bearing (14); A through hole (127) is provided at the center of the bearing box side cover (12), a circle of relatively outwardly bent raised wings (121) is provided at the edge of the through hole (127), a circle of raised stoppers (122) is provided on the outer side of the raised wings (121), the height of the raised stoppers (122) is higher than the height of the raised wings (121), a wedge-shaped groove (123) is provided on the upper surface of the lower end of the raised wings (121), and an oil return groove (124) is provided between the lower end of the raised wings (121) and the lower end of the raised stoppers (122).

2. A fan bearing box according to claim 1, characterized in that: A filling groove (125) is provided on the inner wall of the end of the bearing box side cover (12) away from the raised wing (121), and a silicone sealing ring is provided in the filling groove (125).

3. A fan bearing box according to claim 1, characterized in that: An oil drain hole (126) is provided on the right side bearing box side cover (12), and the oil drain hole (126) is communicated with the oil return groove (124).

4. A fan bearing box according to claim 3, characterized in that: The height of the oil drain hole (126) is consistent with the height of the oil level line of the bearing box.

5. A fan bearing box according to claim 1, characterized in that: The bearing (14) and the main shaft (13) are fixed via a shaft shoulder, a bearing isolation ring (141) is provided at the shaft shoulder, and the bearing isolation ring (141) adopts a stepped shaft style.

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