Waterproof trapezoidal screw rod elevator
Patent Information
- Application Number
- CN202522392080.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-11
- Publication Date
- 2026-10-09
- Estimated Expiration
- 2035-11-11
AI Technical Summary
传统丝杆升降机一般用于室内干燥的环境中，但是有些恶劣工况如淋雨、水下等环境，由于传统丝杆升降机不具备防水功能，会导致传统丝杆升降机因进水而无法正常使用
[0016]本实用新型防水梯形丝杆升降机的壳体通过其底部的若干安装孔固定安装在工作位置上，动力源与蜗杆轴传动连接，梯形丝杆的顶端与负载连接，通过动力源带动蜗杆轴转动，蜗杆轴上的蜗杆部驱动蜗轮部转动，蜗轮套管驱动梯形丝杆带动负载上升或下降，第一油封和第二油封能够有效防止内部润滑油泄露以及外部水进入壳体内部，梯形丝杆表面的LDC涂层具有较高的硬度、较好的润滑性以及较低的摩擦系数，能够显著降低梯形丝杆与蜗轮套管在工作过程中的磨损，提高升降机的使用寿命，保护筒能够有效保护梯形丝杆，排水孔能够平衡保护筒内外的压力，避免产生额外阻力。本实用新型具有很好的方式功能，能够防止升降机在使用过程中外界的水进入升降机内部，确保升降机能够在外部水汽较多的环境中或水下工况正常使用。
Smart Images
Figure CN224832099U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of lifting equipment technology, and in particular to a waterproof trapezoidal screw jack. Background Technology
[0002] A screw jack, also known as a screw drive mechanism, is mainly used to convert rotary motion into linear motion of a trapezoidal screw. It is widely used in applications requiring lifting, lowering, or tilting of loads. Traditional screw jacks are generally used in dry indoor environments; however, in harsh conditions such as rain or underwater environments, the lack of waterproofing can cause them to malfunction due to water ingress. Utility Model Content
[0003] The purpose of this utility model is to provide a waterproof trapezoidal screw jack, which has excellent waterproof function and can prevent external water from entering the jack during use, ensuring that the jack can be used normally in environments with high external moisture or underwater conditions.
[0004] To achieve the above and other related objectives, this utility model provides a waterproof trapezoidal screw jack, comprising: a housing, a worm gear assembly, a worm assembly, and a screw assembly. The housing has a first mounting cavity and a second mounting cavity inside. The second mounting cavity is located within the housing on one side of the first mounting cavity and is perpendicular to the first mounting cavity. A first cover and a second cover are fixedly installed on the outer walls of the housing at both ends of the first mounting cavity, respectively. The first cover and the second cover are respectively sealed to the inner walls at both ends of the first mounting cavity. End caps and end caps are fixedly installed on the outer walls of the housing at both ends of the second mounting cavity, respectively. The end caps and end caps are respectively sealed to the inner walls at both ends of the second mounting cavity. The bottom edge of the housing has several mounting holes. The worm gear assembly includes a worm gear sleeve, with a worm gear portion in the middle of the outer wall of the worm gear sleeve. The outer walls of the worm gear sleeve on both sides of the worm gear portion are respectively... The worm gear sleeve is rotatably connected to the first cover and the first mounting cavity via a first bearing. The outer walls of both ends of the worm gear sleeve are respectively sealed to the first cover and the second cover via a set of first oil seals. The worm assembly includes a worm shaft, and a worm portion is provided in the middle of the outer wall of the worm shaft. The worm portion meshes with the worm wheel portion. The outer walls of the worm shaft on both sides of the worm portion are rotatably connected to the inner walls of both ends of the second mounting cavity via a second bearing. One end of the worm shaft passes through and is rotatably installed in the end cover. The end of the worm shaft is sealed to the end cover via a set of second oil seals. The lead screw assembly includes a trapezoidal lead screw and a protective cylinder. The trapezoidal lead screw passes through the worm gear sleeve and is threadedly connected to the worm gear sleeve. One end of the protective cylinder is threadedly connected to the end of the second cover away from the housing. A drain hole is provided on the end face of the other end of the protective cylinder. The protective cylinder is sleeved around the trapezoidal lead screw.
[0005] In one example of the waterproof trapezoidal screw jack of this utility model, a pin head is fixedly installed at the end of the trapezoidal screw away from the protective tube.
[0006] In one example of the waterproof trapezoidal screw jack of this utility model, the first cover is provided with a plurality of first connecting holes, and the top surface of the housing is provided with a plurality of second connecting holes. The plurality of first connecting holes and the plurality of second connecting holes cooperate with each other and are fixedly connected by a plurality of first bolts.
[0007] In one example of the waterproof trapezoidal screw jack of this utility model, the second cover is provided with a plurality of third connecting holes, and the bottom surface of the housing is provided with a plurality of fourth connecting holes. The plurality of third connecting holes and the plurality of fourth connecting holes cooperate with each other and are fixedly connected by a plurality of second bolts.
[0008] In one example of the waterproof trapezoidal screw jack of this utility model, a first insertion part is provided on the end face of the first cover facing the housing. The outer wall of the first insertion part is matched with one end of the inner wall of the first mounting cavity. A first sealing groove is provided on the outer wall of the first insertion part. A first sealing ring is installed in the first sealing groove. The first sealing ring is sealed to the inner wall of the first mounting cavity.
[0009] In one example of the waterproof trapezoidal screw jack of this utility model, the inner rings of the two first bearings are respectively tightly fitted with the outer walls of the worm gear sleeves on both sides of the worm gear portion, the outer ring of one of the first bearings is tightly fitted with the inner wall of the first insertion portion, and the outer ring of the other first bearing is tightly fitted with the inner wall of the first mounting cavity.
[0010] In one example of the waterproof trapezoidal screw jack of this utility model, a second insertion part is provided on the end face of the second cover facing the housing. The outer wall of the second insertion part cooperates with the other end of the inner wall of the first mounting cavity. A second sealing groove is provided on the outer wall of the second insertion part. A second sealing ring is installed in the second sealing groove. The second sealing ring is sealed to the inner wall of the first mounting cavity.
[0011] In one example of the waterproof trapezoidal screw jack of this utility model, the outer walls of the two sets of first oil seals are tightly fitted with the inner walls of the first insertion part and the second insertion part, respectively, and the inner walls of the two sets of first oil seals are rotatably fitted with the outer walls of both ends of the worm gear sleeve.
[0012] In one example of the waterproof trapezoidal screw jack of this utility model, a third insertion part is provided on the end face of the end cap facing the housing. The outer wall of the third insertion part cooperates with the inner wall of one end of the second mounting cavity. A third sealing groove is provided on the outer wall of the third insertion part. A third sealing ring is installed in the third sealing groove. The third sealing ring is sealed to the inner wall of the second mounting cavity.
[0013] In one example of the waterproof trapezoidal screw jack of this utility model, a fourth insertion part is provided on the end face of the end cover facing the housing. The outer wall of the fourth insertion part cooperates with the inner wall of the other end of the second mounting cavity. A fourth sealing groove is provided on the outer wall of the fourth insertion part. A fourth sealing ring is installed in the fourth sealing groove. The fourth sealing ring is sealed to the inner wall of the second mounting cavity.
[0014] In one example of the waterproof trapezoidal screw jack of this utility model, the outer wall of the second oil seal is tightly fitted with the inner wall of the end cover, and the inner wall of the second oil seal is rotatably fitted with the outer wall of the worm shaft.
[0015] In one example of the waterproof trapezoidal screw jack of this utility model, the first oil seal and the second oil seal are polytetrafluoroethylene skeleton oil seals, each group of the first oil seals includes two first oil seals, each group of the second oil seals includes two second oil seals, and the surface of the trapezoidal screw is provided with a DLC coating.
[0016] This utility model relates to a waterproof trapezoidal screw jack. The housing of the jack is fixedly installed in the working position via several mounting holes at its bottom. The power source is connected to the worm shaft drive, and the top of the trapezoidal screw is connected to the load. The power source drives the worm shaft to rotate, and the worm portion on the worm shaft drives the worm wheel portion to rotate. The worm wheel sleeve drives the trapezoidal screw to raise or lower the load. The first and second oil seals effectively prevent internal lubricating oil leakage and external water from entering the housing. The LDC coating on the surface of the trapezoidal screw has high hardness, good lubricity, and a low coefficient of friction, significantly reducing wear between the trapezoidal screw and the worm wheel sleeve during operation, thus improving the service life of the jack. The protective sleeve effectively protects the trapezoidal screw, and the drainage hole balances the pressure inside and outside the protective sleeve, preventing additional resistance. This utility model has excellent protective functions, preventing external water from entering the jack during use, ensuring normal operation in environments with high external humidity or underwater conditions. Attached Figure Description
[0017] Figure 1 This is a three-dimensional structural diagram of an embodiment of the waterproof trapezoidal screw jack of this utility model; Figure 2 A cross-sectional view of an embodiment of the waterproof trapezoidal screw jack of this utility model. Figure 1 ; Figure 3 This is a partial sectional view of an embodiment of the waterproof trapezoidal screw jack of this utility model; Figure 4 A cross-sectional view of an embodiment of the waterproof trapezoidal screw jack of this utility model. Figure 2 ; Figure 5 This is a cross-sectional view of the housing in one embodiment of the waterproof trapezoidal screw jack of this utility model; Figure 6 This is a cross-sectional view of the first cover in one embodiment of the waterproof trapezoidal screw jack of this utility model; Figure 7 This is a cross-sectional view of the second cover in one embodiment of the waterproof trapezoidal screw jack of this utility model; Figure 8 This is a sectional view of the end cover in one embodiment of the waterproof trapezoidal screw jack of this utility model; Figure 9 This is a cross-sectional view of the end cap in one embodiment of the waterproof trapezoidal screw jack of this utility model.
[0018] Component designation: 100 Housing; 110 First mounting cavity; 120 Second mounting cavity; 130 First cover; 131 First connecting hole; 132 First insertion part; 133 First sealing groove; 134 First sealing ring; 140 Second cover; 141 Third connecting hole; 142 Second insertion part; 143 Second sealing groove; 144 Second sealing ring; 150 End cap; 151 Third insertion part; 152 Third sealing groove; 153 Third sealing ring; 160 End cap; 161 Fourth insertion part Part; 162 Fourth sealing groove; 163 Fourth sealing ring; 170 Second connecting hole; 180 Fourth connecting hole; 190 Mounting hole; 200 Worm gear assembly; 210 Worm gear sleeve; 211 Worm gear part; 220 First bearing; 230 First oil seal; 300 Worm gear assembly; 310 Worm shaft; 311 Worm gear part; 320 Second bearing; 330 Second oil seal; 400 Lead screw assembly; 410 Trapezoidal lead screw; 411 Pin head; 420 Protective cylinder; 421 Drain hole. Detailed Implementation
[0019] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. It should also be understood that the terminology used in the embodiments of this utility model is for describing specific implementation schemes and not for limiting the scope of protection of this utility model. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or according to the conditions recommended by the respective manufacturers.
[0020] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise specified in this invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention, as well as the prior art known to those skilled in the art and the description of this invention, may be implemented using any prior art methods, equipment, and materials similar to or equivalent to those in the embodiments of this invention.
[0021] Please see Figures 1 to 9This utility model provides a waterproof trapezoidal screw jack, comprising: a housing 100, a worm gear assembly 200, a worm gear assembly 300, and a screw assembly 400. The housing 100 has a first mounting cavity 110 and a second mounting cavity 120 inside. The second mounting cavity 120 is located inside the housing 100 on one side of the first mounting cavity 110 and is perpendicular to the first mounting cavity 110. A first cover 130 and a second cover 140 are respectively fixedly installed on the outer walls of the housing 100 at both ends of the first mounting cavity 110. The first cover 130 and the second cover 140 are respectively sealed to the inner walls at both ends of the first mounting cavity 110. An end cap 150 and a blind cap 160 are respectively fixedly installed on the outer walls of the housing 100 at both ends of the second mounting cavity 120. The end cap 150 and the blind cap 160 are respectively sealed to the inner walls at both ends of the second mounting cavity 120. The bottom edge of the housing 100 has a plurality of mounting holes 190. The worm gear assembly 200 includes a worm gear sleeve 210, and a worm gear portion 211 is provided in the middle of the outer wall of the worm gear sleeve 210. The outer walls of the worm gear sleeve 210 on both sides of the worm gear portion 211 are respectively rotatably connected to the first cover 130 and the first mounting cavity 110 through a first bearing 220. The outer walls at both ends of the worm gear sleeve 210 are respectively sealed to the first cover 130 and the second cover 140 through a set of first oil seals 230. The worm gear assembly 300 includes a worm shaft 310, a worm portion 311 is provided in the middle of the outer wall of the worm shaft 310, the worm portion 311 meshes with the worm wheel portion 211, the outer walls of the worm shaft 310 on both sides of the worm portion 311 are respectively rotatably connected to the inner walls of both ends of the second mounting cavity 120 through a second bearing 320, one end of the worm shaft 310 passes through and is rotatably installed in the end cover 150, and the end of the worm shaft 310 is sealed to the end cover 150 through a set of second oil seals 330. The lead screw assembly 400 includes a trapezoidal lead screw 410 and a protective sleeve 420. The trapezoidal lead screw 410 passes through the worm gear sleeve 210 and is threadedly connected to the worm gear sleeve 210. One end of the protective sleeve 420 is threadedly connected to the end of the second cover 140 away from the housing 100. A drain hole 421 is provided on the end face of the other end of the protective sleeve 420. The protective sleeve 420 is sleeved around the trapezoidal lead screw 410.
[0022] The housing 100 of this utility model is fixedly installed in the working position through several mounting holes 190 at its bottom. The power source is connected to the worm shaft 310 for transmission, and the top end of the trapezoidal lead screw 410 is connected to the load. The power source drives the worm shaft 310 to rotate, the worm part 311 on the worm shaft 310 drives the worm wheel part 211 to rotate, and the worm wheel sleeve 210 drives the trapezoidal lead screw 410 to drive the load to rise or fall. The first oil seal 230 and the second oil seal 330 can effectively prevent internal lubricating oil leakage and external water from entering the housing 100. The LDC coating (diamond-like carbon film) on the surface of the trapezoidal lead screw 410 has high hardness, good lubricity and low coefficient of friction, which can significantly reduce the wear of the trapezoidal lead screw 410 and the worm wheel sleeve 210 during operation and improve the service life of the elevator. The protective cylinder 420 can effectively protect the trapezoidal lead screw 410, and the drain hole 421 can balance the pressure inside and outside the protective cylinder 410 and avoid generating additional resistance.
[0023] Please see Figure 1 and Figure 2 In one example of the waterproof trapezoidal screw jack of this utility model, a pin head 411 is fixedly installed at the end of the trapezoidal screw 410 away from the protective tube 420. The pin head 411 is used to connect to the load.
[0024] Please see Figure 3 as well as Figures 5 to 7 In one example of the waterproof trapezoidal screw jack of this utility model, the first cover 130 is provided with a plurality of first connecting holes 131, and the top surface of the housing 100 is provided with a plurality of second connecting holes 170. The plurality of first connecting holes 131 and the plurality of second connecting holes 170 cooperate with each other and are fixedly connected by a plurality of first bolts. The second cover 140 is provided with a plurality of third connecting holes 141, and the bottom surface of the housing 100 is provided with a plurality of fourth connecting holes 180. The plurality of third connecting holes 141 and the plurality of fourth connecting holes 180 cooperate with each other and are fixedly connected by a plurality of second bolts.
[0025] Please see Figure 3 and Figure 6In one example of the waterproof trapezoidal screw jack of this utility model, a first insertion portion 132 is provided on the end face of the first cover 130 facing the housing 100. The outer wall of the first insertion portion 132 mates with one end of the inner wall of the first mounting cavity 110. A first sealing groove 133 is provided on the outer wall of the first insertion portion 132, and a first sealing ring 134 is installed in the first sealing groove 133. The first sealing ring 134 is sealed to the inner wall of the first mounting cavity 110. The inner rings of the two first bearings 220 are respectively tightly fitted with the outer walls of the worm gear sleeves 210 on both sides of the worm gear portion 211. The outer ring of one first bearing 220 is tightly fitted with the inner wall of the first insertion portion 132, and the outer ring of the other first bearing 220 is tightly fitted with the inner wall of the first mounting cavity 110.
[0026] Please see Figure 3 and Figure 7 In one example of the waterproof trapezoidal screw jack of this utility model, a second insertion portion 142 is provided on the end face of the second cover 140 facing the housing 100. The outer wall of the second insertion portion 142 mates with the other end of the inner wall of the first mounting cavity 110. A second sealing groove 143 is provided on the outer wall of the second insertion portion 142, and a second sealing ring 144 is installed in the second sealing groove 143. The second sealing ring 144 is sealed to the inner wall of the first mounting cavity 110. The outer walls of the two sets of first oil seals 230 are tightly fitted with the inner walls of the first insertion portion 132 and the second insertion portion 142, respectively. The inner walls of the two sets of first oil seals 230 are rotatably fitted with the outer walls at both ends of the worm gear sleeve 210.
[0027] Please see Figure 4 , Figure 8 and Figure 9In one example of the waterproof trapezoidal screw jack of this utility model, the end cap 150 has a third insertion part 151 on the end face facing the housing 100. The outer wall of the third insertion part 151 mates with the inner wall of one end of the second mounting cavity 120. The outer wall of the third insertion part 151 has a third sealing groove 152, and a third sealing ring 153 is installed in the third sealing groove 152. The third sealing ring 153 is sealed to the inner wall of the second mounting cavity 120. The end cap 160 has a fourth insertion part 161 on the end face facing the housing 100. The outer wall of the fourth insertion part 161 mates with the inner wall of the other end of the second mounting cavity 120. The outer wall of the fourth insertion part 161 has a fourth sealing groove 162, and a fourth sealing ring 163 is installed in the fourth sealing groove 162. The fourth sealing ring 163 is sealed to the inner wall of the second mounting cavity 120. The outer wall of the second oil seal 330 is in close fit with the inner wall of the end cover 150, and the inner wall of the second oil seal 330 is in rotatable fit with the outer wall of the worm shaft 310.
[0028] In one example of the waterproof trapezoidal screw jack of this utility model, the first oil seal 230 and the second oil seal 330 are polytetrafluoroethylene skeleton oil seals. Each group of first oil seals 230 includes two first oil seals 230, and each group of second oil seals 330 includes two second oil seals 330. The two first oil seals 230 are installed in opposite directions, and the two second oil seals 330 are installed in opposite directions, which can improve the waterproof effect. The trapezoidal screw 410 is provided with a DLC coating on its surface.
[0029] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.
Claims
1. A waterproof trapezoidal screw jack, characterized in that, include: The housing has a first mounting cavity and a second mounting cavity inside. The second mounting cavity is located inside the housing on one side of the first mounting cavity and is perpendicular to the first mounting cavity. A first cover and a second cover are fixedly installed on the outer walls of the housing at both ends of the first mounting cavity, respectively. The first cover and the second cover are respectively sealed to the inner walls at both ends of the first mounting cavity. An end cap and a blind cap are fixedly installed on the outer walls of the housing at both ends of the second mounting cavity, respectively. The end cap and the blind cap are respectively sealed to the inner walls at both ends of the second mounting cavity. The bottom edge of the housing has several mounting holes. A worm gear assembly, comprising a worm gear sleeve, a worm gear portion in the middle of the outer wall of the worm gear sleeve, the outer walls of the worm gear sleeve on both sides of the worm gear portion being rotatably connected to the first machine cover and the first mounting cavity respectively through a first bearing, and the outer walls at both ends of the worm gear sleeve being sealed to the first machine cover and the second machine cover respectively through a set of first oil seals; A worm gear assembly, comprising a worm shaft, a worm portion located in the middle of the outer wall of the worm shaft, the worm portion meshing with the worm wheel portion, the outer walls of the worm shaft on both sides of the worm portion being rotatably connected to the inner walls at both ends of a second mounting cavity via a second bearing, one end of the worm shaft passing through and rotatably mounted in the end cover, and the end of the worm shaft being sealed to the end cover via a set of second oil seals; A lead screw assembly, comprising a trapezoidal lead screw and a protective sleeve, wherein the trapezoidal lead screw passes through the worm gear sleeve and is threadedly connected to the worm gear sleeve, one end of the protective sleeve is threadedly connected to the end of the second cover away from the housing, and a drainage hole is provided on the end face of the other end of the protective sleeve, and the protective sleeve is sleeved around the trapezoidal lead screw.
2. The waterproof trapezoidal screw jack as described in claim 1, characterized in that, The first cover is provided with a plurality of first connecting holes, and the top surface of the housing is provided with a plurality of second connecting holes. The plurality of first connecting holes and the plurality of second connecting holes cooperate with each other and are fixedly connected by a plurality of first bolts. The second cover is provided with a plurality of third connecting holes, and the bottom surface of the housing is provided with a plurality of fourth connecting holes. The plurality of third connecting holes and the plurality of fourth connecting holes cooperate with each other and are fixedly connected by a plurality of second bolts.
3. The waterproof trapezoidal screw jack as described in claim 1, characterized in that, The first cover has a first insertion part on the end face facing the housing. The outer wall of the first insertion part matches one end of the inner wall of the first mounting cavity. The outer wall of the first insertion part has a first sealing groove. A first sealing ring is installed in the first sealing groove. The first sealing ring is sealed to the inner wall of the first mounting cavity.
4. The waterproof trapezoidal screw jack as described in claim 3, characterized in that, The inner rings of the two first bearings are respectively tightly fitted to the outer walls of the worm gear sleeves on both sides of the worm gear portion, the outer ring of one first bearing is tightly fitted to the inner wall of the first insertion portion, and the outer ring of the other first bearing is tightly fitted to the inner wall of the first mounting cavity.
5. The waterproof trapezoidal screw jack as described in claim 3, characterized in that, The second cover has a second insertion part on the end face facing the housing. The outer wall of the second insertion part matches the other end of the inner wall of the first mounting cavity. The outer wall of the second insertion part has a second sealing groove. A second sealing ring is installed in the second sealing groove. The second sealing ring is sealed to the inner wall of the first mounting cavity.
6. The waterproof trapezoidal screw jack as described in claim 5, characterized in that, The outer walls of the two sets of first oil seals are tightly fitted with the inner walls of the first insertion part and the second insertion part, respectively, and the inner walls of the two sets of first oil seals are rotatably fitted with the outer walls of both ends of the worm gear sleeve.
7. The waterproof trapezoidal screw jack as described in claim 1, characterized in that, The end cap has a third insertion part on the end face facing the housing. The outer wall of the third insertion part matches the inner wall of one end of the second mounting cavity. The outer wall of the third insertion part has a third sealing groove. A third sealing ring is installed in the third sealing groove. The third sealing ring is sealed to the inner wall of the second mounting cavity.
8. The waterproof trapezoidal screw jack as described in claim 7, characterized in that, The end face of the cover facing the housing is provided with a fourth insertion part. The outer wall of the fourth insertion part is matched with the inner wall of the other end of the second mounting cavity. The outer wall of the fourth insertion part is provided with a fourth sealing groove. A fourth sealing ring is installed in the fourth sealing groove. The fourth sealing ring is sealed to the inner wall of the second mounting cavity.
9. The waterproof trapezoidal screw jack as described in claim 7, characterized in that, The outer wall of the second oil seal is in close fit with the inner wall of the end cap, and the inner wall of the second oil seal is in rotatable fit with the outer wall of the worm shaft.
10. The waterproof trapezoidal screw jack as described in claim 1, characterized in that, The first oil seal and the second oil seal are polytetrafluoroethylene skeleton oil seals. Each group of first oil seals includes two first oil seals, and each group of second oil seals includes two second oil seals. The surface of the trapezoidal lead screw is coated with DLC.