A horizontal milling machine spindle

Abstract

This invention discloses a horizontal milling machine spindle, comprising a bearing chamber and a spindle core passing through the bearing chamber. A front bearing assembly and an inner spacer ring are fitted onto the spindle core. A front stepped portion is formed at the front end of the spindle core. The inner spacer ring is sandwiched between the front stepped portion and the front bearing assembly. An outer spacer ring is fitted around the outer side of the inner spacer ring with a gap between them. A front bearing cap is fixed to the front end of the bearing chamber, with a gap between the front bearing cap and the spindle core. A rear abutting protrusion ring is formed at the rear end of the front bearing cap, sandwiched between the inner wall of the front opening of the bearing chamber and the front stepped portion, and the rear abutting protrusion ring abuts against the outer spacer ring. Compared to the prior art, this invention allows the front bearing cap to be pushed in from the front end of the spindle core, which not only reduces assembly difficulty and helps save maintenance costs, but also meets rigidity requirements.

Description

Technical Field

[0001] This invention relates to spindles, and more particularly to a horizontal milling machine spindle. Background Technology

[0002] Horizontal CNC milling machines are high-efficiency and stable-quality machine tools. Due to the large number of roughing operations, their milling spindles typically have characteristics such as high rigidity and heavy-duty cutting capacity. With the development of the domestic machine tool industry and the functional specialization of machining processes, horizontal CNC milling machine spindles are increasingly widely used in the market. However, the existing spindle structure is too complex and cannot meet the needs of mass production. Due to the high precision of the assembly process, most of it can only be done manually. Therefore, the efficiency of the assembly process is also very important in the entire spindle production process. In the existing milling machine spindle assembly technology, due to the large mounting surface of the front cutter head of the spindle core, the front bearing cover can only be pushed in and installed at the rear end of the spindle core before the bearing is installed. The height of the end face step of the bearing cover determines the amount of bearing outer ring press-in. It needs to be matched by measuring the height difference between the end face of the bearing housing and the end face of the spacer. As a part that needs to be measured and then machined, if its installation sequence is before the bearing, it needs to be matched before the bearing is installed. The existing method is to first install the bearing into the bearing housing, measure the height difference between the end face of the bearing housing and the end face of the spacer, then match the bearing cover, then take the bearing out of the bearing housing, and then put the bearing cover, spacer, and bearing into the spindle core in sequence, and then install the bearing housing. This process is not only complicated to install, but especially when removing the bearing from the bearing housing, because the outer ring of the roller bearing has a transition fit with the bearing housing, the knocking process is time-consuming and can easily damage the bearing. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a horizontal milling machine spindle that can be pushed into the front bearing cover from the front end of the spindle core, thereby reducing assembly difficulty, saving maintenance costs, and meeting rigidity requirements, in order to address the shortcomings of the prior art.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution.

[0005] A horizontal milling machine spindle includes a bearing chamber and a spindle core passing through the bearing chamber. A front bearing assembly and an inner spacer ring are sleeved on the spindle core. A front stepped portion is formed at the front end of the spindle core. The inner spacer ring is sandwiched between the front stepped portion and the front bearing assembly. An outer spacer ring is sleeved on the outer side of the inner spacer ring with a gap between them. A front bearing cap is fixed at the front end of the bearing chamber. A gap is formed between the front bearing cap and the spindle core. A rear abutting protrusion ring is formed at the rear end of the front bearing cap. The rear abutting protrusion ring is sandwiched between the inner wall of the front opening of the bearing chamber and the front stepped portion, and the rear abutting protrusion ring abuts against the outer spacer ring.

[0006] Preferably, a waterproof cover is fixed to the front side of the front bearing cap, and there is a gap between the waterproof cover and the shaft core. A front abutment protrusion is formed at the front end of the front bearing cap, and the rear end of the waterproof cover is sleeved on the outside of the front abutment protrusion.

[0007] Preferably, the waterproof cover has two first labyrinth grooves on its inner side, and the gap between the waterproof cover and the shaft core is connected to the first labyrinth groove. The front bearing cap has a second labyrinth groove on its inner side, and the gap between the waterproof cover and the shaft core is connected to the second labyrinth groove.

[0008] Preferably, the waterproof cover has a first drain hole and a second drain hole in its side wall, the first drain hole and the second drain hole are respectively connected to two first labyrinth grooves, and the front bearing cover has a third drain hole in its side wall, the third drain hole is connected to the second labyrinth groove.

[0009] Preferably, a drainage baffle is fixed to the outside of the front bearing cap and the waterproof cap, and a drainage hole is provided on the drainage baffle. The second drain hole and the third drain hole are both connected to the drainage hole.

[0010] Preferably, the outer wall of the shaft core has two shaft core stepped portions, each corresponding to one of the first labyrinth grooves. The inner side of each shaft core stepped portion has an inclined step opening, which is aligned with the first labyrinth groove.

[0011] Preferably, the front bearing assembly includes a front tapered roller bearing and a thrust angular bearing, with an inner and outer spacer assembly sandwiched between the front tapered roller bearing and the thrust angular bearing.

[0012] Preferably, a rear bearing cap is fixed to the rear end of the bearing chamber, a rear bearing assembly is sleeved on the shaft core, and the rear bearing cap abuts against the rear end of the rear bearing assembly.

[0013] Preferably, a pulley is fixed to the rear end of the shaft core. The pulley is located behind the rear bearing cover and there is a gap between them. The rear end face of the rear bearing cover forms a rearwardly protruding multi-layered outer stepped portion. The front end face of the pulley has an inwardly recessed multi-layered inner stepped portion. The multi-layered outer stepped portion is inserted into the multi-layered inner stepped portion and a drainage channel is formed between them. A radial drainage groove is formed on the inner side of each step of the multi-layered outer stepped portion.

[0014] Preferably, keyways are provided on the inner side of the pulley and the outer side of the shaft core, a flat key is inserted in the keyway, and a rear receiving port is provided at the rear end of the pulley, with a rear end cover plate fixed in the rear receiving port.

[0015] In the horizontal milling machine spindle disclosed in this invention, the maximum diameter of the front shoulder of the spindle core is designed to be smaller than that of the front bearing cover. This allows the front bearing cover to be pushed in from the front of the spindle core for installation. During the overall spindle installation process, it is not necessary to install the bearing cover first and then the bearing. The advantage of this structure lies in the new adjustment to the overall installation sequence. During installation, the front bearing cover, spacer ring, and front bearing assembly can be directly fitted into the spindle core in sequence, and then the assembled assembly is installed in the bearing housing. Finally, the gap between the bearing and the spacer ring is eliminated by tooling clamping. After that, the height difference between the end face of the bearing housing and the end face of the spacer ring is measured. At this point, a suitable front bearing cover can be selected. Based on the above principle, this invention can achieve one-time assembly of the spindle core, bearing assembly, and front bearing cover. Compared with the prior art, this invention allows the front bearing cover to be pushed in from the front of the spindle core, which not only reduces the assembly difficulty but also helps save maintenance costs, while still meeting rigidity requirements. Attached Figure Description

[0016] Figure 1 This is a sectional view of the spindle of a horizontal milling machine.

[0017] Figure 2 for Figure 1 Enlarged view of section A;

[0018] Figure 3 This is a three-dimensional view of the shaft core;

[0019] Figure 4 This is a structural diagram of the front bearing cap;

[0020] Figure 5 This is a structural diagram of the waterproof cover;

[0021] Figure 6 This is a structural diagram of the outer spacer ring;

[0022] Figure 7 This is a structural diagram of the inner diaphragm ring;

[0023] Figure 8 This is a structural diagram of the bearing housing;

[0024] Figure 9 This is a diagram showing the internal structure of a horizontal milling machine spindle.

[0025] Figure 10 for Figure 9 Enlarged view of section B;

[0026] Figure 11 for Figure 9 Enlarged view of section C;

[0027] Figure 12 This is a schematic diagram showing the liquid flow direction on the rear side of the rear bearing cap;

[0028] Figure 13This is a structural diagram of the rear bearing cap;

[0029] Figure 14 Here is a structural diagram of the pulley;

[0030] Figure 15 This is a structural diagram of a flat key;

[0031] Figure 16 This is a structural diagram of the rear cover plate. Detailed Implementation

[0032] The present invention will now be described in more detail with reference to the accompanying drawings and embodiments.

[0033] This invention discloses a horizontal milling machine spindle, combined with Figures 1 to 8 As shown, it includes a bearing chamber 1 and a shaft core 2 passing through the bearing chamber 1. A front bearing assembly 3 and an inner spacer ring 40 are sleeved on the shaft core 2. A front step portion 20 is formed at the front end of the shaft core 2. The inner spacer ring 40 is sandwiched between the front step portion 20 and the front bearing assembly 3. An outer spacer ring 41 is sleeved on the outer side of the inner spacer ring 40 with a gap between them. A front bearing cover 5 is fixed at the front end of the bearing chamber 1. A gap is provided between the front bearing cover 5 and the shaft core 2. A rear abutting protrusion ring 50 is formed at the rear end of the front bearing cover 5. The rear abutting protrusion ring 50 is sandwiched between the inner wall of the front opening of the bearing chamber 1 and the front step portion 20, and the rear abutting protrusion ring 50 abuts against the outer spacer ring 41.

[0034] In the above structure, the maximum diameter of the front shoulder of the shaft core 2 is designed to be smaller than that of the front bearing cover 5, so that the front bearing cover 5 can be pushed in from the front end of the shaft core for installation. During the installation of the entire shaft, it is not necessary to install the bearing cover first and then the bearing. The advantage of the above structure is that it has made a new adjustment to the overall installation sequence. During installation, the front bearing cover 5, the spacer ring, and the front bearing assembly 3 can be directly put into the shaft core in sequence, and then the assembled whole assembly is installed in the bearing chamber 1. Finally, the gap between the bearing and the spacer ring is eliminated by tooling. Then, the height difference between the end face of the bearing chamber and the end face of the spacer ring is measured. At this time, the appropriate front bearing cover 5 can be selected. Based on the above principle, the present invention can realize the one-time assembly of the shaft core, bearing assembly and front bearing cover. Compared with the prior art, the present invention can push the front bearing cover in from the front end of the shaft core, which not only reduces the assembly difficulty, but also helps to save maintenance costs, while also meeting the rigidity requirements.

[0035] As a preferred structure, a waterproof cover 6 is fixed to the front side of the front bearing cover 5, and a gap is provided between the waterproof cover 6 and the shaft core 2. A front abutment protrusion 50 is formed at the front end of the front bearing cover 5, and the rear end of the waterproof cover 6 is sleeved on the outside of the front abutment protrusion 50.

[0036] In order to provide waterproofing and auxiliary drainage, in this embodiment, the waterproof cover 6 has two first labyrinth grooves 60 on its inner side, and the gap between the waterproof cover 6 and the shaft core 2 is connected to the first labyrinth grooves 60. The front bearing cover 5 has a second labyrinth groove 52 on its inner side, and the gap between the waterproof cover 6 and the shaft core 2 is connected to the second labyrinth groove 52.

[0037] Furthermore, the waterproof cover 6 has a first drain hole 61 and a second drain hole 62 inside its side wall. The first drain hole 61 and the second drain hole 62 are respectively connected to two first labyrinth grooves 60. The front bearing cover 5 has a third drain hole 53 inside its side wall. The third drain hole 53 is connected to the second labyrinth groove 52. A drainage baffle 63 is fixed to the outside of the front bearing cover 5 and the waterproof cover 6. The drainage baffle 63 has a drain hole 64. The second drain hole 62 and the third drain hole 53 are both connected to the drain hole 64.

[0038] In the above structure, in order to ensure sufficient radial rigidity, the front bearing needs to be set close enough to the face milling cutter mounting position. However, the closer the distance, the greater the possibility of cutting fluid entering the bearing. This requires a reliable labyrinth to ensure that cutting fluid cannot enter the bearing. The multi-segment labyrinth structure of the spindle, combined with three drain holes, provides multiple guarantees to prevent cutting fluid from entering. At the same time, a baffle plate is installed at the drain hole opening near the bearing position to prevent the possibility of cutting fluid radially spraying back into the drain hole.

[0039] Furthermore, the double-stepped, inclined surface at the spindle core position of this invention allows high-speed intruding cutting fluid to be introduced into the drainage groove of the waterproof cover, flowing downwards to the drainage hole under gravity. In this embodiment, the outer wall of the spindle core 2 has two spindle core step portions 21, each corresponding to a first labyrinth groove 60. The inner side of each spindle core step portion 21 has an inclined step opening 210, which is aligned with the first labyrinth groove 60.

[0040] Regarding the preferred structure of the front bearing assembly 3, in this embodiment, the front bearing assembly 3 includes a front tapered roller bearing 30 and a thrust angular bearing 31, with an inner and outer spacer assembly 32 sandwiched between the front tapered roller bearing 30 and the thrust angular bearing 31. The main shaft bearing employs a combination of front and rear double-row cylindrical roller bearings and thrust ball bearings. The double-row cylindrical roller bearings have a small cross-sectional area, high load capacity, and high radial rigidity, while the thrust ball bearings supplement sufficient axial rigidity. The combination of the two achieves complementary rigidity, thus enhancing radial rigidity while ensuring sufficient axial rigidity.

[0041] In the above structure, the front bearing cap is locked to the bearing end face and the bearing inner hole to ensure its parallelism and concentricity, thereby maintaining a sufficiently small gap between it and the spindle core. The frontmost waterproof cover is locked to the bearing cap and the outer circle of the rear step of the bearing cap to ensure its accuracy and the gap between it and the spindle core. The appropriate gap of the labyrinth can also prevent machining debris and cutting fluid from entering the spindle.

[0042] Furthermore, combined Figures 9 to 16 As shown, a rear bearing cover 7 is fixed to the rear end of the bearing chamber 1, and a rear bearing assembly 70 is sleeved on the shaft core 2. The rear bearing cover 7 abuts against the rear end of the rear bearing assembly 70.

[0043] As a preferred embodiment, a pulley 8 is fixed to the rear end of the shaft core 2. The pulley 8 is located behind the rear bearing cover 7 and there is a gap between them. The rear end face of the rear bearing cover 7 forms a rearwardly protruding multi-layered outer step portion 71. The front end face of the pulley 8 has an inwardly recessed multi-layered inner step portion 80. The multi-layered outer step portion 71 is inserted into the multi-layered inner step portion 80 and a drainage channel 81 is formed between them. A radial drainage groove 72 is formed on the inner side of each step of the multi-layered outer step portion 71.

[0044] In the above structure, the rear bearing cap is locked to the rear end face of the bearing housing. The front step is pressed into the inner bore of the bearing housing by a grinding wheel to provide the pressing amount. The rear end is designed as an integrated radial oil drain groove. At the same time, the pulley is provided with an end face groove, which cooperates with the oil drain groove of the rear bearing cap to form a labyrinth. Dirty oil, water, etc. at the rear end are affected by gravity and fall down towards the bottom of the spindle along the oil drain groove and the end face groove of the pulley. The step on the inner bore surface of the rear bearing cap can also prevent oil and water from continuing to invade inward along the inner bore.

[0045] Regarding the preferred transmission method between the pulley 8 and the shaft core 2, in this embodiment, a keyway 82 is provided on the inner side of the pulley 8 and the outer side of the shaft core 2. A flat key 83 is inserted into the keyway 82. A rear receiving port 84 is provided at the rear end of the pulley 8. A rear end cover plate 85 is fixed in the rear receiving port 84.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the technical scope of the present invention should be included within the scope of protection of the present invention.

Claims

1. A horizontal milling machine spindle, characterized in that, The device includes a bearing housing and a shaft core passing through the bearing housing. A front bearing assembly and an inner spacer are fitted onto the shaft core. A front stepped portion is formed at the front end of the shaft core. The inner spacer is sandwiched between the front stepped portion and the front bearing assembly. An outer spacer is fitted on the outside of the inner spacer with a gap between them. A front bearing cap is fixed at the front end of the bearing housing. A gap is formed between the front bearing cap and the shaft core. A rear abutting protrusion is formed at the rear end of the front bearing cap. The rear abutting protrusion is sandwiched between the inner wall of the front opening of the bearing housing and the front stepped portion, and the rear abutting protrusion abuts against the outer spacer. In the above structure, the maximum diameter of the front stepped portion of the shaft core is smaller than the inner diameter of the front bearing cap, so that the front bearing cap can be pushed in from the front end of the shaft core for installation. During the installation of the entire shaft, it is not necessary to install the bearing cap first and then the bearing.

2. The horizontal milling machine spindle as described in claim 1, characterized in that, A waterproof cover is fixed to the front side of the front bearing cap, and there is a gap between the waterproof cover and the shaft core. A front abutment protrusion is formed at the front end of the front bearing cap, and the rear end of the waterproof cover is sleeved on the outside of the front abutment protrusion.

3. The horizontal milling machine spindle as described in claim 2, characterized in that, The waterproof cover has two first labyrinth grooves on its inner side, and the gap between the waterproof cover and the shaft core is connected to the first labyrinth groove. The front bearing cover has a second labyrinth groove on its inner side, and the gap between the waterproof cover and the shaft core is connected to the second labyrinth groove.

4. The horizontal milling machine spindle as described in claim 3, characterized in that, The waterproof cover has a first drain hole and a second drain hole in its side wall, and the first drain hole and the second drain hole are respectively connected to two first labyrinth grooves. The front bearing cover has a third drain hole in its side wall, and the third drain hole is connected to the second labyrinth groove.

5. The horizontal milling machine spindle as described in claim 4, characterized in that, A drainage baffle is fixed to the outside of the front bearing cover and the waterproof cover. A drainage hole is provided on the drainage baffle. The second drain hole and the third drain hole are both connected to the drainage hole.

6. The horizontal milling machine spindle as described in claim 3, characterized in that, The outer wall of the shaft core has two shaft core stepped portions, each corresponding to one of the first labyrinth grooves. The inner side of each shaft core stepped portion has an inclined step opening, which is aligned with the first labyrinth groove.

7. The horizontal milling machine spindle as described in claim 1, characterized in that, The front bearing assembly includes a front tapered roller bearing and a thrust angular bearing, with an inner and outer spacer assembly sandwiched between the front tapered roller bearing and the thrust angular bearing.

8. The horizontal milling machine spindle as described in claim 1, characterized in that, A rear bearing cover is fixed to the rear end of the bearing chamber, and a rear bearing assembly is sleeved on the shaft core. The rear bearing cover abuts against the rear end of the rear bearing assembly.

9. The horizontal milling machine spindle as described in claim 8, characterized in that, A pulley is fixed to the rear end of the shaft core. The pulley is located behind the rear bearing cover and there is a gap between them. The rear end face of the rear bearing cover forms a multi-layered outer step portion that protrudes rearward. The front end face of the pulley has a multi-layered inner step portion that is recessed inward. The multi-layered outer step portion is inserted into the multi-layered inner step portion and a drainage channel is formed between them. A radial drainage groove is formed on the inner side of each step of the multi-layered outer step portion.

10. The horizontal milling machine spindle as described in claim 9, characterized in that, Keyways are provided on the inner side of the pulley and the outer side of the shaft core. A flat key is inserted into the keyway. A rear receiving port is provided at the rear end of the pulley, and a rear end cover plate is fixed in the rear receiving port.

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