Spindle device and manufacturing method for a spindle device

Abstract

Provided is a spindle device and a manufacturing method for a spindle device, which can stably maintain the amount of lubricating grease inside a bearing for a long period of time, does not require long-time break-in operation, prolongs the life of the lubricating grease, and realizes long life. In the spindle device (100), an outer ring (41, 21) of a rolling bearing (40, 20) is provided with a base oil supply hole (47, 27) that penetrates in the radial direction, and a housing (103) is provided with lubricating grease paths (133a) to (133e) that communicate with the base oil supply hole (47, 27). The rolling bearing (40, 20) is enclosed with lubricating grease in a bearing space. The lubricating grease paths (133a to 133e) constitute a lubricating grease accumulation portion in an operating state of the spindle device (100).

Description

Technical Field

[0001] This invention relates to a spindle assembly and an improvement on the manufacturing method of the spindle assembly. Background Technology

[0002] The significant advancement in high-speed machine tool spindles has led to the widespread adoption of oil-air lubrication as a method for lubricating bearings that enable high-speed spindle operation. However, in recent years, demands for environmental improvement, energy conservation, and resource efficiency have increased. In addition to considering noise from compressed air, environmental issues caused by oil splatter, and the large volume of air required, oil-air lubrication also necessitates auxiliary equipment such as an oil-air supply system, resulting in cost disadvantages.

[0003] Grease lubrication is a low-noise lubrication method that prevents oil from scattering without using air. Grease lubrication involves pre-sealing grease into the bearings assembled in the equipment, using the base oil in the pre-sealed grease to lubricate the bearing. The amount of grease (base oil) that can be sealed into the bearing is limited, and the amount of grease sealed affects the grease life (bearing life). Increasing the amount of grease sealed into the bearing extends the grease life, but increasing the grease filling increases viscous resistance and stirring resistance, which can cause heat generation, especially at high speeds, potentially leading to high bearing temperatures. If the grease deteriorates prematurely due to the increased bearing temperature, the base oil film may rupture, causing the bearing to burn out. Therefore, the amount of grease sealed into the bearing is determined by balancing the temperature rise characteristics at high speeds with the grease life. Furthermore, sealing excess grease into the bearing prolongs the break-in time for grease adaptation, and the production line requires time to recover after bearing replacement, thus reducing production efficiency.

[0004] In the rolling bearing described in Patent Document 1, in order to extend the grease life, it is known to install a grease deposit forming member in a spacer adjacent to the bearing, and use the temperature difference during operation to cause the base oil in the grease to seep out from the gap between the grease deposit forming member and the outer ring to lubricate the bearing.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2007-182917 Summary of the Invention

[0008] The technical problem that the invention aims to solve

[0009] However, in the rolling bearing described in Patent Document 1, since the grease deposit forming part is adjacent to the raceway surface of the outer ring, the outer ring needs to be machined. In addition, when a large amount of grease enters the rolling surface of the bearing, the temperature may rise sharply and cause it to burn out.

[0010] The present invention was made in view of the above-mentioned problems, and its purpose is to provide a spindle device and a method for manufacturing a spindle device, which can maintain the amount of grease inside the bearing stably for a long time, and does not require long-term break-in operation, thereby extending the grease life and achieving long service life.

[0011] Technical means for solving problems

[0012] The above-mentioned objective of the present invention is achieved through the following structure.

[0013] (1) A spindle device, characterized in that it comprises:

[0014] Casing; and

[0015] Multiple rolling bearings, which rotatably support the main shaft relative to the housing,

[0016] The outer ring of the rolling bearing has a radially penetrating base oil supply hole.

[0017] The housing has a grease path communicating with the base oil supply hole.

[0018] The bearing space of the rolling bearing is sealed with grease.

[0019] When the spindle device is in operation, the grease is arranged in a path to form a grease accumulation section.

[0020] (2) A method for manufacturing a spindle device, which is a method for manufacturing the spindle device described in (1).

[0021] The method for manufacturing the spindle assembly includes:

[0022] The sealing process involves sealing grease into the bearing space of the rolling bearing; and

[0023] The storage process involves storing grease in the grease path before the spindle assembly is operated.

[0024] Invention Effects

[0025] According to the spindle assembly and its manufacturing method of the present invention, the base oil of the grease stored in the grease passage on the housing side is supplied to the grease inside the bearing through the capillary effect of the thickener. Therefore, the amount of grease inside the bearing can be maintained stably for a long period, eliminating the need for prolonged break-in operation, and providing a spindle assembly that extends grease life and achieves a long service life. Attached Figure Description

[0026] Figure 1 This is a half-sectional view of the spindle device according to the first embodiment of the present invention.

[0027] Figure 2 (a) is Figure 1 Enlarged view of Part II, (b) is Figure 1 Enlarged view of part II′.

[0028] Figure 3 This is a cross-sectional view of the main part of the spindle device according to the second embodiment of the present invention.

[0029] Figure 4 This is a cross-sectional view of the main part of the spindle device according to the third embodiment of the present invention.

[0030] Figure 5 This is a cross-sectional view of the main part of the spindle device according to the fourth embodiment of the present invention.

[0031] Figure 6 This is a cross-sectional view of the main part of the spindle device according to a variation of the fourth embodiment of the present invention.

[0032] Figure 7 This is a cross-sectional view of the main part of the spindle device according to the fifth embodiment of the present invention.

[0033] Figure 8 yes Figure 7 Sectional view of section VIII.

[0034] Figure 9 (a) to (d) are variations of the fifth embodiment involving the spindle device and Figure 8 The corresponding sectional view.

[0035] Figure 10 This is a cross-sectional view of the main part of the spindle device according to another variation of the fifth embodiment of the present invention.

[0036] Figure 11 (a) is a partial sectional view of the spindle device according to the sixth embodiment of the present invention. Figure 11 (b) is a partial cross-sectional view of a variation of the sixth embodiment.

[0037] Symbol Explanation

[0038] 20 cylindrical roller bearing (rolling bearing)

[0039] 21, 41 Outer ring

[0040] 22, 42 Inner ring

[0041] 23. Cylindrical rollers (rolling elements)

[0042] 27, 47 base oil supply holes

[0043] 40° angular contact ball bearing (rolling bearing)

[0044] 43 Ball bearings (rolling elements)

[0045] 44 retainer

[0046] 100, 100a~100h spindle assembly

[0047] 101 Spindle

[0048] 103 Casing

[0049] Application routes for greases 133, 133a-133e

[0050] Linear portions 134, 134a~134e

[0051] 135 Common Path

[0052] Branch paths 136a to 136d

[0053] 140 Grease Groove Detailed Implementation

[0054] Hereinafter, various embodiments of the spindle device for machine tools will be described in detail based on the accompanying drawings, as the spindle device involved in the present invention.

[0055] (First Implementation)

[0056] like Figure 1 As shown, in the machine tool spindle assembly 100 of this embodiment, the spindle 101 is rotatably supported in the housing 103 by an angular contact ball bearing 40 and a cylindrical roller bearing 20, which are rolling bearings.

[0057] The housing 103 includes: a housing body 104; a front bearing housing 105, which is embedded and fixed to the front end of the housing body 104 (left side in the figure); and a rear bearing housing 106, which is embedded and fixed to the rear side of the housing body 104 (right side in the figure). An outer ring pressing member 107 is provided at the end of the front bearing housing 105, and the outer ring pressing member 107 forms a labyrinth seal with the inner ring pressing member 108 fastened to the main shaft 101.

[0058] The rear end face of housing 103 is covered by cover 109. A sleeve 114 supporting a cylindrical roller bearing is embedded in the rear bearing housing 106.

[0059] like Figure 2 As shown in (a), the four angular contact ball bearings 40 embedded in the front bearing housing 105 include: an outer ring 41; an inner ring 42; a plurality of balls 43 as rolling elements, which are arranged between the outer ring 41 and the inner ring 42 with contact angles; and a retainer 44 that holds the balls 43 at equal intervals in the circumferential direction. Additionally, as... Figure 2 As shown in (b), a cylindrical roller bearing 20 embedded in the sleeve 114 also includes: an outer ring 21; an inner ring 22; a plurality of rollers 23 as rolling elements, which are freely arranged between the outer ring 21 and the inner ring 22; and a retainer (not shown) that holds the rollers 23 at equal intervals in the circumferential direction.

[0060] Outer ring spacers 110 are arranged between the outer rings 41 of the four angular contact ball bearings 40. Each outer ring 41 is positioned and fixed by an outer ring pressing member 107 fixed to the front bearing housing 105. Similarly, inner ring spacers 111 are arranged between the inner rings 42. Each inner ring 42 is positioned and fixed by an inner ring pressing member 108 fastened to the spindle 101. Furthermore, an outer ring pressing member 112 is also arranged on the rear side of the outer ring 21 of the cylindrical roller bearing 20. The outer ring pressing member 112 is fixed to the sleeve 114, thereby positioning and fixing the outer ring 21. Additionally, inner ring spacers 113 are arranged on both axial sides of the inner ring 22. The inner ring 22 is positioned and fixed by a nut 115 fastened to the spindle 101.

[0061] Furthermore, in this embodiment, the cover 109, the sleeve 114, and the outer ring pressing member 112 also constitute part of the housing 103.

[0062] return Figure 1 The spindle assembly 100 houses a built-in motor consisting of a rotor 120 and a stator 121. The rotor 120 is externally fixed to approximately the center of the spindle 101 along its axial direction. The stator 121 is coaxially arranged on the outer circumferential surface of the rotor 120 at predetermined intervals. The stator 121 is fixed to the housing body 104 via a stator fixing member 122 disposed on the outer circumferential surface of the stator 121. A plurality of grooves 123 are formed along the circumference of the spindle 101 between the housing body 104 and the stator fixing member 122. Cooling refrigerant for the stator 121 flows within these grooves 123.

[0063] Similarly, a plurality of grooves 124 are formed at the location between the front bearing housing 105 and the cooling sleeve 125 embedded in the housing 105 and on the outer peripheral side of the angular contact ball bearing 40, for the flow of refrigerant for cooling the housing and bearing. The plurality of grooves 124 are formed circumferentially on the outer peripheral surface of the front bearing housing 105.

[0064] Within the housing 103, multiple greases corresponding to each rolling bearing 40, 20 are formed in the circumferential direction at different phases via paths 133a to 133e (in... Figure 1 For convenience, the grease paths 133a to 133e are shown in the same cross section. Specifically, the grease paths 133a to 133d corresponding to each angular contact ball bearing 40 open on the inner circumferential surface of the front bearing housing 105 that fits with the outer ring 41 of each angular contact ball bearing 40. After extending radially from this opening, they bend rearward and extend to the connection surface with the housing body 104. Furthermore, they extend axially within the housing body 104, the rear bearing housing 106, and the cover 109, and open at the rear end face of the cover 109. In addition, the grease path 133e corresponding to the cylindrical roller bearing 20 opens on the inner circumferential surface of the sleeve 114 that fits with the outer ring 21 of the cylindrical roller bearing 20. After extending radially from this opening, it bends rearward and extends to the connection surface with the outer ring pressing member 112. Furthermore, it opens at the rear end face of the outer ring pressing member 112.

[0065] Radial through-holes 47 and 27 are formed on the outer rings 41 and 21 of each bearing 40 and bearing 20, respectively. The inner diameter side of each base oil supply hole 47 and 27 opens near the raceway surfaces 41a and 21a, respectively, while the outer diameter side opens on the outer diameter surfaces of the outer rings 41 and 21. The openings on the bearing side of each grease supply path 133a to 133e communicate with the base oil supply holes 47 and 27 of each outer ring 41 and 21. Furthermore, the openings on the side opposite to the base oil supply holes 47 and 27 of each grease supply path 133a to 133e are sealed by the sealing bolt 126 when the spindle assembly 100 is in operation.

[0066] Furthermore, in this embodiment, the straight portions (radial paths in this embodiment) 134a-134e of each grease path 133a-133e on the outlet side, which are continuous with the base oil supply holes 47 and 27, are circular in cross-section and have the same diameter (cross-sectional area). The diameter of each straight portion 134a-134e is preferably less than or equal to the bearing width, preferably less than or equal to φ12mm, and more preferably φ1-φ5mm.

[0067] In addition, since the base oil is easily supplied due to the gravity acting on the grease, each grease path 133a to 133e is preferably positioned in the vertical direction above the spindle assembly 100 during operation.

[0068] In this embodiment, grease approximately equivalent to 10% to 30% of the internal volume of the rolling bearings 40 and 20 is sealed in the bearing space. In addition, when the spindle assembly 100 is in operation, the grease formed in the housing 103 is stored in a grease reservoir through paths 133a to 133e.

[0069] The grease sealed in the bearing and the grease stored in each grease passage 133a-133e contain a base oil as the lubricating oil and a thickener that maintains the fibrous structure of the base oil. The base oil can move between the fibers of the thickener via capillary action. By bringing the grease passages 133a-133e, which form grease reservoirs on the outer diameter surfaces of the outer rings 41, 21 after break-in operation, into contact with the base oil supply holes 47, 27 of the outer rings 41, 21, the base oil is also connected to the thickener required for movement. As a result, the base oil in the grease passages 133a-133e is added to (replenished to) the base oil of the grease sealed in the bearing.

[0070] In this embodiment, utilizing this mechanism, even if the base oil of the grease inside the bearing is consumed, the base oil of the grease stored in the grease supply paths 133a to 133e on the housing side will be supplied to the grease inside the bearing through the capillary effect of the thickener. Furthermore, since the base oil supply holes 47 and 27 of the outer rings 41 and 21 are located very close to each other on the raceway surfaces 41a and 21a of the outer rings 41 and 21, the base oil supply can be performed efficiently.

[0071] Therefore, insufficient base oil will not cause poor lubrication, as base oil is always supplied to the bearing. This ensures a stable and long-term maintenance of the amount of grease inside the bearing, extending the grease life and extending the lifespan of the spindle assembly 100. In other words, from the start of use of the spindle assembly 100 until the replacement of the rolling bearings 40 and 20, or until the replacement of the spindle assembly 100 itself, no external grease supply is required, achieving long-term maintenance-free operation.

[0072] In addition, in this embodiment, grease of approximately 10 to 30% of the internal volume of the bearing is sealed in the bearing space, so long-term break-in operation is not required.

[0073] In particular, in the high-speed rotating spindle assembly 100 of this embodiment, the temperature around the bearing also rises. However, this also causes the temperature of the grease near the bearing to rise and soften, making the base oil more prone to flow. Furthermore, since the base oil for the grease is supplied from the grease reservoir (grease passages 133a-133e), the grease life can be extended even under long-term use at high speeds. Additionally, the amount of grease sealed within the bearing is an appropriate 10-30% of the space volume, thus shortening the break-in time and reducing the production line recovery time after bearing replacement. Moreover, since the base oil is supplied using the capillary effect of the thickener, there is no oversupply, allowing for appropriate replenishment of the grease within the bearing.

[0074] Furthermore, during the assembly of the spindle assembly 100 of this embodiment, grease is sealed into the bearing spaces of the rolling bearings 40 and 20 (sealing process). Additionally, grease can be stored in the grease paths 133a-133e before the spindle assembly 100 is operated via a supply device 200 connected to an opening opposite to the base oil supply holes 47 and 27 (storage process). Then, once grease storage in the grease paths 133a-133e is complete, the supply device 200 is removed, and a sealing plug 126 is installed in the opening (sealing process).

[0075] Therefore, the replenishment device 200 is used to store grease in the grease passages 133a to 133e. Thus, the replenishment device 200 is used when manufacturing the spindle assembly 100, but in fact, the replenishment device 200 is not needed when the spindle assembly 100 is in operation (i.e., when the spindle assembly 100 is being produced), which can suppress the manufacturing cost of the spindle assembly 100.

[0076] Alternatively, a predetermined amount of grease can be pre-filled into the bearing space before assembling the bearings 40 and 20 into the spindle assembly 100. However, at least a portion of the grease can also be pre-filled using the replenishment device 200 via grease passages 133a-133e and base oil supply holes 47 and 27. In this case, after the grease is filled, the grease passages 133a-133e containing the grease constitute a grease reservoir.

[0077] Furthermore, the grease can be sealed in through grease passages 133a to 133e and base oil supply holes 47 and 27 before or during the break-in period. That is, the grease inside the bearing can also be sealed in by pressurizing the grease through grease passages 133a to 133e using a pump or similar device from the supply device 200 while the spindle 101 is rotating.

[0078] Furthermore, if a predetermined amount of grease is pre-sealed in the bearing space and in the base oil supply holes 47 and 27, the grease is stored in the grease supply path 133a to 133e by the replenishment device 200 before the bearings 40 and 20 are assembled into the spindle assembly 100.

[0079] (Second Implementation)

[0080] Next, refer to Figure 3 The spindle assembly of the second embodiment will be described. In this spindle assembly 100a, similar to the first embodiment, grease paths 133a to 133d are formed corresponding to each of the front angular contact ball bearings 40. On the other hand, in this embodiment, the diameter of the straight portion (radial path in this embodiment) 134a to 134d of each grease path 133a to 133d increases as the distance to the built-in motor decreases (Da < Db < Dc < Dd).

[0081] When the spindle assembly, including its built-in motor, generates high temperatures, the base oil of the grease can evaporate due to the high temperature, easily leading to poor lubrication. Therefore, as in this embodiment, in situations where there is a temperature difference within the spindle at each bearing 40, the diameter of the linear portions 134a to 134d can be designed to be larger on the high-temperature side and smaller on the low-temperature side. By storing a large amount of grease in the linear portions 134a to 134d near the base oil supply hole 47, the base oil of the grease in the linear portions 134a to 134d can be easily supplied to the bearing interior via the base oil supply hole 47.

[0082] The other structures and functions are the same as those in the first embodiment.

[0083] (Third Implementation)

[0084] Next, refer to Figure 4 The spindle assembly of the third embodiment will be described. In this spindle assembly 100b, a grease path 133 is formed corresponding to the four angular contact ball bearings 40 on the front side. The grease path 133 has multiple branch paths (radial paths) 136a to 136d that branch off from the axial portion 135a of the common path 135 and are respectively connected to the base oil supply path 47 of the multiple angular contact ball bearings 40.

[0085] Furthermore, in this case, the diameters of the branch paths 136a to 136d connected to each bearing 40 can be the same, but if... Figure 4 As shown, when using supply device 200 (refer to...) Figure 1When the grease is pumped and sealed in by a pump, the diameter of the branch paths 136a to 136d of each bearing 40 can increase as it moves away from the supply device 200 (Da > Db > Dc > Dd). As a result, the grease can be stored uniformly in the multiple branch paths 136a to 136d through which the grease passes.

[0086] The other structures and functions are the same as those in the first embodiment.

[0087] It should be noted that, in the case where multiple grease paths are formed corresponding to each bearing 40, and in the case where a single grease path is formed for each bearing 40, the diameter of the straight portions 134a to 134d of the grease paths 133a to 133d and the branch paths 136a to 136d of the grease path 133 can also be designed taking into account factors other than those mentioned above.

[0088] For example, when using a grease whose viscosity changes with temperature, the supply of grease in the grease path on the high-temperature side tends to increase. Therefore, the diameters of the straight portions 134a to 134d of the grease path 133a to 133d and the branch paths 136a to 136d of the grease path 133 can also be further considered to be set to decrease on the high-temperature side and increase on the low-temperature side.

[0089] (Fourth Implementation)

[0090] Next, refer to Figure 5 The spindle assembly according to the fourth embodiment will be described. In this spindle assembly 100c, grease paths 133a to 133d are respectively formed corresponding to the front bearings 40. The straight portions 134a to 134c of the grease paths 133a to 133d within the front bearing housing 105 are inclined relative to the axial direction of the spindle 101. As a result, the opening size of the straight portions 134a to 134c is widened axially, allowing for the supply of base oil without problems even if the axial position is misaligned with the base oil supply hole 47.

[0091] Furthermore, by tilting the straight sections 134a to 134c on the outlet side, the base oil can flow more easily along the direction of gravity, enabling a more stable supply of base oil. Moreover, in cases such as pressurized grease and sealing it inside the bearing, grease buildup that occurs at the 90° bend in the path disappears, thus allowing the grease to be smoothly delivered into the bearing.

[0092] The other structures and functions are the same as those in the first embodiment.

[0093] In addition, Figure 5In the spindle assembly 100c shown, the straight portions 134a to 134c of the grease paths 133a to 133c are formed at different angles from the same axial position as the straight portion 134d of the radially extending grease path 133d. However, it is also possible to... Figure 6 As shown in the modified example of the spindle assembly 100d, the straight portions 134a to 134c of the grease path 133a to 133c are formed at the same angle within the range of 45 to 90° and connected to the axial portion 137.

[0094] (Fifth Implementation)

[0095] Next, refer to Figure 7 and Figure 8 The spindle assembly of the fifth embodiment will now be described. In this spindle assembly 100e, a grease path 133 is formed corresponding to the four angular contact ball bearings 40 on the front side. The grease path 133 has multiple branch paths (radial paths) 136a to 136d that branch off from the axial portion 135a of the common path 135 and communicate with the multiple angular contact ball bearings 40 respectively.

[0096] In addition, a grease groove 140 is formed on the inner circumferential surface of the front bearing housing 105, which extends axially in phase with the multiple branch paths 136a to 136d in the circumferential direction.

[0097] Therefore, the grease groove 140 is connected to multiple branch paths 136a to 136d, and is also connected to the base oil supply hole 47 of each angular contact ball bearing 40.

[0098] In this case, the grease groove 140 has an axial length that connects the base oil supply holes 47 of the four angular contact ball bearings, and in this embodiment, it is formed from the position of the angular contact ball bearing 40 near the motor to the end of the front bearing housing 105.

[0099] Therefore, the grease reservoir 140 also functions as a grease storage unit, supplying base oil to the grease in the grease passage 133 and the grease reservoir 140 when the base oil of the grease inside the bearing is consumed. In particular, the grease reservoir 140 allows for easy storage of grease during bearing replacement, thus extending the grease life.

[0100] In addition, the shape of the grease groove 140 is not limited to Figure 8 The cross-sectional triangle shown can also be Figure 9 The cross-sectional shapes shown in (a) to (d) are semi-circular, rectangular, trapezoidal, etc.

[0101] In addition, Figure 10In the spindle assembly 100f of the modified example shown, a straight portion 134 of a grease path 133 opens into a grease reservoir 140, and the grease path 133 communicates with a base oil supply hole 47 via the grease reservoir 140. In this case, the grease reservoir 140 is also part of the grease passage 133, constituting a grease accumulation section.

[0102] (Sixth Implementation Method)

[0103] Next, refer to Figure 11 (a) The spindle assembly according to the sixth embodiment will be described. In this spindle assembly 100g, a cylindrical roller bearing is shown as the front bearing. In this case, a base oil supply hole 27 is formed on the raceway surface 21a of the outer ring 21, opposite to the cylindrical roller 23, and the base oil supply hole 27 communicates with the grease path 133. Furthermore, in the operating state of the spindle assembly 100g, the grease path 133 constitutes a grease accumulation section.

[0104] The other structures and functions are the same as those in the first embodiment.

[0105] In addition, such as Figure 11 As shown in (b) the spindle assembly 100h, the base oil supply hole 27 can also be located at a position in the raceway surface 21a of the outer ring 21 that opens axially away from the cylindrical roller 23.

[0106] Furthermore, the present invention is not limited to the above-described embodiments and variations, and can be appropriately modified and improved.

[0107] For example, in the above embodiments, the spindle device of the present invention was described using a spindle device for machine tool spindles, but the spindle device of the present invention can also be applied to spindle devices that support spindles for high-speed motors such as AC servo motors.

[0108] Alternatively, a circumferential groove can be provided on at least one of the inner circumferential surfaces of the front bearing housing 105 and sleeve 114, which have openings in the grease paths 133a to 133e, and on the outer circumferential surfaces of the outer rings 41 and 21, which have openings in the base oil supply holes 47 and 27, so that the circumferential phase of the grease paths 133a to 133e is consistent with that of the base oil supply holes 47 and 27.

[0109] As stated above, the following contents are disclosed in this specification.

[0110] (1) A spindle device, characterized in that it comprises:

[0111] Casing; and

[0112] Multiple rolling bearings that rotatably support the main shaft relative to the housing, wherein,

[0113] The outer ring of the rolling bearing has a radially penetrating base oil supply hole.

[0114] The housing has a grease path communicating with the base oil supply hole.

[0115] The bearing space of the rolling bearing is sealed with grease.

[0116] When the spindle device is in operation, the grease is arranged in a path to form a grease accumulation section.

[0117] According to this structure, the base oil of the grease stored on the housing side is supplied to the bearing interior via the capillary effect of the thickener. This allows for a stable and long-term maintenance of the amount of grease inside the bearing, eliminating the need for prolonged break-in operation, thus extending the grease life and achieving a longer service life.

[0118] (2) The spindle assembly according to (1), wherein, in the operating state of the spindle assembly, the opening on the side of the grease supply path opposite to the base oil supply hole is sealed.

[0119] This structure prevents grease from leaking through the opening of the grease path on the side opposite to the base oil supply hole.

[0120] (3) The spindle device according to (1) or (2), wherein the grease path has a plurality of grease paths corresponding to the plurality of rolling bearings respectively.

[0121] This structure enables a stable supply of grease to each rolling bearing.

[0122] (4) The spindle assembly according to (1) or (2), wherein the grease path has multiple branch paths branching from a common path and communicating with the multiple rolling bearings respectively.

[0123] Each of the branch paths has a different diameter.

[0124] This structure reduces the number of grease paths formed in the housing, making it easier to process.

[0125] (5) The spindle assembly according to any one of (1) to (4), wherein the straight portion of the grease path that is continuous with the base oil supply hole is inclined relative to the axial direction of the spindle.

[0126] According to this structure, the opening size of the straight section widens axially, allowing for base oil supply without problems even if the axial position is misaligned with the base oil supply hole. Furthermore, by tilting the straight section on the outlet side, the base oil flows more easily down the direction of gravity, enabling a more stable base oil supply.

[0127] (6) The spindle assembly according to any one of (1) to (5), wherein an axially extending grease groove is formed between the rolling bearing and the grease path.

[0128] According to this structure, the grease groove can also store grease, which can maintain the amount of grease inside the bearing stably for a long time.

[0129] (7) The spindle device according to any one of (1) to (6) is used in a machine tool.

[0130] According to this structure, the spindle of a high-speed rotating machine tool spindle unit can be supported by bearings with long service life, making maintenance easier.

[0131] (8) The spindle assembly according to any one of (1) to (6), wherein,

[0132] The spindle assembly is used for high-speed motors.

[0133] According to this structure, the spindle of a high-speed motor spindle unit can be supported by bearings with long service life, making maintenance easier.

[0134] (9) A method for manufacturing a spindle assembly according to any one of (1) to (8), wherein the assembly comprises:

[0135] The sealing process involves sealing grease into the bearing space of the rolling bearing; and

[0136] The storage process involves storing grease in the grease path before the spindle assembly is operated.

[0137] According to this structure, the base oil of the grease stored on the housing side is supplied to the bearing interior via the capillary effect of the thickener. This allows for a stable long-term maintenance of the amount of grease inside the bearing, eliminating the need for prolonged break-in operation, extending grease life, and achieving a longer lifespan for the spindle assembly.

[0138] (10) The method of manufacturing the spindle device according to (9) further includes a sealing process, wherein before the spindle device is operated, the opening on the side opposite to the base oil supply hole of the grease path is sealed.

[0139] This structure prevents grease from leaking through the opening of the grease path on the side opposite to the base oil supply hole.

[0140] (11) The method of manufacturing the spindle device according to (9) or (10), wherein, in the sealing process, at least a portion of the sealed grease is delivered via the grease path and the base oil supply hole.

[0141] According to this structure, grease can also be sealed near the raceway surface of the outer ring, which can shorten the break-in time.

[0142] Furthermore, this application is based on Japanese Patent Application No. 2021-8786, filed on January 22, 2021, the contents of which are incorporated herein by reference.

Claims

1. A spindle device, characterized in that, have: Casing; and Multiple rolling bearings, wherein the multiple rolling bearings rotatably support the main shaft relative to the housing, The outer ring of the rolling bearing has a radially penetrating base oil supply hole. The housing has a grease path communicating with the base oil supply hole. The bearing space of the rolling bearing is sealed with grease. When the spindle assembly is in operation, the grease is arranged in a path to form a grease accumulation section. During the period from the start of use of the spindle assembly to the replacement of the rolling bearing, or until the replacement of the spindle assembly itself, the opening on the side of the grease path opposite to the base oil supply hole is sealed with a sealing plug.

2. The spindle device according to claim 1, characterized in that, The grease path has multiple grease paths corresponding to the multiple rolling bearings respectively.

3. The spindle device according to claim 1, characterized in that, The grease path has multiple branch paths that branch off from a common path and connect to the multiple rolling bearings respectively. Each of the branch paths has a different diameter.

4. The spindle assembly according to any one of claims 1 to 3, characterized in that, The straight portion of the grease path that is continuous with the base oil supply hole is inclined relative to the axial direction of the spindle.

5. The spindle assembly according to any one of claims 1 to 3, characterized in that, An axially extending grease groove is formed between the rolling bearing and the grease path.

6. The spindle assembly according to any one of claims 1 to 3, characterized in that, The spindle assembly is used in machine tools.

7. The spindle assembly according to any one of claims 1 to 3, characterized in that, The spindle assembly is used for high-speed motors.

8. A method for manufacturing a spindle assembly, characterized in that, It is a method for manufacturing the spindle assembly according to any one of claims 1 to 7. The method for manufacturing the spindle assembly includes: In the sealing process, grease is sealed into the bearing space of the rolling bearing; The storage process involves storing grease in the grease path before the spindle assembly is operated; and In the sealing process, before the spindle assembly is operated, the opening on the side opposite to the base oil supply hole of the grease supply path is sealed using the sealing plug.

9. The method for manufacturing the spindle device according to claim 8, characterized in that, In the sealing process, at least a portion of the grease is sealed in via the grease path and the base oil supply hole.

Images