Sealing device, spindle device, grinding device, and cutting device
The seal device with a deformation suppression ring addresses the issue of foreign matter entry and plastic deformation in spindle devices, ensuring stable sealing and reduced fluid consumption, thus extending device life and preventing damage.
Patent Information
- Application Number
- JP2024111791
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-07-11
- Publication Date
- 2026-01-23
AI Technical Summary
Existing spindle devices face issues with foreign matter entering through gaps between rotating and fixed parts, leading to potential damage and increased load, as conventional V-ring seals are prone to plastic deformation and loss of sealing effectiveness.
A seal device with a deformation suppression ring fitted into a circumferential groove of the seal member, preventing excessive deformation and maintaining a stable sealing function by allowing elastic deformation during rotation, while blocking fluid passages when stationary.
Prevents foreign matter entry and extends seal member lifespan, reduces frictional resistance, and minimizes fluid consumption by ensuring stable sealing and reducing heat generation, thereby prolonging device life and lowering operational costs.
Smart Images
Figure 2026011302000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to a sealing device, a spindle device, a grinding device, and a cutting device. [Background technology]
[0002] Conventionally, among devices that perform machining by rotating tools, spindle devices in which tools are interchangeably attached to a rotatable spindle have been known. Spindle devices generally include a rotating part supported by bearings and a fixed part other than the rotating part. Various machining tools (e.g., grinding wheels, cutting tools, etc.) are attached to the tip of the rotating shaft that constitutes the rotating part, and these machining tools are used to perform machining (polishing, cutting, etc.) on the workpiece.
[0003] This means that foreign matter such as machining fluid and chips may enter the spindle device through the gap between the rotating and fixed parts during machining, which may cause the rotating shaft to rotate impedimentally or may cause a large load to be applied, potentially damaging the spindle device.
[0004] Previously, there have been proposals for a spindle head (Patent Document 1) that can prevent chips and other particles from entering the interior of the spindle when the spindle is rotating and when it is stopped, and a cutting device (Patent Document 2) that can prevent foreign matter from entering the spindle housing.
[0005] The spindle head described in Patent Document 1 supplies air to an air chamber through an air supply passage provided inside the housing and discharges the air from this air chamber to the outside of the housing. When the spindle is stopped, the lip of the lip seal seals the gap between the inner surface of the housing and the outer surface of the spindle in the air chamber. When the spindle is rotating, the centrifugal force caused by the rotation of the spindle separates the lip of the lip seal from the inner surface of the housing, and in this state the air supplied to the air chamber is discharged to the outside of the housing through a gap formed further towards the tip than the air chamber.
[0006] In other words, in the device described in Patent Document 1, when the spindle is stopped, the lip seal maintains a sealed state inside the housing, preventing foreign matter from entering the housing, and when the spindle is rotating, air is discharged to the outside of the housing through a gap formed on the tip side of the air chamber, preventing foreign matter from entering the housing through such a gap.
[0007] Furthermore, the cutting device described in Patent Document 2 includes a spindle, a spindle housing that rotatably supports the spindle with an air bearing, an air supply means that supplies air to the air bearing, and a mount member that attaches a cutting blade to the tip of the spindle. In this case, the air in the air bearing is exhausted to the outside air through an air seal exhaust path, and the device includes an openable seal member that opens and closes the outlet of the air seal exhaust path.
[0008] That is, in the device described in Patent Document 2, when air is supplied to the air bearing, air is ejected through an air seal exhaust path, and when air is not supplied, the outlet of the air seal exhaust path is closed by a seal member. Therefore, when air is supplied, the air is ejected to prevent foreign matter from entering the cutting device, and when air is not supplied, the seal member prevents foreign matter from entering. [Prior art documents] [Patent documents]
[0009] [Patent Document 1] Patent Publication No. 2021-110690 Summary of the Invention [Problem to be solved by the invention]
[0010] In Patent Documents 1 and 2, a V-ring is used as the sealing member. The V-ring consists of a flexible conical seal lip connected to a main body by an elastic hinge. Therefore, the lip exerts sealing properties by closely contacting the lip-matching surface, and when the lip moves away from the lip-matching surface, a gap is formed between the lip and the lip-matching surface, allowing the inflow and outflow of fluid.
[0011] In other words, when the lip is in close contact with the lip mating surface and exerts a sealing effect, the lip's elastic restoring force maintains the close contact, but when fluid is allowed to flow in and out, an external force must be applied to the lip in a direction that moves it away from the lip mating surface, against the elastic restoring force.
[0012] However, in the V-rings described in Patent Documents 1 and 2, the lip may be significantly separated from the lip-matching surface depending on the external force acting on it. In the case of such plastic deformation, even if the external force in the direction of separation from the lip-matching surface is released, the lip may no longer be in close contact with the lip-matching surface, or the seal member itself may be damaged due to excessive deformation of the lip.
[0013] Therefore, the present invention provides a sealing device, a spindle device, a grinding device, and a cutting device that can prevent deformation of the sealing member and provide a stable sealing function for a long period of time. [Means for solving the problem]
[0014] The present invention provides a seal device for sealing a fluid passage for ejecting a fluid provided at an axial end of a housing that rotatably supports a rotating shaft via a bearing, the seal device comprising a seal member having a lip portion that closes the fluid passage when the rotating shaft is stationary and opens the fluid passage when the rotating shaft is rotating, the lip portion being separated from a press-contact portion that presses against the housing under at least one of a centrifugal force due to rotation of the rotating shaft and a pressing force of the fluid, thereby opening the fluid passage and allowing the fluid to eject from both axial ends of the housing, the seal member comprising a main body portion made of a ring member and the ring-shaped lip portion connected to the main body portion via a circumferential groove, the circumferential groove of the seal member receiving the lip portion and fitted with a deformation suppression ring that prevents excessive deformation from the press-contact portion during rotation of the rotating shaft. Here, excessive deformation refers to deformation due to damage or deformation that does not return to its original shape due to plastic deformation, etc. In other words, without the deformation suppression ring, if a force (external force) acts to separate the lip from the press-contact portion and then the force (external force) is removed, the lip would not return to its original state due to its restoring force, and the fluid passage would be open. In contrast, the deformation that occurs when the lip separates from the press-contact portion that presses against the housing, opening the fluid passage and allowing fluid to jet out from both axial ends of the housing is due to elastic deformation. When the force (external force) to cause this deformation is removed, the lip would return to its original state due to its restoring force, thereby blocking the fluid passage. Therefore, when the deformation suppression ring is fitted into the circumferential groove of the seal member, it restricts deformation that does not return to its original shape due to plastic deformation or the like, and allows deformation due to elastic deformation.
[0015] The seal device of the present invention blocks the fluid passage when the rotating shaft is stationary, preventing foreign matter such as machining fluid and chips from entering the seal device. Furthermore, when the rotating shaft is rotating, fluid is ejected from both axial ends of the housing, preventing foreign matter from entering the seal device even in this state. Furthermore, because a deformation suppression ring is fitted into the circumferential groove of the seal member, the lip portion is not subject to excessive deformation (deformation that does not return to its original shape due to plastic deformation, etc.).
[0016] The deformation suppression ring can be configured to be fixed via a fastener to a cover member that is attached to the rotating shaft and closes the axial end opening of the housing. By configuring it in this way, the deformation suppression ring can be stably fixed to the cover member, and the function of the deformation suppression ring (deformation suppression function) can be effectively exhibited.
[0017] The spindle device of the present invention is a spindle device comprising a rotating shaft having a machining tool attached to its tip, a housing that pivotally supports the rotating shaft so that it can rotate freely, and a fluid supply mechanism that supplies fluid ejected from at least one of one axial end and the other axial end of the housing to at least one of the housing and the rotating shaft, wherein fluid passages through which fluid from the fluid supply mechanism is supplied are provided at both axial ends of the housing, and the sealing device is attached to the fluid passages, and the sealing device closes the fluid passage when the rotating shaft is stationary and opens the fluid passage when the rotating shaft is rotating.
[0018] The spindle device according to the present invention has a fluid passage provided in at least one of the axial end and the other axial end of the housing, and the sealing device is used in the fluid passage. Therefore, foreign matter can be prevented from entering the fluid passage whether the rotating shaft is stopped or rotating, thereby preventing the inflow of foreign matter into the spindle device. Moreover, because the lip portion does not undergo excessive deformation (deformation that does not return to its original shape due to plastic deformation, etc.), the sealing device provides a stable sealing effect over a long period of time. Furthermore, when the rotating shaft is not rotating, i.e., when the machining tool at the tip of the rotating shaft is not machining a workpiece, fluid does not flow out of the device, thereby reducing fluid consumption.
[0019] The fluid ejected from at least one of the axial ends of the housing is preferably compressed air supplied to at least one of the housing and the rotary shaft. Compressed air can stably blow away foreign matter and effectively prevent foreign matter from entering the device. Furthermore, even if compressed air is ejected at the workpiece, it does not adversely affect the workpiece or its vicinity.
[0020] The grinding device according to the present invention is a grinding device equipped with the spindle device, in which the processing tool attached to the tip of the rotating shaft is a grinding wheel. In the grinding device according to the present invention, whether the rotating shaft is stopped or rotating, the inflow of foreign matter into the fluid passage can be prevented, and the inflow of foreign matter into the grinding device can be avoided.
[0021] The cutting apparatus according to the present invention is a cutting apparatus including the spindle device, and the machining tool attached to the tip of the rotating shaft is a cutting tool. In the cutting apparatus according to the present invention, whether the rotating shaft is stopped or rotating, the inflow of foreign matter into the fluid passage can be prevented, and the inflow of foreign matter into the cutting apparatus can be avoided. [Effects of the Invention]
[0022] The present invention prevents foreign matter from entering the sealing device, whether the rotating shaft is rotating or not, and thus prevents a shortened device life due to the intrusion of foreign matter. Furthermore, since the lip portion does not undergo excessive deformation (deformation that does not return to its original shape due to plastic deformation or the like), the seal member's lifespan can be extended. In particular, during rotation, the lip portion separates from the mating lip pressure contact portion (separation in this case occurs due to elastic deformation), eliminating frictional resistance caused by contact or pressure contact. This suppresses heat generation in the rotating portion (rotating shaft side) and the fixed portion (housing side), effectively preventing premature damage to components within the device (e.g., bearings that rotatably support the rotating shaft) due to temperature rise. Furthermore, since compressed air or other fluids do not need to be ejected when the rotating shaft is stationary, consumption of compressed air or other fluids can be reduced, contributing to cost reduction. [Brief explanation of the drawings]
[0023] [Figure 1] 1 is a cross-sectional view of a spindle device using a seal device according to the present invention. [Figure 2] FIG. [Figure 3] 1A and 1B show the front sealing device, in which FIG. 1A is an enlarged cross-sectional view when the rotary shaft is not rotating, and FIG. 1B is an enlarged cross-sectional view when the rotary shaft is rotating. [Figure 4] 1A and 1B show the rear sealing device, in which FIG. 1A is an enlarged cross-sectional view when the rotary shaft is not rotating, and FIG. 1B is an enlarged cross-sectional view when the rotary shaft is rotating. DETAILED DESCRIPTION OF THE INVENTION
[0024] An embodiment of the present invention will now be described with reference to Figures 1 to 4. Figure 1 is a cross-sectional view of a spindle device using a seal device according to the present invention, and Figure 2 is an enlarged cross-sectional view thereof. Note that hatching has been omitted in Figure 1.
[0025] The spindle device includes a rotating shaft 1 and a housing 5 that rotatably holds (pivotally supports) the rotating shaft 1 via a pair of bearings 2 and 3. The rotating shaft 1 is driven to rotate about its axis by a rotational driving force from an external power source such as a motor (not shown) transmitted through a power transmission mechanism 4. The power transmission mechanism 4 can be configured using a known or commonly used gear mechanism, belt mechanism, coupling mechanism, or the like.
[0026] A machining tool is mounted directly or indirectly to the mounting portion 1a on the reaction force transmission mechanism side (i.e., the front end) of the rotating shaft 1. The rotating shaft 1 also has a fluid passage 7 through which a fluid flows. The fluid passage 7 is provided at the axial center of the rotating shaft 1 and has a main passage 7a extending in the axial direction, and branch passages 7b and 7c connected to the front end side (reaction force transmission mechanism side) and rear end side (power transmission mechanism side) of the main passage 7a. The front end of the main passage 7a does not open to the front end of the rotating shaft 1, but the rear end of the main passage 7a opens to the rear end of the rotating shaft 1. Each branch passage 7b and 7c extends radially, perpendicular to the axial direction of the rotating shaft 1, and each branch passage 7b and 7c opens to the outer diameter surface of the rotating shaft 1.
[0027] A fluid supply mechanism (not shown) having a fluid supply source is connected to the rear end opening of the main body passage 7a. In this embodiment, the fluid is compressed air, and therefore the fluid supply source of the fluid supply mechanism is an air compressor.
[0028] The housing 5 comprises a cylindrical housing body 5a and cover members 5b and 5c that close both axial openings of the housing body 5a. The cover members 5b and 5c are attached to the rotary shaft 1 and rotate integrally with the rotary shaft 1. In this case, the front end face of the housing 5 is provided with a circumferential notch 30 into which one of the cover members 5b is fitted. In this case, it consists of a large diameter portion 30a on the opening side and a small diameter portion 30b on the back side.
[0029] The front cover member 5b has a disk-shaped main body 31 and an inner flange 32 on the inner end surface of the main body 31, and the main body 31 is fitted into the notch 30 with the inner flange 32 fitted into the small diameter portion 30b. A spacer 33 is interposed between the front-row bearing 2a and the cover member 5b. The spacer 33 has a hole 33a that communicates with the front branch passage 7b of the fluid passage 7 of the rotating shaft 1. The hole 33a communicates with a space 34 between the front-row bearing 2a and the spacer 33.
[0030] In this case, a circumferential cutout portion 35 into which the other cover member 5c is fitted is provided on the rear end surface of the housing 5. In this case, it is composed of a large diameter portion 35a on the opening side and a small diameter portion 35b on the inner side.
[0031] The rear cover member 5b has a disk-shaped main body 36 and an inner flange 37 on the inner end surface of the main body 36. The main body 36 is fitted into the large diameter portion 35a with the inner flange 37 fitted into the small diameter portion 35b. A spacer 38 is interposed between the rearmost bearing 3b and the cover member 5c. The spacer 38 has a hole 38a that communicates with the front branch passage 7b of the fluid passage 7 of the rotating shaft 1. The hole 38a communicates with a space 39 between the rearmost bearing 2b and the spacer 38.
[0032] The housing body 5a also has a fluid passage 6. This fluid passage 6 includes an annular main passage 6a provided in the trunk of the housing body 5a and radial branch portions 6b, 6c provided on both axial ends of the main passage 6a. The inner diameter side of each branch portion 6b, 6c is connected to the main passage 6a, but a plug member 41 is fitted to the outer diameter side, so that the outer diameter portion does not open to the outer diameter surface of the housing body 5a. An injection passage 6d is provided in the axial center of the housing body 5a for injecting fluid (compressed air) into the fluid passage 6 from the outer diameter surface. In this case, branch portion 6b is connected to the space 34 between the front-row bearing 2a and the spacer 33, and branch portion 6c is connected to the space 39 between the rear-row bearing 2b and the spacer 38.
[0033] The injection passage 6d is connected to a fluid supply mechanism (not shown) having a fluid supply source. In this embodiment, the fluid is compressed air, and the fluid supply source of the fluid supply mechanism is an air compressor. The front pair of bearings 2a and 2a and the rear pair of bearings 2b and 2b each include inner rings 2a1 and 2b1, outer rings 2a2 and 2b2, and balls 2a3 and 2b3 interposed between the inner and outer rings. Between the front pair of bearings 2a and 2b and the rear pair of bearings 2b and 2b, spacers 41 and 42 are interposed between the inner rings, and spacers 43 and 44 are interposed between the outer rings. In addition, a spacer 45 is interposed between the outer rings of the front bearing 2b and the rear bearing 3a.
[0034] 3 and 4, sealing members 51 and 52 are attached to the cover members 5b and 5c, respectively. The sealing members 51 and 52 are made up of ring-shaped main bodies 51a and 52a and ring-shaped lip portions 51c and 52c connected to the main bodies 51a and 52a via circumferential grooves 51b and 52b. That is, so-called V-rings are used as the sealing members 51 and 52.
[0035] In this case, a ring-shaped groove 53 is formed on the inner surface of the cover member 5b, and the main body portion 51a of the seal member 51 is fitted into this groove 53, with the lip portion 51c having its lip end in close contact with the housing main body 5a. The contact portion of the lip portion 51c is the contact surface 30b1, which is the bottom surface of the small-diameter portion 30b on the far side of the circumferential cutout portion 30 of the housing main body 5a. The lip portion 51c is inclined at a predetermined angle with respect to the axial direction of the housing. In this case, the inclination angle θ is set to, for example, 50° to 60°. The tip of the lip portion 51c forms an annular end surface 51c1 that is in surface contact with the contact surface 30b1 of the housing main body 5a.
[0036] A deformation suppression ring 55 is fitted into the circumferential groove 51b of the seal member 51 to receive the lip portion 51c and prevent excessive deformation from the contact surface 30b1 during rotation of the rotating shaft. Here, excessive deformation refers to deformation due to damage or plastic deformation that does not return to its original shape. In other words, without the deformation suppression ring 55, if a force (external force) acts to separate the lip portion 51c from the press-contact portion and then the force (external force) is removed, the lip portion 51c may not return to its original state due to its restoring force, and the fluid passage 61 may become open. In contrast, the deformation that occurs when the lip portion 51c separates from the press-contact portion that presses against the housing 5, opening the fluid passage 61 and allowing fluid to jet out from both axial ends of the housing 5 is elastic deformation. When the force (external force) that caused this deformation (deformation) is removed, the lip portion 51c returns to its original state due to its restoring force, thereby blocking the fluid passage 61. Therefore, when the deformation suppression ring 55 is fitted into the circumferential groove 51b of the seal member 51, it restricts deformation that would prevent the ring from returning to its original shape due to plastic deformation or the like, while allowing deformation due to elastic deformation. The deformation suppression ring 55 comprises a ring main body 55a and a sub-portion 55b connected to the inner end surface of the outer diameter side of the ring main body 55a, and the inner diameter portion of the ring main body 55a fits into the circumferential groove 51b. Therefore, the outer shape of the inner diameter portion of the ring main body 55a is the same as the inner shape of the circumferential groove 51b. The deformation suppression ring 55 is fixed to the cover member 5b via a fastener 56. In this case, the fixing device 56 comprises a screw member 58 inserted into a through-hole 57 provided in the cover member 5b, with the externally threaded tip portion 58a of the screw member 58 threadedly engaging with the threaded hole 59 of the deformation suppression ring 55, and the head portion 58b of the screw member 58 fitting into a recess 57a provided at the opening of the through-hole 57, thereby fixing the deformation suppression ring 55 to the cover member 5b. As a result, the deformation suppression ring 55 receives a portion of the lip portion 51c excluding the tip portion. A space 60a into which fluid from the gap 34 flows is provided on the inner diameter side of the lip portion 51c.
[0037] A ring-shaped groove 53 is formed on the inner surface of the cover member 5c, and the main body 52a of the seal member 52 is fitted into this groove 53, with the lip portion 52c having its lip end in intimate contact with the housing main body 5a. The contact portion of the lip portion 52c is the contact surface 35b1, which is the bottom surface of the small-diameter portion 35b at the rear side of the circumferential cutout 35 of the housing main body 5a. The lip portion 52c is inclined at a predetermined angle with respect to the axial direction of the housing. In this case, the inclination angle θ is set, for example, between 50° and 60°. The tip of the lip portion 52c forms an annular end surface 52c1 that is in surface contact with the contact surface 35b1 of the housing main body 5a.
[0038] Furthermore, a deformation suppression ring 55 is fitted into the circumferential groove 52b of the seal member 52 to receive the lip portion 52c and prevent excessive deformation from the press-contact portion during rotation of the rotating shaft. Here, excessive deformation refers to deformation due to damage or plastic deformation that does not return to its original shape. In other words, without the deformation suppression ring 55, if a force (external force) acts to separate the lip portion 52c from the press-contact portion and then the force (external force) is removed, the lip portion 52c may not return to its original state due to its restoring force, and the fluid passage 61 may become open. In contrast, the deformation that occurs when the lip portion 52c separates from the press-contact portion that presses against the housing 5, opening the fluid passage 61 and allowing fluid to jet out from both axial ends of the housing 5 is due to elastic deformation. When the force (external force) that caused this deformation (deformation) is removed, the lip portion 52c returns to its original state due to its restoring force, thereby blocking the fluid passage 62. Therefore, when the deformation suppression ring 55 is fitted into the circumferential groove 52b of the seal member 52, it restricts deformation that would prevent the ring from returning to its original shape due to plastic deformation or the like, while allowing deformation due to elastic deformation. The ring comprises a ring main body 55a and a sub-portion 55b connected to the inner end surface of the outer diameter side of the ring main body 55a, and the inner diameter portion of the ring main body 55a fits into the circumferential groove 52b. Therefore, the outer shape of the inner diameter portion of the ring main body 55a is the same as the inner shape of the circumferential groove 52b. The deformation suppression ring 55 is fixed to the cover member 5c via a fastener 56. In this case, the fixing device 56 comprises a screw member 58 inserted into a through-hole 57 formed in the cover member 5b. The externally threaded tip portion 58a of the screw member is threaded into the threaded hole of the deformation suppression ring 55, and the head portion 58b of the screw member 58 fits into a recess 57a formed at the opening of the through-hole 57, thereby fixing the deformation suppression ring 55 to the cover member 5c. As a result, the deformation suppression ring 55 receives a portion of the lip portion 52c excluding the tip portion. A space 60b into which fluid flows from the gap 39 is provided on the inner diameter side of the lip portion 52c. For this reason, a communication hole 40 is provided between the space 60b and the gap 39.
[0039] The seal members 51, 52 seal fluid passages 61, 62 for ejecting fluid, which are provided at both axial ends of the housing 5. In this case, the fluid passage 61 for ejecting fluid is made up of a gap formed between the bottom of the cutout portion 30 and the outer diameter end face of the cutout portion 30, in the range of the seal member 51, the ring 55, the inner flange portion 32, the outer diameter side of the inner flange portion 32, and the outer diameter end of the cover member 5b.
[0040] In this case, the fluid passage 62 for fluid ejection is composed of the gap formed between the bottom of the cutout portion 35 and the outer diameter end face of the cutout portion 35, in the range of the sealing member 52, the ring 55, the inner flange portion 37, the outer diameter side of the inner flange portion 37, and the outer diameter end of the cover member 5c.
[0041] 1 and 2, a turning device or a cutting device can be configured by attaching a processing tool (for example, a grinding wheel or a cutting tool) to the tip of the rotating shaft of the spindle device. In this case, when no fluid (compressed air) is supplied to the fluid path 6 of the housing 5 or the fluid path 7 of the rotating shaft 1, the fluid passages 61 and 62 for ejecting the fluid are sealed by the sealing members 51 and 52, preventing foreign matter from entering the device.
[0042] When the rotating shaft 1 is driven to rotate, a fluid (compressed air) is supplied to the fluid path 6 of the housing 5 and the fluid path 7 of the rotating shaft 1. In this case, the fluid that enters the rotating shaft 1 and the housing 5 flows into the spaces 60a and 60b through the gaps 34 and 39. The fluid that enters the spaces 60a and 60b pushes up the lips 51c and 52c. Furthermore, as the rotating shaft 1 rotates, centrifugal force pushes up the tips of the lips 51c and 52c, separating them from the contact surfaces. This separation is due to elastic deformation. When this deforming force is released, the restoring force of the lips 51c and 52c returns them to their original state, and the lips 51c and 52c contact the contact surfaces 30b1 and 35b1, blocking the fluid passages 61 and 62.
[0043] As a result, the contact surfaces are separated from the tips of the lip portions 51c, 52c, the seal members 51, 52 are in an open state, and the fluid that has entered the spaces 60a, 60b flows through the fluid passages 61, 62 and is sprayed out of the device from the nozzles of the fluid passages 61, 62. In this case, since the nozzle port of the fluid passage 61 opens outward along the axial direction of the rotation shaft, the fluid that has entered the fluid passage 61 is sprayed forward in the axial direction of the housing 5, and the fluid that has entered the fluid passage 62 is sprayed backward in the axial direction of the housing 5.
[0044] Therefore, while the rotary shaft 1 is rotating, the fluid is jetted outward, thereby preventing foreign matter from entering the device.
[0045] The seal device according to the present invention blocks the fluid passages 61, 62 when the rotating shaft is stationary, thereby preventing the intrusion of foreign matter, such as machining fluid and chips, into the seal device. Furthermore, even when the rotating shaft is rotating, fluid is ejected from both axial ends of the housing 5, preventing the intrusion of foreign matter into the seal device. Furthermore, because the deformation suppression rings 55, 55 are fitted into the circumferential grooves 51b, 52b of the seal members 51, 52, the lip portions 51c, 52c are not excessively deformed (deformation that does not return to its original shape due to plastic deformation, etc.). In other words, without the deformation suppression rings 55, if a force (external force) acts to separate from the press-contact portion, causing excessive deformation, the lip portions 51c, 52c would not return to their original shape due to their restoring force, even if the force (external force) causing the excessive deformation is removed, and the fluid passages 61, 62 would be open. Therefore, when the deformation suppression ring 55 is fitted into the circumferential grooves 51b, 52b of the sealing members 51, 52, it restricts excessive deformation (deformation that does not return to its original shape due to plastic deformation, etc.) and allows deformation due to elastic deformation.
[0046] The present invention prevents foreign matter from entering the sealing device, whether the rotating shaft is rotating or not, and thus prevents a shortened device life due to the intrusion of foreign matter. Furthermore, because the lip portions 51c, 52c are not excessively deformed (deformation that does not return to its original shape due to plastic deformation, etc.), the seal members 51, 52 can be extended in life. In particular, during rotation, the lip portions 51c, 52c are separated from the mating lip pressure contact portion, eliminating frictional resistance caused by contact or pressure contact. This suppresses heat generation in the rotating portion (rotating shaft side) and the fixed portion (housing side), effectively preventing premature damage to components inside the device (e.g., bearings that rotatably support the rotating shaft) due to temperature rise. Furthermore, because compressed air or other fluids do not need to be ejected when the rotating shaft 1 is stationary, consumption of compressed air or other fluids can be reduced, contributing to cost reduction.
[0047] The deformation suppression ring 55 can be configured to be fixed via fasteners 58 to the cover members 5b, 5c that are attached to the rotating shaft side and close the axial end openings of the housing 5. By configuring it in this way, the deformation suppression ring 55 can be stably fixed to the cover members 5b, 5c, and the function of the deformation suppression ring 55 (deformation suppression function) can be effectively exerted.
[0048] The spindle device of the present invention is a spindle device comprising a rotating shaft 1 having a machining tool attached to its tip, a housing 5 that pivotally supports the rotating shaft 1 so that it can rotate freely, and a fluid supply mechanism that supplies fluid sprayed from both axial ends of the housing 5 to at least one of the housing 5 and the rotating shaft 1, wherein fluid passages 61, 62 for spraying fluid are provided at both axial ends of the housing 5, and sealing devices are attached to the fluid passages 61, 62, which block the fluid passages 61, 62 when the rotating shaft is stationary and open the fluid passages when the rotating shaft is rotating.
[0049] The spindle device according to the present invention has fluid passages 61, 62 for ejecting fluid at both axial ends of the housing, and uses sealing devices in the fluid passages 61, 62. This prevents foreign matter from entering the fluid passages, whether the rotating shaft is stopped or rotating, and thus prevents foreign matter from entering the spindle device. Furthermore, because the lip portions 51c, 52c are not subject to excessive deformation (deformation that does not return to its original shape due to plastic deformation, etc.), the sealing devices provide a stable sealing effect over a long period of time. Furthermore, when the rotating shaft 1 is not rotating, i.e., when the machining tool at the tip of the rotating shaft 1 is not machining a workpiece, fluid does not flow out of the device, thereby reducing fluid consumption.
[0050] The fluid ejected from both axial ends of the housing 5 is preferably compressed air supplied to at least one of the housing 5 and the rotary shaft 1. Compressed air can stably blow away foreign matter and effectively prevent foreign matter from entering the device. Furthermore, even if compressed air is ejected at the workpiece, it does not adversely affect the workpiece or its surroundings.
[0051] The grinding device according to the present invention is a grinding device equipped with a spindle device, and the processing tool attached to the tip of the rotating shaft is a grinding wheel. In the grinding device according to the present invention, whether the rotating shaft 1 is stopped or rotating, the inflow of foreign matter into the fluid passage can be prevented, and the inflow of foreign matter into the grinding device can be avoided.
[0052] The cutting apparatus according to the present invention is a cutting apparatus equipped with a spindle device, and a cutting tool is attached to the tip of the rotating shaft. In the cutting apparatus according to the present invention, whether the rotating shaft 1 is stopped or rotating, foreign matter can be prevented from entering the fluid passages 61, 62, and the inflow of foreign matter into the cutting apparatus can be avoided.
[0053] While the above describes an embodiment of the present invention, various modifications are possible without being limited to the above embodiment. In the above embodiment, the lip portion separates from the press-contact portion pressed against the housing due to centrifugal force and fluid pressure. However, separation may occur due to only one of centrifugal force and fluid pressure. That is, there are three cases: both centrifugal force and fluid pressure, centrifugal force only, and fluid pressure only. In addition, in the above embodiment, fluid is ejected from both axial ends of the housing. However, it may be ejected from only one axial end of the housing, only the other axial end of the housing, or both axial ends. Furthermore, fluid may be supplied even while the rotating shaft 1 is rotating. Furthermore, the fluid may be gas or liquid, and is not limited to compressed air as in the above embodiment, but may also be cleaning fluid, cooling medium, etc. Incidentally, a so-called V-ring is used as a sealing member. However, V-rings include A-type, S-type, and other types. There are three types: L type, L type, and E type, and any of these types can be used. Materials available include nitrile rubber (NBR), fluoro rubber (FPM), chloroprene rubber (CR), ethylene propylene rubber (EPDM), ethylene acrylic rubber (EACM), and silicone rubber (Q). [Explanation of symbols]
[0054] 1 Rotation axis 5. Housing 51a Main body 51b Circumferential groove 51c Lip 52 Sealing material 52 Main body 52 Sealing material 52b Circumferential groove 52c lip 55 Deformation suppression ring 51, 52 sealing member 61,62 Fluid passage
Claims
1. A sealing device for sealing a fluid passage for ejecting a fluid, the sealing device being provided at an axial end of a housing that rotatably supports a rotary shaft via a bearing, comprising: a seal member having a lip portion that closes the fluid passage when the rotating shaft is stationary and opens the fluid passage when the rotating shaft is rotating, wherein the lip portion separates from the pressure-contact portion that presses against the housing due to at least one of the centrifugal force caused by the rotation of the rotating shaft and the pressing force of the fluid, thereby opening the fluid passage and allowing the fluid to spray from both axial ends of the housing, and wherein the seal member comprises a main body portion made of a ring member and the ring-shaped lip portion connected to the main body portion via a circumferential groove, and a deformation suppression ring is fitted in the circumferential groove of the seal member to receive the lip portion and suppress deformation from the pressure-contact portion when the rotating shaft rotates.
2. 2. The sealing device according to claim 1, wherein the deformation suppression ring is fixed via a fastener to a cover member that is attached to the rotary shaft and closes an axial end opening of the housing.
3. 10. A spindle device comprising: a rotating shaft having a machining tool attached to its tip; a housing that pivotally supports the rotating shaft so that it can rotate freely; and a fluid supply mechanism that supplies fluid ejected from at least one of one axial end and the other axial end of the housing to at least one of the housing and the rotating shaft, wherein fluid passages through which fluid from the fluid supply mechanism is supplied are provided at both axial ends of the housing, and the seal device according to claim 1 or 2 is attached to the fluid passages, and the seal device closes the fluid passage when the rotating shaft is stationary and opens the fluid passage when the rotating shaft is rotating.
4. 4. The spindle device according to claim 3, wherein the fluid ejected from at least one of the axial end and the other axial end of the housing is compressed air supplied to at least one of the housing and the rotary shaft.
5. 4. A grinding machine equipped with the spindle device according to claim 3, wherein the processing tool attached to the tip of the rotary shaft is a grindstone.
6. 4. A cutting apparatus comprising the spindle device according to claim 3, wherein the processing tool attached to the tip of the rotary shaft is a cutting tool.
Citation Information
Patent Citations
Inspection method, inspection apparatus and control method of rolling apparatus
JP2021110690A