CN205278273U - External circulation ball screw - Google Patents

Abstract

An external circulation type ball screw comprises a screw shaft, a screw cap and a reflux unit, wherein the screw shaft is provided with an external thread groove, the screw cap is movably sleeved on the screw shaft and is provided with an internal thread groove, the internal thread groove corresponds to the external thread groove of the screw shaft and forms a load channel with the external thread groove of the screw shaft, the reflux unit is provided with two guide pieces and a cover plate, each guide piece is arranged on the screw cap and is provided with a first reflux groove and a first bearing surface adjacent to the first reflux groove, the cover plate is arranged on the screw cap and is provided with a second reflux groove and two convex parts, each convex part is provided with an extension guide groove and a second bearing surface, two ends of the extension guide groove are respectively connected with the first reflux groove and the second reflux groove, and the second bearing surface is abutted to the first bearing surface of the guide piece, and the structural configuration can achieve the effect of improving the actuation smoothness.

Description

External circulation ball screw

technical field

The utility model relates to a ball screw, in particular to an external circulation ball screw which can improve smoothness of operation.

Background technique

The applicant has previously applied for a patent case of Taiwan, China Announcement No. M485984 to provide a circulation fitting. The circulation fitting has a cover and two guides. The cover has a return channel and two positioning grooves. Each guide has a The positioning part and a guiding part, the guiding part is installed in the positioning groove of the cover part through the positioning part, and the guiding part is installed in a mounting groove of the nut through the guiding part, so that the rolling part can pass through the guiding part of the guiding part. Guided by the leading part, it enters the return channel of the cover.

However, after actual operation, it is found that there will be a step difference between the guide part of the guide part and the return channel of the cover part. This step difference will cause vibration and noise due to the continuous impact of the rolling parts, which will inevitably affect the ball. The movement smoothness and service life of the screw have a certain degree of influence. Therefore, there is a need for improvement in the structure of the aforementioned prior patents.

Utility model content

The main purpose of the present utility model is to provide an external circulation type ball screw, which can improve the smoothness of operation and prolong the service life.

In order to achieve the above purpose, the external circulation ball screw of the present invention includes a screw shaft, a nut, and a recirculation unit. The screw shaft has an external thread groove; the nut can be sleeved on the screw shaft along the axial displacement of the screw shaft and has an internal thread groove, the internal thread groove corresponds to the external thread groove of the screw shaft, A load channel is formed between the internal thread groove of the nut and the external thread groove of the screw shaft. In addition, the nut has a first abutment plane, and two ends of the first abutment plane respectively have a The installation hole of the internal thread groove; the return unit has two guides and a cover plate, each guide has a guide part, the guide part is embedded in the installation hole of the nut and has a connection with the The first backflow groove of the load channel and a first receiving surface adjacent to the first backflow groove, the cover plate has a second abutment plane, and the second abutment plane is abutted against the first abutment surface of the nut It is flat and has a second return groove and two protrusions. Each of the protrusions is embedded in the mounting hole of the nut and has an extension guide groove and a second receiving surface. The two ends of the extension guide groove are respectively Connecting the first and second return grooves, the second receiving surface abuts against the first receiving surface of the guide member.

Wherein the two ends of the first abutting plane of the nut respectively have a screw hole adjacent to the mounting hole, and each of the guides further has a positioning part connected to the guiding part and a positioning part passing through the positioning part. Each of the guides is fixed to the nut by a screw, and the screw passes through the positioning hole of the guide and is fixed in the screw hole of the nut. The second abutment plane of the cover plate Each end has a positioning groove, and the positioning groove is sleeved on a positioning portion of the guide piece.

From the above, it can be seen that the outer circulation ball screw of the present invention utilizes the extended design of the convex part of the cover plate, which can effectively improve the step difference problem in the prior art, so that the ball will not have the problem of impact point during the turning process , so as to achieve the purpose of improving the smoothness of movement and prolonging the service life.

Description of drawings

In order to further illustrate the technical content of the present utility model, below in conjunction with embodiment and accompanying drawing, describe in detail as follows, wherein:

Fig. 1 is a perspective view of the utility model.

Fig. 2 is a three-dimensional exploded view of the utility model.

Fig. 3 is a partial perspective view of the utility model, mainly showing the structural relationship between the guide member and the cover plate.

Fig. 4 is a radial sectional view of the utility model.

Fig. 5 is an axial sectional view of the utility model.

detailed description

Please refer to FIG. 1 and FIG. 2 , the external circulation ball screw 10 of the present invention includes a screw shaft 20 , a nut 30 , a return unit 40 , and a plurality of balls 70 .

The outer peripheral surface of the screw shaft 20 has an external thread groove 22 .

The nut 30 is sleeved on the screw shaft 20 and has an internal thread groove 31, the internal thread groove 31 corresponds to the external thread groove 22 of the screw shaft 20 and forms a load channel 12 with the external thread groove 22 of the screw shaft 20 (such as Figure 5). In addition, the nut 30 has a first abutting plane 32 , and two ends of the first abutting plane 32 respectively have a mounting hole 33 communicating with the internal thread groove 31 and a screw hole 34 adjacent to the mounting hole 33 .

The return unit 40 has two guides 50, and each guide 50 has a guide portion 51 and a positioning portion 52. The guide portion 51 is embedded in the mounting hole 33 of the nut 30 and has a joint connecting the load channel 12. The first backflow groove 53 and a first receiving surface 54 adjacent to the first backflow groove 53, one end of the positioning part 52 is connected to the guide part 51, and the other end of the positioning part 52 has a positioning hole 55, and each guide part 50 passes through A screw 56 is fixed on the nut 30 , and the screw 56 passes through the positioning hole 55 of the guide member 50 and is fixed in the screw hole 34 of the nut 30 . In addition, as shown in FIG. 3 to FIG. 5 , the return unit 40 further has a cover plate 60 , the cover plate 60 has a second abutment plane 61 , and the second abutment plane 61 abuts against the first abutment of the nut 30 The plane 32 has a second return groove 62, two protrusions 63 and two positioning grooves 64, each protrusion 63 is embedded in the mounting hole 33 of the nut 30 and has an extending guide groove 65 and a second receiving surface 66, the two ends of the extended guide groove 65 are connected to the first and second return grooves 53 and 62 respectively, the second receiving surface 66 abuts against the first receiving surface 54 of the guide member 50, and the positioning groove 64 is adjacent to the convex part 63 and sleeve the positioning portion 52 of the guide 50 so that the cover 60 and the guide 50 can be assembled together.

Each ball 70 is disposed in the load channel 12 and circulates through the first and second return grooves 53 and 62 .

From the above, it can be known that the external circulation ball screw 10 of the present invention uses the protrusion 63 of the cover plate 60 to extend into the installation hole 33, so that the second receiving surface 66 abuts against the first receiving surface 54 of the guide member 50, and also allows the The guide groove 65 connects with the first return groove 53 , so that after the ball 70 enters the first return groove from the load passage 12 , the ball 53 can quickly contact the protrusion 63 and be guided by the guide groove 65 . Let the utility model improve the level difference generated at the joint in the prior art, and also allow the ball 70 to run smoothly in the load channel 12, the nut 30 and the return unit 40 when changing directions, reducing the ball 70 caused by the level difference Vibration and noise, thereby improving the smoothness of movement and prolonging the service life.

Claims (2)

1. an external circulation type ball bolt, it is characterised in that, include:

One screw shaft, has an outside screw groove;

One nut, can being sheathed on this screw shaft axially and there is an internal thread groove along this screw shaft, this internal thread groove is corresponding to the outside screw groove of this screw shaft, make to be formed between the internal thread groove of this nut and the outside screw groove of this screw shaft a load channel, this nut has one first against plane, this first open holes respectively against the two ends of plane with this internal thread groove of a connection; And

One backflow unit, there is two guide members and a cover plate, respectively this guide member has a guiding portion, this guiding portion is embedded in the open holes of this nut and first backflash and with this load channel of linking is adjacent to the first continuing surface of this first backflash, this cover plate has one the 2nd against plane, 2nd is connected to the first of this nut against plane against plane and has one the 2nd backflash and two protuberances, respectively this protuberance is embedded in the open holes of this nut and has extension guiding groove and one the 2nd continuing surface, this extension guiding groove two ends be connected respectively this first, 2nd backflash, 2nd continuing surface is connected to the first continuing surface of this guide member.

2. external circulation type ball bolt as claimed in claim 1, it is characterized in that, wherein the first of this nut has, against the two ends of plane, the screw that is adjacent to this open holes respectively, the pilot hole of this location division is run through in the location division and that respectively this guide member has more this guiding portion of a connection, respectively this guide member is fixed on this nut by a screw, this screw is arranged in the pilot hole of this guide member and is fixed in the screw of this nut, the 2nd of this cover plate has a locating slot respectively against the two ends of plane, and this locating slot is sheathed on the location division of this guide member.