DE102007046382B4 - Rotation-translation converter, actuator assembly and clutch assembly - Google Patents

Abstract

Rotary translation converter (40 ^IV ) with Wälzkörperumlauf, comprising a spindle (23 ^IV ), which is formed as a hollow spindle, on the outer periphery of a first part (62 ^IV ) of a raceway (66 ^IV ) is formed, a nut on the inner circumference second part (64) of the raceway groove (66 ^IV ), a plurality of rolling elements arranged in the raceway groove (66 ^IV ), and a return channel (70 ^IV ) connecting opposite ends of the raceway groove (66 ^IV ), to rotate around the rolling elements (68), wherein the return channel (70 ^IV ) on the spindle (23 ^IV ) is formed as a straight channel through the spindle (23 ^IV ) through which in an axial projection on the spindle (23 ^IV ) follows the course of a secant.

Description

The present invention relates to a rotation-displacement converter with Wälzkörperumlauf, comprising a spindle, on whose outer periphery a first part of a raceway groove is formed, a nut on the inner periphery of which a second part of the raceway groove is formed, a plurality of rolling elements arranged in the raceway groove and a return passage connecting opposite ends of the raceway groove to allow the rolling elements to revolve, the return passage being formed through the spindle.

Such a rotary-to-translation converter in the form of a ball screw is well known.

The present invention further relates to an actuator assembly for axially displacing an actuator by means of a driving force generated by an electric machine, in particular for a clutch assembly of a step change gear, wherein the actuator is mounted axially displaceable with respect to a rotary shaft, the electric machine fixed to a housing Stator and a rotor which is coupled to the actuator and disposed coaxially with the actuator.

Such an actuator arrangement is known from the document DE 101 03 664 A1 ,

The present invention further relates to a clutch assembly for a variable speed transmission, in particular for motor vehicles, having a guide sleeve which is fixed to a rotary shaft and having a guide sleeve toothing, with a sliding sleeve, which has a sliding sleeve toothing, which is in engagement with the guide sleeve toothing, so that Shift sleeve is rotatably and axially displaceably mounted with respect to the rotary shaft, and with a coupling body which is fixed to a loose wheel, which is rotatably mounted on the rotary shaft, and having a Kupplungsungskörperverzahnung into which the sliding sleeve teeth can be inserted to the idler gear rotatably connected to the rotary shaft, wherein the shift sleeve is axially displaceable by means of an actuator assembly.

From the document DE 100 21 368 A1 a mechatronic actuator is known in which a rotor of an electric motor is designed as a ring gear, as a planet carrier or integrated into the planet wheels of a planetary gear set. A sun gear of the planetary gear set is designed as a spindle for a linear drive.

An electromechanically actuated disc brake is from the document DE 195 11 287 B4 known. A rotor is formed as a hollow shaft and surrounds a reduction gear in the form of a roller screw whose output member serves as an actuator for the disc brake. Between the rotor and the roller screw, a planetary gear can be switched.

The document DE 10 2004 013 450 B4 relates to a switching device for a variable speed transmission. Switching and synchronization processes are realized electromagnetically. A loose wheel and a guide sleeve are designed to guide a magnetic flux generated by a stator. On the guide sleeve shift pins are mounted axially displaceable, which serve to produce a positive connection with a loose wheel.

From the document DE 199 47 405 A1 is a stepped change gear in countershaft design known in which a shift sleeve of a synchronous clutch by means of an electric linear stepper motor can be actuated. The stepper motor can be designed as a reluctance motor and accommodated in the transmission housing.

Further, the above-mentioned document discloses DE 101 03 664 A1 a synchronizer in which the shift sleeve is formed as part of the electric drive. In this case, the drive can be designed as a linear motor or as a rotary drive. In the latter case, the shift sleeve via rolling or sliding bearing with respect to a spindle is rotatable, but slidably mounted with this. The spindle carries an electromotive component and forms a rotation-translation converter with two spindle nuts supported on the housing.

From the document DE 10 2005 017 026 A1 an actuator assembly for a clutch assembly is known, which includes a concentric to a rotational axis arranged electrical machine with a housing fixed stator and a rotor. The rotor is coupled via a pin and a coil spring with a ring member. The ring member is axially displaceable by suitable measures relative to the stator, but not rotatable. The ring member has on the inner circumference of an annular projection which engages in a circumferential groove of a shift sleeve of the clutch assembly. Here, the rotor is only driven when an axial displacement of the shift sleeve is desired.

The publication DE 33 23 345 A1 discloses a ball screw helical gear classical design. The DE 33 23 347 A1 discloses a similar recirculating ball screw drive in which a flexible band secures balls from falling out of a channel.

Furthermore, it is from the document DE 103 33 909 A1 known to realize the return channel of a ball screw by a deflection, which returns the rolling elements after a little less than one revolution from the end point to the starting point and in the axial projection is approximately on the circular profile formed by the track groove. As a result, space is saved in the radial direction. However, a plurality of such revolutions with respective deflection piece is provided in the mother.

The connection of end points of a raceway with multiple revolutions, however, takes place in the prior art via a return channel, which is arranged outside the raceway, in particular radially outside in a special return channel of the mother. Such a return channel lies in the axial projection outside of the circular profile formed by the track groove.

From the DE 101 282 52 A1 a screw drive is known, which has a threaded nut, a threaded spindle, supporting rolling elements, which are formed as in threaded grooves of the threaded nut and the threaded spindle rotating balls, and a return area for the balls. In order to significantly reduce the manufacturing costs, in particular by non-cutting production of the threaded nut, and to achieve a higher power density by a Vergleichmäßigung the supporting portion of the screw, it is proposed that the threaded nut consists of a spirally wound profile material.

From the DE 24 51 665 A1 is a recirculating ball screw drive for converting a rotary motion in a progressive movement or vice versa known, with at least one substantially continuous within the screw ball return channel, wherein the screw has a coaxial bore into which a bolt is inserted, the lateral surface of a screw-shaped ball return channel with having a free passage of the balls enabling cross-section, wherein the length of the ball return passage is less than that of the circulation channel between the screw and nut, and wherein the screw has in the region of the end portions of the ball return passage substantially radially extending bores, the connection between the ball circulation channel and make the ball return passage, and that in the region of the bore guide elements are arranged, which ensure a forced operation of the balls between the ball circulation channel and the ball return channel.

From the DE 101 00 878 A1 a hydrodynamic coupling device, in particular torque converter or fluid coupling, is disclosed for selectively establishing a torque transmission connection between a housing assembly and a turbine wheel comprising a first friction surface assembly configured for common rotation with the housing assembly, a second friction surface assembly adapted for common rotation with the turbine wheel; which can be brought into frictional interaction with the first friction surface arrangement in the region of at least one of the friction surface arrangements, a fluid inlet region via which working fluid present in the housing arrangement can enter the fluid flow channel arrangement, a fluid outlet region over which working fluid present in the fluid flow channel arrangement can escape from this. It is provided that the frictionally interacting Reibflächenanordnungen no direct fluid passage connection from the fluid inlet region to the fluid outlet region via the fluid flow channel arrangement is provided or can be produced.

From the DE 10 2006 014 051 A1 a roller screw is known whose return channel consists of a straight line section and two return sections. The curvature needed for the track and circulating rollers is distributed to the two return elements to form the two return sections. The return elements are made by injection molding or casting process from one piece, wherein the straight section is designed as a recess on the nut, in which engages a cover plate. The two return elements can be fixed with the cover plate, which ensures easy production and installation of the return channel. In addition, the straight portion of the return passage is in the nut, while the two return portions connect the both ends of the straight portion and the spiral groove to form a channel whose front and rear ends are connected to each other. In this way, the distance of the return channel can be shortened, wherein the contour of the cross section of the return channel is maintained, which causes an increase in the mobility of the rollers in the return.

Against this background, it is the object of the invention to provide an improved rotational-translation converter, which is particularly useful for an actuator assembly.

The above object is achieved according to the present invention by a rotation-translation converter having the features of claim 1.

Characterized in that the return channel is formed as a straight channel through the spindle, the in an axial projection on the spindle follows the course of a secant, the spindle can be made compact even in the form of a hollow spindle in the radial direction.

Characterized in that the return channel is connected in a substantially straight line from one located on the outer circumference of the spindle end of the raceway groove to another, also located on the outer circumference of the spindle end of the raceway, the manufacturing cost can be simplified.

It is particularly advantageous if the nut is longer in the axial direction than the spindle.

Here, the principle of a ball screw is reversed by the mother is longer than the spindle and thus moves the inner spindle along the mother. In this case, it is possible to make the spindle compact in the axial direction, so that it is particularly suitable for use in an actuator arrangement for a clutch assembly.

It is also advantageous if the return channel is arranged through the spindle outside the circular projection of the track groove, so as to bridge more than one revolution of the track groove in this way. In this way, the spindle can be made compact even in the axial direction.

In the best case, the return channel can be formed as a bore, which passes through the body of the spindle.

According to a further preferred embodiment, a plurality of grooves, each having an associated return channel is formed between the spindle and the nut.

Although a raceway with a gear for application in an actuator assembly for a clutch is usually sufficient, it is of course also possible, if necessary, to perform the rotation-translation converter more continuous. The return channels do not have to end in the same groove. Rather, the rolling elements can also be guided into another raceway (another gear), so that the rolling elements then pass through several raceways or passages in succession.

Overall, it is advantageous if the rolling elements are balls.

Alternatively, it is also possible that the rolling elements are each formed as cylindrical rollers, which are referred to below for the sake of simplicity as a cylinder.

In the latter case, the cylinder axes of adjacent cylinders in the raceway groove are preferably each entangled with each other by an angle greater than zero or offset from one another. As a result, axial forces can be transmitted efficiently to the spindle (or the nut).

It is particularly advantageous if the cylinders are arranged alternately crossed by 90 ° in the track groove.

In general, with the rotation-translation converter according to the invention, a low-friction conversion of a rotational movement into an axial movement for actuating an actuator arrangement or a clutch can be converted, for example for adjusting a shift sleeve by means of a hollow-shaft electric motor in a vehicle transmission.

In general, the use in all automated manual transmissions and dual-clutch transmissions is conceivable, which have switchable clutches on the gear ratios. Particularly interesting here is the application for an automated manual transmission or dual-clutch transmission or automatic transmission, which can be designed without a hydraulic system.

As rolling elements, as mentioned, balls or other rolling elements such as cylinders can be used. It is understood that between the rolling elements spacers such. B. spacer balls can be arranged. The grooves may be circular in cross-section or with other shapes to achieve the most possible flat or selective contact as possible between the rolling elements and the track groove as needed.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description. Show it:

1 a schematic longitudinal sectional view through a clutch assembly;

2 a highly schematic longitudinal sectional view through another clutch assembly;

3 a perspective, partially broken away view of a portion of a clutch assembly with a rotation-translation converter;

4 a plan view of a switching ring in the form of a spindle of a rotation-translation converter according to the invention;

5 a sectional view taken along the line VI-VI of 4 ,

In 1 is a first embodiment of an actuator assembly generally with 10 designated.

The actuator assembly 10 serves to actuate a clutch assembly 12 a step change gearbox 13 ,

The clutch assembly 12 is a rotary shaft 14 assigned. On opposite sides of the clutch assembly 12 are a first loose wheel 16 and a second idler gear 18 arranged, which rotatably on the rotary shaft 14 are stored.

The clutch assembly 12 has a guide sleeve 20 with an unspecified outer guide sleeve toothing on. The guide sleeve 20 is non-rotatable on the rotary shaft 14 established. Furthermore, the clutch assembly 12 a shift sleeve 22 with an internal sliding sleeve toothing on. The sliding sleeve toothing is engaged with the guide sleeve toothing such that the sliding sleeve 22 in relation to the rotary shaft 14 is rotatably mounted and axially displaceable. The sliding sleeve 22 is externally circumferentially provided with a circumferential groove in a conventional manner. A switching element in the form of a switching ring 23 is by means of the actuator assembly 10 displaceable in the axial direction and engages in this groove. The switching ring 23 is in relation to the case 34 rotatably mounted.

At the first idler wheel 16 is a first coupling body 24 set having an outer coupling body toothing. In a corresponding manner is on the second idler gear 18 a second coupling body 26 set having a corresponding outer coupling body toothing.

The sliding sleeve 22 can be axially displaced so that the sliding sleeve teeth is inserted into each one of the Kupplungskörperverzahnungen, so as to each assigned idler gear 16 . 18 rotatably with the rotary shaft 14 connect to.

The axial displacement of the shift sleeve 22 required axial force 27 is generated by an electric machine, which will be described below.

The clutch assembly 12 may include any conventional synchronization, such as with a synchronizer ring (shown in FIG 1 not shown), but may also be designed as a dog clutch (without synchronization).

In 1 is at 28 a ball-spring Rastiersystem shown, as it is also generally used in cone synchronizers.

Further is at 30 in 1 a rotation axis of the rotation shaft 14 shown.

As mentioned above, the driving force becomes 27 by means of an electric machine 33 generates a stator 32 and a rotor 36 having.

The stator 32 is on a housing 34 the step change gear set.

The electric machine 33 is as a rotary machine concentric to the axis of rotation 30 educated. The electric machine 33 For example, it may be a brushless machine with a permanently energized rotor or a rotor similar to a three-phase asynchronous machine.

The electric machine 33 is radially around the clutch assembly 12 arranged around. The stator 32 includes electrically energized coils (field coils) 38 on a stand package 37 are wound and, for example, through the housing 34 can be electrically connected.

The rotor 36 is in the axial direction generally with the stator 32 aligned and is axially mounted for this purpose. This can be done via sliding, preferably via roller bearings.

Between the rotor 36 and the switching ring 23 is a rotation-translation converter 40 provided, for example in the form of a screw, a slotted guide, a ball screw or the like.

The rotation-translation converter 40 puts one from the electric machine 33 generated rotational movement of the rotor 36 in an axial movement of the switching ring 23 around. The switching ring 23 engages, as I said, in a circumferential groove of the shift sleeve 22 and thus actuates the clutch assembly 12 , As a result, either the idler gear 16 or the idler gear 18 rotatably with the rotary shaft 14 connected to in the manual transmission 13 for example, to engage a certain gear or similar.

The actuator assembly 10 points to the axial bearing of the rotor 36 a first ring land 42 and a second ring land 44 on, which are designed as radial webs and the rotor 36 between them. More precisely, between the rotor 36 and the first ring bridge 42 a first thrust 46 arranged, for example, a rolling bearing. Between the opposite end of the rotor 36 and the second ring land 44 is a second thrust bearing 48 arranged, which may be formed identical to the first thrust bearing 46 ,

The ring bridges 42 . 44 also take the stator package between them 37 of the stator 32 on, and the field windings 38 of the stator are outside around the ring lands 42 . 44 wrapped around. In other words, enforce the ring lands 42 . 44 the stator 32 , As a result, a total of a compact arrangement of the annular webs 42 . 44 be achieved.

At the radially inner ends of the annular webs 42 . 44 are guide pins 50 provided (in the present case, for example, three or more guide pins) extending between the ends of the two ring lands 42 . 44 extend. The guide pins 50 are beyond the scope of the actuator assembly 10 arranged distributed and serve the switching ring 23 to lead in the axial direction and to secure against rotation.

Furthermore, the ring lands 42 . 44 as axial stops for the switching ring 23 be formed, so that a control of the electric motor 33 can be configured according to simple. In 1 is the switching ring 23 shown in a position where he the shift sleeve 22 so far to the left has taken that the sliding sleeve teeth in the teeth of the coupling body 24 of the idler wheel 16 occurred in order in this way the rotary shaft 14 rotatably with the idler gear 16 connect to.

It is generally conceivable that the rotor 36 supported on annular webs in the axial direction, the (for example via corresponding recesses in the sliding sleeve 22 ) on the guide sleeve 20 are fixed and not on the housing 34 ,

The actuator assembly 10 and the driven with this clutch assembly 12 can be used with all stage change gears 13 Use, in particular in automated manual transmissions, in dual-clutch transmissions, etc. It is particularly advantageous here that a hydraulic is generally no longer necessary. This can be particularly advantageous if, for example, the associated starting clutch (or dual clutch) is not adjusted hydraulically but by electric motor.

In the actuator assembly 10 of the 1 it is also advantageous for assembly purposes, when the rotor 36 and / or the stator 32 are formed shared.

In the stage change gearbox 13 is preferably for each clutch assembly 12 a separate actuator arrangement 10 intended. As a result, it is also possible to use the different clutch arrangements 12 assigned gears in overlapping manner to operate.

The path control can either be detected by sensors and then controlled. However, it is also possible to perform the path control without path detection by the shift sleeve 22 in their final positions against attacks is driven. This can ensure that the rotor 36 always in the field area of the stator 32 remains.

However, the end stops can also be scanned by sensors.

2 generally shows in a very schematic form an alternative actuator arrangement 10 ^II . The actuator assembly 10 ^II corresponds in terms of design and operation generally the actuator assembly 10 of the 1 , The same elements are therefore indicated by the same reference numerals. In the following, only the differences are discussed.

So is in 2 the preassembled unit described above indicated by dashed dotted lines and with 61 designated. The in 2 illustrated rotation-translation converter 40 ^II is schematically indicated as a ball screw.

3 generally shows another actuator assembly 10 ^III , the structure and operation of the actuator assembly generally 10 of the 1 equivalent. The same elements are therefore indicated by the same reference numerals. In the following, only the differences are discussed.

3 shows in particular details of a rotation-translation converter 40 ^III like him for the actuator assembly 10 ^III (and also for the actuator arrangements described above) is usable.

The rotation-translation converter 40 ^III is designed as a ball screw and includes a spindle in the form of the switching ring 23 ^III and a mother in the form of the rotor 36 ^III . It is understood that the rotation-translation converter 40 ^{III can} also be trained with other types of spindles and nuts. However, for ease of illustration, these elements will be referred to hereafter by rotor or switching ring.

So has the switching ring 23 ^III on its outer circumference a first part 62 a running groove 66 on. The rotor 36 ^III has on its inner circumference a second part 64 the track groove 66 on. More specifically, these parts are formed by approximately semicircular helical circumferential grooves which together form the track groove 66 or form the thread. In the track 66 is a plurality of rolling elements in the form of balls 68 used. Further, one end of the track groove 66 over one on the switching ring 23 ^III provided return channel 70 with the opposite end of the track groove 66 connected. The rotation-translation converter 40 ^III therefore has a rolling element circulation. The rolling elements can be directly adjacent to each other in the track groove 66 be introduced, or it can be interspersed spacer balls. It is also possible to combine the balls into a ball chain, which can be made in one piece or endless. The cross section of the track groove 66 is on the one hand designed so that forces in the axial direction are transferable and on the other hand, the rolling elements and optionally the spacers (or links of the ball chain) as low friction through this track 66 can be performed.

The spacers may be formed for example in the form of balls or as elements with concave recesses on both sides. The spacers preferably exert no pressure on the thread flanks of the track groove 66 Therefore, they are not subject to the compulsion to take part or to pass them on.

In 3 It can also be seen that the track groove 66 includes approximately two revolutions around the circumference. The return channel 70 can, as shown, outside of the switching ring 23 Be formed ^III or within the switching ring 23 ^III .

The switching ring 23 ^III shorter in the axial direction than the rotor 36 ^III . The axial length of the switching ring 23 ^III is in 3 denoted by L ₂ , the axial length of the rotor 36 ^III with L ₁ . Since L ₂ <L ₁ , the return channel is 70 preferably on the switching ring 23 ^III trained.

The axial length L _{2 of} the switching ring 23 ^III preferably corresponds to the axial length L _{3 of} an annular groove 72 a shift sleeve 22 ^III a clutch assembly, as described above.

4 shows a preferred embodiment of a spindle for a rotation-translation converter according to the invention forming switching ring 23 ^IV , for example, the rotation-translation converter 40 ^{III of} the 3 can be used. It can be seen that the return channel 70 ^IV as a hole through the switching ring 23 ^{IV is formed} through, in the in 4 shown axial projection as a secant. 5 , which is a section along the line VI-VI in 4 shows, reveals that the return channel 70 ^{IV is formed} as a straight bore and slightly oblique to a longitudinal axis 30 extends to the opposite ends of the track groove 66 ^IV to connect with each other.

In 4 is further shown that the switching ring 23 ^IV three distributed over the circumference axial bores 74 through which the guide pins pass 50 the actuator assembly according to the invention can be performed.

In the actuator arrangements, an energy recovery during braking of the rotor can take place. Furthermore, the electric machine 33 , depending on the embodiment of the rotation-translation converter 40 support critical synchronous operations.

Claims (7)

Rotation-translation converter ( 40 ^IV ) with Wälzkörperumlauf, comprising a spindle ( 23 ^IV ), which is formed as a hollow spindle, on whose outer periphery a first part ( 62 ^IV ) a running groove ( 66 ^IV ) is formed, a nut on the inner circumference of a second part ( 64 ) of the raceway ( 66 ^IV ) is formed, a plurality of rolling elements in the raceway ( 66 ^IV ) are arranged, and a return channel ( 70 ^IV ), the opposite ends of the track ( 66 ^IV ) with each other to the rolling elements ( 68 ), wherein the return channel ( 70 ^IV ) on the spindle ( 23 ^IV ) as a straight channel through the spindle ( 23 ^IV ) is formed through which in an axial projection on the spindle ( 23 ^IV ) follows the course of a secant. A rotation-translation converter according to claim 1, wherein the nut is longer in the axial direction than the spindle ( 23 ^IV ). Rotary translation converter according to one of claims 1 or 2, wherein between the spindle ( 23 ^IV ) and the mother a plurality of grooves, each having an associated return channel ( 70 ^IV ) is formed. Rotary translation converter according to one of claims 1 to 3, wherein the rolling elements ( 68 ) Are balls. A rotation-translation converter according to any one of claims 1 to 3, wherein the rolling elements are cylinders. A rotary-to-translation converter according to claim 5, wherein the cylinder axes of adjacent cylinders in the track groove (Fig. 66 ^IV ) are each crossed by an angle greater than zero against each other. Rotary translation converter according to claim 6, wherein the cylinders are alternately crossed by 90 ° in the track groove ( 66 ^IV ) are arranged.

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